The oldest and youngest records of afrosoricid placentals ... · The oldest and youngest records of afrosoricid placentals from the Fayum Depression of northern Egypt ERIK R. SEIFFERT

The oldest and youngest records of afrosoricid placentalsfrom the Fayum Depression of northern Egypt

ERIK R SEIFFERT

Seiffert ER 2010 The oldest and youngest records of afrosoricid placentals from the Fayum Depression of northernEgypt Acta Palaeontologica Polonica 55 (4) 599ndash616

Tenrecs (Tenrecoidea) and golden moles (Chrysochloroidea) are among the most enigmatic mammals alive today Mominuslecular data strongly support their inclusion in the morphologically diverse clade Afrotheria and suggest that the twolineages split near the KminusT boundary but the only undoubted fossil representatives of each superfamily are from earlyMiocene (~20 Ma) deposits in East Africa A recent analysis of partial mandibles and maxillae of EochrysochlorisJawharia and Widanelfarasia from the latest Eocene and earliest Oligocene of Egypt led to the suggestion that thederived ldquozalambdomorphrdquo molar occlusal pattern (ie extreme reduction or loss of upper molar metacones and lowermolar talonids) seen in tenrecoids and chrysochloroids evolved independently in the two lineages and that tenrecoidsmight be derived from a dilambdomorph group of ldquoinsectivoranminusgraderdquo placentals that includes forms such asWidanelfarasia Here I describe the oldest afrosoricid from the Fayum region ~37 Ma Dilambdogale gheerbranti genet sp nov and the youngest ~30 Ma Qatranilestes oligocaenus gen et sp nov Dilambdogale is the most generalizedof the Fayum afrosoricids exhibiting relatively broad and wellminusdeveloped molar talonids and a dilambdomorph arminusrangement of the buccal crests on the upper molars whereas Qatranilestes is the most derived in showing relatively exminustreme reduction of molar talonids These occurrences are consistent with a scenario in which features of thezalambdomorph occlusal complex were acquired independently and gradually through the later Paleogene Phylogenminusetic analysis places Dilambdogale and Widanelfarasia as sister taxa to the exclusion of crown afrosoricids but derivedfeatures that these taxa share with early Miocene Protenrec hint at the possibility that both taxa might be stemtenrecoids Late Paleocene Todralestes and Afrodon from Morocco are similarly placed as stem afrosoricids indicatminusing that African adapisoriculids (including Garatherium) might also be relevant to the origin of the tenrecoid andchrysochloroid clades

Key words Mammalia Adapisoriculidae Tenrecidae Garatherium Widanelfarasia Eocene Oligocene Egypt

Erik R Seiffert [erikseiffertstonybrookedu] Department of Anatomical Sciences Stony Brook University StonyBrook New York 11794minus8081 USA

Received 18 February 2010 accepted 14 June 2010 available online 17 June 2010

IntroductionPaleocene and Eocene mammals of AfrominusArabia are verypoorly documented relative to those of other major landminusmasses Among the more rarely recovered members ofPaleogene African mammal faunas are a variety of diminuminustive insectivorous placentalsmdashgenerally represented solelyby isolated teethmdashthat were originally placed in higherminusleveltaxa such as Cimolesta and Lipotyphla and the familiesAdapisoriculidae Chambilestidae Cimolestidae Palaeorycminustidae and Todralestidae (eg Gheerbrant 1992 1994 1995Gheerbrant et al 1998) Lipotyphla are now widely considminusered to be diphyletic on the basis of nucleotide and othergenomic data (Springer et al 1997 Madsen et al 2001Murphy et al 2001 AmrineminusMadsen et al 2003 Asher et al2003 Springer et al 2004 Asher and Hofreiter 2006 Seifminusfert 2007 Asher 2007) and two former members of thatgroupmdashthe AfrominusMalagasy tenrecs (herein treated together

as a superfamily Tenrecoidea containing a monophyleticPotamogalidae (African otterminusshrews) and Tenrecidae (Malminusagasy tenrecoids) see Asher and Helgen 2010 for an alterminusnative classification and African golden moles (Chrysominuschloroidea Chrysochloridae) have come to be placed in theirown order Afrosoricida within a larger endemic Africanclade Afrotheria (Stanhope et al 1998) that also includes elminusephants sea cows hyraxes aardvarks and sengis (Fig 1)Molecular divergence estimates suggest that crown afrominussoricids last shared a common ancestor in the latest Cretaminusceous or Paleocene (Douady and Douzery 2003 Springer etal 2003) opening up the possibility that afrosoricid originsmight be traced back to some of the poorly known ldquocimominuslestanrdquo andor ldquolipotyphlanrdquo fossils that have been recoveredfrom the Paleocene and Eocene of North Africa (Seiffert2010)

At present there is however no unambiguous fossil eviminusdence for this hypothesis The crux of the issue is that all exminus

doi104202app20100023Acta Palaeontol Pol 55 (4) 599ndash616 2010

tant afrosoricids have a ldquozalambdomorphrdquo occlusal patternon their molarsmdashie a condition in which upper molar metaminuscones and lower molar talonids are greatly reduced or absentaltogether (see also Asher and SanchezminusVillagra 2005) Optiminusmization of zalambdomorphy onto a cladogram of extantplacentals alone (eg Springer et al 2004) would reconstructthis dental pattern as having been present in the last commonancestor of tenrecs and golden moles (Fig 1) If this ancestorwas in fact ~66ndash63 Ma in age as estimated by molecular seminusquence datamdashand if Afrosoricida is indeed an endemic Afriminuscan clademdashthen zalambdodomorph fossil afrosoricids shouldhave been present in AfrominusArabia during the time periods forwhich there is paleontological coverage on that landmass (ielatest Paleocene early Eocene early middle Eocene lateEocene and early Oligocene) Zalambdomorph species arehowever completely absent from AfrominusArabian mammal fauminusnas of these time periods (Seiffert 2010) suggesting that either(i) afrosoricids were not present in AfrominusArabia during thePaleogene (ii) zalambdomorph afrosoricids were present inAfrominusArabia during the Paleogene but not in the areas thathave been sampled thus far (iii) tenrecs and golden moles diminusverged much later (eg in the Oligocene) than suggested bymolecular data or (iv) zalambdodomorphy was not present inthe last common ancestor of tenrecs and golden moles andevolved convergently later in the Paleogene

There is now a small but growing body of fossil evidencethat has been interpreted by Seiffert et al (2007) as supportminusing the latter scenario The oldest definitive euzalambdominusmorph tenrecoids and chrysochlorids (ie forms that comminuspletely lack upper molar metacones) are from the early Miominuscene of Kenya and Uganda (Butler and Hopwood 1957 Butminusler 1969 1984) but Seiffert et al (2007) have recently idenminustified tribosphenic latest Eocene (~34 Ma Seiffert 2006Seiffert et al 2007) Widanelfarasia and early OligoceneJawharia as stem tenrecoids and early Oligocene Eochrysominuschloris as a stem chrysochlorid (see Fig 2) Because thesegenera all retain wellminusdeveloped molar metacones andorlower molar talonid basins these identifications would reminusquire that euzalambdomorphy evolved convergently withinAfrosoricida In particular Widanelfarasiarsquos combinationof a dilambdomorph M1 and protozalambdomorph M2ndash3would suggest that the stem lineage leading to crown Tenreminuscoidea either passed through a dilambdodomorph phase priorto acquisition of zalambdomorphy or that Widanelfarasiarsquosdilambdomorphy is autapomorphic Furthermore it has longbeen known that the extant potamogalid tenrecoid Potaminus

mogale is protozalambdomorph (McDowell 1958 Butler1972 1988) lending additional support to the hypothesisthat this condition might be plesiomorphic within Afrosoriminuscida Alternatively this condition is simply an autapomorphyof Potamogale this possibility is supported by the observaminustion that the molar metacones of Potamogalersquos sister taxonthe smaller genus Micropotamogale vary from being veryreduced to absent

Here I present additional evidence that contributes to thedebate surrounding the homology of zalambdomorphy intenrecs and golden moles Recent work at the earliest Priaminusbonian (earliest late Eocene ~37 Ma) Birket Qarun locality 2(or BQminus2) has led to the recovery of the oldest Fayum afrominus

600 ACTA PALAEONTOLOGICA POLONICA 55 (4) 2010

In what follows I employ the terminology recently proposed by Lopatin (2006) which is useful for distinguishing important differences between taxa thathave been termed ldquozalambdodontrdquo and ldquodilambdodontrdquo (Gill 1883) The broad category of ldquozalambdomorphyrdquo is defined by Lopatin (2006 S215) as folminuslows ldquothe trigon of the upper molars is formed by a large lingually located paracone a paracrista that is Vminusshaped in projection and styles the metaconeand protocone are considerably reduced or absent the conules are absent hellip in this pattern the lower molars are characterized by reduced talonids and exminuscessively developed trigonids including the formation of the oblique paracristid and a very high and broad transverse protocristidrdquo ldquoEuzalambdominusmorphyrdquo which is present in most extant afrosoricids is described as ldquocomplete loss of the metacone and protocone the lingual displacement of theparacone to the position of the protocone excessive development of the stylar shelf and appearance of supplementary cingular elements hellip the talonid isextremely reduced and resembles a postcingulidrdquo (Lopatin 2006 S215) while in ldquoprotozalambdomorphyrdquo which occurs in extant Potamogale and earlyMiocene Protenrec ldquothe metacone is considerably reduced (however its rudiment is preserved between a shortened centrocrista and postmetacrista) theparacone is displaced to the center the protocone and talonid are reducedrdquo (Lopatin 2006 S215)

Fig 1 Relationships of extant placental mammalian orders based on theanalysis of Roca et al (2004) with zalambdomorph groups (Afrosoricidaand Solenodontidae) highlighted

soricids including a new genus described below that is eviminusdently even more generalized than Widanelfarasia and thatappears to document an even more primitive dilambdomorphphase in either stem afrosoricid or stem tenrecoid evolutionThe material also provides a clearer look at the upper molarand P4 morphology of a primitive afrosoricid previouslyknown solely from 3minusD reconstructions derived from miminuscrominusCT scans of a damaged Widanelfarasia maxilla (Seiffertet al 2007) A distal humerus from BQminus2 is also attributed tothe new genus described here providing the first look at oneaspect of postcranial morphology in this poorly documentedevolutionary radiation In addition less informative tenreminuscoid fossils that were collected in the 1960s at one of theyoungest vertebrate fossil localities in the Fayum area(~295ndash30 Ma Quarry I Fig 2) have recently been relocatedin the collections of the Yale Peabody Museum and thesespecimens are described named and figured here for thefirst time Though fragmentary it is clear that the Quarry Ifossils more closely approximate the euzalambdomorph conminusdition than any of the older afrosoricids from the successionand provide support for gradual acquisition of zalambdominusmorphy through the later Paleogene

Institutional abbreviationsmdashCGM Egyptian GeologicalMuseum Cairo Egypt DPC Duke Lemur Center Divisionof Fossil Primates Durham North Carolina USA YPMYale Peabody Museum New Haven Connecticut USA

Systematic paleontology

Supercohort Afrotheria Stanhope WaddellMadsen de Jong Hedges Cleven Kao andSpringer 1998Order Afrosoricida Stanhope Waddell Madsen deJong Hedges Cleven Kao and Springer 1998Suborder Tenrecomorpha Butler 1972Genus Dilambdogale novType species Dilambdogale gheerbranti sp nov see below

Etymology From Greek di two and lambda eleventh letter of the Greekalphabet (L)mdashin reference to the dilambdomorph arrangement of thebuccal crests on the genusrsquo first upper molar and gale weaselmdasha comminusmon suffix in generic names of extant tenrecoids

DiagnosismdashSame as for the species

Dilambdogale gheerbranti sp novFigs 3ndash7

Etymology In honor of the French paleontologist Emmanuel Gheerminusbrant for his numerous contributions to the study of Paleogene AfrominusArabian placental mammals including ldquoinsectivoranminusgraderdquo placentals

Holotype CGM 66005 a maxillary fragment preserving the distalalveolus for P3 the crowns of P4 and M1 the mesiobuccal root of M2and the infraorbital foramen (Fig 3)

Type locality Birket Qarun locality 2 (BQminus2) northern Egypt

Type horizon Earliest Priabonian (earliest late Eocene) Umm RiglMember of Birket Qarun Formation

MaterialmdashThe type specimen DPC 23306E left M2 DPC23307A right M3 DPC 23007H left m2 DPC 23736Aright mandibular fragment with m1 and talonid of p4 DPC

doi104202app20100023

SEIFFERTmdashPALEOGENE AFROSORICIDS FROM EGYPT 601

C1

0C

11

C1

2C

13

C1

5C

16

C1

7

38

37

36

35

34

33

32

31

30

29

GPTS Sta

ge

Ep

och

Je

be

lQ

atr

an

iF

orm

atio

nQ

asr

el-S

ag

ha

Fo

rma

tio

n

low

er

se

qu

en

ce

up

pe

rse

qu

en

ce

Dir

Ab

uL

ifa

Mb

rTe

mp

leM

br

BirketQarunFmn

Fayumsuccession

and

zones

Afrosoricid

Ma

gn

eto

str

atig

rap

hic

co

rre

latio

np

refe

rre

db

yS

eiffe

rt(2

00

6)

Qatranilestesoligocaenus

Eochrysochloristribosphenus

Jawharia tenrecoides

Widanelfarasia bowniWidanelfarasia

rasmusseni

Dilambdogalegheerbranti

polarity

RU

PE

LIA

N

OL

IGO

CE

NE

EO

CE

NE

PR

IAB

ON

IAN

Ma

I

E

L-41

BQ-2

localitiesAfrosoricid

taxa

Fig 2 Stratigraphic placement of afrosoricidminusbearing localities in the laterPaleogene rocks exposed in the Fayum area and proposed correlation of lominuscal polarity zones to the Geomagnetic Polarity Timescale (GPTS) followminusing Seiffert (2006) and Seiffert et al (2008) Locality BQminus2 which yieldedthe remains of Dilambdogale gheerbranti described here is estimated to be~37 Ma Quarry I which produced remains of Qatranilestes oligocaenusis estimated to be ~295ndash30 Ma

23780C left m2 DPC 23784D right M1 DPC 23983Cright mandibular fragment with p4ndashm1 DPC 24001A leftP4 DPC 24081B right mandibular fragment with p2ndash4DPC 24103A right mandibular fragment with m1ndash3 uncataminuslogued specimens at the CGM

DiagnosismdashDiffers from MioceneminustominusRecent tenrecoids priminusmarily in retaining a wellminusdeveloped metacone and protoconeon M1ndash3 small conules on M1ndash2 a cuspate (rather thancrestiform) stylocone on M1ndash3 and wellminusdeveloped talonidand hypoconulid cusps on the lower molars Further differsfrom tenrecoids other than Protenrec in having the distal rootof P3 placed lingual to the mesiobuccal root of P4 Differsfrom Widanelfarasia in having a relatively wellminusdeveloped P4ectostyle a shorter postmetacrista on M1 wellminusdevelopedand cuspate (rather than crestiform) metacone stylocone andparastyle on M3 a cuspate rather than crestiform styloconeon M2 and in having an m1 with a relatively broad talonid andmore buccally placed cristid obliqua delimiting a relativelypoorlyminusdeveloped hypoflexid Differs from late PaleoceneTodralestes in having a ldquowrdquominusshaped arrangement of the buccalcrests on M1ndash2 relatively broad stylar shelves no preminus orpostcingula on M1ndash3 and a P4 ectostyle minuscrista and minusfossaDiffers from late Paleocene Afrodon chleuhi in having adilambdodont M2 relatively broad stylar shelves and slightlytaller molar trigonids Differs from Garatherium todrae(known only from upper molars) in lacking distinct upper mominuslar premetaconule cristae and postparaminus and premetacristaethat contact the mesostyle buccally

DescriptionmdashThe dental morphology of D gheerbranti isknown from four upper tooth loci (P4 M1 M2 M3) and sixlower tooth loci (p2 p3 p4 m1 m2 m3) (Figs 3ndash6) Meaminussurements for upper and lower teeth are provided in Table 1and Table 2 respectively The holotype partial maxilla(CGM 66005 Fig 3) contains P4ndashM1 and preserves theinfraorbital foramen the alveolus for the distal root of P3and the mesial halves of the lingual and mesiobuccal alveolifor M2 P4 M1 M2 and M3 are also known from isolated


alveolus for distalroot of P3

1 mm

mesiobuccalroot of M2

P4

rim of orbitInfraorbitalforamen

M1

Fig 3 Holotype maxilla of the afrosoricid placental Dilambdogale gheerbranti gen et sp nov from the earliest late Eocene (earliest Priabonian) localityBQminus2 Birket Qarun Formation Fayum Depression northern Egypt A Occlusal view of CGM 66005 left maxillary fragment preserving the alveolus forthe distal root of P3 crowns of P4ndashM1 and partial alveoli for the mesiobuccal and lingual roots of M2 B Line drawing of CGM 66005 in lateral viewshowing the position of the infraorbital foramen and the orbital rim

Table 1 Measurements (in mm) of upper teeth of Dilambdogale gheerminusbranti gen et sp nov BL buccolingual breadth MD mesiodistal length

Specimen LocusM

axim

umM

Dle

ngth

[ldquoL

labrdquo

inG

heer

bran

t(19

92)]

Mes

ialB

Lw

idth

[ldquoIM

rdquoin

Ghe

erbr

ant(

1992

)]

Dis

talB

Lw

idth

[ldquoID

rdquoin

Ghe

erbr

ant(

1992

)]

Wid

thfr

omba

seof

para

cone

topr

otoc

one

apex

[ldquolp

roto

rdquoin

Ghe

erbr

ant(

1992

)]

MD

leng

thof

trig

on[ldquo

Lm

drdquoin

Ghe

erbr

ant(

1992

)]

DPC 23306E M2 175 225 215 030 090DPC 23307A M3 113 250 155 035 080DPC 23780C M2 158 228 228 020 088DPC 24001A P4 170DPC 27784D M1 158 205 205 025 090CGM 66005 P4 175CGM 66005 M1 158 195 195 025 083

Table 2 Measurements (in mm) of lower teeth of Dilambdogale gheerminusbranti gen et sp nov MD mesiodistal length

Specimen Locus MDlength

Trigonidwidth

Talonidwidth

DPC 23307H M2 170 098 090DPC 23736A M1 160 095 095DPC 23783B M2 160 103 085DPC 23783B M3 163 103 080DPC 23983C P4 160 085DPC 23983C M1 153 090DPC 24081B P2 120 050DPC 24081B P3 083 060DPC 24081B P4 080DPC 24103A M1 150 100 093DPC 24103A M2 160 105 093DPC 24103A M3 153 090 075

teeth (Fig 6) Partial mandibles together preserve p2ndashm3 inplace (Figs 4 5) and most of these loci are also known fromisolated teeth (Table 1) Though found in isolation the M2ndash3are assigned to this species because (i) they are of similar sizeto and occlude well with the m2ndash3 in the hypodigm and (ii)they bear a strong resemblance to the upper teeth of youngerWidanelfarasia P2ndashM3 of which are preserved in place in asingle maxilla (Seiffert et al 2007)

A partial alveolus that is preserved mesial to the douminusbleminusrooted p2 (Fig 4A) is relatively large and as in Widanelminusfarasia was presumably for the lower canine If this interpreminustation is correct then (d)p1 was absent in Dilambdogale asin Widanelfarasia and all extant afrosoricids (Seiffert andSimons 2000) The p3 and p4 both bear tall protoconids thatof p3 is mesially inclined and has a long postprotocristid onits gradually sloping distal face There is a tiny paraconid atthe base of the p3 protoconid which is slightly lingual to the

mesiodistal long axis of the tooth and a larger hypoconidthat is present at the distal terminus of the postprotocristidThere is a very faint and short lingual cingulum just distal tothe paraconid but it does not continue across the rest of thecrown The base of the crown is somewhat staggered with reminusspect to the alveolar plane the distal aspect of the crownbase above the distal root extends closer to the alveolarplane than the mesial part of the crown base

The p4 also has a small paraconid at the base of theprotoconid (Fig 4A C) this cusp is relatively large and rominusbust when compared with the p3 paraconid but is nevertheminusless still very small in comparison to the tall p4 protoconid(Fig 4C2) The metaconid is approximately half the heightof the protoconid (Fig 4C2) and is placed lingual andslightly distal to that cusp (Fig 4C) A faint protocristid exminustends from the protoconid to the metaconid Distinct andclosely situated entoconid and hypoconid cusps are presenton the lingual aspect of the talonid with the hypoconid beminusing slightly larger than the entoconid There are very faintentocristid and hypocristid crests but no cristid obliquaand the p4 hypoflexid is deep There are no lingual orbuccal cingulids

On m1 (Fig 4B C E) the paraconid is large mesiallyoriented and is placed slightly buccal and far mesial to themetaconid There is no premetacristid descending mesiallyfrom the metaconid leaving the trigonid broadly open linminusgually The paraconid is connected to the protoconid by anelongate paracristid that bears a distinct notch along its midminuspoint The protocristid connecting the metaconid and protominusconid varies from being perpendicular to the long axis of thetooth to being slightly oblique The metaconid is slightly

doi104202app20100023


1 mm

Fig 4 Lower dentition of the afrosoricid placental Dilambdogale gheerbranti gen et sp nov from the earliest late Eocene (earliest Priabonian) localityBQminus2 Birket Qarun Formation Fayum Depression northern Egypt A Oblique lingual view of DPC 24081B a right mandibular fragment preserving thealveolus for the lower canine and the crowns of p2ndash4 B DPC 24103A right mandibular fragment preserving the worn crowns of m1ndash3 in oblique lingual(B1) and occlusal (B2) views C DPC 23983C a right mandibular fragment preserving p4ndashm1 in occlusal (C1) and lingual (C2) views D DPC 23783B aleft mandibular fragment preserving m2ndash3 in occlusal (D1) and lingual (D2) views E Occlusal view of DPC 23736A a right mandibular fragment preservminusing the talonid of p4 and the complete crown of m1 F DPC 23307H a left m2 in occlusal view

1 mm

Fig 5 Buccal view of DPC 23783B a left mandibular fragment of the afrominussoricid placental Dilambdogale gheerbranti gen et sp nov from the earliminusest late Eocene (earliest Priabonian) locality BQminus2 Birket Qarun Formaminustion Fayum Depression northern Egypt preserving m2ndash3

lower than the protoconid The talonid is preserved on DPC23736A (Fig 4E) the basin is subequal in width to thetrigonid has a relatively shallow hypoflexid and distinctentoconid hypoconid and hypoconulid cusps the latter ofwhich projects distally The cristid obliqua meets the posteminusrior wall of the trigonid slightly buccal to its midpoint Them2ndash3 (Fig 4B D) differ from m1 in having oblique cristidsthat terminate midway between the protoconid and metaminusconid cusps protocristids that are consistently transverselyoriented and relatively deep hypoflexids All lower molarshave talonids that are slightly longer than trigonids obliquecristids and hypocristids that meet at a sharp angle and disminustinct precingulids

The mesiobuccal aspect of P4 is missing on all of the speciminusmens that have been recovered thus far but the alveolus for themesiobuccal root is placed mesial to the preserved part of thecrown suggesting that Dilambdogale probably had a promiminusnent parastyle on P4 as has been documented for Todralestes(Gheerbrant 1991b) and Widanelfarasia (Seiffert et al 2007)The P4 bears a tall paracone cusp and a very small andmesially placed protocone Like many crown tenrecoidsDilambdogale also has a distinct ectostyle cusp distal andbuccal to the apex of the paracone DPC 24001A has a veryfaint ectocrista descending from the buccal face of the paraminuscone to meet the ectostyle Together with the elongate postminusparacrista these structures delimit a shallow distolabial ectominusfossa The P4 has no conules and no preminus and postcingula buta tiny crestiform hypocone is present and is connected to theprotocone by a weak postprotocrista Though the parastylarregion is missing it is clear that it would have protruded froma very low point on the mesial face of the paracone

A relatively unworn M1 is present in the holotype speciminusmen (Fig 3) This locus is also represented by an isolated toothwith a more worn stylar region (DPC 23784D Fig 6D) TheM1 resembles Widanelfarasia in having a ldquoWrdquominusshaped arminusrangement of the preminus and postparacristae and preminus and postminusmetacristae In mesial and distal view the paracone metaminuscone and protocone are approximately equal in height Theparacone and metacone show some ldquofusionrdquo of their basesThe stylar region of the M1 in the holotype specimen exhibitssome wear but it is clear that the stylocone would have beenthe largest and tallest cusp on the buccal aspect of the toothfollowed by the parastyle It appears that there was also a verysmall mesostyle at the trough of the ectoflexus and a similarlysmall cusp ldquoDrdquo on the periphery of the metastylar lobe Thisinterpretation is supported by the clear presence of these cuspson M2 (see below) The trigon is restricted due to encroachminusment of the centrally placed paraminus and metacone and is borminus


1 mm

Fig 6 Upper dentition of the afrosoricid placental Dilambdogale gheerminusbranti gen et sp nov from the earliest late Eocene (earliest Priabonian) lominuscality BQminus2 Birket Qarun Formation Fayum Depression northern EgyptA DPC 23307A right M3 in occlusal (A1) and distal (A2) views B DPC23306E left M2 in occlusal view C DPC 23780C left M2 in occlusal(C1) and buccal (C2) views D DPC 23784D right M1 in occlusal (D1) andmesial (D2) views E DPC 24001A left P4 in distal (E1) and occlusal (E2)views

dered lingually by distinct preminus and postprotocristae A smalllinguallyminusplaced paraconule is present and bears a postparaminusconule crista on DPC 23784D but not on CGM 66005 thepreprotocrista bypasses the lingual aspect of the paracone andis continuous with the parastylar area There is a short but disminustinct hypoparacrista that connects the paraconule and the linminusgual face of the paracone on DPC 23784D but this is absenton the holotype specimen A small metaconule is present but ismore buccally placed than the paraconule A distolabially oriminusented postmetaconule crista leaves the trigon open distally onDPC 23784D but this crest is not present on CGM 66005There is no premetaconule crista and no preminus or postcingulaon either specimen

M2 is represented by two isolated specimens (DPC23306E Fig 6B DPC 23780C Fig 6C) The M2 is muchbroader (buccolingually) than M1 Of the two primary buccalcusps the paracone is closest to the protocone (and is placedfarther from the buccal margin than is the metacone) In linminusgual and buccal view the paracone is taller than the metacone(Fig 6C2) When compared with M1 the protocone is relaminustively prominent but the trigon is more constricted mesiominusdistally The stylar shelf bears a tall and distinct stylocone anda much smaller mesostyle and cusp ldquoDrdquo (Fig 6C2) Theparastyle is prominent and the parastylar lobe forms a promiminusnent mesial ldquohookrdquo which based on the placement of themesiobuccal root of M2 implanted in the holotype partialmaxilla would have curved around the buccal aspect of themetastylar lobe of M1 as in Widanelfarasia (Seiffert et al2007) A paraconule is not evident on DPC 23780C but ispresent though minute on DPC 23306E on the latter speciminusmen the paraconule is connected to the base of the paracone bya short postparaconule crista As on M1 the paraconule is situminusated closer to the protocone than is the metaconule there is nopremetaconule crista and there are no preminus or postcingula

M3 (represented solely by DPC 23307A Fig 6A) haswellminusdeveloped paracone and metacone cusps the postparaminusand premetacristae of which are slightly buccally oriented ina weakly ldquoWrdquominusshaped arrangement The metacone is smallerthan the paracone both in height and in volume The postminusmetacrista is buccally (rather than distally) oriented and iscontinuous with the buccal aspect of a very broad stylarshelf The stylocone and parastyle are distinct and wellminusdeminusveloped and at least on DPC 23307A an accessory cuspuleis present on the buccal face of the tooth just distal and labialto the parastyle A crestiform metaconule is present but noparaconule is evident perhaps due to wear It is clear thatthere is no postparaconule crista and no preminus or postcingula

Various fragments of the mandibular corpus are preserved(see eg Figs 4A B 5) The corpus is fairly shallow beingonly slightly taller than trigonid height and bears a mental fominusramen below m1 (Fig 5) and p2 Little is preserved of the disminustal part of the mandible but the anterior part of the massetericfossa appears to have been wellminusdeveloped

HumerusmdashA small distal humerus (Fig 7) from localityBQminus2 (DPC 24108A) is attributed to Dilambdogale gheerminus

branti on the basis of size morphology and relative abunminusdance The only other small mammals known from BQminus2 thatthe humerus could be attributable to (on the basis of size alone)is the chiropteran Qarunycteris (Gunnell et al 2008) and theanomaluroid rodent Shazurus (Sallam et al 2010a) DPC24108A exhibits none of the distinctive derived features ofchiropteran distal humeri (see eg Simmons and Geisler1998) excluding the possibility that the specimen is attributminusable to Qarunycteris The morphology of a distal humerus ofthe large anomaluroid Kabirmys from BQminus2 (Sallam et al2010b c) is radically different from that of DPC 24108A sugminusgesting that its smaller relative Shazurus is unlikely to exhibitthe morphology observable on DPC 24108A

DPC 24108A does bear clear morphological resemblanceto the distal humeri of some extant tenrecoids particularlyspecies of Microgale which lends additional support for itsattribution to Dilambdogale Features shared with many speminuscies of Microgale such as the presence of an entepicondylarforamen a moderately developed brachioradialis flange adeep radial fossa a shallow olecranon fossa and an ovoidcapitulum with a proximodistally tall but laterally taperingcapitular tail are however presumably primitive withinAfrosoricida and possibly within Afrotheria Perforation ofthe bony lamina separating the olecranon and radial fossaeas occurs in DPC 24108A also occurs variably in species ofMicrogale (Salton and Sargis 2008) The medial aspect of thetrochlea is missing but in distal view there is a distinct notchseparating the capitulum from the lateral aspect of the trominus

doi104202app20100023


1 mm

entepicondylarforamen

Fig 7 DPC 24108A right distal humerus attributed to the afrosoricid placenminustal Dilambdogale gheerbranti gen et sp nov from the earliest late Eocene(earliest Priabonian) locality BQminus2 Birket Qarun Formation Fayum Depresminussion northern Egypt

chlea as in species such as Microgale talazaci DPC 24108Aalso preserves the distal part of a sharp deltopectoral crestthe more proximal part of which trends laterally DPC24108A bears no special resemblance to the humeri of Malaminusgasy Geogale and African potamogalids which are likely tobe autapomorphic in lacking entepicondylar foramina andhaving relatively reduced brachioradialis flanges The huminusmeri of golden moles reflect their highly fossorial existencein having features such as elongate medial epicondyles globminusular capitula mediolaterally long trochleae and humeralshafts that are strongly laterally canted relative to the longaxis of the distal articulation (eg Asher and Avery 2010)None of these features are seen in DPC 24108A

The morphology of DPC 24108A is consistent withDilambdogale having been a very generalized terrestrialquadruped The combination of a shallow olecranon fossaand a deep radial fossa suggest that Dilambdogale habituallymaintained postures in which the forearms were typicallyheld in acute flexion DPC 24108A bears none of the strucminustural features of the distal humerus that are typically correminuslated with saltatory locomotion habitual fossoriality arbominusreality or dedicated aquatic behavior in extant mammals

ComparisonsmdashAs already noted the fossil record of smallmammals is relatively poor in AfrominusArabia (Seiffert 2010)and as such it is rare for ldquoinsectivoranminusgraderdquo placentals(sensu Asher 2005) to be documented by more than a fewtooth loci Therefore Dilambdogale despite being repreminussented solely by P4ndashM3 and p2ndashm3 and a distal humerus acminustually allows for more extensive comparisons than manyother important taxa from AfrominusArabian Paleogene some ofwhich are only documented by upper teeth (eg Garaminustherium Chambilestes)

The genus that is bestminusdocumented from older horizons inAfrica is latest Paleocene Todralestes variabilis (Gheerbrant1991b 1994) Todralestes differs from Dilambdogale in reminustaining upper molar features which based on their occurrencein other afrotherians (eg Seiffert 2007) may be primitivewithin that clademdasheg relatively narrow stylar shelves short

preparaminus and postmetacristae linear centrocristae absence ofdeep ectoflexi presence of preminus and postcingula and in someindividuals small hypocones on M1ndash2 (Fig 8F) Stylar cuspsare also poorlyminusdeveloped and crestiform in Todralestes butare much more prominent in Dilambdogale and Todralesteslacks an ectostyle on P4 whereas this cusp is very prominentin Dilambdogale The morphology of P4 in Todralestes is othminuserwise also very similar to that of Dilambdogale in having along postparacrista and a very low small and mesially posiminustioned protocone Dilambdogale is more similar to Todraminuslestes in the lower dentition differing primarily in havinglarger paraminus and hypoconid cusps on p3 an entoconid on p4relatively broad lower molars with more distinct talonid cuspsand molar protocristids that tend to be less obliquely orientedwith respect to the long axis of the molar crown

Seiffert et al (2007) noted that Todralestes Widanelminusfarasia and Protenrec all have an odd configuration of themaxilla and P3ndash4 complex in which the distal root of P3 islingually placed being mesial to the lingual root of P4 ratherthan being mesial to the mesiobuccal root as in other afrominustherians This feature is also seen in Dilambdogale (Fig 3)This morphology appears to be related to the placement ofthe rostral aperture of the infraorbital foramen in all of theaforementioned taxa the rostral aperture is placed just dorsalto the mesiobuccal root of P4 and the alveolar process of themaxilla lateral to the P3 is similarly offset medially leadingto a distinctive constriction of the palate at the junction beminustween P3 and P4 This morphology is also seen in the extantMalagasy tenrec Geogale (Butler 1984) and interestinglythe early Eocene hyaenodontid Koholia from Algeria (Crominuschet 1988) These taxa also all have a greatly enlargedparacone on P4 a mesiobuccal root of P4 that is widely exminusposed in lateral view and in those taxa that preserve a P3 inplace (Widanelfarasia Protenrec and Geogale) there is adistinctly ldquosteppedrdquo transition from the apex of the P4 to thatof P3 (Fig 3) This surely would have also been the case inDilambdogale and Todralestes given the small size of theoccluding p3 and the position of the distal P3 alveolus fardorsal to the base of the P4 crown As strange as this overall


Widanelfarasia Dilambdogale Chambilestes Garatherium Afrodon Todralestes

Fig 8 Comparison of occlusal morphology of the upper second molar (scaled to the same approximate buccolingual width) in a series of Paleogene Africanmammals with possible afrosoricid affinities A Widanelfarasia bowni (latest Eocene Jebel Qatrani Formation Egypt) based on Seiffert et al (2007)B Dilambdogale gheerbranti (earliest late Eocene Birket Qarun Formation Egypt) C Chambilestes foussanensis (late early or early middle EoceneChambi Tunisia) based on Gheerbrant and Hartenberger (1999) D Garatherium todrae (late Paleocene Jebel Guersif Formation Morocco) based onGheerbrant et al (1998) E Afrodon chleuhi (late Paleocene Jbel Guersif Formation Morocco) based on Gheerbrant (1988) F Todralestes variabilis (latePaleocene Jbel Guersif Formation Morocco) based on Gheerbrant (1991b)

pattern may be its presence in a variety of early PaleogeneAfrican mammals with very different dental morphologysuggests that this condition may be plesiomorphic at a hightaxonomic level within Afrotheria

The upper dentition of the alleged adapisoriculid Afrodonchleuhi from the same latest Paleocene deposits that yieldedremains of Todralestes variabilis (Gheerbrant 1988 1995Gheerbrant et al 1998) is more similar to Dilambdogalethan is Todralestes in having relatively broad stylar shelveslonger and more buccally oriented preparaminus and postmetaminuscristae more pronounced ectoflexi a relatively linguallyplaced paraconule and absence of preminus and postcingulaHowever A chleuhi is not as derived as Dilambdogale in thatit retains a linear centrocrista and a stylar shelf that is not asbroad (Fig 8E) the stylar cusps are also more crestiform inA chleuhi The lower molars and p4 of A chleuhi are alsorelatively broad with deep hypoflexids (as in Dilambdominusgale) and its p4 talonid is more complex than that of Todraminuslestes Afrodon tagourtensis from the earliest Eocene of Mominusrocco (Gheerbrant 1993 Gheerbrant et al 1998) is evenmore similar to Dilambdogale than is A chleuhi in having arelatively elongate buccal margin on M1 and on p4 a disminustinct entoconid

Of all other older AfrominusArabian mammals Dilambdogaleis most similar in its occlusal morphology to Garatheriummahboubii from the early Eocene of Algeria (Crochet 1984Mahboubi et al 1986) A similar species that has been referredto as Garatherium todrae is also known from the latestPaleocene localities that preserve remains of Afrodon chleuhiand Todralestes variabilis (Gheerbrant et al 1998) UnlikeAfrodon and Todralestes but as in Dilambdogale Garaminustherium exhibits wellminusdeveloped dilambdomorphy with aldquoWrdquominusshaped arrangement of crests connecting the paraconeand metacone (Fig 8D) Like Dilambdogale Garatheriumhas distinct parastyle stylocone mesostyle and ldquoDrdquo cuspsalong the buccal margin but in Garatherium the mesostyleand cusp ldquoDrdquo are even more prominent and the mesostyle ismet by the postparaminus and premetacristae Further resemblancesinclude the lack of preminus and postcingula At present no lowerteeth or upper premolars have been attributed to Garatheriumlimiting comparisons with Dilambdogale however the disminustinctive upper molar features shared by the two taxa increasethe likelihood that the two species may be closely related andthat G mahboubii is indeed a placental as argued by Gheerminusbrant (1991a) and not a peradectine marsupial as was initiallysuggested (Crochet 1984 Mahboubi et al 1986)

The enigmatic genus Chambilestes from the early or earlymiddle Eocene of Tunisia (Gheerbrant and Hartenberger1999 Fig 8C) differs from Dilambdogale in having distinctpreminus and postcingula small hypocones on M1ndash2 wellminusdevelminusoped postparaminus and premetaconule cristae and a relativelynarrow stylar shelf On the basis of predicted occlusal relationminusships Seiffert and Simons (2000) suggested that Chambilestesmight have affinities with Widanelfarasia but now that theupper dentition of Widanelfarasia is known (Seiffert et al2007) this possibility appears remote Chambilestes might be

more closely related to Todralestes (Seiffert 2010) specifiminuscally early Eocene Todralestes butleri (Gheerbrant 1993)

Of all Paleogene AfrominusArabian taxa Dilambdogale ismost similar to latest Eocene Widanelfarasia (Seiffert andSimons 2000 Seiffert et al 2007) The upper and lower teethof these genera exhibit a series of striking resemblances butDilambdogale appears to be more primitive in having relaminustively broad lower molar talonids (Fig 9) a larger metaconeon M2 and a distinct and cuspate metacone on M3 In eachof these features Dilambdogale is similar to early Africanldquoadapisoriculidsrdquo such as Afrodon while Widanelfarasia exminushibits derived features that arguably align the genus withlater tenrecoids (Seiffert et al 2007)

Stratigraphic and geographic rangemdashEarliest Priaboniannorthern Egypt

Suborder Tenrecomorpha Butler 1972Superfamily Tenrecoidea Gray 1821Genus Qatranilestes novType species Qatranilestes oligocaenus sp nov see belowEtymology From Arabic qatran tarmdashin reference to the dark basaltcapping the Jebel Qatrani Formation cobbles of which drape the hillsnorth of Quarry I and which give that Formation its name (Jebel Qatrani= ldquotar hillrdquo) and from Greek lestes robbermdasha common suffix in genericnames of insectivoranminusgrade placentals

Diagnosis Same as for the species

Qatranilestes oligocaenus sp novFigs 10 11B

Holotype YPM 24203 a right mandibular fragment preserving thetalonids of m2ndash3 (Fig 10B)Etymology In reference to the Oligocene age of the speciesType locality Quarry I northern EgyptType horizon Late early Oligocene upper sequence of Jebel QatraniFormation northern Egypt (~295ndash30 Ma)

DiagnosismdashSmall species (about 65 the size of Dilambminusdogale gheerbranti) that differs from other Fayum afrominussoricids (Dilambdogale Widanelfarasia and Jawharia) inhaving relatively reduced talonid basins and capacious hypominusflexids on m2ndash3 (Figs 9 10) differs from Dilambdogale inhaving very reduced molar entoconids

DescriptionmdashQatranilestes is only known from very fragminusmentary material notably the holotype mandible preserving

doi104202app20100023


D

Fig 9 Relative talonid breadth in Paleogene afrosoricids Plot of the disminustance from the entoconid to hypoconid on m2 divided by the maximumbreadth of the m2 trigonid Note that relative talonid breadth decreasesthrough the later Paleogene

the talonids of m2ndash3 the horizontal ramus distal to p4 and thebase of the ascending ramus (Fig 10B) A complete but badlyabraded and worn m3 is implanted in another partial mandible(YPM 24200 Fig 10A) Even from such poorly preservedmaterial it is clear that Qatranilestes is unique among Fayumtenrecoids in having very reduced talonids (Figs 9 11) andcapacious hypoflexids (m2 talonid width = 045 mm m3talonid width = 045 mm) The m2 talonid preserves a concavecristid obliqua and small hypoconid hypoconulid and entominusconid cusps The trigonid of m3 on YPM 24200 is very wornbut clearly would have had wellminusdeveloped metaconid paraminusconid and protoconid cusps and was elevated high above thevery low and mediolaterally narrow talonid basin whichshows little clear differentiation of cusps aside from thehypoconid The m3 of the holotype specimen is not as wornand damaged but similarly shows only very small and indisminustinct talonid cusps with the hypoconid and hypoconulidclosely approximated Relative to trigonid breadth the m3talonid of Qatranilestes is very reduced relative to those ofWidanelfarasia and Jawharia Seiffert et al (2007) noted thatWidanelfarasia exhibits slight external rotation of the longaxis of the lower molar crowns leading to an arrangement inwhich the lower molar paraconids are situated distal to thehypoconulid (rather than the entoconid) of the adjacent molar


2

05 mm

hcnld

hfxd

hcnd

cr obl

05 mm

Fig 10 Dental morphology of the afrosoricid placental Qatranilestes oligocaenus gen et sp nov from the late early Oligocene (late Rupelian) Quarry Iupper sequence of the Jebel Qatrani Formation northern Egypt A YPM 24200 right mandibular fragment with crown of m3 in occlusal (A1) and lingual(A2) views B YPM 24203 holotype right mandible with talonids of m2ndash3 in occlusal stereo view (B1 and B2)

1 mm

1 mm

Fig 11 Comparison of talonid morphology in lingual view of two Egyptianafrosoricid placentals A Dilambdogale gheerbranti (DPC 24103A) from theearliest late Eocene (earliest Priabonian ~37 Ma) locality BQminus2 Birket QarunFormation Fayum Depression northern Egypt B Qatranilestes oligocaenus(YPM 24203) from the late early Oligocene (late Rupelian ~30 Ma) QuarryI upper sequence of the Jebel Qatrani Formation northern Egypt Specimensare scaled to the same approximate m2ndash3 length to facilitate comparison Notethe much larger hypoconid and relatively capacious and concave talonid basinin Dilambdogale Also note that the m2 entoconid is broken in DPC 24103Abut is relatively wellminusdeveloped in other specimens

This orientation decreases the size of the trough for the occludminusing upper molar metacone and increases the buccal exposureof the paracristid for occlusion with the upper molar postminusmetacrista Judging from the orientation of the m2 talonidQatranilestes had a similar external rotation of the molarcrowns The preserved morphology and orientation of Qatraminusnilestesrsquo m2ndash3 suggests that the occluding M2 would have hada greatly enlarged paracone (to occlude in the large hypominusflexid) a reduced metacone and an elongate postmetacristaand probably more closely approximated the ldquoeuzalambdominusmorphrdquo occlusal pattern than did any of the older species thathave been recovered thus far

Phylogenetic analysisAfrodon chleuhi Dilambdogale gheerbranti and Todralestesvariabilis were added to the characterminustaxon matrix of afrominustherian mammals that was originally compiled by Seiffert(2007) and which was recently augmented by Barrow et al(2010) Although Eochrysochloris Jawharia and Qatraniminuslestes may prove to be key taxa for understanding afrosoricidinterrelationships available specimens preserve too few charminusacters to be included in the analysis The matrix now includes403 morphological characters 18 369 nucleotide characters(from three mitochondrial genes and 20 nuclear genes) deminusrived from the analysis of AmrineminusMadsen et al (2003) tenchromosomal association presenceabsence characters deminusrived from various analyses (Yang et al 2003 Robinson et al2004 Kellogg et al 2007) and eight SINE presenceabsencecharacters derived from the analysis of Nikaido et al (2003)See Seiffert (2007) for additional information including charminusacter descriptions the modified matrix in NEXUS format isavailable at httpwwwmorphobankorg

The matrix was analyzed under two assumption sets usminusing the maximum parsimony algorithm in PAUP 40b10(Swofford 1998) results are presented in Figs 12 and 13 Inone analysis (Fig 12A) some multistate characters were orminusdered and scaled in the other assumption set all multistatecharacters were unordered and equally weighted (Fig 12B)Analysis of the matrix with some multistate characters orminusdered and scaled recovered a single tree of length 18745188(Fig 12A) Despite very minor perturbations to the matrix ofSeiffert (2007) in terms of character and taxon additionafrotherian superordinal relationships are remarkably differminusent from those recovered in his original analysismdashie inminusstead of a ([Macroscelidea + Afrosoricida] [Tubulidentata +Paenungulata]) arrangement Afrosoricida is instead placedas the sister group of all other afrotherians a Macroscelidea+ Tubulidentata clade is placed as the sister group of Paenunminusgulata and within the latter group Sirenia joins Hyracoidearather than Proboscidea These results reinforce Seiffertrsquos(2007) conclusion that two bursts of superordinal cladominusgenesismdashone at the base of crown Afrotheria and one at thebase of Paenungulatamdashoccurred so rapidly that interordinalrelationships might not be convincingly resolved by parsiminus

mony analyses of combined molecularminusmorphological datasets Within Afrosoricida Protenrec was placed as the nearminusest sister group of chrysochloroids and tenrecoids followedby a DilambdogalendashWidanelfarasia clade Todralestes wasplaced as the most basal stem afrosoricid Analysis of allcharacters unordered recovered 63 MPTs of length 19568(Fig 12B) The strict consensus of these trees provides noresolution among crown afrosoricids or Paleogene taxa apminusparently due to Early Cretaceous Prokennalestes and Monminustanalestes which acted as ldquowildminuscardrdquo taxa by falling eitheras a sister group of placentals or as a sister group of Tominusdralestes Dilambdogale and Widanelfarasia across the 63equally most parsimonious trees An Adams consensus of the63 MPTs reveals that a (Todralestes [Dilambdogale Widaminusnelfarasia]) clade was nevertheless consistently placed withafrosoricids though in various positions and in most of thetrees this clade was placed as the sister group of Protenrecfollowed by Potamogale When the poorlyminusknown genusAfrodon was added to the matrix (Fig 13) the phylogeneticrelationships among afrotherians remained the same andAfrodon was placed as a sister group of a DilambdogalendashWidanelfarasia clade whether certain multistates weretreated as ordered and scaled or as unordered

DiscussionIn many ways the dentitions of Dilambdogale and Widaminusnelfarasia are morphologically intermediate between thoseof the highly derived euzalambdomorph afrosoricids fromthe early Miocene of East Africa and those of the much moregeneralized protodilambdomorph adapisoriculids and todraminuslestids from the latest Paleocene of northern Africa An interminusmediate phylogenetic position is supported by parsimonyanalyses with some multistate characters ordered and scaled(Figs 12 13) but analyses with all characters unorderedsometimes nest Afrodon Dilambdogale Todralestes andWidanelfarasia deep within Tenrecoidea as sister taxa ofProtenrec or alternatively as stem afrosoricids joined byEarly Cretaceous Montanalestes and Prokennalestes (the latminuster of which are generally considered to be basal eutherians[eg KielanminusJaworowska et al 2004]) These results must beinterpreted with considerable caution because the matrixemployed here was originally compiled in order to test hyminuspotheses of superordinal relationships among the morphominuslogically diverse afrotherian crown group and might not besufficiently detailed to accurately resolve relationshipsamong stem and crown afrosoricids

Certain aspects of occlusal morphology in Dilambdogaleand Widanelfarasia are somewhat unexpected given theirposition as possible ldquointermediaterdquo taxamdashfor instance deminusspite exhibiting features that are typical of protozalambdominusmorphs (eg transversely broad molar crowns broad stylarshelves with elongate and buccally oriented preparaminus andpostmetacristae reduced metacones that are placed buccalto paracones a deep ectoflexus on M1ndash2 and complete

doi104202app20100023


absence of preminus and postcingula) the buccal crests of theFayum afrosoricids are nevertheless arranged in a typicallydilambdomorph ldquoWrdquo shape This odd combination of molarfeatures either suggests that tenrecoid (or afrosoricid) zalamminusbdomorphy is derived from dilambdomorphy or that Dilamminusbdogale and Widanelfarasia are merely highly derived sistertaxa that are members of a dilambdomorph stem afrosoricidclade By placing Dilambdogale and Widanelfarasia as sistertaxa to the exclusion of all other afrotherians parsimonyanalysis favors an interpretation in which their dilambdominusmorph arrangement of the buccal crests is simply a specialminusization of an extinct side branch (Figs 12 13)

Parsimony analyses provide a simple and straightforwarddirectional explanation for the distribution of molar occlusalfeatures among afrosoricids through time and are also highlyconsistent with stratigraphic ordering of the taxa concerned

mdashie older taxa generally exhibit primitive dental featureswhile successively younger taxa acquire features of the euzaminuslambdomorph dental pattern through the later PaleogeneThe only undoubted fossil afrosoricid in the analysis earlyMiocene Protenrecmdasha genus that has consistently been inminusterpreted as a tenrecoid despite its relatively generalizeddental morphology (Butler and Hopwood 1957 Butler 19691972 1978 1984 Asher and Hofreiter 2006)mdashis surprisminusingly most parsimoniously placed as a sister taxon of crownAfrosoricida when some multistate characters are orderedand scaled (Figs 12A 13A) In the absence of contradictoryevidence a logical interpretation of this phylogenetic patternwould be that the absence of euzalambdomorphs in thePaleogene of AfrominusArabia is best explained by a very late diminusvergence of chrysochloroids and tenrecoids possibly in thelater Oligocene


Fig 12 Phylogenetic analysis of living and extinct afrotherians with Dilambdogale and Todralestes added to a modified version of the matrices employedby Seiffert (2007) and Barrow et al (2010) A Single most parsimonious tree derived from analysis with some multistate characters ordered and scaled treelength = 18746434 consistency index excluding uninformative characters = 049 retention index = 044 rescaled consistency index = 028 B Adams conminussensus of 63 equally parsimonious trees derived from analysis with all multistate characters unordered and Afrodon excluded tree length = 19579 consisminustency index excluding uninformative characters = 049 retention index = 044 rescaled consistency index = 028 Dashed lines indicate branches that arepresent in the Adams tree but not in the strict consensus of all MPTs

The possibility of such a late origin for crown Afrominussoricida is strongly contradicted however by molecular diminusvergence estimates that place the chrysochloroidminustenrecoidsplit about 40 million years earliermdashin either the latest Cretaminusceous or earliest Paleocene (Springer et al 2003 Gilbert etal 2006 Poux et al 2008) Indeed the relationship betweentenrecs and golden moles is distant enough that the two havenot consistently been recovered as sister taxa in molecularphylogenetic analyses (Murata et al 2003 Waddell andShelley 2003 Kitazoe et al 2007 Arnason et al 2008) It isunlikely that the timing of the chrysochloroidminustenrecoid diminusvergence has been dramatically overestimated by these mominuslecular analyses because dating of other splits within Afrominustheria particularly those within Paenungulata are generallyremarkably consistent with that grouprsquos much better fossilrecord

When one of the topologies recovered by the parsimonyanalyses presented here (Fig 13A) is plotted against timewithin the context of a latest Cretaceous divergence ofchrysochloroids and tenrecoids (Fig 14) and rooted withthe oldest known paenungulate Eritherium (Gheerbrant2009) the picture becomes much more complicated andthe topology arguably becomes far less likely becausesuch an ancient split implies extraordinarily long Paleogeneldquoghost lineagesrdquo for all of crown Afrosoricida and anunsampled gt45 Maminuslong interval for the lineage leading toProtenrec The extremely short internodes along the afrominussoricid stem lineage also leave very little time for the evoluminustion of zalambdomorphy As such when metacone loss isreconstructed within Afrosoricida using a maximum likeliminushood approach on the timeminuscalibrated phylogeny (Fig 14)the last common ancestor of crown Afrosoricida and even

doi104202app20100023


Fig 13 Phylogenetic analysis with the poorlyminusknown latest Paleocene genus Afrodon included A Single most parsimonious tree derived from analysiswith some multistate characters ordered and scaled tree length = 18748435 consistency index excluding uninformative characters = 049 retention index= 044 rescaled consistency index = 028 B Adams consensus of 97 equally parsimonious trees derived from analysis with all multistate characters unorminusdered and Afrodon included tree length = 19582 consistency index excluding uninformative characters = 049 retention index = 045 rescaled consisminustency index = 028 Dashed lines indicate branches that are present in the Adams tree but not in the strict consensus of all MPTs

the last common ancestor of crown Tenrecoidea is optiminusmized as having had distinct but reduced M2 metaconesParsimony analysis cannot incorporate these considerationsas background information but such evidence calls intoquestion the likelihood of the topology itself at least as itrelates to the origin of zalambomorphy

There are additional taxa from the Fayum succession thatare currently too fragmentary to be included in the parsimonyanalysis but that nevertheless might come to bear decisivelyon this issue should more material be recovered Notably thetiny species Eochrysochloris tribosphenusmdashat present repreminussented solely by mandibular fragments a partial p3 and


OL

IGO

CE

NE

Fig 14 Implied ghost lineages and maximum likelihood reconstructions of M2 metacone size (treated as an ordered character with four states) given one ofthe topologies (Fig 12A) recovered by parsimony analysis of morphological data Here the topology is plotted against time with major divergences amongclades with extant representatives based on the molecular estimates of Douady et al (2003) for Macroscelidea Poux et al (2008) for Tenrecoidea andGilbert et al (2006) for the origin of crown Chrysochloroidea The depth of the PotamogalendashMicropotamogale divergence has not been estimated usingmolecular data and is here arbitrarily placed at half the time depth of Potamogalidae An origin of crown Afrotheria at ~80 Ma is supported by various studminusies (eg Springer et al 2003) Although parsimony reconstructs metacone loss as homologous in tenrecs and golden moles note that when branch lengthsare taken into account for maximum likelihood reconstructions (ldquoMLRrdquo computed in Mesquite v 272 Maddison and Maddison 2005) the common anminuscestors of crown Afrosoricida and crown Tenrecoidea are reconstructed as having had a reduced but distinct M2 metacone the former with high proporminustional likelihood (0779) These data combined with the numerous zalambdomorph Paleogene ghost lineages that are required by the parsimonyminusbased tominuspology arguably call into question the likelihood of the topology itself

crowns of p4 and m2 (Seiffert et al 2007)mdashexhibits an m2talonid morphology in which the cristid obliqua is orientedonly slightly lingually leaving a relatively shallow hypoflexidfor an occluding paracone when compared with those ofDilambdogale Widanelfarasia Jawharia and QatranilestesEochrysochloris also has a very tall trigonid and the occlusalpattern of M2 is predicted to be associated with an occludingm2 that would be transversely broad but not dilambdomorph(Seiffert et al 2007) This poorlyminusknown but very distinctivegenus reveals that there are two groups of probable afrominussoricids in the Paleogene of northern Africa the other beingrepresented by Dilambdogale Widanelfarasia Jawharia andQatranilestes all of which have deep hypoflexids It was preminusviously argued by Seiffert et al (2007) that the latter groupdocuments gradual acquisition of tenrecoid zalambdomorphyfrom dilambdomorphy through the later Paleogene whileEochrysochloris documents acquisition of chrysochloroidzalambdomorphy through a very different transformation ofupper molar occlusal morphology This scenario is howeverstill highly speculative and must be tested by the recovery ofmuch more complete fossil material

While it appears increasingly likely that the Fayum afrominussoricids are of relevance for understanding the origins ofTenrecoidea and Chrysochloroidea these taxa also providesome interesting clues that might help to explain the higherminuslevel affinities of older insectivoranminusgrade placentals fromAfrominusArabia such as Afrodon Garatherium and TodralestesGaratherium was originally identified as a peradectine marsuminuspial on the basis of an isolated upper molar from the earlyEocene El Kohol locality in Algeria (Crochet 1984) but wassubsequently reinterpreted as a dilambdomorph adapisoriculid(Gheerbrant 1991a 1995) The wellminusdeveloped dilambdominusmorphy seen on the M1 of Dilambdogale and Widanelfarasiais similar to though less extreme than that of Garatheriumand all three taxa have broad stylar shelves restricted trigonselongate postmetacristae no preminus or postcingula and smallconules Like Garatherium Dilambdogale has relatively disminustinct (as opposed to crestiform) stylar cusps and variablyexhibits a postparaconule crista which was not previouslyclearly present in the microminusCT reconstructions of Widanelminusfarasia In many ways therefore Dilambdogale appears to bestructurally intermediate between Garatherium and Widanelminusfarasia while Widanelfarasia is in turn structurally intermediminusate between the older dilambdomorphs and tenrecoids IfGaratherium is an early stem tenrecoid its age (~56ndash54 Ma)would be in line with molecular estimates for the timing of thechrysochloridminustenrecoid divergence

Dilambdogalersquos position as a morphological and phylominusgenetic intermediate between tenrecoids and adapisoriculidstakes on new significance in light of a recent analysis that hassuggested a close relationship between Afrodon and the enigminusmatic Late Cretaceous placental Deccanolestes from India(Prasad et al 2010) Analysis of adapisoriculid tarsals fromthe late Paleocene of Europe has also suggested that Deccanominuslestes is closely related to European adapisoriculids (Smith etal 2009) On the basis of tarsal morphology Deccanolestes

has however been interpreted as a possible ldquoarchontanrdquo oreuarchontan (Prasad and Godinot 1994 KielanminusJaworowskaet al 2004 Smith et al 2009) and not as a possible afrominustherian If Deccanolestes is in fact allied with adapisoriculidsas argued by Prasad et al (2010) this interpretation would apminuspear to be consistent with Storchrsquos (2008) recent analysis ofadapisoriculid humeri which led him to suggest that the famminusily has plesiadapiform (and hence euarchontan and possiblyeven primate) affinities Notable exceptions to the interpretaminustion of Deccanolestes as a basal euarchontan are the studies ofWible et al (2007) which placed Deccanolestes as a stem plaminuscental and that of Rana and Wilson (2003) who consideredDeccanolestes to be of uncertain affinities within PlacentaliaMost recently Boyer et al (2010) described a distal humerusand proximal ulna of Deccanolestes and concluded that itsdistal humerus is more primitive than the adapisoriculid huminusmeri described by Storch (2008) and morphologically interminusmediate between Late Cretaceous Protungulatum and Prominuscerberus and definitive euarchontans Breakage of the distalhumerus that is here attributed to Dilambdogale does not alminuslow for extensive comparison but in preserved morphologythe humeral morphology of Dilambdogale appears to be quitesimilar to that of Deccanolestes and both are similar to generminusalized tenrecoids such as Microgale

Given the enormous amount of homoplasy that has ocminuscurred in the dentition of placental mammals the meaning ofthe occlusal similarities shared by Deccanolestes adapisoriminusculids and afrosoricids is by no means clear at the momentThere can be little doubt however that the dental morphologyof Deccanolestes closely approximates the primitive morphominustype for crown placentals as was argued by KielanminusJawominusrowska et al (2004 505) ldquomolar morphology of Deccanominuslestes differs substantially from that of Cimolestes and similartaxahellipmainly in the presumed retention of plesiomorphiesrdquoPrimitive adapisoriculids such as Afrodon and Bustylus aresimilarly generalized to the extent that the latter was first deminusscribed as a marsupial by Crochet and Sigeacute (1983) The factthat adapisoriculids have been proposed as possible marsupiminusals basal euarchontans and herein as possible basal afrominussoricidsmdashthe latter two of which are now known to be verydistantly related within Placentalia (Fig 1)mdashcould indicatethat many if not most aspects of dental morphology in Afrominusdon Bustylus and Deccanolestes were present in the last comminusmon ancestor of crown Placentalia (a hypothesis that is supminusported by the very basal placement of Deccanolestes in Wibleet alrsquos [2007] phylogenetic analysis) and that the most basalmembers of Afrotheria Euarchontoglires Laurasiatheria andXenarthra might be identified as ldquoadapisoriculidrdquo on the basisof dental features This possibility is particularly compelling inlight of the results of the phylogenetic analyses presented herewhich consistently placed Afrosoricida as the sister group ofall other afrotherians rather than as the sister group of Macrominusscelidea andor Tubulidentata as in many molecular studies(Fig 1) This phylogenetic arrangement implies an insectiminusvoranminusgrade (and perhaps dentally adapisoriculidminuslike) ratherthan condylarthranminusgrade ancestor for crown Afrotheria (see

doi104202app20100023


discussion in Seiffert 2002 Robinson and Seiffert 2004Seiffert 2007 Tabuce et al 2008 Asher and Seiffert 2010)Paleontological sampling in the Late Cretaceous of Africaideally from horizons near the estimated time of origin ofAfrotheria (ie ~80 Ma early to midminusCampanian) is now desminusperately needed to test these and other hypotheses bearing onafrotherian origins

AcknowledgementsI would like to thank the staff of the Egyptian Mineral Resources Auminusthority and the CGM for supporting and facilitating paleontological reminussearch in the Fayum area Elwyn L Simons and Prithijit Chatrath (bothDPC) for providing access to the Duke collections and facilitating fieldminuswork in the Fayum area Hesham Sallam (University of Oxford Oxminusford UK) Michelle Gignac (Duke University Durham USA) andOwen Green (University of Oxford Oxford UK) for assistance withscanning electron micrography Emmanuel Gheerbrant (Museacuteum Naminustional drsquoHistoire Naturelle Paris France) Bernard Marandat (Uniminusversiteacute Montpellier 2 Montpellier France) and Rodolphe Tabuce(Universiteacute Montpellier 2 Montpellier France) for providing access tocomparative fossil material from Algeria and Morocco Walter Joyce(YPM) for relocating and providing access to the specimens of Qatraminusnilestes housed in the Yale Peabody Museum and 2001ndash2009 Fayumfield crews for work at locality BQminus2 that led to the recovery of fossilsdescribed here Robert Asher (Cambridge University Cambridge UK)Richard L Cifelli (Sam Noble Oklahoma Museum of Natural HistoryNorman USA) and an anonymous reviewer provided helpful comminusments that improved the manuscript This research was funded by theUS National Science Foundation and The Leakey Foundation This isDuke Lemur Center publication No 1182

ReferencesAmrineminusMadsen H Koepfli KminusP Wayne RK and Springer MS 2003

A new phylogenetic marker apolipoprotein B provides compelling evminusidence for eutherian relationships Molecular Phylogenetics and Evoluminustion 28 225ndash240 httpdxdoiorg101016S1055-7903 (03)00118-0

Arnason U Adegoke JA Gullberg A Harley EH Janke A andKullberg M 2008 Mitogenomic relationships of placental mammalsand molecular estimates of their divergences Gene 421 37ndash51httpdxdoiorg101016jgene200805024

Asher RJ 2005 Insectivoranminusgrade placentals In KD Rose and JDArchibald (eds) The Rise of Placental Mammals Origins and Relaminustionships of the Major Extant Clades 50ndash70 Johns Hopkins UniversityPress Baltimore

Asher RJ 2007 A webminusdatabase of mammalian morphology and a reanalysisof placental phylogeny BMC Evolutionary Biology 7 (108) 1ndash10

Asher RJ and Avery DM 2010 New golden moles (Afrotheria Chrysominuschloridae) from the Pliocene of South Africa Paleontologica Electronica13 (1) 3A

Asher RJ and Helgen KM 2010 Nomenclature and placental mammalphylogeny BMC Evolutionary Biology 10 (102) 1ndash9

Asher RJ and Hofreiter M 2006 Tenrec phylogeny and the noninvasiveextraction of nuclear DNA Systematic Biology 55 181ndash194httpdxdoiorg10108010635150500433649

Asher RJ and SanchezminusVillagra MR 2005 Locking yourself out diverminussity among dentally zalambdodont therian mammals Journal of Mamminusmalian Evolution 12 265ndash282httpdxdoiorg101007s10914-005-5725-3

Asher RJ and Seiffert ER 2010 Systematics of endemic African mamminusmals In WJ Sanders and L Werdelin (eds) Cenozoic Mammals ofAfrica 911ndash928 University of California Press Berkeley

Asher RJ Novacek MJ and Geisler JH 2003 Relationships of enminusdemic African mammals and their fossil relatives based on morphologiminuscal and molecular evidence Journal of Mammalian Evolution 10131ndash194 httpdxdoiorg101023A1025504124129

Barrow E Seiffert ER and Simons EL 2010 A primitive hyracoid(Mammalia Paenungulata) from the early Priabonian (late Eocene) ofEgypt Journal of Systematic Palaeontology 8 213ndash244

Boyer DM Prasad GVR Krause DW Godinot M Goswami AVerma O and Flynn JJ 2010 New postcrania of Deccanolestes fromthe Late Cretaceous of India and their bearing on the evolutionary andbiogeographic history of euarchontan mammals Naturwissenschaften97 365ndash377 httpdxdoiorg101007s00114-010-0648-0

Butler PM 1969 Insectivores and bats from the Miocene of East Africanew material In LSB Leakey (ed) Fossil Vertebrates of Africa1ndash37 Academic Press London

Butler PM 1972 The problem of insectivore classification In KAJoysey and TS Kemp (eds) Studies in Vertebrate Evolution 253ndash265Oliver and Boyd Edinburgh

Butler PM 1978 Insectivora and Chiroptera In VJ Maglio and HBSCooke (eds) Evolution of African Mammals 56ndash68 Harvard Univerminussity Press Cambridge Mass

Butler PM 1984 Macroscelidea Insectivora and Chiroptera from the Miominuscene of east Africa Palaeovertebrata 14 117ndash200

Butler PM 1988 Phylogeny of the insectivores In MJ Benton (ed) ThePhylogeny and Classification of the Tetrapods Volume 2 Mammals117ndash141 Clarendon Press Oxford

Butler PM and Hopwood AT 1957 Insectivora and Chiroptera from theMiocene rocks of Kenya colony Fossil Mammals of Africa 13 1ndash35

Crochet JminusY 1984 Garatherium mahboubii nov gen nov sp marsupialde lEocegravene infeacuterieur dEl Kohol (Sud Oranais Algeacuterie) Annales dePaleacuteontologie 70 275ndash294

Crochet JminusY 1988 Le plus ancien Creacuteodonte africain Koholia atlasensenov gen nov sp (Eocegravene infeacuterieur dEl Kohol Atlas saharienAlgeacuterie) Comptes Rendus de lAcadeacutemie des Sciences Paris Ser II307 1795ndash1798

Crochet JminusY and Sigeacute B 1983 Les Mammifegraveres montiens de Hainin(Paleacuteocegravene de Belgique) Part III Marsupiaux Palaeovertebrata 1351ndash64

Douady CJ Catzeflis F Raman J Springer MS and Stanhope MJ2003 The Sahara as a vicariant agent and the role of Miocene climaticevents in the diversification of the mammalian order Macroscelidea (elminusephant shrews) Proceedings of the National Academy of Sciences USA100 8325ndash8330 httpdxdoiorg101073pnas0832467100

Douady CJ and Douzery EJP 2003 Molecular estimation of eulipotyphlandivergence times and the evolution of ldquoInsectivorardquo Molecular Phylominusgenetics and Evolution 28 285ndash296httpdxdoiorg101016S1055-7903 (03)00119-2

Gheerbrant E 1988 Afrodon chleuhi nov gen nov sp ldquoinsectivoresrdquo(Mammalia Eutheria) lipotyphleacute () du Paleacuteocegravene marocain donneacuteespreacuteliminaires Comptes Rendus de lAcadeacutemie des Sciences Paris II307 1303ndash1309

Gheerbrant E 1991a Bustylus (Eutheria Adapisoriculidae) and the absenceof ascertained marsupials in the Palaeocene of Europe Terra Nova 3586ndash592 httpdxdoiorg101111j1365-31211991tb00200x

Gheerbrant E 1991b Todralestes variablis n g n sp nouveau Proteuminustheacuterien (Eutheria Todralestidae fam nov) du Paleacuteocegravene du MarocComptes Rendus de lAcadeacutemie des Sciences Paris Ser II 3121249ndash1255

Gheerbrant E 1992 Les mammifegraveres paleacuteocenes du Bassin dOuarzazate(Maroc) I Introduction geacuteneacuteral et palaeoryctidae PalaeontographicaAbteilung A 224 67ndash132

Gheerbrant E 1993 Premiegraveres donneacutees sur les mammifegraveres ldquoinsectivoresrdquo delYpreacutesian du Bassin dOuarzazate (Maroc site de NTagourt 2) NeuesJahrbuch fuumlr Geologie und Palaumlontologie Abhhandlungen 187 225ndash242


Gheerbrant E 1994 Les mammifegraveres paleacuteocenes du Bassin dOuarzazate(Maroc) II Todralestidae (Proteutheria Eutheria) PalaeontographicaAbteilung A 231 133ndash188

Gheerbrant E 1995 Les mammifegraveres paleacuteocegravenes du Bassin dOuarzazate(Maroc) III Adapisoriculidae et autres mammifegraveres (Carnivora Creominusdonta Condylarthra Ungulata et incertae sedis) PalaeontographicaAbteilung A 237 39ndash132

Gheerbrant E 2009 Paleocene emergence of elephant relatives and therapid radiation of African ungulates Proceedings of the National Acadminusemy of Sciences USA 106 10717ndash10721httpdxdoiorg101073pnas0900251106

Gheerbrant E and Hartenberger JminusL 1999 Nouveau mammifegravere insectiminusvore (Lipotyphla Erinaceomorpha) de lEocegravene infeacuterieur de Chambi(Tunisie) Palaumlontologische Zeitschrift 73 143ndash156

Gheerbrant E Sudre J Sen S Abrial C Marandat B Sigeacute B andVianeyminusLiaud M 1998 Nouvelles donneacutees sur les mammifegraveres duThaneacutetien et de lYpreacutesian du Bassin dOuarzazate (Maroc) et leurcontexte stratigraphique Palaeovertebrata 27 155ndash202

Gilbert C OBrien PC Bronner G Yang F Hassanin A FerguminussonminusSmith MA and Robinson TJ 2006 Chromosome painting andmolecular dating indicate a low rate of chromosomal evolution ingolden moles (Mammalia Chrysochloridae) Chromosome Research14 793ndash803 httpdxdoiorg101007s10577-006-1091-0

Gill T 1883 On the classification of the insectivorous mammals Bulletinof the Philosophical Society of Washington 5 118ndash120

Gray JE 1821 On the natural arrangement of vertebrose animals LondonMedical Repository 15 296ndash310

Gunnell GF Simons EL and Seiffert ER 2008 New bats (MammaliaChiroptera) from the late Eocene and early Oligocene Fayum Depresminussion Egypt Journal of Vertebrate Paleontology 28 1ndash11httpdxdoiorg1016710272-4634 (2008)28[1NBMCFT]20CO2

Kellogg ME Burkett S Dennis TR Stone G Gray BA McGuirePM Zori RT and Stanyon R 2007 Chromosome painting in themanatee supports Afrotheria and Paenungulata BMC Evolutionary Biminusology 7 6

KielanminusJaworowska Z Cifelli RL and Luo ZminusX 2004 Mammals fromthe Age of Dinosaurs Origins Evolution and Structure 630 pp Cominuslumbia University Press New York

Kitazoe Y Kishino H Waddell PJ Nakajima N Okabayashi TWatabe T and Okuhara Y 2007 Robust time estimation reconcilesviews of the antiquity of placental mammals PLoS ONE 2 (4) e384httpdxdoiorg101371journalpone0000384

Lopatin A 2006 Early Paleogene insectivore mammals of Asia and establishminusment of the major groups of Insectivora Paleontological Journal 40 supminusplement 3 S205ndashS405 httpdxdoiorg101134S0031030106090012

Maddison WP and Maddison DR 2005 Mesquite A modular system forevolutionary analysis Version 106 httpmesquiteprojectorg

Madsen O Scally M Douady CJ Kao DJ DeBry RW Adkins RAmrine HM Stanhope MJ de Jong WW and Springer MS2001 Parallel adaptive radiations in two major clades of placental mamminusmals Nature 409 610ndash614 httpdxdoiorg10103835054544

Mahboubi M Ameur R Crochet JminusY and Jaeger JminusJ 1986 El Kohol(Saharan Atlas Algeria) A new Eocene mammal locality in northwestminusern Africa Palaeontographica Abteilung A 192 15ndash49

McDowell SB 1958 The Greater Antillean insectivores Bulletin of theAmerican Museum of Natural History 115 115ndash214

Murata Y Nikaido M Sasaki T Cao Y Fukumoto Y Hasegawa Mand Okada N 2003 Afrotherian phylogeny inferred from complete mitominuschondrial genomes Molecular Phylogenetics and Evolution 28 253ndash260httpdxdoiorg101016S1055-7903 (03)00035-6

Murphy WJ Eizirik E OBrien SJ Madsen O Scally M DouadyCJ Teeling E Ryder OA Stanhope MJ de Jong WW andSpringer MS 2001 Resolution of the early placental mammal radiaminustion using Bayesian phylogenetics Science 294 2348ndash2351httpdxdoiorg101126science1067179

Nikaido M Nishihara H Hukumoto Y and Okada N 2003 Ancient

SINEs from African endemic mammals Molecular Biology and Evoluminustion 20 522ndash527 httpdxdoiorg101093molbevmsg052

Poux C Madsen O Glos J de Jong WW and Vences M 2008 Mominuslecular phylogeny and divergence times of Malagasy tenrecs Influenceof data partitioning and taxon sampling on dating analyses BMC Evoluminustionary Biology 8 16 httpdxdoiorg1011861471-2148-8-102

Prasad GVR and Godinot M 1994 Eutherian tarsal bones from the lateCretaceous of India Journal of Paleontology 68 892ndash902

Prasad GVR Verma O Gheerbrant E Goswami A Khosla AParmar V and Sahni A 2010 First mammal evidence from the LateCretaceous of India for biotic dispersal between India and Africa at theKT transition Comptes Rendus Palevol 9 63ndash71

Rana RS and Wilson GP 2003 New Late Cretaceous mammals from theIntertrappean beds of Rangapur India and paleobiogeographic frameminuswork Acta Palaeontologica Polonica 48 331ndash348

Robinson TJ and Seiffert ER 2004 Afrotherian origins and interrelationminusships New views and future prospects Currents Topics in DevelopmentalBiology 63 37ndash60 httpdxdoiorg101016S0070-2153 (04)63002-X

Robinson TJ Fu B FergusonminusSmith MA and Yang F 2004 Crossminusspeminuscies chromosome painting in the golden mole and elephantminusshrew supportfor the mammalian clades Afrotheria and Afroinsectiphillia but not Afrominusinsectivora Proceedings of the Royal Society London B 271 1477ndash1484httpdxdoiorg101098rspb20042754

Roca AL BarminusGal GK Eizirik E Helgen KM Maria R SpringerMS OrsquoBrien SJ and Murphy WJ 2004 Mesozoic origin for WestIndian insectivores Nature 429 649ndash651httpdxdoiorg101038nature02597

Sallam H Seiffert ER and Simons EL 2010a A highly derivedanomalurid rodent (Mammalia) from the earliest late Eocene of EgyptPalaeontology 53 803ndash813

Sallam H Seiffert ER Boyer DM and Simons EL 2010b Postcranialmorphology of an anomaluroid rodent from the late Eocene of EgyptJournal of Vertebrate Paleontology 30 (Supplement) 155A

Sallam HM Seiffert ER Simons EL and Brindley C 2010c Alargeminusbodied anomaluroid rodent from the earliest late Eocene of EgyptPhylogenetic and biogeographic implications Journal of VertebratePaleontology 30 1579ndash1593

Salton JA and Sargis EJ 2008 Evolutionary morphology of the Tenreminuscoidea (Mammalia) forelimb skeleton In EJ Sargis and M Dagosto(eds) Mammalian Evolutionary Morphology A Tribute to FrederickS Szalay 51ndash71 Springer New York

Seiffert ER 2002 The reality of afrotherian monophyly and some of itsimplications for the evolution and conservation of AfrominusArabias enminusdemic placental mammals Afrotherian Conservation 1 3ndash6

Seiffert ER 2006 Revised age estimates for the later Paleogene mammal fauminusnas of Egypt and Oman Proceedings of the National Academy of Sciminusences USA 103 5000ndash5005 httpdxdoiorg101073pnas0600689103

Seiffert ER 2007 A new estimate of afrotherian phylogeny based on simultaminusneous analysis of genomic morphological and fossil evidence BMC Evominuslutionary Biology 7 224 httpdxdoiorg1011861471-2148-7-224

Seiffert ER 2010 Paleogene ldquoinsectivoresrdquo In WJ Sanders and LWerdelin (eds) Cenozoic Mammals of Africa 253ndash260 University ofCalifornia Press Berkeley

Seiffert ER and Simons EL 2000 Widanelfarasia a diminutive plaminuscental from the late Eocene of Egypt Proceedings of the NationalAcademy of Sciences USA 97 2646ndash2651httpdxdoiorg101073pnas040549797

Seiffert ER Bown TM Clyde WC and Simons EL 2008 Geologypaleoenvironment and age of Birket Qarun locality 2 (BQminus2) FayumDepression Egypt In JG Fleagle and CC Gilbert (eds) Elwyn LSimons A Search for Origins 71ndash86 Springer New York

Seiffert ER Simons EL Ryan TM Bown TM and Attia Y 2007New remains of Eocene and Oligocene Afrosoricida (Afrotheria) fromEgypt with implications for the origin (s) of afrosoricid zalambdodontyJournal of Vertebrate Paleontology 27 (4) 963ndash972httpdxdoiorg1016710272-4634 (2007)27[963NROEAO]20CO2

Simmons NB and Geisler JH 1998 Phylogenetic relationships of Icarominus

doi104202app20100023


nycteris Archaeonycteris Hassianycteris and Palaeochiropteryx to exminustant bat lineages with comments on the evolution of echolocation and forminusaging strategies in Microchiroptera Bulletin of the American Museum ofNatural History 235 4ndash182

Smith T De Bast E and Sigeacute B 2009 Adapisoriculid mammals from thePaleocene of Hainin (Belgium) shed light on the phylogenetic affinitiesof the enigmatic arboreal Cretaceous Deccanolestes from the DeccanTraps of India Journal of Vertebrate Paleontology 29 183A

Springer MS Cleven GC Madsen O de Jong WW Waddell VGAmrine HM and Stanhope MJ 1997 Endemic African mammalsshake the phylogenetic tree Nature 388 61ndash64httpdxdoiorg10103840386

Springer MS Murphy WJ Eizirik E and OBrien SJ 2003 Placentalmammal diversification and the CretaceousndashTertiary boundary Prominusceedings of the National Academy of Sciences USA 100 1056ndash1061httpdxdoiorg101073pnas0334222100

Springer MS Stanhope MJ Madsen O and de Jong WW 2004 Molminusecules consolidate the placental mammal tree Trends in Ecology andEvolution 19 430ndash438 httpdxdoiorg101016jtree200405006

Stanhope MJ Waddell VG Madsen O de Jong W Hedges SBCleven GC Kao D and Springer MS 1998 Molecular evidencefor multiple origins of Insectivora and for a new order of endemic Afriminuscan insectivore mammals Proceedings of the National Academy of Sciminusences USA 95 9967ndash9972 httpdxdoiorg101073pnas95179967

Storch G 2008 Skeletal remains of a diminutive primate from the Paleoceneof Germany Naturwissenschaften 95 927ndash930httpdxdoiorg101007s00114-008-0401-0

Swofford DL 1998 PAUP Phylogenetic Analysis Using Parsimony(and Other Methods) Version 4 Sinauer Associates Sunderland MA

Tabuce R Asher RJ and Lehmann T 2008 Afrotherian mammals a reminusview of current data Mammalia 72 2ndash14httpdxdoiorg101515MAMM2008004

Waddell PJ and Shelley S 2003 Evaluating placental interminusordinalphylogenies with novel sequences including RAG1 minusfibrinogen ND6and mtminustRNA plus MCMCminusdriven nucleotide amino acid and codonmodels Molecular Phylogenetics and Evolution 28 197ndash224httpdxdoiorg101016S1055-7903 (03)00115-5

Wible JR Rougier GW Novacek MJ and Asher RJ 2007 Cretaminusceous eutherians and Laurasian origin for placental mammals near theKT boundary Nature 447 1003ndash1006ttpdxdoiorg101038nature05854

Yang F Alkalaeva EZ Perelman PL Pardini AT Harrison WROBrian PCM Fu B Graphodatsky AS FergusonminusSmith MAand Robinson TJ 2003 Reciprocal chromosome painting among huminusman aardvark and elephant (superorder Afrotheria) reveals the likelyeutherian ancestral karyotype Proceedings of the National Academyof Sciences USA 100 (3) 1062ndash1066httpdxdoiorg101073pnas0335540100


tant afrosoricids have a ldquozalambdomorphrdquo occlusal patternon their molarsmdashie a condition in which upper molar metaminuscones and lower molar talonids are greatly reduced or absentaltogether (see also Asher and SanchezminusVillagra 2005) Optiminusmization of zalambdomorphy onto a cladogram of extantplacentals alone (eg Springer et al 2004) would reconstructthis dental pattern as having been present in the last commonancestor of tenrecs and golden moles (Fig 1) If this ancestorwas in fact ~66ndash63 Ma in age as estimated by molecular seminusquence datamdashand if Afrosoricida is indeed an endemic Afriminuscan clademdashthen zalambdodomorph fossil afrosoricids shouldhave been present in AfrominusArabia during the time periods forwhich there is paleontological coverage on that landmass (ielatest Paleocene early Eocene early middle Eocene lateEocene and early Oligocene) Zalambdomorph species arehowever completely absent from AfrominusArabian mammal fauminusnas of these time periods (Seiffert 2010) suggesting that either(i) afrosoricids were not present in AfrominusArabia during thePaleogene (ii) zalambdomorph afrosoricids were present inAfrominusArabia during the Paleogene but not in the areas thathave been sampled thus far (iii) tenrecs and golden moles diminusverged much later (eg in the Oligocene) than suggested bymolecular data or (iv) zalambdodomorphy was not present inthe last common ancestor of tenrecs and golden moles andevolved convergently later in the Paleogene

There is now a small but growing body of fossil evidencethat has been interpreted by Seiffert et al (2007) as supportminusing the latter scenario The oldest definitive euzalambdominusmorph tenrecoids and chrysochlorids (ie forms that comminuspletely lack upper molar metacones) are from the early Miominuscene of Kenya and Uganda (Butler and Hopwood 1957 Butminusler 1969 1984) but Seiffert et al (2007) have recently idenminustified tribosphenic latest Eocene (~34 Ma Seiffert 2006Seiffert et al 2007) Widanelfarasia and early OligoceneJawharia as stem tenrecoids and early Oligocene Eochrysominuschloris as a stem chrysochlorid (see Fig 2) Because thesegenera all retain wellminusdeveloped molar metacones andorlower molar talonid basins these identifications would reminusquire that euzalambdomorphy evolved convergently withinAfrosoricida In particular Widanelfarasiarsquos combinationof a dilambdomorph M1 and protozalambdomorph M2ndash3would suggest that the stem lineage leading to crown Tenreminuscoidea either passed through a dilambdodomorph phase priorto acquisition of zalambdomorphy or that Widanelfarasiarsquosdilambdomorphy is autapomorphic Furthermore it has longbeen known that the extant potamogalid tenrecoid Potaminus

mogale is protozalambdomorph (McDowell 1958 Butler1972 1988) lending additional support to the hypothesisthat this condition might be plesiomorphic within Afrosoriminuscida Alternatively this condition is simply an autapomorphyof Potamogale this possibility is supported by the observaminustion that the molar metacones of Potamogalersquos sister taxonthe smaller genus Micropotamogale vary from being veryreduced to absent

Here I present additional evidence that contributes to thedebate surrounding the homology of zalambdomorphy intenrecs and golden moles Recent work at the earliest Priaminusbonian (earliest late Eocene ~37 Ma) Birket Qarun locality 2(or BQminus2) has led to the recovery of the oldest Fayum afrominus


In what follows I employ the terminology recently proposed by Lopatin (2006) which is useful for distinguishing important differences between taxa thathave been termed ldquozalambdodontrdquo and ldquodilambdodontrdquo (Gill 1883) The broad category of ldquozalambdomorphyrdquo is defined by Lopatin (2006 S215) as folminuslows ldquothe trigon of the upper molars is formed by a large lingually located paracone a paracrista that is Vminusshaped in projection and styles the metaconeand protocone are considerably reduced or absent the conules are absent hellip in this pattern the lower molars are characterized by reduced talonids and exminuscessively developed trigonids including the formation of the oblique paracristid and a very high and broad transverse protocristidrdquo ldquoEuzalambdominusmorphyrdquo which is present in most extant afrosoricids is described as ldquocomplete loss of the metacone and protocone the lingual displacement of theparacone to the position of the protocone excessive development of the stylar shelf and appearance of supplementary cingular elements hellip the talonid isextremely reduced and resembles a postcingulidrdquo (Lopatin 2006 S215) while in ldquoprotozalambdomorphyrdquo which occurs in extant Potamogale and earlyMiocene Protenrec ldquothe metacone is considerably reduced (however its rudiment is preserved between a shortened centrocrista and postmetacrista) theparacone is displaced to the center the protocone and talonid are reducedrdquo (Lopatin 2006 S215)

Fig 1 Relationships of extant placental mammalian orders based on theanalysis of Roca et al (2004) with zalambdomorph groups (Afrosoricidaand Solenodontidae) highlighted













doi104202app20100023


C1

0C

11

C1

2C

13

C1

5C

16

C1

7

38

37

36

35

34

33

32

31

30

29

GPTS Sta

ge

Ep

och

Je

be

lQ

atr

an

iF

orm

atio

nQ

asr

el-S

ag

ha

Fo

rma

tio

n

low

er

se

qu

en

ce

up

pe

rse

qu

en

ce

Dir

Ab

uL

ifa

Mb

rTe

mp

leM

br

BirketQarunFmn

Fayumsuccession

and

zones

Afrosoricid

Ma

gn

eto

str

atig

rap

hic

co

rre

latio

np

refe

rre

db

yS

eiffe

rt(2

00

6)





rasmusseni


polarity

RU

PE

LIA

N

OL

IGO

CE

NE

EO

CE

NE

PR

IAB

ON

IAN

Ma

I

E

L-41

BQ-2


taxa







1 mm


P4


M1



Specimen LocusM

axim

umM

Dle

ngth

[ldquoL

labrdquo

inG

heer

bran

t(19

92)]

Mes

ialB

Lw

idth

[ldquoIM

rdquoin

Ghe

erbr

ant(

1992

)]

Dis

talB

Lw

idth

[ldquoID

rdquoin

Ghe

erbr

ant(

1992

)]

Wid

thfr

omba

seof

para

cone

topr

otoc

one

apex

[ldquolp

roto

rdquoin

Ghe

erbr

ant(

1992

)]

MD

leng

thof

trig

on[ldquo

Lm

drdquoin

Ghe

erbr

ant(

1992

)]




Trigonidwidth

Talonidwidth







doi104202app20100023


1 mm


1 mm






1 mm









doi104202app20100023


1 mm

























doi104202app20100023


D




2

05 mm

hcnld

hfxd

hcnd

cr obl

05 mm


1 mm

1 mm








doi104202app20100023









doi104202app20100023






OL

IGO

CE

NE







doi104202app20100023










































































doi104202app20100023



























doi104202app20100023


C1

0C

11

C1

2C

13

C1

5C

16

C1

7

38

37

36

35

34

33

32

31

30

29

GPTS Sta

ge

Ep

och

Je

be

lQ

atr

an

iF

orm

atio

nQ

asr

el-S

ag

ha

Fo

rma

tio

n

low

er

se

qu

en

ce

up

pe

rse

qu

en

ce

Dir

Ab

uL

ifa

Mb

rTe

mp

leM

br

BirketQarunFmn

Fayumsuccession

and

zones

Afrosoricid

Ma

gn

eto

str

atig

rap

hic

co

rre

latio

np

refe

rre

db

yS

eiffe

rt(2

00

6)





rasmusseni


polarity

RU

PE

LIA

N

OL

IGO

CE

NE

EO

CE

NE

PR

IAB

ON

IAN

Ma

I

E

L-41

BQ-2


taxa







1 mm


P4


M1



Specimen LocusM

axim

umM

Dle

ngth

[ldquoL

labrdquo

inG

heer

bran

t(19

92)]

Mes

ialB

Lw

idth

[ldquoIM

rdquoin

Ghe

erbr

ant(

1992

)]

Dis

talB

Lw

idth

[ldquoID

rdquoin

Ghe

erbr

ant(

1992

)]

Wid

thfr

omba

seof

para

cone

topr

otoc

one

apex

[ldquolp

roto

rdquoin

Ghe

erbr

ant(

1992

)]

MD

leng

thof

trig

on[ldquo

Lm

drdquoin

Ghe

erbr

ant(

1992

)]




Trigonidwidth

Talonidwidth







doi104202app20100023


1 mm


1 mm






1 mm









doi104202app20100023


1 mm

























doi104202app20100023


D




2

05 mm

hcnld

hfxd

hcnd

cr obl

05 mm


1 mm

1 mm








doi104202app20100023









doi104202app20100023






OL

IGO

CE

NE







doi104202app20100023










































































doi104202app20100023




















1 mm


P4


M1



Specimen LocusM

axim

umM

Dle

ngth

[ldquoL

labrdquo

inG

heer

bran

t(19

92)]

Mes

ialB

Lw

idth

[ldquoIM

rdquoin

Ghe

erbr

ant(

1992

)]

Dis

talB

Lw

idth

[ldquoID

rdquoin

Ghe

erbr

ant(

1992

)]

Wid

thfr

omba

seof

para

cone

topr

otoc

one

apex

[ldquolp

roto

rdquoin

Ghe

erbr

ant(

1992

)]

MD

leng

thof

trig

on[ldquo

Lm

drdquoin

Ghe

erbr

ant(

1992

)]




Trigonidwidth

Talonidwidth







doi104202app20100023


1 mm


1 mm






1 mm









doi104202app20100023


1 mm

























doi104202app20100023


D




2

05 mm

hcnld

hfxd

hcnd

cr obl

05 mm


1 mm

1 mm








doi104202app20100023









doi104202app20100023






OL

IGO

CE

NE







doi104202app20100023










































































doi104202app20100023




















doi104202app20100023


1 mm


1 mm






1 mm









doi104202app20100023


1 mm

























doi104202app20100023


D




2

05 mm

hcnld

hfxd

hcnd

cr obl

05 mm


1 mm

1 mm








doi104202app20100023









doi104202app20100023






OL

IGO

CE

NE







doi104202app20100023










































































doi104202app20100023



















1 mm









doi104202app20100023


1 mm

























doi104202app20100023


D




2

05 mm

hcnld

hfxd

hcnd

cr obl

05 mm


1 mm

1 mm








doi104202app20100023









doi104202app20100023






OL

IGO

CE

NE







doi104202app20100023










































































doi104202app20100023






















doi104202app20100023


1 mm

























doi104202app20100023


D




2

05 mm

hcnld

hfxd

hcnd

cr obl

05 mm


1 mm

1 mm








doi104202app20100023









doi104202app20100023






OL

IGO

CE

NE







doi104202app20100023










































































doi104202app20100023





































doi104202app20100023


D




2

05 mm

hcnld

hfxd

hcnd

cr obl

05 mm


1 mm

1 mm








doi104202app20100023









doi104202app20100023






OL

IGO

CE

NE







doi104202app20100023










































































doi104202app20100023




























doi104202app20100023


D




2

05 mm

hcnld

hfxd

hcnd

cr obl

05 mm


1 mm

1 mm








doi104202app20100023









doi104202app20100023






OL

IGO

CE

NE







doi104202app20100023










































































doi104202app20100023

















2

05 mm

hcnld

hfxd

hcnd

cr obl

05 mm


1 mm

1 mm








doi104202app20100023









doi104202app20100023






OL

IGO

CE

NE







doi104202app20100023










































































doi104202app20100023





















doi104202app20100023









doi104202app20100023






OL

IGO

CE

NE







doi104202app20100023










































































doi104202app20100023






















doi104202app20100023






OL

IGO

CE

NE







doi104202app20100023










































































doi104202app20100023

















doi104202app20100023






OL

IGO

CE

NE







doi104202app20100023










































































doi104202app20100023


















OL

IGO

CE

NE







doi104202app20100023










































































doi104202app20100023




















doi104202app20100023










































































doi104202app20100023























































































doi104202app20100023























































doi104202app20100023




























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The oldest and youngest records of afrosoricid placentals ... · The oldest and youngest records of afrosoricid placentals from the Fayum Depression of northern Egypt ERIK R. SEIFFERT