[ANNALB N. Y. ACAD. %I., Val. XXVII, pp. 17-22, P11. I-V. 26 January, 19181

AN EXTINCT OCTODONT FROM THE ISLAND OF PORT0 RICO, WEST INDIES

BY J. A. ALLEN

(Presented in abstract before the Academy, S November, 1916)

CONTENTS Page

Introduction. .......................................................... 17 . Description. .......................................................... 19 SkUll.. ........................................................... 19 Dentition.. ....................................................... 20 Scapula.. ........................................................ 21 Clavicle.. ................ +. ....................................... 21 Humerus.. ................. :. ..................................... 21 Ulna and radius.. ................................................ 21 Sacrum.. ......................................................... 21 Pelvic girdle.. .................................................... 21 Tibia and flbuln.. ................................................ 22

Summan ............................................................. 22

INTRODUCTIOIT

The mammal remains hcrc described wcre taken from n cave near the center of the island of Porto Rico in excavations directcd by Dr. Franz Boas, in charge of the anthropologicnl division of the Natural History Survey of Porto Rieo, now being carried on jointly by the New York Academy of Scicnccs ant1 thc American Mnscum of Natural History, in cooperation with the Government of Forto Rico. These remains have been kindly placed iu my hnnds by Dr. Boas for dctermination. Aside from a few human honey, they consist almost wholly of the bones of a large rodent allictl to PZa~iodor,firl.* With them are R few bird bones, too imperfect for satisfnctorv idcntificntion. Thesr havc been referred to Mr. W. De \V. Miller, :lssistnnt Chrntor in Ornithology in the American Museum, who informs me that they represent, principally at least, a pigeon and n parrot, thc latter probably rcfernhlc to the genus Amnzonu.

I n reply to my inquiries rqprding the manner of occurrence of these

lManiiacrlpt rccelved by the Edltor, 27 November. 1915. 'Then la a slnKle dorsnl vertebra of a milch lnrger nolmnl. ns yet not determlned.

(17)

18 ANNALS NEW YORK AUADBMY OF SUIDNURY

remains, I)r. Boas hns kindly furnished me (i~r lill.) with the following details: “The rcniains werc found iii a I i c a v ~ tlcposit of ashes in n cave in the Job0 district, bctwccn Utuado ant1 Arccibo. In the same deposit wilk the burial of n cliiltl. A vcry large iiumhcr of shells of crabs nnd of vuriou6 kinds of snnils were foiind. ‘l’lic deposit \va6 undoubtedly nrti- ficial. I do not bclicvc that it wis purely an nccunidation of kitchen refusc. It seems niorc likely tlirit it IYILS mnclc lor some othcr pnrposc. There is no indication of p~ist-Culirriil~iiin tlintiirlinncc or thc deposit, but I do not prcsumc t h t . it. is I I I ( J ~ ~ tliilll it fe\\f Iiiuitlretl ycars old.”

The niammnl rcaiiiiiis iiicludc nc:u.Iy 400 pieces, representing iienrlp all parts of thc skcleton, and n l l arc apparently refcrnble to a single spc- cies. They arc for thc nicist pnrt frilgnientary, but some of them arc complete, thcrc being ciitirc IJOIICS of all t!ie principal pnrts of the skcleton except thc vcrtebim nnil tlic fect. ‘T l~cy arc liglitlg contcd with a gray ashy covering, cnsily rcmovctl witli n sort l)rush, arid li\vc thc appearnncc arid gcncrnl chnractrr nf rreriit. I J ~ J I C S . linviiig iin(1crgonc. iio mineraliza- tion nor mnch diwoloriition. TIicsc remains niny hc listed ns follows : 20 ~ l i d l s , iione of tl icni qiiitc romplctc, t l ic occipital and parictnl re-

gions and tlic iiasals Iioiiig usncilly lwking, ivhilc niaiiy consist of only the middle portion of the skull.

1.50 mandibnlnr ronii. incletling a score or iiiorc in ncitrly pcrfcct con- dition; in many tlic condylar portioii is defective or wholly lacking.

15 scapulz, including sevcrnl nearly cntirc.

15 humeri, scvcrnl coniplctc a n d others ncarly so. 30 uIn:p, mostlj a.cII prcscrwl. 10 radii, mostly in good coritlition. 25 femora, sonic prrfrct, otlwrs nrnrly complctc. 40 tibiz, mnny in good condition.

1 clnviclc. thc clist.al cnd wnnting.

5 fibulz, mostly in fnir roiiilition. 1 sacrum, almost p f c t t .

50 ribs, man? ncll prescrvcil. SO innominntr Imncs. a f c w w i t h tlir Iiordcrs oiily slightly nbrade(1,

h i t the grcnter pnrt nrc frngniciitnry. Besides thc above, blicrc nrc sc\.cwl Iiiuidrcd Eriigmcnts of little or no

scientific vnluc. Thcse remains indicate ill1 nn in i i i l c i h i t tlic s i x of C~/JJ.O,J,!/S piloritks,

Lilt with a hrondcr nnd s lwtr r s k d l . niit l :I slriidcrer Iiody nntl longer limbs. It tliffcrs widely in cicntitiori f rom ( ~ ~ ~ I ~ o J I I ~ s , in n.liicli rcspect it npproaches Plqiodoniin, ns it does dso in tlic sizc nnd d inpe nf tlic skull. Jt is generically distilid from citlirr. :itid mny bc Ilcscrihcd ns fnlloms:

19 ALLEN, EX'I'INCT OC1'ODOXII' FROM I'OR'I'O RlCO

Isolobodon' portoricensis gen. et sp. nov.

Type, No. 3640% from the Cuervn de la Selbn, nenr Utundo, Porto Rlco; coll. Dr. Frnnz Bons. The type ~ltull hns the iinsals nnd entlre upper deiitltloii complete, but lacks part of one xygonin :ind the braincase posterlor to the fronto-pnrletnl suture.

I>ESCRll'TIUN

SkuZl.--The skull (Platc I, Figs. 3 4 ) closely resembles in outline and proportions thnt of Pluyiorlontia, being shorter and broader than the ekuU of Caprornys. The most ncnrly complete skull of the eerics (No. 38409b), which lacks only the nnsnls, the occipital rcgioii nnd most of the teeth, when laid ovcr F. Cuyier's outlinc iigiirc of tlic skull of PlaqWdontia4 is found to be csscntiully of tlic same size mid form. The lower jaw is of the same Him, hit diffcrs somcwliiit. j i i tliv [orin of the coiidylnr portion, wliicli, Iio\vcver, is not well SIKJ\YII i t i (!iivicr's Pliltt:. Tlic nasnls are of nearly uiiiforni brendth froin .base to tip, widcliiilg oiily slightly and uniformly from the base nntcriorly.

The most ncnrly complctc skull of the scrics is above tlic nverage in sizc, niid is also cvidcntlv t.hc sknll 0 1 R w r y old individunl. This skull affords tlic following mensurcnieiits : front border of premaxillaries to occipitnl suture, 73 mm.; lcngth of fi*onhls on niidlinc, 28; lcngth of pnrietii!s on niidliac, 2.7 : Icnpth of rostnini. 2s ; \vidfh nf rost,rum at mtcrior root o f zJg(Jn1ntii. I ; { ; (Ic1dli or rosl riini at same poilit, 1'3; inter- orbitnl brcndtli, 23.-1; zygoniatic brcatltli, .kS.!i ; Srrntest I)rcndth of brain- casc (at posterior b n ~ c of zygomah), 2.1.; palatal length, 33.5; brcnrlth of pnlnte bctmeen premolars, 3 ; hrcatlth of pnlnte bctnwn last molnrs, 7, the toothrows I)ciiig strongly coiiwrgciit. 'I'hc type h l l , fully adult but smnllcr 3iid cvitlently joiingcr t l in i i Xi). :18-i09b, furnishes the following: Intcrorbihl l)reatltIi. 22; Iciigtli (II t'nmtiils ( I I I inidlinc. 25 ; lcngtli of nnsals, 23 ; Iircatltli of i ~ i i s i i I s a t I t i i . ~ . S.2 : l)rr:iiltlt of nnsnls ncnr I'rolit bordcr, !); length of ni:isillnry t o o t l i 1 . i I W (crown siirrncc) 16.5: pilntnl lcngth, 33.5 ; pnlatnl l ~ r ~ ~ : ~ ~ I ~ l i I i c t w o i i prciiiiiliirs. 2.5 ; pnlatnl Iirendth bctween last nio1nr.c. ,;..-i : :wiitiSGt I ~ w i i i l t l i ( i f skull (heliiild I)nsc of zyqminta), 2G.

I n n c ~ r j a w ( l ! l i i t i~ I . l:i,:s. 1-2: 1'ht.f: 11, 1cigs. 1-1, $-!I) varics grcntly iii tlifl(wiit s p w i i i i w s . ;ipIiiiwiit.ly IIIW Iliailily, to nge hut perhnps pnrtly to ROS. Ailiilt iiinnililiiilnr rnmi ~ i r y in total length (I,:isc of incisor to tjp o l niignl:ir proww), from nl,out .IS tn *X mm. : deptli nt

Tllc size of

20 ANNALS N E W YORK AOADEMY OB SGIENOES

m', 12.5 to 14.5; depth a t coronoid process, 17 to 22; depth a t condylar process, 18 to 24 mm.

The maxillary toothrow (crown 'surface) varies in le;igth, in adults, from 15.5 to 17 mm. ; the mandibular toothrow from 17.5 to I D mm. The teeth evidently increase in size with age, not only in length and breadth but in height, becoming more hxposodont as well as larger in old adults, and the angles of the folds more prominent.

Dentition.-In Cupromjs the transverse axis of the molar teeth forms a right angle with the axis of the toothrow; in Pzagiodontia the trans- verse axis of the niolars is highly oblique to the axis of the toothrow (Plate 11, Fig. 10) ; in Zsobbodon the obliquity is about 45' &. The in- cisors are weak, nearly flat on the outer face, without grooves, and rounded on the inner face. Their color, still well preserved, is pale yellow.

The molariform teeth in Isolobodon (Plate 11, Figs. 5-7) resemble those of Plagiodontia in size and shape, in the obliquity of their inser- tion, and in the number 6f folds on the outer and inner borders, but not a t all in the enamel pattern. They are tlius modeled on a basis common to both types, and both thus differ widely from the teeth of Caprornys. In Plagiodontia the cement area of the crown surface of each tooth con- sists of three transverse divisions, united and continuous, thus constitut- ing a single sigmoid area, deeply cut by the infolding of the enamel border. In Isolobodon the cement of the crown surface of each molar forms two transverse, nearly equal oval lakes, entirely separate and encir- cled by an enamel border. The enamel walls of the two loops touch each other by a slight point of contact near the outer border of the upper teeth and the inner border of the lower teeth. The enamel pattern of the lower molars differs from that of the upper through a deep indentation of the anterior enamel lake by the infolding of the enamel border on the inner side of the front third of the tooth.

All of the molars liove each two verticnl ribs or folds on both the ex- ternal and internal borders, but the upper premolar differs from the molars in having three external and two internnl. The lower molars liave each three external and two intcrnnl folds. The lower premolar 11:s three folds on each side, but the anterior fold is prcntly rctluccd in tlcpth. and thus gives rise to a small trefoil termination to thc crown snrface of the front border of the tooth.

The upper teeth successivcly tlccrcnsc in six from tlie premolar to ms,

6 If the upper molnr serlerc Is corrrctly rrprrsrntrd In Ciivler's plate. the mnxlllarg teeth In Ploptodontin hnvc the trunsverse oxlr of the teeth nrnrly colncldent wlth the loogltndlonl 0x1s of the tootlirow, n h l l e In thc mnndlbiilnr aerlrs tlir nnfile Is only about 46'. 88 In Zsolobodon. I cnnnot realat the lmprrsslon thnt thc obllqiilty of the mnxlllary teeth la hlghly eraggernted In Cuvlcr's drnnlng.

21 /IfiLf:N, ~ X T J N C I ' OCTOUONT FRO,+[ IJORTO ~ 1 0 0

which is only about half the size of m'. The lower teeth are of nearly equal size, except that the premolar is narrower than the molars, with the anterior third terminating in a narroiv projecting terminal angle, nlltl is thus slightly trilobcd on the anterior face.

S c a p b - T h e scapula resembles that of Cupr.o/qs pilorides,8 but is longer nnd I1arrower. in correlation with the more slender form of the whole animal (the skull excepted) in Isolobodon. It has a total length of 45.mm., and a breadth at the middle of 2-15 mm. The free end of the spine (ocrominn proccss) is nearly as long as the nttuched portion. (For fmther details see Plate 111, Figs. 1-1.)

CZavicle.-A single f r q p e n t , if identifiable as this bone, is much longer and slenderer than the corresponding bone in Cupromps pilovides. I t lacks both cpiphyses, but still has a length of 26 mni.

1Iumerus.-Grentcst length, 45 nim. ; diameter of proximal end, 11.5 X 9.5; transverse diameter of distal end, 11.5 x 5 mm. The supratroch- leer forameii is of medium size and the deltoid ridge is rather strongly developed (Plate 111, Figs, 5-7) .

Ulna and radiils.-Length of ulna without distal epiphysis, 57 mm. Olecranon process is strongly devcloped, forming about l/Gth of the length of the bone. All of the radii lack the distal epiphgses. The length, minus this portion, is about 1 6 mm. (Plate 111, Figs. 5-14). .

Sacrum.-The single sacrum in tlie collcctioii is fortunately well pre- served. I t consists of four perfectly ankylosed vertebrz and presents nothing of noteworthy importnncc. t t tins n Icngtli of 51 mm.; breadth at the prosinial end, 31 mm., nt tlic distal end, 15 mm. It is represented in three views, nll natural size, in Plnte IV, Figs. 4-6.

Pelvic girdle.-Of tlie ninny innominatc bones in tlic collection all are to some extcnt' fibratled on their cpiphysial borders, hiit scveral of them nre sufficiently complete t.0 show all of the csscntinl clinmctcrs. The one chosen for representation in Plate 117, Figs. 1-3, of which t h e e views are given, naturnl size, indicntc its gencml chnracter. The mnin axis is nearly straight, not slightly C ~ I I Y C X (lorsally, ns in Cnpromys pilorides. T h usual tuberosities arc strongly dcvclopctl. The total length is about 81 mm., of wliicli tlie ilinm constitiitcs nhout two thirds. Grcntest Orcwltli of ilinm, 2.1 Innl., of tlic ischiurn and phis. oppositc the mitldle of the thyroid fornmen, respectively 9 nntl (i mni. The thyroid fornmcn is Inrgc. ovd in outline, nenrly twice as long ns bronc\, tlic lcngth in n h l t speci- niens being about 20 mm.

-- #The only pcrtlnent skeletal mnterlal avnllnble far compnrlsoa s l t h thnt Of Isohboilon

Iq a llgamrntni, badly dlscn8ed mcnngrrlr pkrlrton nC Caprnmys plloridrt. to whlch my romparlsons arc here neceasarlly restrlcted.

22 ANNALI N E W YORK .?OdI)BhfY OF SOIENOES

Tibia and fibula.-Most of the tibi= lack thc distal epiphysis. The greatest lengtli of a complete adult tibia is abont G4 ium. Thc digital fossa. is very deep, and there is a slight indication of a third trocltiinter iit

old individuals (Plnte V, Figs. 1-2). The fibulac arc all except m e more or less fragmentary, lucking tlic distal epiphysis. The single cornpletc bone has a length of 44 mm. (Plate V, Figs. 5-9’). TIM boiies of tlie hind limb in Cuprornys i d o d e s arc n h t onc jiftli shortcr and much thicker than in lsolobodoa.

SUXXARY

IsoIobotIon, likc l’lagindonlia, is cuidcntl~ of rcccnt cntinctioti. In tlic case of Plagiodontin, thc only extant spccinicii, SO far as LIIOWJI to me. is the type of the species in the Paris Museum of Natural History, descrihctl by F. Ciivier in 183G, to wliicli nccoutit all thc snbecquetit ~.cfcrcitces yc-

vert. Cuvier Iind apparently only a singlc specimen, sent to him ironi Santo Domingo by M. Ricord, from wlioni Ciivier’s brief account of its habits was doubtless derived. It is nicntioncd as being nocturnal and frugivorous, its flesh RS very good to cat, arid tlint for this reason “les Haitiens, qui en sont trhs friands, les rechcrclicnt si soigitcuscment, yu’ile ont fini par rendre ces animaux tris rare.” I n all probability it mas soon after completely cxterminatetl. I t is nlw probnblc that IsoZototion Iind

already become extinct i t 1 tlic iicighboring islnnd of l’nrto Rico, tlon\)tlcsh from a similar cnusc, ant1 ])cr”ltnps not 10llg prior to the discovcry of the island by Europeans. At least the fresh condition of its rcmeins fonnd in Seiba Cave seems to imply recent extinction.

PLATE I

SXULG ABD MWEB JAW OF Isolobodon pofloncensis gen. et Sp. UOV.

FIOS. 1 and 2.--hft mandibular ramus, outer and inner views. (Natural size.) Fme. M.-Three views of the type skull. (Natural elzt) FIOB. M,--Three viewe of a paratype skull, rather older and larger tlioii t h e

type rrhll. (Natural size.)

PIATE 11

U)VEIL JAW, ANG m n r m o a OF Iaolobodon portonccnsis gal. et sp. nov.

Woe. l4-Right mandibular ramw of a young adult. (Natural size.) Fro. 5.-l&wer toothrow, left ramus. From same speclmen as P1. I, Figs. 1

and 2. (Twfce naturnl she.) Fro. B.-l&wer toothrow, rlght ramua, of a young adult. From same speciinm

as Nga 1-4. (Twice natural size.) WO. 'I.--Right maxillary toothrow. (Twice natural size.) FIQS. 8 and 0.-Upper nnd lower v lem of the left mandibular i'nmuv shown i t t

P1. I, Np. 1 and 2. (Naturnl size.) FIO. 10.-Upper nnd lower dentitton of Plagfodontia @durn F. Cuvler, for cum-

parleon with thnt of Iaolobodon. After F. Cuvier. Aitii.

dea %I. nnt, wr. 2, Voi. V1, l S 6 , p1. rvil, flgs. 4 niid 5. (Nnturrl slze.)

PLATE 111

BOAPUU, HULIEIUB, ULNA AKD RADIUS OF Isolobodon portoriceneis geD. et YP. nov.

FIOS. 14-Three views of the scapula and its articular face. (Natural slze.) Fro& b7.-Three vlews of the humerus, (Natutal size.) Roe. 8 and 9.--Two vlewe of the ulna. (Natural slze.) FIO~. 10-12.-Three vlewe of the radios. (Natural slze.) Fros. 13 and 14.-Proxlmal and dlstal articulnr surfaces of the radius. (Nat-

ural size.)

PLATE I\'

EACBUM OF Zsolobodon portoricensis &en. et 8p. nov.

Roe. 14-Three vlewe of n right lunomtnnte bone. (Nnturnl size.) Fros. 4-6.-Three vlewfi of the sncrum. (Natural she.)

A U X A L S S. Y. ACAD. Scl.

PUTPI V

~ M W AND TIBIA OF Ieolobodon portoricensis gen. et SP. nov.

F~os. li(.-Three views of a rlght femur. (Natural Size.) FIO. 4.-Dfstal articular surface of the -me femur. (Natural size.) Blos. bT.-’l!hree views of a right tibia. (Natural she.) Froe. 8 and 9.-Views of the articular faces of the same tibin. (Natural she.)

A Y N A L S N. Y. ACAD. SCI