FOSSIT, BIKD REXAINS FROM TERTIARY DNPOSITS IN THE UNITED STATES

ALEXANDER WETMORF Seiii7~aoizin~i Instilalion, Washington, Dtstrict of CoEuinbia

FOURTEEN FIGURES

I. A FRAGMENT O F A FOSSIL LOON PROM THE ETCHEGOIN PLIOCENE O F CALIFORNIA

In some fragiiiciitary fossil vertebrate remains forwarded to the U. S. National Museum by Nr. Carl J. Bleifus of Hollistcr, California, there is included part of the ulna of a bird that is of iniportaiice as it is from a loon, a family scldoiri i~q3resentcd in fossil deposits. While the ulna in birds ordi- iiai*ily does not carry speeific characters of diagnostic value the present spociiiieii is an exception in that it is not only cviclently a loon but also it d i fe rs pertiiiently from all living mcriibers of that family. It seems proper therefore to dcsig- nate it with a specific na~ i i e .~

Cauia couwiwnu sp. 11017.

Cliaractcrs. Ulria (figs. 1 to 4) similar to that of modern Uavia stellata (Pontoppidan *), but with tubercle for attach- ii~eiit of anterior ligament shorter and broader ; intermecliate in size between modern Gavia stellata and Gavia iiiimer.

Descriptlow. Type, proximal two-thirds of left ulna, U. S. Sational Museum No. 16,160, from Etchegoin beds of Lowcr Pliocene, associated with Tamiosoina and Ralanus, collected by Carl J . Rleifus in a sandpit in Sweetwater Canyon, about 5+ iiiilcs cast of King City, in the north central part of S. 5,

Dramiiigs illustretiiig this report have been made by Sydnry Prentice, tl student xith Professor McClung, uiider Dr. S. W. Williston, at the University of Eansas. ’ Colgiiibus stellxtus Pontoppidan, Danske Atlas, col. 1, 1763, p. 627.

2.5

26 ALESAN DER WETLIIORE

T. 205, R 9 E., Monterey County, California. Olecranon rounded at the end, truncated, the tip projecting little ; internal cotyla rather broadly elliptical, deeply cupped ; external cotyla tl broad groove, bounded laterally aiid distally by a sharply raised margin that inarks a roughly triangular form, but open behind where the articular surface extends internally as a rial-row hand around beneath the margin of the inner

4

Figs. 1 t o 4 Type of Gavia eoncinaa, about natural size.

cotyla ; depressioii for the articulation of the proximal end of the radius abruptly and sharply depressed, the slightly convex line of its proximal limit forming the margin of the external cotyla ; tubercle for the attachment of the anterior ligament on an elongated boss that distally contracts to a line and inerges with the shaft, the tubercle itself relatively broad and short, not, elongated as in other loons : below it on the inside

FOSSIL BIR,D REMAINS FROM TERTIARY DEPOSITS 27

a sharply angular, elongated depression for the brachialis anticus attachment ; tricipital attachment well impressed, triangular in form; the bone extended externally beyond this in a narrowed, triangular form; shaft somewhat compressed, with inner surface rounded, outer surface ridged, the exposed area where the secondaries were attached wavy as usual in loons ; an intermuscular line on the palmar surface beginning below radial depression and swinging toward the anconal side as it passes forward. Bone well preserved, brownish white in color.

Measurememts. Greatest transverse breadth of shaft near center 7.2 mni. ; least transverse breadth of shaft near center 5.8 mm. ; width across proximal end 11.7 mm.

Remurks. The ulna in the four species of living loons is quite uniform, aside from differences in size, except that Gavia stellata has the tubercle for. the attachment of the anterior ligament projecting somewhat more from the side of the shaft and the impression f o r the brachialis anticus correspondingly deeper. In this Gavia concinna agrees with stellata, while in size concinna is intermediate between stellata and immer.

According to data supplied by Mi.. Carl J. Bleifus the type specimen was obtained in a sand pit where it was associated with shells of Balanus and Tamiosoma. Mr. James M. Kirby, at the request of Dr. William S. W. Kew, has kindly furnished me with a diagram of the geologic formations of the region concerned in which it is indicated that the fossil-bearing sands in question are of Etcfieioin age in the Lower Pliocene. My thanks are due these gentlemen, both of the Standard Oil Company of California, for their friendly assistance in this important matter.

Remains of loons allied to Gavia immer have been reported from the Pleistocene of California, and froin deposits in hlin- nesota attributed by Bryan and MacClintock to the Pleistocene, but by others considered of a later age. These birds, however, have not been identified specifically. The only other fossil record for the family Gaviidae in North America is Gavia pusilla described bp Shufeldt from a specimen that he noted

as of unknown geologic age and which he attributed uncer- tainly to Wyoming.

Through the courtesy of Dr. G. E. Lewis I have had the privilege of studying the type of Gavia pusilla in the collec- tions of the Peabody Museum at Yale University. The speci- men, bearing catalog number 864, consists of the proximal end of a left metacarpal, and is marked in the accession data as collected by ,J . B. Hatcher and party, and as received from Lusk, Wyoming, Dlarch 21, 1892. As just stated the specinien consists of the proximal end of the bone only and has the articular surface for the pollex inissing and the projecting angles somewhat worn by abrasion. While highly peculiar in form Shufeldt's allocation of it ainong the loons appears correct. However, it is not closely allied to the living Gaviidae and its characters are such that it must be placed in a distinct genus and this in turn segregated in a subfamily separate from the other loons. Should more material becoiiie available it is probable that it may be set apart still farther as a distinct family, a step that seems logical now, but one that I hesitate to undertake because of the very fragmentary nature of the specimen.

Gaviella gen. nov.

as represented by its type Gavia immer,4 but proxinial base of metacarpal I much elevated, forming a high, compressed crest (figs. 5 and 6 ) ; articular surface (viewed from the inner side) shorter, more rounded ; pisiforla process much reduced ; metacarpal I11 at proximal end relatively narrower.

Type, Gaviu pusilla Shufeldt,; which becomes Gaviella pusilla (Shufeldt).

Following is a detailed description of Gaviella pusilla based on the type. Xetacarpal I a high much compressed crest, ex-

Somewhat similar to modern Gavia

'Gal-ia J. R. Forster, Enchilid. Hist. Nat., 1788, p. 38, Type, by subs. design., Colymbus immer Briinnich.

Colymbus Iniiner Briinnich, O m . Borealis, 1764, p. 38. Gavia pusilla Shnfeldt, Trans. Connecticut Acad. Arts Sei., vol. 19, February

1915, p. 70, pl. 13, fig. 106.

FOSSIL BIRD REMAINS FROM TERTIARY DEPOSITS 29

panded anteriorly as a support for the articulation with the pollex, the actual articular surface missing through breakage ; slightly expanded also at the proximal end, rising high above the proximal end of metacarpal 11; pisiform area some- what bulging, the pisiform process broken but evidently small and little developed; fused portion of metacarpals I1 and I11 relatively long, as indicated by the impressed groove on the inner side that marks the beginning of their separation; a deep impression on the outer face of the trochlea, somewhat modified perhaps by crushing ; trochlea considerably com- pressed, with its outer margin cut away on the outer side; the small section preserved of metacarpal 111, seen from below, very narrow; no indication of a groove for tendinal guidance on outer face.

Figs. 5 and 6 Type of Gaviella pusilla (Sliufeldt), twice natural size.

While the essential characters of the bone may be made out in the photograph published with Shufeldt’s original desc.ription it must be noted that this is reproduced upside down. While the caption with this photograph indicates that it is slightly more than natural size as a matter of fact it is slightly less. The actual length of the type of pusilla as preserved is 15 mm., its height 8.9 mm., and the greatest thickness of the trochlea 4.1 m. The specimen comes from a bird decidedly smaller than the red-throated loon (Gavia stellata), one possibly the size of a Holboell’s grebe (Colymbus grisegena holboelli). It is interesting to note that it is dis- tinctly a loon, and that in its modifications as compared with living Gavia there is no suggestion of resemblance to the

30 ALEXAR-DEEl WETMORE

grebes, nor of any linkage between the Gaviifornxs and the Colymbiformes.

The living loons are so similar in forni and tho fossil so different from them in the characters designated as marking Gaviella as a new genus, that the latter must be segregated in a distinct subfamily Gaviellinae. I n fact Gaviella pusilla is so different that it could easily be given full family rank.

I n the original description Shufeldt marked this specimen as of uncertain geologic age, but data is available that may give it more definite status. As already stated the bird was collected by J . B. Hatcher and party, and was received from Lusk, Wyoming, on March 21, 1892. At this date travel in that part of Wyoming was not rapid, particularly at the open- ing of spring, indication that the collections including Gaviella pasilla were rnade in that general area. Near Lusk tliere are known to be fossiliferous deposits in the Lance, the White River, and in sniall areas of Miocene age. The Lance can be discarded at once, leaving the Tertiary as the source of the specinien under discussion. It seems probable further that it comes froin White River beds. The specimen, when T first examined it had adhering to it tiny bits of dark brown soil, very fine and hard, but still not consolidated. It is my impression that the bone was a weathered fragment that the collector had picked up on the surface.

11. A GRUIFORM EIRD FROM THE WHITE ltIVER OLIGOCENE O F SOUTH DAKOTA

A h . James D. Bump of the South Dakota School of Mines placed in my hands a number of months ago an exceptionally complete nietatarsus of a bird from the White River Oligocene that proves to be representative of an unknown genus and species in the family of courlans or limpkins, the Rramidae, in the order Gruiformes. It iiiay be known as

Badistoritis arainus gon. et spec. nov. CXarncters. Metatarsus (figs. 7 to 10) similar to that of

modern Aramus scolopaceus (Gmelin 6, but decidedly larger ; ‘Ardea scolopaoea Gmelin, Syet. Nat., vol. 1, pt. 2, 1789, p. 647.

FOSSIL BIRD REMAINS FROM TERTIARY DEPOSITS 31

7 ' 8

-..

19 Figs. 7 t o 10 Type of Badistornis aramus, natural size.

iiiiier troch1t:a I ~ O L ' ~ -u;.iclcly separated from middle trochlea, proj cct iiig far the r pos teriorly, and swung farther inward to- 1var(1 the central axis, distal end of sliaft relatively mow c,omprcssed in an untcro-posterior direction ; facet for liallus relativelv larger and more distinct ; outer trochlea more angular on the inner distal margin ; depression below head cleepci., iiiorc angular; facet for articulation of liallns i*cla- tivol7 larger.

11c.sc.viptio7~ Typc, South Dakota State School of llliiic>s So. 3631, il nearly complete left metatarsus, collected in tlie 1Cetainynodon zone river channel sandstone of the Brulc Rcds, TVhite River Oligocene, 35 miles southwest of Scenic, Hout l i Ilakota, during summpr, 193G, by James I). Buiiip. I I ~ a t l with the liypotarsus missing through fracture ; level of iniier cot;vla decidedly higher than that of outer ; inner cotvla ii distinctly concave cup, with well-rounded angles, but with tl1c ;intei*ior and cstcma2 boundaries flattened so that they form approximately straight lines in their central portions j external cotyla narrower., and more elongated, open in front and behind, with its outer wall elevated; intercotylar promi- nence iiiuch elevated, triangular in form when seen from in front, with Ihe inner margin straighter, more nearly in line with the axis of the shaft, and the outer margin more sloping, cut away in ti long slope behind ; head decidedly broader trans- versely than the shaft; an abrupt and deep depressioii on anterior face of shaft immediately below the head of irregular outline and angular form, the tubercles for tendinal attach- ment ~vliich are located within this large arid well developed; shaft seen from in front long, in general narrow, with parallel sides, concave until it begins to expand below to support the trochlea, tlie concavity deep and angular below the head, broad and shallow below; outer side of shaft so slightly rounded that until examined closely it seems nearly plane, gradually narrowed below the center until at the lower end it appears much compressed ; inner surface much rounded, sloping smoothly around to merge with the posterior surface, which is concavc for its central section; the inner facc decidedly

FOSSIL BI€LD €i.EMdIKS FROM TERTIARY DEPOSITS 33

narrower than the outer, with a slightly impressed, rather broad tendinal channel crossing it a t an angle; at the distal eighth of its length the shaft compressed and broadened, with a large distal foramen situated at the bottom of a deep groove that is continuous with the anterior metatarsal groove, the foramen set in a t an angle toward the center so that when viewed from directly in front the opening is concealed by the overhang of the inner wall; facet for articulation of first toe an elongated, elliptical space of good size ; inner trochlea swung to a level that brings it completely posterior to the central axis of the shaft and the other two trochlea, large, compressed, rounded in outline, with a strong broad base at its attachment to the shaft, a thin, flattened, rounded plate pro- jecting from its posterior margin, inner surface much ex- cavated; the inner trochlea elevated on the shaft so that its distal margin comes just to the level of the base of the other two trochlea; middle trochlea fairly strong, of moderate size, its free margin rounded, the two lateral faces excavated, and a heavy groove around the free surface; seen from behind the inner margin cut away so that the trochlea is much narrowed here ; outer trochlea projecting distally for three-fourths of the length of the middle trochlea; the outer margin fractured so that the form of the outer plate is not known; inner face much excarated. Bone light brown in color (broken areas repaired with plaster).

X!easwememts. Total length 155 mm. ; greatest breadth of head 14.9 mm.; greatest breadth across trochlea 17.1 mm.; smallest transverse breadth of shaft 6.5 mm.

Rew2arh.s. The close general reseniblance of this fossil speci- men to the metatarsus of living Aramus scolopaceus is such as to leave no doubt almost at glance that it is a species of the family Aramidae. Its differences from Aramus however tend to ally it to the cranes, the Gruidae, so that it appears ancestral to the modern limpkins. As it gives a closer ap- proach to the cranes than does living Aramus it indicates more certainly the presupposed line of ancient connection between the Aramidae and the Gruidae. The characters in which the

fossil resembles the Gruidac (using living Grus canadensis canadensis in comparison) and differs from the Aramidae are as follows:

1. Relatively larger size of the internal trochlea. 2. Sligli tlp greater elevation of inner trochlea above middle

2. Tlie extent to which the innel. timhlea is swung inward

4. Relatively greater size of the inteimal cotyla. 5. The relatively greater size of the inferior foranicn. Tlie only other fossil form of tlie family Aramidae at

present known is Araniornis longurio Wetmore described from the Middle PIIiocene of the Snake Creek Quarries of Sioux County, Nebraska. Aramornis differs from Badistornis aramus in the same characters that separate Badistornis from Ai-amus, namely, in having the lower end of tlie shaft of the metatarsus more rounded on the anterior face, in having the ala iiiterna of the inner trochlea produced as a slender pro- jecting point instead of being broader and more rounded, and in the idativcly narrow transverse width of the shaft. The two are very certainly distinct. The indication is that Badistornis is more immediately ancestral to living Aramus, with Arainornis as a specialized offshoot that stands more apart.

ii*ochlca.

toward the median line of the shaft.

111. AN BUT< ?d’RO~,I TITE CALVERT MJOCESE OF b r A H V I A ~ 4 ~ I )

Tlic hlioccwe horizons found in tlie bluffs that border Chcsa- peake Bay in Calvert County, Maryland, have been a profita- ble source of interesting fossils since tlie days of Conrad. A i d aniong their vertebrate remains have been occasional fragments of the bones of birds. Members of the staff of the U. S. Satioiial Museum and friends of that iiistitution make annnal inspectioil of tlic weatliei-ing faces of t h e w cai.thmi cliffs and so add steadily to our knowledge of the life of the period. The latest find in the group of birds is a nearly com-

figs. 1 t o 4. ‘ Aramornis lonpurio Wrtmore, Am. Mus. Nov. No. 211, March 11, 1928, p. 1,

FOSSIL BIRD IlEMAINS PROM TERTIARY DEPOSITS 35

plete humerus discovered by Dr. W. F. Foshag of the National Iluseum in the summer of 1939. This proves to be a species of the auk family, the Alcidae, that is new to science, the group being one not previously known from the Calvert forma- tion. It may be known as

Miocepphus mcclumgi gen. et sp. nov.

Characters. Humerus (figs. 11 to 14) in general similar to that of modern Cepphuss but shaft heavier and broader, more rounded, less flattened on anconal surface at proximal end ; ectepicondylar process decidedly longer ; deltoid crest shorter.

Descriptioa. Type, U. S. National Museum, No. 16159, right humerus, with projecting portions of head partly missing but otherwise nearly complete, from Zone 12 (in brownish, sandy clay with molluscan shells) , Calvert formation of the Miocene, found in the face of the cliff about 7 feet above beach level at the south end of a small cove 0.9 of a mile north of the mouth of Parker Creek, Calvert County, Maryland, b~ W. F. Foshag, July 15, 1939. Shaft relatively strong, decidedly flattened as in all known members of its family, expanded slightly to support head, definitely rounded, less flattened on anconal aspect at proximal end; in cross section a much flattened ellipse; a small foramen placed in a short, slightly impressed groove on the palniar aspect just above the lower margin at about one-fourth of the length of the shaft from its proximal end ; caput humeri rising as a pronounced, elongated prominence (the portion external to the incisura capitis miss- ing) with a fairly deep impression beneath it on the anconal surface ; tuberculum exterior elongate, well outlined, and slightly elevated ; insertion of latissimus dorsi a long, slightly indicated line placed slightly above center of shaft ; crista superior elevation narrow in outline, and as viewed from the outside, well rounded; insertion for pectoralis major an impressed ellipse of good size; lower end of shaft compressed

Cepphiis Pallas, Spic. Zool., vol. 1, fasc. 5, 1769, p. 33.

JOUR.XAL O F XORPIIOI.QGY, VOb. 66, NO. 1

3G ALEXANDER WETMORE

@ 13 14

Figs. 11 t o 14 Type of i\lioccl)plius inccluiigi, twice natural size. The loxer dr:iviiig at the lef t is a cross scrtioii of the shaft slightly below t h e ccwtcr.

FOSSIL BIIX) REMAINS FROM TERTIARY DEPOSITS 37

aiid flattened ; radial trochlea compressed, elevated, elliptical in outline, rising as a relatively narrow plate, that on its proximal margin meets the shaft abruptly; ulnar trochlea swung at a distinct angle with the transverse axis of the shaft, as usual in the Aleidae, relatively narrow and compressed, with its external section elevated and rising free of the shaft ; olecranal depression deep, irregular, extending across behind this condyle, and on the actual distal end of the bone ; ectepicondylar process long, projecting as a narrowed plate from the side of the distal end of the shaft, with the proximal end abruptly delimited from the shaft and the free margin slightly sinuated ; entepicondyle slightly projecting ; attach- ment for anterior ligament large, elongated, slightly raised ; brachial depression slightly impressed, irregular, placed on a flattened surface of the shaft. Bone light brownish white in color, rather fra<gile.

Measurements. Total length 58.2 mm., greatest transverse breadth of shaft near center 5.5 mm., least thickness of shaft near center 3.3 mm., transverse width across distal condyles 9 mm.

Remarks. This hitherto unknown bird is to be placed in the subfamily L41cinae where it has definite affinity with the living species of the genera Cepphus and Brachyramphus. Although appearing nearer to these than to any other it differs from the remaining modern genera of Alcinae much as it does from Cepphus. It was seemingly about the size of the living black guillemot Cepplius grylle, but was of stronger form.

Xiocepphus mcclnngi is definitely a peculiar form and in- troduces a new element into the previously known avifauna of the Calvert Miocene. It is named in honor of Dr. Clarence E. McClung in recognition of his interest in vertebrate paleon- tology when I was enrolled under him as a student in zoology at the University of Kansas.