Through the courtesy of the Southwest Museum and the California Institute
of Technology, I have been privileged to study the bird remains fram Smith Creek
Cave, a limestone cave near Baker, Nevada. A general account of the excavations
ß during July and August, 1934, has been written by M. R. Harrington (Masterkey,
8, 1934, pp. 165-169), leader of the expedition during which the field work was done,
and does not need to be repeated here.
This cave deposit, like the many others of its kind which have come to light
within the last few years, is questionably Pleistocene. The Pleistocene horse is
present and, among the birds, two species described originally from the Pleistocene
of Rancho La Brea. These are Vultur clarki (Miller) which has clever before been
recorded outside of California, and Coragyps occidentalis (Miller), known also from
Conkling Cavern in New Mexico. It has been remarked before that the presence
of Coragyps in any great numbers, contrasted with an absence or scant representa-
tion of Cathartes, is indicative of the Pleistocene. However, in this case, though
Cathartes is absent, Coragyps is represented by .a single fragmentary tarsomctatarsus,
so that its presence, though important, is not as instructive as might be desired.
A third extinct species of bird occurs in this deposit. This is a large 'eagle
which does not agree with any other species, living or extinct, with which I have
ß been able to compare it. Unfortunately, it is represented with certainty only by
the distal end of the tarsometatarsus. A nearly complete femur, a fragmentary proximal
end of the tibiotarsus and several phalanges of eagles are also found, but it is prob-
able that at least the femur and one of the phalanges are of Aquila chrysatos. The
tibiotarsus appears too large for Aquila and likely may belong to the different eagle
in question; however, it is too fragmentary tO furnish any definite information about
the species.
The most marked characteristics of the tarsometatarsus are its large size and
conspicuous facet for metatarsal I. The size is ßsuggestive of Thrasagtus harpyia,
though upon comparison it does .not quite equal this form in breadth of distal end
,and is not so heavily built nor so rugose. Comparisons were made also .with Pithe-
cophaga ]efferyi; the breadth across the trochleae in the specimen. of Pithecophaga
examined does not equal that of the cave bone, but the general build of the bone is
similar. However, detailed characters indicate no real relationship of the two forms.
Other species compared .were Haliaetus leucocephalus, H. albicilla, Thalas-
soatus pelagicus, Neogyps errans, Morphnus woodwardi, Morphnus guianensis (.cast),
Buteo (Geranoagtus) mdanoleucus, B. borealis, Urubitlnga fragilis, Aquila chry:
santos, $pizatus grinnelli, and 8. ornatus. For the opportunity to examine speci-
mens of' many of these species I am indebted to the American Museum of Natural
History, to Dr. A. Wetmore and the United Staxes National Museum, to Dr. Loye
Miller, and to Mr. A. J. van Rossera, in charge of the Donald Dickey collection.
After a careful comparison of the cave tarsometatarsus with these forms, it appears
that the nearest relationship is to be found with $pizatus and Aquila, with the
balance in favor of the former. I have noted in previous studies that Aquila and
8pigatus have many characters in common, and for that reason I have used the
subfamily 'term, Aquilinae, in discussing them in an earlier paper (Howard, Car-
negle Institution of Washington, Publ. 429). The tarsus under consideration appar-
ently belongs to this subfamily and is sufficiently dose to $pigatus to warrant placing
it in that genus. The only living species of 8pi.agtus which attains a size large
enough to agree with the cave specimen is 8. bellicosus of SOUth Africa. The chances
of identity of the Nevada species and the living South African bird are remote.
'rhe cave bird is therefore here described as
Spizatus willetti, new species
TYpe.--Distal end of tarsometatarsus, slightly broken at edges of internal and
external trochleae. Specimen no. 1791, collection of California Institute of Tech-
nology; collected by M. R. Harrington; trench 5, depth 2 to 4 feet, Smith Creek' Cave'
(loc. 251), 34 miles north of Baker, White Pine County, Nevada; Quaternary age.
Deseription.--Mot striking characters are large size and conspicuous facet for
metatarsal I, which is Placed high above distal end. Detailed characters follow:
ß (1) Archirig of trochleae similar to Sp/zagtus (well-arched, but less markedly so
than 'in AqgiIa).
(2) Distal contour of trochlea for digit 2, in both lateral and distal aspects, nearly
straight, having only a very gentle curve as viewed distally (closest to Sp/zagus
ornaus in this respect; S. grinnelli and Aqi/a slightly indented near the tip).
(3) Median trochlea with' external edge noticeably more developed antero-pos-
teriorly than internal edge (this is true of both Spizagtus and Aqgil).
(4) External ridge of trochlea for digit 4 projecting as a slender flange well
posterior to the internal ridge (development of external ridge varies in the different
species examined, from the short stubby form in M. u'oodwardi and Thrast?tus to
the long slender type, similar to the fossil, found in Aquila and Spizatus).
(5) Shaft narrowing slightly above trochleae (closest to Spizatus; Aquila narrow-
ing decidedly).
(6) Facet for netatarsal I located high on shaft, facing more laterally than is
the case in other species examined; facet long and, although not hollowed as in
Thrasat,, is so excavated as to cause a noticeable indentation in outline of internal
Fig. 40. Tarsometatarsus of Spiza?tus willertl,
Calif. Inst. Tech. coil. no. 1791. Type specimen,
natural size: o, anterior view; b, distal viexv;
c, posterior view.
Photograph by H. Win. Menkc, retouched hy John L. Ridga..
edge of shaft as seen in posterior view. High position of facet relative to breadth
of distal end agrees with certain specimens of Thcasatus, Pithecophoga, and Spizats.
There is some variation in this ratio within a species, enough so that it might be
possible to include Aq,ila in the list. However, in such forms as Haliactns Icuco-
cephalus and H. albicilla, Thalassootus pelogics, Morphines woodwardi and Butco
ß melanolecus the facet is definitely lower in position.
(7) Tendinal groove on anterior face wide and clearly marked, though not
sharply edged, the shaft rounding away from it gradually on external side. Although
the character of the groove itself is similar to SpizaPt,s, the rounded edge oœ the shaft
is not duplicated in any specimen at hand. Unfortunately the bone is broken away
on this side, so that its exact contour is lost.
(8) Anterior surface of shaft, on internal slope, slightly concave and devoid of
ridges (Spizatus closest in this regard, but appears a little more rugose toward
internal edge).
(9) Contour of internal edge of shaft, above facet for metatarsal I, slightly
concave. the shaf curvin? ouwar0 at point where bone is broken, thus precluding
possibility of bone being of long, straight type such as found in Morphnus voodward
or 12nteo; shape more on the order of Halioctus, Aquila or Spizats, though not
identical with any of them.
(10) In posterior view, internal edge of shaft, above metatarsal facet. rounding
posteriorly to slightly overhang posterior face of shaft, as in Aq.ila and Spizagtus;
other forms vary from a curved, though not overhanging, edge, as in B.teo, to the
flaring type found in Thrasagtns and Pithccophoga.
Measrements.--Greatest'breadth of distal end, approximately 8.5 mm.; breadth
of distal end across anterior edge of trochleae, 23.2; height of metatarsal facet, 40.0;
depth of external ridge of middle trochlea, 13.0; depth of internal ridge of middle
trochlea, 11.3; breadth of shaft at distal foramen, 18.2.
The species name is chosen in honor of Mr. George Willett, ornithologist of the
Los Angeles Museum, whose interest and assistance not only in the matter of the
specimen at hand, but in the many problems that beset the comparativ.e osteologist,
have been deeply appreciated.
Los ,tngeles Museum, Los ztngele, California, March 8, 1935.