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NUMBER 89 179
FIGURE 2.—Geographic location of fossiliferous localities in the Pampean region of Argentina: 1, 2, Farola de
Monte Hermoso; 3, Cascada Grande on Quequen Salado River; 4, south of the Loberia stream; 5, Chasico
stream; 6, Monte Hermoso City.
REMARKS.—Moreno and Mercerat (1891) originally described
Dryornis pampeanus based on a distal end of a left humerus
(lectotype, MLP 20-169) and an abraded distal end of a
right femur (MLP 20-170). As was pointed out previously by
Patterson and Kraglievich (1960) and by Brodkorb (1967), the
assignment of the femur (MLP 20-170) to a condor was erroneous.
Our reexamination of this specimen agrees with prior revisions
in attributing it to a phorusrhacoid bird.
Dryornis pampeanus is recognized by having a humerus
with the following characters: (1) size similar to that of Vultur
gryphus, but distal shaft width just proximal to the epicondylus
dorsalis greater; (2) condylus dorsalis longer and straighter
than in Vultur, Gymnogyps, or Geronogyps; (3) condylus ventralis
narrower than in Vultur or Gymnogyps, similar to Geronogyps;
slightly rotated anteriad, giving moderately flexed distal
end as in Geronogyps, Gymnogyps, and Vultur, with marked
flexion of distal end of humerus; (4) epicondylus dorsalis
rounded as in Gymnogyps and less protrudent proximally than
in Vultur, Gymnogyps, or Geronogyps; (5) insertions of M. brachialis
anticus, M. pronator brevis (=M. p. superficialis), and
M. flexor carpi ulnaris deeper than in Gymnogyps or Geronogyps;
(6) fossa M. brachialis less extended laterally than in all
species compared; (7) sulcus scapulotricipitalis less marked
than in Geronogyps or Vultur; (8) fossa olecrani relatively
more excavated and proximal, and less extended laterally, than
in Vultur, Gymnogyps, or Geronogyps; and (9) intercondylar
furrow nearly straight.
Historically there has been some agreement that Dryornis
pampeanus is a valid genus within the Vulturidae (see Tonni,
1980; Emslie, 1988a). Our direct comparison of the material
with other known fossil and living vultures supports the anatomical
distinctness of Dryornis pampeanus from the other
members of the family. Thus, based on the set of characters
listed above, we consider Dryornis pampeanus to be a valid genus
and species and to be one of the earliest fossil condors in
South America.
Vultur gryphus Linnaeus, 1758
REFERRED MATERIAL.—Proximal end of humerus, MLP 48-
XII-16-225 (Figure 4); Farola de Monte Hermoso (39°S,
61°50'W), Coronel Rosales County, Buenos Aires Province;
early-middle Pliocence (Montehermosan?-Chapadmalalan
Age.
Shaft of Ulna, MLP 63-VI-10-15; Cascada Grande locality
on the right margin of Quequen Salado River (38°30'S,
60°30'W), Coronel Dorrego County, Buenos Aires Province;
middle Pliocene (Lower Chapadmalalan Age).
REMARKS.—The humerus, which comes from the same locality
as Dryornis pampeanus, was attributed to Vultur gryphus
by Tambussi (1989), Tambussi et al. (1993), and Tambussi and
Noriega (1996). The ulna shaft was referred to Vultur gryphus
by Tambussi (1989) and shows 12 papillae remigiales ventrales
and caudales (of secondary remiges). The cross section of the
shaft is triangular and forms a smooth, sigmoid curve.
cf. Vultur sp.
REFERRED MATERIAL.—Distal end of femur, MMH 561;
seashore close to Monte Hermoso city (39°S, 61°15'W); late
Pleistocene (Lujanian Age).
REMARKS.—Tonni (1984) pointed out that this femur is indistinguishable
from that of Vultur, but it is too badly preserved
for a more accurate identification.
VULTURIDAE, genus and species indeterminate
REFERRED MATERIAL.—Incomplete right ulna and articulated
proximal end of radius, MLP 90-X-l-l (Figures 5, 6), collected
by Ulyses Pardinas and Maximiliano Lezcano; south of
the mouth of Arroyo Loberia (38°15'S, 57°40'W); middle
Pliocene (Upper Chapadmalalan Age).
MEASUREMENTS (in mm).—Ulna: Total length as preserved,
253; width of proximal end, 40.8; width of midshaft,