Morphology, Phylogenetic Taxonomy, And Systematics Of Ichthyornis And Apatornis (Avialae: Ornithurae)
Author
CLARKE, JULIA A.
text
Bulletin of the American Museum of Natural History
2004
2004-09-07
2004
286
1
179
http://www.bioone.org/doi/abs/10.1206/0003-0090%282004%29286%3C0001%3AMPTASO%3E2.0.CO%3B2
journal article
10.1206/0003-0090(2004)286<0001:MPTASO>2.0.CO;2
0003-0090
5355565
Ichthyornis victor
Ichthyornis victor
was named by
Marsh (1876)
and differentiated from the
holotype
of
Ichthyornis dispar
(YPM 1450)
as being onethird larger than that species (
Marsh, 1876
).
HOLOTYPE
SPECIMEN:
YPM
1452 includes a proximal right coracoid, proximal right scapula, and three fragments of a poorly preserved left humerus (fig. 11). As discussed in the Historical Background, some or all of the material incorporated into the
YPM
Ichthyornis victor
panel mount frequently appears to have been mistaken for
holotype
of
Ichthyornis victor
. The
YPM
Catalogue entry for
YPM
1452 included the phrase ‘‘Ma jor portions of skeleton’’ for most of the 20th century.
LOCALITY
AND
HORIZON:
Marsh (1880: 199)
reported that
YPM
1452 was ‘‘found in
May 1876
, by Mr. H. A. Brous, in Wallace County,
Kansas
.’’ No locality information was given in the original description of the species (
Marsh, 1876
), while the listing in
Marsh (1880)
was repeated in
Brodkorb (1967)
.
DISCUSSION: Several morphologies described for the
holotype
(
Marsh, 1876
) but not used to differentiate it are also present in the
holotype
of
Ichthyornis dispar
. These are now known to be ancestral for more inclusive avialan clades (e.g., expanded deltopectoral crest and dorsal humerus condyle larger than the ventral; see appendix 1: characters 113, 125). Only humeri can be directly compared between the
holotypes
of
Ichthyornis dispar
and
Ichthyornis victor
and, while they are different in size, there are no appreciable differences in morphology. The morphology of YPM 1452 is discussed in the Anatomical Description.
Fig. 12. The
Ichthyornis validus
holotype (YPM 1740), a right ulna:
(A)
the distal end in dorsal view and
(B)
the complete element in ventral view.
REFERRED SPECIMENS: The majority of YPM specimens were referred (
Marsh, 1880
) to this species (see table 1).