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"Proornis" Lim vide Pak and Kim 1996
"P. coreae" Lim vide Pak and Kim 1996 Barremian?, Early Cretaceous Sinuiju series, North Korea Holotype- skull, cervicals, forelimb, feathers Diagnosis- metacarpal I longer than Confuciusornis,
but shorter than Changchengornis.
Description-
This specimen was discovered in 1993 and first
reported with photographs in the popular press in Korea (October 22, 1993 issue
of Nodong Sinmum). It has generally been compared to Archaeopteryx,
although Holtz said it could also be a small dromaeosaurid and Chiappe thinks it
is dissimilar enough from Archaeopteryx to be in another genus. Pak and
Kim (1996) claimed the bird was named by Lim in 1993, although such a
publication has not been located to my knowledge. This is why the name is
in quotations above. I provisionally assign the Siniuju series to the
Barremian based on the presence of the osteoglossomorph fish Lycoptera, also
known from the Yixian Formation.
The specimen consists of a skull, some anterior
cervicals and a nearly complete forelimb.
The skull is triangular, but further details are
difficult to see. It may be preserved in ventral view, showing the
basicranium and parasphenoid rostrum, but this is uncertain.
Similarily, little can be said of the series of
cervical vertebrae extending posteriorly from the skull.
The proximal tip of the humerus is missing.
The shaft is straight and the proximal end is expanded posteriorly. The
ulna has a slightly sigmoid posterior edge, while the radius is straight
and half of the ulnar width. The first metacarpal is similar to
Archaeopteryx in length, being more elongate than Confuciusornis. Phalanx
I-1 extends past metacarpal II, showing it is less derived than Jibeinia and
ornithothoracines. There is a large manual ungual on the first digit,
indicating it is also less derived than Protopteryx. Phalanx II-1 is
flattened and expanded, as in pygostylians, but unlike the slight condition in
Archaeopteryx and other maniraptorans. Phalanx II-2 is slightly
longer than II-1, showing "Proornis" to be less derived than Jibeinia and
ornithothoracines. Manual ungual II is much smaller than the other manual
unguals, a condition only known in confuciusornithids. Metacarpal III is
slightly short than metacarpal II. Digit III is about the same length as
digit II, which is more primitive than Protopteryx, Jibeinia and
ornithothoracines. There are presumedly three phalanges, of which the last
is very elongate. The ungual is intermediate in size between I and
III.
Feather imprints are said to be present, although I
cannot see them.
Relationships-
There are a series of characters advocating a
position between Archaeopteryx and Protopteryx, as well as a confuciusornithid
synapomorphy.
Pygostylia
- phalanx II-1 flattened and expanded
- phalanx II-2 only slightly longer than
II-1
Confuciusornithidae
- manual ungual II much smaller than I and
III
not Protopteryx + Jibeinia +
Ornithothoraces
- large manual ungual I
- digit III not reduced in length compared to II,
with large ungual
not Jibeinia + Ornithothoraces
- phalanx I-1 extends past metacarpal
II
- phalanx II-2 longer than II-1
The characters above suggest that "Proornis" be
referred to the Confuciusornithidae. Compared to Confuciusornis sactus,
metacarpal I and phalanx II-1 are more elongate. The manus/ulnar ratio is
identical (1.43). The first metacarpal is shorter than Changchengornis,
but other comparisons are difficult. I think "Proornis" should be
provisionally valid, until a more in depth analysis is performed. The
identification as a confuciusornithid is consistant with its stratigraphic
position.
Those who want a scan of the holotype contact me
offlist.
References- Pak and Kim, 1996. Mesozoic Era, in
Geology of Korea.
Lee, Yuong-Nam, Kang-Min Yu, and Craig B. Wood. 2001. A review of vertebrate faunas from the Gyeongsang Supergroup (Creataceous) in South Korea. Palaeogeography, Palaeoclimatology, Palaeoecology. 165: 357-373. Mickey Mortimer
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