No, it's not a Details on...., yet. This is
just to inform you all of a few things about the newly discovered coelurosaur-
Eotyrannus lengi. This is the inaccurately described "cat-like" theropod
first announced July 7, 1998. A good portion of the skeleton (MIWG
1997.550) is known (premaxilla, partial maxilla, nasals, lacrimal,
quadrate, axial arch, cervicals, dorsals, last sacral centrum, caudals?,
scapula, coracoid, humerus, partial ulna, radius fragment, carpal, metacarpals,
manual phalanges, manual unguals, ilial fragment, proximal tibia, proximal
fibula, metatarsals, phalanges, pedal ungual), although much is
incomplete. Hutt et al. place this in the Tyrannosauroidea based on-
D-shaped premaxillary teeth, premaxillary arcade aligned close to
mediolaterally, premaxilla taller than long, fused nasals, premaxillary teeth
smaller than maxillary teeth, acromion more than twice shaft width. The
premaxilla isn't nearly as tall as that of tyrannosaurids, it's more similar to
the plesiomorphic condition in Allosaurus for instance. Similar things
could be said for the acromial expansion. It is also more primitive
than tyrannosaurids because of the coracoid tubercle and unreduced forelimbs,
among other features. Actually, entering it into my data matrix makes
it come out as a dromaeosaurid (fused interdental plates, posterior serrations
much larger than anterior serrations). However, I have not added a couple
potential tyrannosauroid synapomorphies yet and there are some characters I will
hopefully know the states of soon which will help place it securely. Some
odd characters of this taxon are the apically complete denticulation,
pleurocoelous last sacral vertebra, last sacral with ventral keel and extremely
elongate manus (95% humeral length). Makes me wonder if the sacral is
actually a cervicodorsal ;-) . Finally, the true identity of Thecocoelurus
is revealed-
"BMNH R181, the incomplete holotype cervical
vertebra of Thecocoelurus daviesi, has a distinctive hourglass-shaped ventral
sulcus and ventrolateral raised edges. In these features and others (absent from
the vertebrae of Eotyrannus) T. daviesi is reminiscent of the cervical vertebrae
of Chirostenotes pergracilis (Sues, 1997) and probably represents an
oviraptorosaur
(Naish, 1999a; Naish & Martill, submitted)." Look forward to Details on Eotyrannus, after I get
the new characters entered, and after I finish Details on Liaoxiornis (is it
small because it's a juvenile?........).
Mickey Mortimer
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