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Sereno et al.'s Chinese discoveries



Well, it seems as if Sereno and his team are leaving Inner Mongolia.  I've assembled a list of dinosaur discoveries they mention and photograph on the site.  There are several very cool looking specimens.  I can't wait to see what will be published in Science next year.
 
 
Theropoda indet.
Late Cretaceous
material- partial skull including jaws and teeth
description- This is a large form.  The premaxillary teeth are said to be non-incisiform, which indicates it is not a tyrannosauroid.  The lateral teeth also suggest this, as they are narrow and blade-like, not robust as in tyrannosaurids.  Being in the Late Cretaceous, there are few possibilities for its identity- abelisaurid, carcharodontosaurid, basal coelurosaur, dryptosaurid, dromaeosaurid.
 
Coelurosauria? incertae sedis
Late Cretaceous
material- (juvenile?) vertebrae, ribs, caudal series, radius, ulna, manus, hindlimbs, pedes
description- Not nearly enough was said of this specimen.  Something with an elongate, tridactyl manus.
 
Coelurosauria? indet.
Cretaceous
material- pedal phalanx
 
Dryptosauridae? incertae sedis
Early Cretaceous
material- forelimb elements, manual ungual (127 mm)
description- The manual ungual resembles Dryptosaurus most, differing only in the more extensive area under the lateral groove proximally and possibly the more anteriorly placed flexor tubercle (assuming the area isn't broken).  Perhaps the two are related.
 
Segnosauria incertae sedis
Late Cretaceous
material- partial skeleton including forelimb
 
Troodontidae? incertae sedis
Late Cretaceous
material- many elements including two cervical vertebrae and manual ungual
description- Sereno et al. refer to this as a dromaeosaurid, but based on the photos, I have some doubts.
Differences from Deinonychus- much more elongate cervicals; ventral margin of centra more concave; much lower neural spines; more gently curved dorsal margin of prezygopophyses; very low epipophyses; manual ungual less recurved; flexor tubercle more prominent, placed further anteriorly.  Saurornitholestes is also reported to have short cervicals,  tall neural spines and large epipophyses than project past the postzygopophyses (Makovicky 1995).  Saurornitholestes' manual unguals (Sues, 1978) differ in the same ways as Deinonychus'.  Now perhaps the neural spines and epipophyses are broken in Sereno's specimen, but it doesn't look that way.  I suppose some taxa close to dromaeosaurids (Sinornithosaurus, etc.) may have more elongate cervicals with different morphologies, but this is unknown at present.  I would say these vertebrae and ungual are not dromaeosaurid. 
An obvious alternative is the Troodontidae.  Troodontid cervicals are poorly illustrated in the literature, but are described in detail by Makovicky.  They resemble Sereno's specimen more than dromaeosaurids in having more elongate centra, low neural spines and reduced epipophyses.  In addition, Makovicky describes the ventral edge of the centrum as having a sigmoid curve, which is present in the new specimens.  The manual claws of troodontids are also more similar to the new form, as they have less curvature and more distally placed flexor tubercles.
Coelurus is also quite similar to the new specimen, as it also has elongate centra, low neural spines, reduced epipophyses, a sigmoid ventral outline, poorly curved unguals and distally placed flexor tubercles.  Differences from Coelurus include more decurved prezygopophyses, more slender centra, taller postzygopophyses, a more concave ventral margin and smaller flexor tubercles.
Another taxon with elongate cervicals is the Ornithomimosauria.  These share the characters listed above for Coelurus, but differ in that their postzygopophyses are more elongate, the sigmoid curve is interupted by the enlarged parapophyses and the unguals are much straighter with lower and more distally placed flexor tubercles.  It was clearly not an ornithomimosaur.
Segnosaurs have somewhat elongate cervicals, but shorter centra, lower neural spines and much deeper manual unguals.
Oviraptorosaur claws vary quite a bit.  The ungual is similar to caenagnathid unguals, assuming the proximodorsal lip is broken.  Only posterior cervicals are known for caenagnathids, but they have the large parapophyses like ornithomimids, lower neural spines and less angled central faces.  Oviraptorid unguals are quite different and their cervicals are shorter with lower neural spines than Sereno's specimen.
Finally, Avimimus cervicals have somewhat elongate centra and reduced epipophyses, but non-decurved prezygopophyses, longer postzygopophyses and more prominent rectangular neural spines.
In conclusion, this taxon resembles Coelurus and troodontids most, the latter identification being more temporally parsimonious.
 
Eumaniraptora incertae sedis
Early Cretaceous
material- teeth, limb elements
description- The teeth lack anterior serrations, which is only known in some troodontids and eumaniraptorans.  The former have very distinctive teeth, and since Sereno calls this a dromaeosaurid tooth, it's probably from a dromaeosaurid or related deinonychosaur.
 
Iguanodontia incertae sedis
Early Cretaceous
material- ribs and other elements
 
Hadrosauridae incertae sedis
Late Cretaceous
material- dorsal vertebrae, scapula, manual elements
 
Psittacosaurus sp.
Early Cretaceous
material- partial skull
articulated skeleton with gastroliths
description- Shorter, rounder skull than P. mongoliensis.
 
Protoceratops sp.
Late Cretaceous
material- (juvenile) partial mandible
 
Mickey Mortimer