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Dinosaur Genera List update #183



This week's issue of Nature carried the description of a new dinosaur, as 
cited in this meaty email (slightly edited) from Tom Holtz:

Subj:    Introducing: Sinovenator changii
Date:   2/13/02 5:12:43 PM EST
From:   tholtz@geol.umd.edu (Thomas R. Holtz, Jr.)

Xu, X., M.A. Norell, X.-L. Wang, P.J. Makovicky & X.-C Wu.  2002. A basal 
troodontid from the Early Cretaceous of China.  Nature 415: 780-784.

Troodontids have "traditionally" (since 1969) been considered the sister 
taxon to dromaeosaurids, in a clade Colbert & Russell called 
Deinonychosauria.  This position has been found by most, but not all, authors.

Okay, back in 1994 I published a paper which placed troodontids as the sister 
taxon to ornithomimosaurs, in the new clade Bullatosauria.  This study 
suggested that some features (previously observed by others, such as Currie) 
shared by ornithomimosaurs and troodontids (bulbous parasphenoid, 
arctometatarsalian pes, and more) were signs of the common ancestry of these 
two, while the similarities between troodontids and dromaeosaurids were 
convergences and/or basal features "overprinted" by the derived 
ornithomimosaurs.  A similar conclusion was reached by Perez-Moreno et al. at 
just about the same time.

In 2000 (analysis done in early 1999) my study found troodontids to be 
equally parsimoniously explained as bullatosaurs or as the sister taxon to 
dromaeosaurids plus birds.  Analyses by Norell et al. (finally published in 
2001) and some of the Chinese teams found troodontids to be the sister to 
"enigmosaurs."

As I discussed in the Ostrom Symposium, part of this problem stems from the 
lack of basal members of the Troodontidae, to resolve which features are 
ancestral in that lineage, and which derived.  That lack has ended.

Enter Sinovenator changii, (Meeman Chang's China hunter) based on a partial 
skull and skeleton and a referred skeleton from the lowest part of the Yixian 
Formation.  Associated fauna are Psittacosaurus, Jeholosaurus, and the mammal 
Repenomamus.  Sadly, the horizon it is from does not preserve the integument 
of the critter, one way or the other.

The anatomy, briefly:
The promaxillary fenestra is present and in the basal position.
The parasphenoid capsule is NOT inflated.
The basipterygoid processes do not appear to be hollow.
Denticles are absent on anterior teeth and small on maxillary teeth.
Dorsals have fan-shaped neural spines (shades of Sinosauropteryx!)
Glenoid fossa on scap-coracoid faces laterally.
Pelvis is *OPISTHOPUBIC* (not vertically oriented, but well past 90 degrees)
Metatarsal III is somewhat constricted, but non-arctometatarsalian.

The analysis includes species-level OTUs, which I won't reproduce entirely 
here.  Although they do not include all the higher level names I will use, 
here is their tree:
Avetheropoda
 Allosaurus
 Coelurosauria
   Tyrannosauridae
   Maniraptoriformes
     Ornithomimosauria
     Maniraptora
       Ornitholestes
       Metornithes
         Alvarezsauridae
         ye olde classic maniraptorans
           "enigmosaurs"
             Therizinosauroidea
             Oviraptorosauria (incl. Avimimus)
           Paraves
             Avialae
             Deinonychosauria
               Troodontidae
                 Sinovenator
                 all later troodontids
               Dromaeosauridae
                 Sinornithosaurus
                 all later dromaeosaurids

You know, I am quite pleased with these results, and think we (theropod 
systemicists) are reaching a consensus for this part of the tree.

So, to sum up:
Troodontids are almost certainly deinonychosaurs. I was wrong about 
troodontids in 1994, but don't care. The Yixian is the place to find cool 
specimens And even more are on their way... :-)

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Later there were these emails concerning Sinovenator to the dinosaur list 
from David Marjanovic (which, incidentally, never arrived here), Nick 
Pharris, and Ben Creisler:

Subj:   Sinovenator:  Emendation needed!
Date:   2/15/02 3:07:16 AM EST
From:   NJPharris@aol.com

David Marjanovic sent this earlier, but no one seems to have taken notice.

In a message dated 2/14/02 3:50:28 AM Eastern Standard Time, 
david.marjanovic@gmx.at writes:

> Just had a look at
>  http://www.fieldmuseum.org/museum_info/press/press_sinovenator.htm... says
>  Zhang Miman is a woman. Thus the name *Sinovenator chang_ii_* must already
>  be emended, no?

Dang, beat me to it!  However, you are correct.  From the article:

"Etymology...The specific name honours Meeman Chang of the IVPP for *her* 
significant role in the study of the Jehol fauna" (emphasis added).

The name will need to be emended to S. changiae.  The -i- Latinizes Chang's
name, but it does not make her male!

Subj:   Sinovenator changiae (NOT changii)
Date:   2/15/02 3:13:15 AM EST
From:   bh480@scn.org

From: Ben Creisler bh480@scn.org
Sinovenator changiae (NOT changii)

I haven't seen the Nature paper yet but the press release at (all one line):

http://www.fieldmuseum.org/museum_info/press/press_sinovenator.htm 

states that the species name honors a woman. Therefore the species name needs 
to be emended to changiae (feminine gender).

Sinovenator changii is named after Dr. Meeman Chang, a leading Chinese 
paleontologist who spent more than a year time studying fossil fishes at The 
Field Museum on different occasions, most recently in 1998.

"As head of the Beijing's Institute of Vertebrate Paleontology and 
Paleoanthropology for many years, Dr. Chang has helped raise the standards 
for paleontological inquiry in China," says Lance Grande, PhD, curator of 
fossil fishes at The Field Museum. "She is dedicated to improving the quality 
and productivity of Beijing's natural science institutions through training 
students, publishing, and improving collection and research facilities in 
China. She has also played an important role in making it easier for foreign 
paleontologists to work in China, thereby broadening the scope and importance 
of paleontological sciences there."

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Accordingly, I add as genus #937

Sinovenator Xu, Norell, Wang, Makovicky & Wu, 2002

and the species entry in the forthcoming Mesozoic Meanderings #3 second 
edition will read something like this:

Sinovenator Xu, Norell, Wang, Makovicky & Wu, 2002
    S. changiae Xu, Norell, Wang, Makovicky & Wu, 2002 emend.â
        = Sinovenator changii Xu, Norell, Wang, Makovicky & Wu,
            2002âÂ

with the emendation credited to whoever gets it into print first (ideally, 
one or more of the original authors). In case the special characters fail to 
transmit, there's a dagger following the first species name to indicate that 
it is the type species, and a dagger and section sign following the second 
species name to indicate that this was originally the type species but was 
emended to the immediately preceding name.

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Then I received this interesting email:

Subj:   NEW SAUROPOD: FERGANASAURUS VERZILINI
Date:   2/16/02 1:24:46 PM EST
From:   mrossi83@hotmail.com (mark reds)

I tried to send this message to the DML, but for some reason it doesn't 
appear  on the archives.So,I decided to send it to someone on the list to 
spread the news. I hope it will be a new update to your Dinosaur Genera 
List...:)

Here's the link:

  http://www.magtech.ab.ca/jurassic/averianov.htm

Don't forget to look at the other projects:

  http://www.magtech.ab.ca/jurassic/prevgrnt.htm

Sorry if you know about it yet.

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I am passing the message along as requested. I visited the URLs and 
discovered that the "sauropod from Fergan," which I have been carrying in my 
dinosaur lists as a dinosaur "to be described" since the 1970s(!), will at 
last receive its name and description in an article by Alifanov and Averianov 
in a forthcoming issue of JVP. When that happens, I'll cheerfully add 
Ferganasaurus to the Dinosaur Genera List; but I can't add it just yet 
because as far as I know it exists only as an Internet name.