Re: 18 Questions on Old and New Dinosaur Species

[Thomas_R_HOLTZ@umail.umd.edu (th81)]

>I have a few questions:

few? :-)
>
>1) Is the lumping of _Creosaurus atrox_ into _Allosaurus_ valid?

To almost everyone but Bakker it is (see below).
>
>2) Is there a new name for _Epanterias amplexus_ (a.k.a. _Allosaurus
>amplexus_, _Saurophagus_), or do one of the former ones still take
>priority?

Since the taxonomy and hypodigm (list of specimens) associated with
Epanterias amplexus and Saurophagus maximus is VERY confused (e.g., it is
not at all certain that the Camarasaurus bones labelled "Epanterias" are not
the true types), better fossils of the giant Morrison allosaurid have been
given a new name: Saurophaganax maximus, the greatest king lizard eater.
>
>3) Has another species of _Dilophosaurus_ been uncovered?  If so, please
>tell me about the specimen(s) uncovered and what we know about this new
>animal.

This is Dilophosaurus sinensis, from the Lufengosaurus beds of China.  Only
the skull has been described in detail.  The skull is bulkier and the crests
are more massive than those of the North American species, but otherwise
they are very similar.

>4) Has the "long-snouted" daspletosaur (discovered by Bakker) ever been
>named?  What remains is it known by?  Does it sink into existing genera?

Not yet named nor described.  It must be noted, though, that Bakker is
notorious for being one of the most extreme "splitters" in dinosaurian
taxonomy, splitting into five or six species and multiple genera suites of
fossils which others regard as one or two species of one genus.

>5) Is _Archaeopteryx bavarica_ a valid species?  What features are present
>that distinguish it from _A. lithographica_?

The presence of a bony sternum was used as the basis for the new species.
This may indeed be a specific feature, but it may be related to individual
or sexual variation.

>6) What is the new species of _Apatosaurus_?  Does it really belong in
>that genus?

Presumably this is Apatsaurus yahapin (sp?  the trivial nomen comes from the
Native American implament formerly called a "peace pipe".)  It seems to be a
primitive member of the genus Apatosaurus.

>7) What is the difference between _Laosaurus_, _Othnielia_, _Drinker_, and
>_Yandusaurus_?

Not much (hypsilophodontians being one of the most conservative of
dinosaurian lineages).  Yandusaurus is older than the others, for one.

>8) Has the new giant dromaeosaur from Asia been named yet?  Is so, what is
>its name? What is the description?
>
Actually, there are two (or more) of them: one or more Mongolian forms and
the Japanese one.  None have been named, and (unless someone hasn't
published on it yet) the remains are all fragmentary.  They seem to be just
big raptors as far as can be seen.

>9) Has _Albertosaurus megagracilis_ been placed into its own genus,
>_Dinotyrannus_.  And, if so, on what basis?  

Dinogeorge has done so, and he can give his reasons.  However, there remains
the possibility this is simply a subadult T. rex.

>10) Have  _Parasaurolophus_ skulls with short, drooping crests been found
>together with _Parasaurolophus_ skulls with long, straighter crests?  In
>other words, is _Parasaurolophus cyrtocristatus_ (spelling?) really the
>female
>_P. walkeri_?

Good question.  That hypothesis has been put forward, and does make sense.
The recent disovery of a new Parasaurolophus skull might help in this study.

>11) What is the name of the gigantic Como Bluff "megalosaur"?

Presumably this is Edmarka rex (which may simply be a big Torvosaurus
tanneri).

>12) What is the theropod  _Sinraptor_?  When was it
>discovered/described/named, what are its relatives, and what remains are
>it known from?

Sinraptor is a sinraptorid allosauroid, the sister taxon of
Yangchuanosaurus.  There are two species known, both from the Late Jurassic
of China.  Almost the whole animal is known.
>
>13) Has a description of _Pelecanimimus_'s (spelling?) covering been
>published yet?
> If so, what IS the description?

Unless it has just come out, it is yet to be published.  Bernardino
Perez-Moreno will have the details.

>14) Is there an Arizonan species of _Syntarsus_?  If so, when was it
>discovered?  What is the description?

Presumably this is Syntarsus kayentakatae, the southwestern U.S. crested
Syntarsus.  Check _The Dinosauria_ for more info (unless Tim Rowe wants to
post more detail himself!)

>15) Is there any difference between the two coelophysoid genera
>_Lilliensternus_ and _Halticosaurus_?  Are they both valid genera, or is
>only ONE valid?  Have any new specimens of these animals turned up
>recently?

Halticosaurus lilliensterni was regarded as different enough (and distinct),
so it was given its own generic name.  The remaining Halticosaurus fossils
are mostly fragmentary, and may (or may not) be from Lilliensternus-type
animals.

>16) Have any new specimens of _Nanotyrannus_ turned up?  Is the animal
>still known only from its skull?
>
Yes, and the case that it is not a juvenile T. rex is not certain.

>17) What is the description for the new specimens of _Deinonychus_?  What
>do these specimens tell us, particularly about the shape of the skull?

Larry Witmer and Des Maxwell have not published on these yet.  Patience.

>18) Exactly HOW LONG AND TALL was _Deinonychus_?  At least, estimations
>for the various specimens?

Hip height about 3'-4', length 8'-10'.  Check Greg Paul's Predatory
Dinosaurs for some more precise measurements of particular specimens.

Hope this helps.

Thomas R. Holtz, Jr.
Vertebrate Paleontologist
Dept. of Geology
University of Maryland
College Park, MD  20742
Email:Thomas_R_HOLTZ@umail.umd.edu (th81)
Fax: 301-314-9661
Phone:301-405-4084