Re: Pterosaurs, and more pterosaurs!

["Chris Bennett" <cbennett@bridgeport.edu>]

----- Original Message -----
From: "Ivan Kwan" <dino_rampage@hotmail.com>
To: <dinosaur@usc.edu>
Sent: Thursday, February 05, 2004 12:05 PM
Subject: Pterosaurs, and more pterosaurs!


> 1) What sort of crest did _Pterodactylus_ have? Would it be the sort as
> shown in Aspidel's Solnhofen drawing on the Dinosauricon here
> http://dino.lm.com/images/display.php?id=800, and would _P.kochi_ and _P.
> antiquus_ have the same sort of crest?

Pterodactylus had a bony sagittal crest over it naris/antorbital fenestra
and orbit, much like the crests of Germanodactylus and Ctenochasma.  The
bone crest presumably supported a soft tissue crest like that seen in those
two taxa (see Bennett, S. C. 2002. Soft tissue preservation of the cranial
crest of the pterosaur Germanodactylus from Solnhofen.  Journal of
Vertebrate Paleontology, 22:43-48).  The crests in Aspidel's illustration
seem to be based on Frey et al.'s reconstructions of crests (see "New
specimens of Pterosauria .. with soft parts..." pp. 233-266 in the Pterosaur
Symposium volume).  I disagree with Frey et al.'s reconstructions because
the available evidence suggests that the soft tissue extending upward from
the bony crest was cornified epidermis and I do not think that upward
growing cornified epidermis could grow into the shapes illustrated by Frey
et al.


> 2) Are _P. kochi_ & _P. antiquus_ even that closely related anyway? I'd
> always read somewhere (DP's Pterosaur Homepage IIRC) that kochi was
> ancestral to ctenochasmatoids, and antiquus to azhdarchoids. And so does
> _Pterodactylus_ belong to the ctenochasmatoids or in a clade of its own?

I argued in my 2003 SVP talk (see Bennett, S. C.  2003.  New information on
the genera Pterodactylus and Germanodactylus from the Solnhofen Limestone of
southern Germany.  Journal of Vertebrate Paleontology, 23(Suppl. to #3):33A)
that virtually all Solnhofen specimens assigned to P. kochi belong to P.
antiquus.  The holotype of P. kochi is from Kelheim and thus malm Zeta 3 and
so differs slightly in age from P. antiquus and all the other specimens from
Solnhofen (Malm Zeta 2).  It is conceivable that the name P. kochi might be
retained for the holotype specimen alone if differences could be
demonstrated, but in my view P. kochi is a junior synonym of P. antiquus.
Since they are the same thing, there crests would be the same.  As for the
relationship to ctenochasmatoids and azhdarchoids, it depends on who yo talk
to.


> 3) Any crest known for _Nyctosaurus_? (besides the recent 'antler' one?)
I'd
> always seen _Nyctosaurus_ reconstructions with a small stubby
> _Pteranodon_-like crest; is this reflected in the fossil record?

No crest was known for any specimen of Nyctosaurus until the two new
specimens came to light.  Any reconstruction you might have seen with a
crest (e.g., Sibbick's in Wellnhofer's Encyclopedia) was imaginary and not
based on any publication by anyone who actually worked on Nyctosaurus.  I
suspect that that Pteranodon-like crest was a result of the misguided
suggestions by some that there is a close relationship or even an
ancestor-descendant relationship (see Miller) between Nyctosaurus and
Pteranodon.  That supposed relationship is based on somewhat similar feeding
adaptations.  I could produce a data matrix and analyze with PAUP to produce
a "cladogram" showing that Gnathosaurus, gharials, and needlefish were most
closely related if I used enough characters related to adaptations to
feeding on fishes, but that would not prove a close relationship.


> 4) _Istiodactylus_: where the hell does it fit in pterosaur phylogeny? Is
> this the same as that new Isle of Wight pterosaur with a
> _Brasileodactylus_-like crest as well as a snout crest reminiscent of
> _Anhanguera_?

It depends who you talk to.  In my opinion, it is related to
pteranodontoids, which is to say the clade that shares among other things
the warped deltopectoral crest.


> 5) Would _Germanodactylus_ & _Normannognathus_ be considered basal
> dsungaripteroids? And are cristatus & rhamphastinus considered closely
> related enough to be placed in the same genus?

It depends who you talk to.  Unwin and Bakhurina had continued to support
Young's suggestion that there was a relationship between Germanodactylus and
Dsungaripterus.  I disagree.  For the moment G. cristatus and G.
rhamphastinus are viewed as conspecific because they seem to share a number
of features, but some might make a case to split the two.


> 6) _Anhanguera piscator_ - Still valid? Or has it been synonymised with
> _Coloborhynchus robustus_?

It depends who you talk to.   Unwin and Fastnacht have been lumping the
Santana taxa into Greensand taxa, while Kellner does not support such
lumping.


> 7) _Siroccopteryx moroccensis â?" Valid genus or sunk into
_Coloborhynchus_
> as _C. moroccensis_? And did this critter look more like _Anhanguera_ or
> _Coloborhynchus_?

See above.


> 8) _Cearadactylus_ - Ctenochasmatoid or Ornithocheiroid?

It depends who you talk to.


> 9) _Araripedactylus_, _Araripesaurus_, _Brasileodactylus_, _Ludodactylus_,
> _Arthurdactylus_ - all Ornithocheiroids I presume??

As I understand it, theposition of Araripedactylus and Araripesaurus is
unknown.  The others are or probably are pteranodontoids.


> 10) Tapejarids & Tupuxuarids â?" Azhdarchoids or Ornithocheiroids?

I do not think anyone has suggested that tapejarids and tupuxuarids are
close to "ornithocheiroids", but there is some disagreement as to how close
they are to azhdarchoids.  Kellner talked at SVP about them and wanted to
keep them separate.

Chris


S. Christopher Bennett, Ph.D.
Assistant Professor of Basic Sciences
College of Chiropractic
University of Bridgeport
Bridgeport, CT  06601
http://www.bridgeport.edu/~cbennett

"Savor the sun--but when the clouds come make animals"  (Hexum)