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RE: Pteros might be dinos?!? Oh no ...

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Back in May=2C Dave Hone noted Bakker had mentioned pterosaurs could be des=
cended from early dinosaurs=2C to which I replied with the following list o=
f theropod-pterosaur snapomorphies-
- enlarged skull (reversed in Ornitholestes=2C most maniraptoriforms=2C etc=
- quadratojugal squamosal contact absent (reversed in tetanurines)
- elongate distal caudal vertebrae.
- strap-like scapula (reversed in coelophysoids).
- thin walled limb bones.
- penultimate manual phalanges most elongate.
- trenchent=2C recurved manual unguals II and III.
- metacarpal V absent.

In addition=2C pterosaurs share these characters with avepods-

- pneumatic cervical centra.
- at least four sacral vertebrae.
- preacetabular process elongate.
Though as I also wrote there- "I=92m sure pterosaurs wouldn=92t end up as t=
heropods in any well done analysis (you=92d have to get past the missing di=
nosauromorph=2C dinosauriform=2C dinosaurian and saurischian characters for=
 instance)=2C but Novas (1993) had a similar amount of characters supportin=
g a theropod placement for Eoraptor and Herrerasaurus as I have above. Just=
 goes to show the caution needed when conclusions are from small character =
matrices or matrices that only include characters which support the author=
=92s phylogeny."
Mickey Mortimer
The Theropod Database- http://home.comcast.net/~eoraptor/Home.html

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> Date: Mon=2C 9 Nov 2009 19:59:07 -0800
> From: tijawi@yahoo.com
> To: dinosaur@usc.edu
> CC: tijawi@yahoo.com
> Subject: Re: Pteros might be dinos?!? Oh no ...
> B tH wrote:
>> Just when you thought it was safe to go back into the water . . .
> I was throwing a cat among the pterodactyls with this one. No=2C I don't =
*really* think that pterosaurs are saurischians. (Although the skull of the=
 Late Triassic pterosaur _Raeticodactylus_ is weirdly theropod-like...)
> Considering all the unexpected discoveries that have been made over the p=
ast 20 years=2C a saurischian ancestry for pterosaurs would not be THAT wei=
rd. After all=2C we have four-winged dromaeosaurs (microraptorines)=3B an o=
viraptorid as large as a sauropod (_Gigantoraptor_)=3B a fuzzy-coated heter=
odontosaur (_Tianyulong_)=3B an ancestral mini-tyrannosaur with _T. rex_-li=
ke proportions (_Raptorex_)=3B an undersized=2C short-necked sauropod (_Bra=
chytrachelopan)=3B a long-necked stegosaur (_Miragaia_)=3B a sauropod with =
a hadrosaur-like dental battery (_Nigersaurus_)=3B a toothless=2C plant-eat=
ing ceratosaur (_Limusaurus)=3B spiny-tailed _Psittacosaurus_=3B and many=
=2C many more. If any of these are possible=2C why couldn't basal saurischi=
ans take to the air and become pterosaurs?
> Cheers (and with apologies to _Scleromochlus_).
> Tim
>                                         =