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Re: pterosaurs & snakes
>I have a few questions from my 4-year-old (my wording, not his):
>Concerning Paleoworld's umpteenth repeat of the pterosaur episode: How
>did the pterodactyloids come to replace the rhamphryncoids (pardon
>spellings)? Was it direct competition or new species filling in empty
>niches? Did both these stocks come from the same ancestor?
Last question first: they both had the same ancestor, and in fact the
ancestors of the pterodacyloids was a "rhamphorynchoid". The latter is a
paraphyletic group (one with a common ancestor but not all descendants; in
this case, the 'not all descendants' is the Pterodactyloidea.) Competition
is a very difficult thing to demonstrate really well in the fossil record.
I don't know that the record of pterosaur fossils is complete enough for
some fine-scaled stratigraphic correlations between the origin of the
pterodactyloids and the disappearence of the non-pterodactyloid pterosaurs.
Hopefully, Kevin Padian, Dave Unwin, or one of the other pterosaur experts
on the net can give a more complete answer.
>Were snakes around during the dino days, and if so what was the largest?
Snakes arose during the age of dinosaurs. I can't recall the exact size of
any, but I remember a primitive python-like form (_Madstonia_? something
like that) which was comparable to mid-sized pythons & boas of today.
Thomas R. Holtz, Jr.
Vertebrate Paleontologist in Exile Phone: 703-648-5280
U.S. Geological Survey FAX: 703-648-5420
Branch of Paleontology & Stratigraphy
MS 970 National Center
Reston, VA 22092