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Re: Turtles and Crocodylians are not Reptiles - no? What are they?



On Mon, Jul 21, 2008 at 9:20 PM, Erik Boehm <erikboehm07@yahoo.com> wrote:
> Turtles are the closest to archosaurs now?

What I've said is that extant turtles and extant archosaurs *probably*
are the closest relatives each other. And yes, there is conflict
between morphological and molecular data. But here morphological data
is somewhat problematic due to (a) highly morphological derived states
in Testudines/Chelonia, (b) lack of less derived fossils.

> Perhaps specific sex chromosomes are an adaptation to being warm blooded?

Well, many insects, "fishes" and "reptiles" have a chromosomal sex
determination system too - in flies it is more a case of
autosomal/sexual chromosomal balance than a count of sexual
chromosome.

Warner & Shine 2008 - The adaptive significance of
temperature-dependent sex determination in a reptile
http://www.nature.com/nature/journal/v451/n7178/full/nature06519.html

[]s,

Roberto Takata