Re: Archosaur Origins...was:MESENOSAURUS ERRATA.

[ELurio@aol.com]

In a message dated 8/25/01 2:58:21 PM, Dinogeorge@aol.com writes:

<< The P/Tr archosaurs (one genus as far as I know: Archosaurus) had to 
evolve 
from something: earlier archosaurs. According to my simple definition of 
Archosauria, prolacertiforms are basal archosaurs.>>

Of course they evolved from SOMETHING, but there are NO fossil archosaurs 
known prior to the terminal Permian. None Zippo. There are a few during, a 
very few, in fact there are probably more Silurian jawed fish known than 
Permian Archeosaurs.

<< And don't forget to allow  for secondary loss of feathery integument in 
the larger animals, perhaps for  the same reasons that rhinos and elephants 
lose most of their hair. >>

Why should we? We're talking PERMIAN here, when all archeosaurs were one 
(Archosaurus), and we don't have any evidence for fiberous integument in any 
lepidosaurs or turtles in either the fossil record or living species. From 
all the reading that I remember, Archosaurus only had minor differences from 
the lepidosaurs of the time.

eric l.