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Re: feathers, hair and Compsognathus
>> It is ABSOLUTELY NOT useful to stick to the Linnean taxonomic rank of
>> "Reptile." It is Doubly paraphyletic. It is an awful example of Linnean
>> taxonomy. Also, birds are defined cladistically as "All the descendants of
>> the most recent common ancestor of both Archaeopteryx and Corvis", and since
>> Sinosauropteryx does not fall within that clade, it is not a bird.
> Not being up on my basal reptile phylogeny, could someone explain
>to me exactly why reptiles are now considered to be a paraphyletic
>group? I assume this means that thier earliest common ancestor was NOT
>something that shared the traits that has caused scientists to group
>"reptiles" together. What was this common ancestor, and how was it
Reptilia is paraphyletic if birds are excluded, since the ancestors of birds
However, Reptilia is regarded by most systemicists today as a monophyletic
group: all descendants of the most recent common ancestor of turtles,
lepidosaurs, and archosaurs (including birds).
Thomas R. Holtz, Jr.
Vertebrate Paleontologist Webpage: http://www.geol.umd.edu
Dept. of Geology Email:firstname.lastname@example.org
University of Maryland Phone:301-405-4084
College Park, MD 20742 Fax: 301-314-9661
"There are some who call me... Tim."
-- Tim the Enchanter, "Monty Python and the Holy Grail"
---------- subtitle --[Monty Python ik den Holy Grailen]
"Tim?!? They called me TIM?!?!"
-- Tom the Paleontologist, on seeing "The Ultimate Guide to T. rex" :-)