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Re: birds and avians again



> the thought of
> making a clade Thecodontia is horrifying (thecodonts have always been a
> paraphyletic group and should remain so).

_Please_ don't keep Thecodontia, even if you really feel you need a
paraphyletic group at the base of Archosauria (strange, strange). It is such
a misnomer -- the namegiving feature is 1. a synapomorphy of something like
Archosauria, never reversed (save toothless species), and 2. a heavy case of
convergence with many or all synapsids.

>      Once some dust has settled some years down the road, perhaps Aves
will
> need to be expanded somewhat to include various coelurosaur groups, but I
> doubt that a massive expansion will catch on (especially if protofeathers
> and scutes are found to be closely-related variations on a theme).  In the
> meantime, the Archaeopteryx anchoring seems to be fine (and if Dave
> Marjanovic is correct,

Optimist =8-)

> this Archaeopteryx anchoring might automatically
> force us to include dromaeosaurs and various other maniraptors in Aves).
I
> can sort of imagine Tyrannosaurus possibly being called a primitive "giant
> ground bird" in the future, but calling sauropods (even fuzzy ones)
"birds"
> would be extremely hard to swallow.

I agree here -- why base everything on living forms? Why Aves and Crocodylia
and not, say, Dinosauromorpha (or Avemetatarsalia or whatnot) and
Crurotarsi? Or, if you want more widely known names, Dinosauria and Suchia
maybe? (And why Pisces, a term which is still used by a number of people I
can probably count on a hand, for Actinopterygii?)