[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: a prehistoric man movie



On 7/13/07, Brandon Pilcher <trex_kid@hotmail.com> wrote:
We really need a new name for the group that consists of dinosaurs and birds
(with dinosaurs being the non-avian portion of that clade). How
about...Avedinosauria? Or maybe a name that describes a characteristic
shared by birds and all non-avian dinosaurs (saurischian AND ornithoschian).

It's been discussed on this list before. By now, "Dinosauria" is so commonly applied (at least by vertebrate paleontologists, and increasingly by others interested in vertebrate paleontology) to the clade rather than the traditional paraphyletic group that it doesn't really seem that a new name is warranted. If today were July 13, 1987, you could make an excellent case for this, but I feel it's a bit late by now.

There are several terms that correspond more or less to the
traditional usage, depending on your reason for wanting to refer to
it:

- "classic Dinosauria" or "traditional Dinosauria" for discussing
historical usage

- "non-avian Dinosauria" or "non-avialan Dinosauria" for  precisely
delimiting a singly paraphyletic group (depending on whether you're
talking about a stem group [the former] or a plesiomorphically
flightless group [the latter])

- "Mesozoic Dinosauria", when discussing stratigraphy or chronology

- "fossil Dinosauria" or "extinct Dinosauria"

- "stem-avian" refers to the avian stem group, that is, everything
closer to extant birds than to any other extant organisms (e.g.,
crocodylians, etc.), but excluding the crown clade of modern birds
(Aves). This is more inclusive than traditional Dinosauria (possibly
including pterosaurs, and certainly including "lagosuchians", etc.).
In many ways (primarily in terms of phylogenetic bracketing) this is a
more useful paraphyletic group than many of the others listed,
although it isn't currently used very often. (A longer way of saying
the same thing is "non-avian pan-avian".)

- "flightless Dinosauria" (or "nonvolant Dinosauria") might be useful
when discussing functional morphology, although it should be noted
that this is a polyphyletic group, including non-avialan dinosaurs and
neoflightless (secondarily flightless) avialans

- "unfeathered Dinosauria" or "non-avipluman Dinosauria" when
discussing integument. (Of course, you could also discuss unfeathered
Coelurosauria, non-avipluman Saurischia, unfeathered Pan-Aves,
unfeathered Diapsida, etc.). Feathers don't seem to have been entirely
lost in any lineages that had them plesiomorphically, so the two terms
are synonymous (at least until an unfeathered species of bird
evolves).

- "non-pygostylian Dinosauria", "non-avebrevicaudan Dinosauria", and
"non-ornithuran Dinosauria" signify nearly the same paraphyletic
group, including all dinosaurs without the extremely short tails of
birds.

There are a host of others, but these are some of the key ones.

(I should note that not everyone use "Aves" for the crown group [i.e.,
sensu Gauthier], as I do. For more on this debate:
http://www.phylonames.org/forum/viewtopic.php?t=19 )

--
Mike Keesey