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The small, bare-skinned one (aka LN Jeff) writes:
> SCALES are AMNIOTE traits? I thought Tim Holtz just said synapsid
> were probably unscaled. What is the formal diagnosis for "Reptilia"?
> Who diagnosed it originally and when (meaning, why is "amniota" usd
> by cladists for the common ancestor of turtles, lepidosaurs,
> archosaurs, AND synapsids instead of "reptilia"?)
I recently had to chase up a couple of things relating to the life appearance
of various Carboniferous amphibians, and I've now seen 'scaly' skin in an
_Eryops_. It was described in _American Journal of Science_ back in the 1920s
I think. Furthermore, in a paper in _Biological Review_ a couple of decades
back, Bob Carroll figured ventral scales from various late Palaeozoic
amphibians, as well as from the basal synapsid _Ophiacodon_.
(Sorry I haven't posted full refs: will do if anyone badgers me.)
I don't mean to say that Tom is *wrong*, but, hell, I'm confused. Or am I just
out of date? Jeff, don't call him Tim: just makes him mad.
We're all taught that binocular vision is an adaptation allowing predators,
climbers etc to judge depth perception. But a number of non-predatory non-
climbers appear to possess it.
(1) Maryanska has said that it was present in pachycephalosaurs - I would be
interesting if anyone could verify this as a possibility. I understand the case
is pretty hopeless, as amongst living animals, ostriches - which have
overlapping visual fields - don't actually 'see' with binocular vision.
(2) It would also seem that living crocodiles have binocular vision. Can anyone
Then, of course, there are predators that seem to have gotten by without the
adaptation (including a number of theropods). Applying rules to the natural
world seem to be a bad idea.
I know the name for *another* new Santana theropod.
"Diplomatic immunity" "It's just been revoked" (Harris emend. 1996)
"You're using those in *public*?? Good grief!!"