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Re: spine tables



Unfortunately I don't know much about vertebral morphology. What exactly would these neural spine tables do?
Were they there to support or anchor the osteoderms above them (did thyreophorans have spine tables?)? And what would they do in those forms which lacked osteoderms (muscle attachment sites?)?
------Ken
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Mickey Mortimer wrote:

I disagree. A spine table is a structure formed by the distal transverse
expansion of a neural spine. Note a few quotes from Makovicky's (1995)
thesis on coelurosaur vertebral morphology-
on Microvenator- "The spine is not expanded into a spine table distally,
..."
on Avimimus- "The distal end does not expand into a spine table." on Saurornitholestes- "The tip bears a moderately expanded spine table, which is proportionally smaller than in Deinonychus." "Dorsally the cervical neural spine is expanded into a spine table."
on Archaeopteryx- "Each one has a straight dorsal edge that is not expanded
into spine table."
on Ornitholestes- "The distal end is more expanded lateromedially than it is
at midheight, but it does not form a true spine table."
Finally, a character from his phylogenetic analysis- 23. Distal end of dorsal neural spines not transversely expanded = 0.
Distal part of neural spine expanded to form a "spine table" = 1 (Gauthier,
1986).


Rob Gay wrote-

But also present in phytosaurs and aetosaurs. How well developed are they in
those two groups that you mentioned as opposed to known armour-bearing
animals?


I couldn't say, lacking any good references on crurotarsans.  Deinonychus
does have better developed spine tables than Ceratosaurus though.

Mickey Mortimer



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