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Re: Land of the Lost review-spoiler?
According to Bakker 86', cocodiles lack lip muscles, but lizards have
them. Lizard lip muscles seem to be non homologous with ours, however,
and not striated, unlike the lip musculature of ours, and likely not
innervated by nerve VII, unlike our facial muscles.
We should go down to turtles and lissamphibians, and even "fishes" to
see if they have the muscle kind present in lizards (I suppose turtles
may not have the muscles because they have a beak, except perhaps for
tryonichids); if not, the lizard condition may be autapomorphic.
Noticeably, beaks appeared many times in Archosauria, including
poposaurs, some pterosaurs, Silesaurus, Ornithischia, some basal
Sauropodomorpha, and many coelurosaurs. May it be that archosaurs have
something which made it easy for them to acquire beaks? I would think
of lack of lip muscles even in beakless, toothed archosaurs, as
before, but do not really know.
There are two main points in which beaked archosaurs emerged, one in
the early history of Dinosauriformes -Late Trias, Early Jura- and
other in Coelurosauria. I do not know if this means anything.