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Re: Dinosaurian Class (was: DROMAEOSAURS AND OVIRAPTOROSAURS ....)
David Hill wrote
>I think the difference of endothermy and ectothermy should not be excluded.
> The basic rules that you are using have holes in them. Lizards
>look alot like salamanders so that means reptiles are amphibians! Early
>amphibians look like lungfish, therefore amphibians are fish. You see, it
>just keeps going! We need stricter guidelines.
How does one draw the line between ecto/endothermy in the fossil record?
Ideas on extinct physiologies are based on wonderful past-times like
functional anatomy and phylogenetic comparison where, to put it bluntly,
different people see different things. One cannot directly prove that
fossil organism X was actively homeothermic while fossil organism Y was
not. Thus there is no way of ever truly knowing if we really are
classifying endothermic and ectothermic animals together...and if
physiology ever became a REAL criterion for classification we would be at
each others' throats till eternity.
Finally, should endothermic fish such as lamnid sharks be in their own classes?