Re: CROCODYLOMORPH ENDOTHERMY

[Dinogeorge@aol.com]

In a message dated 96-01-26 01:53:27 EST, grenard@herpmed.com writes:

>All living crocodilians have 4 fully formed heart chambers with a
>small "defect" or window known as the foramen of Panizza which diverts
>blood from useless lungs during submergence. Otherwise they have
>separate arteial, pulmonary and venous circulations with little or
>no venous admixture when surfaced or on land. I believe it is 
>the opinion of some that a 4-chambered heart predisposes to endothermy. 
>
>

Right. Nevertheless, crocs are ectotherms, the only extant ectothermic
tetrapods with quadricameral hearts. I regard this as phyletically
significant.