Crocodiles secondarily ectothermic

[Ken Kinman]

Dear All,
      More evidence that crocodiles are secondarily ectothermic, and that Archosauria is basically an endothermic clade.  Thus most (if not all) dinosaurs were probably endotherms.  Same for pterosaurs (not surprising given evidence of having had furry wings, in addition to their energy needs for flight).  As for turtles, if they are cladistically diapsids, their three-chambered heart would lend more credence to the view that they belong to Lepidosauria (not Archosauria).
    ----Cheers,  Ken Kinman

Summers, A.P., 2005.  Evolution: Warm-hearted crocs.
Nature, 434: 833-834.

Seymour, R. S., Bennett-Stamper, C. L., Johnston, S. D., Carrier, D. R. and Grigg, G. C., 2004.  Evidence for endothermic ancestors of crocodiles at the stem of archosaur evolution.  Physiol. Biochem. Zool., 77: 1051-1067.