EXTINCTION AND ENDOTHERMY

["JUAN CASADO GIMENEZ" <casado.j@carburos.com>]

Dear all,
Extinction of big reptiles including most dinosaurs 65 million years ago may
be related of endothermy of at least some of them.
Endothermic animals have a much faster metabolism than ectothermic ones, so
that they need much more food in order to sustain their lives. Bigger
animals also need more food for obvious reasons. Whatever the primary cause
of the extinction was (I rather believe in the meteorite hypothesis), it
most probably passed through an interruption of food chains with the
consequent starvation of animals. Only some small size endothermic animals,
such as mammals and early birds were able to survive, while some big size
exothermic ones such as crocodiles were also survivors due to their
specially low metabolic rate and food needs, and probably to their ability
to eat dead animals (and there were a lot of them for some time). According
to this idea the starvation was around from a few months to about one year.
So extinction appears as another evidence supporting endothermy of at least
some dinosaurs.