TheBicyclingGuitarist wrote:
Birds almost certainly evolved from dinosaurs, but technically dinosaurs do not fly by the definition of what a dinosaur is. So the birds of today are not dinosaurs though they are their descendants. Even pterodactyls are not dinosaurs but are flying reptiles. Similarly ichthyosaurs are not dinosaurs but are marine reptiles. I know when I got bags of toy plastic dinosaurs they often included flying reptiles and marine reptiles that were contemporaries of dinosaurs, but they aren't correctly called dinosaurs even though the label on the toy bag implied that. What's in a name, huh Bill (Shakespeare)?
Those bags of plastic dinosaurs we all used to play with ALSO included demitridon (along with the dinos, pterosaurs, and itchyosaurs,and plesiosaurs).
Those were those big vaguely lizardlike critters with big sails on their backs. Demitridon was not only not a dinosaur, it wasnt even contemporary with the dinosaurs! Atleast those other things were all contemporary with each other and with dinos. Demitridon lived in the Permian (100 million years prior to the dinosaurs) and was closer to us than to the dinosaurs! The sail was a kinda solar panel to power the creature by raising its blood temperature.
Its descendants dispenced with the solar panel and devised internal organs for maintaining high body temperature. These later were creatures called the Therapsids. Often got as big as cows they dominated the planet for about 50 million years. But they got clobbered by the Permian extinction event, and then clobbered again by the rise of the dinosaurs.Latersitll. The only survivors of this linneage were ones highly specialized for minaturization, and for hunting bugs at night ( maintaining high body temperature at a small size at night requires insulation)- hense the invention of fur. So when the dinosaurs rose to dominate the planet the first mammals also appeared- but only as tiny nocternal shrewlike creatures in the underbrush. A little later- a group of carnivorous dinosaurs also became highly specialized for chasing bugs, and for minaturization, and also evolved insulation. This time it was overlappiing reptile scales (feathers) that dig the trick. As an afterthought feathers also turned out to be a good airfoil.
So mammals were originally therapsids (mammal-like reptiles) highly specialized for minaturization. Likewise birds were originally minaturized and insulated versions of T-Rex.
03 Aug 2014, 12:18 pm
It's never too late for payback. 
