> birds are the descendants of Dinosaurs
More like their grand-daddy was a cousin to the dinosaur's grand-daddy.
We love the big dinosaurs because their bones look great in museums. But that's like, 1,000 years from now, they only remember Abe Lincoln and Eric Clapton. In any time and place there's millions of critters, mostly forgotten.
My school is on a sandbar so we don't have T-Rex or Brontosaurus bones in Geology Hall. But at some time the state was over-run by very ordinary medium-small dinosaurs almost exactly the size (100-200 pounds) of the damm deer which now eat our gardens and jump in front of our cars. A local artist mocked one up life-size in fiberglass. Looking at it, I realized that warm-blood cool-blood long-tail short-tail... it hardly matters. These ARE the creatures which browse the lower leaves off shrubs and reproduce like rabbits.
And yet it does matter. Some flood or meteor left the earth a bit too cool for hairless creatures without thermostats. Some of those millions of forgotten creatures had scales that grew different, like hair or feathers, and also thermostat control beyond just moving to a warm rock or cool pond. These are not necessarily "improvements": hair collects parasites and mold, hot-blood means you can't sleep-through the cool season, you gotta run around finding food to keep warm. But in the right situation, there may be advantages. Indeed T-Rex may have run more stable temperature than some of the older dinos, been able to hunt in cooler weather when the others were slow or dormant.
Anyway: while the early dinosaurs were probably scales and poor temperature control, dense filament-like coverings of scale material and thermoregulation were around, like musical talent in the current human population.
One classic way to trace family lines is hip structure. There's several ways to jam legs on the end of the spine, and hip-bones tend to be large and thus survive long burial for eventual study. There's much more modern ways now, but when I was a boy the dinosaurs were sorted by "bird-like" and "lizard" hip plans. Yet modern birds do not seem to trace directly from plans for the last dinosaurs, but were probably doing their own thing long-long before T-Rex.
They've recently found some mud with impressions of a lizard-like critter with pin-feathers and extended finger-bone. Not clear that it could fly; maybe it could run around in cool weather and grab prey. Or pry dino-eggs out of nest-holes. There must have been a lot of different critters to exploit many possible ways of living. Birds seem to be fragile and stupid, yet somehow they (and shrew-like Mammals, g-g-g-g-grandfathers to our own bodies) probably lived with the earliest dinosaurs and somehow evaded whatever happened to the dinos.
Topic: The new neighbors (Read 13770 times)