This is a chicken. Its long-ago ancestors were the dinosaurs we now depict as cheap plastic children’s toys in a futile attempt to downplay their ferociousness. The chicken traded those gnashing teeth for a beak, but it still has its forebears’ claws for ripping and disemboweling.
Also for dust-bathing.
I guess what I’m trying to say is: Whole Foods, your terminology is incorrect.
Baby panda bears have paws. Dinosaurs do not.
Watch me disembowel this hay.
We know a little bit about how dinosaurs probably looked: we’re learning that a lot of them had feathers, and even beginning to be able to figure out what patterns might have been on their plumage. But there’s a lot we don’t know; we may never know for sure.
In evolutionary biology, when you don’t know something about an extinct species—what kind of nest it built, or what sounds it made, or how many babies it had—you look at the species that evolved from it. You infer that it probably was similar to at least some of its descendent lineages. For dinosaurs, then, we would look at birds.
I remember, as a kid, thoughtfully coloring my dinosaur coloring books and paper-mache dinosaur scultures in shades of green and brown. I knew about camouflage, and I was sure that this earthy color palette must have been the one favored by these animals. Silly me.
When you’re little, you play with toy dinosaurs all bright red or blue or painted spotted with many colors. You fill coloring books with purple velociraptors taking down plaid apatosaurs. Then you get older and learn about camouflage; and you watch nature documentaries of brown felines taking down brown gazelles in tall brown grass; and—zebras notwithstanding—you start to think that probably dinosaurs weren’t plaid after all.
Well, buck up! They—at least some of them—probably did look really awesome.
Laughing Gulls in flight
Everything about avian morphology has been shaped by the requirements of flight. Flight is hard. Animals are heavy, being largely composed of water, and air is not dense; you have to work hard to generate any force by manipulating air. The problem for any flying animal is to be light yet powerful – and to still be a viable animal, capable of eating and storing energy and making babies. A hypothetical weak but extremely light animal – think an air-jellyfish – might be able to fly, but would probably starve. While the ocean is filled with floating particles that real jellyfish can catch simply by passively floating, the air is not so bountiful. (You could argue that web spiders filter-feed in air, but… all right, I don’t know if air-jellyfish are impossible. I think we’re getting off-topic here.)
Air-jellyfish wafting through a pink sunset.
(Or, Northeast Pacific sea nettle in an artistically-lit tank at the Shedd Aquarium.)
In any case, birds didn’t start out as light, thin, filmy creatures. They started out as small raptor-y dinosaurs. Natural selection acts only on the traits that are present: massive change to the shape of an organism is hard. (Not impossible! But comparatively rarer.) Birds started out with backbones, four limbs, a head, two eyes, etc., and they evolved flight from that initial morphology.
But how do you make a dinosaur that can fly? Dinosaurs are strong, yes, but they are heavy. Bones are heavy; muscle is heavy; fat is heavy; teeth are heavy.
Tough Little Birds 