Like, I'm aware of there being exceptions like Penguins, Ostriches, and Bats. But in general, why is there such a distinct land/air split between mammals and birds? Why don't mammals share the ground with ecosystems of plant- and meat-eating walking birds? Why didn't we get birds that evolved to slither like snakes, or tunnel like rodents? Why isn't it (land+sky) all just mammals, where we'd have parrot- and vulture-like bats that don't lay eggs? If we started the simulation again, might things like this evolve?

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[–] 1 point 1 year ago (6 children)

Most birds can fly because they are an offshoot of one group of dinosaurs (avian dinosaurs) that survived the last great extinction when their non-flying non-avian dinosaur relatives did not.

Is this accurate? I was always under the impression that birds evolved from "land dinosaurs".

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  • [–] 6 points 1 year ago (1 child)

    Is this accurate? I was always under the impression that birds evolved from "land dinosaurs".

    Well, yes, where else would the flying dinosaurs come from?

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  • [–] 1 point 1 year ago (2 children)

    The first flying dinosaur evolved from a non-flying dinosaur. The word for a "flying dinosaur" is "bird". (Sort of. Bird isn't a scientific term, arguably crown-group birds don't include the first flying dinosaurs. But in that case the first bird evolved from a flying dinosaur which evolved from non-flying dinosaurs, so it still works.)

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  • [–] 2 points 1 year ago (1 child)

    I guess I'm forgetting that there were several different dinosaur periods spanning hundreds of millions of years. My mind defaults to the jurassic period being the only one.

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  • [–] 3 points 1 year ago

    Most of the more famous dinosaurs were actually from the cretaceous period. T. rex, stegosaurus, velociraptor (and the deinonychus and utahraptor that the movie Jurassic Park's depiction of "velociraptor" was based on), triceratops, ankylosaurus. Pretty much all the non-avian dinosaurs the average person could name, other than sauropods like brachiosaurus, lived in the cretaceous. Some of those I named did admittedly first evolve in the jurassic, but most are most well-known in the cretaceous.

    Though fwiw, birds did first evolve in the jurassic.

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  • [–] 1 point 1 year ago*

    I guess that depends on your definition of what a bird is and on where you place the transition between bird-like dinosaurs and birds. Like Archaeopteryx is one of the species in that weird kinda dinosaur kinda bird phase.

    Edit: Genus not species, sorry. I hate taxonomy so much...

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