There were some really dinosaur-like crocodiles, too. Shuvosaurus and poposaurus, for example.
But for whatever reason, they decided to define dinosaurs to exclude pterosaurs and crocodiles; they’re the closest relatives of dinosaurs but are still relatives and not actual dinos.
Biologists like using clades to describe things, these days. A clade is all the descendants of some common ancestor on an evolutionary tree.
That particularly means that they disfavor terms that refer to almost all of the descendants of something, but exclude one branch because reasons. Which does make sense, right? “Paraphyletic groups” are like saying “The Vanderbilt family is all the descendants of Cornelius Vanderbilt… except for Anderson Cooper and his descendants”.
So the technical definition of dinosaur, right now, is anything descended from the most recent common ancestor of triceratops, diplodocus, and the house sparrow.
Crocodiles are clearly dinosaurs while birds have diverged so much they can only reasonably be called descendents of dinosaurs and nothing more. You can look at them and tell.
Various extinct crocodiles like Poposaurus were initially confused with dinosaurs due to some convergent evolution.
But modern crocs lack a lot of distinctive dinosaur traits, like having their legs directly under them.
More to the point, though, look at this fossil of caihong juji and tell me it doesn’t look more like a bird than a crocodile. Through a minor geologic miracle, the feathers were even preserved! It even seems like they were probably quite colorful.
Look at t-rex’s bird-like hips and feet. Compare them to the sprawling legs of a croc. Posture- wise, it looks way more like an ostrich than a croc.
And yeah, T-rex was almost certainly scaly, but evolved from feathered dinosaurs. Other earlier species in tyrannosauroidea like yutyrannus huali and dilong paradoxus had feathers.
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There were some really dinosaur-like crocodiles, too. Shuvosaurus and poposaurus, for example.
But for whatever reason, they decided to define dinosaurs to exclude pterosaurs and crocodiles; they’re the closest relatives of dinosaurs but are still relatives and not actual dinos.
Birds, though, are legit dinosaurs.
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Biologists like using clades to describe things, these days. A clade is all the descendants of some common ancestor on an evolutionary tree.
That particularly means that they disfavor terms that refer to almost all of the descendants of something, but exclude one branch because reasons. Which does make sense, right? “Paraphyletic groups” are like saying “The Vanderbilt family is all the descendants of Cornelius Vanderbilt… except for Anderson Cooper and his descendants”.
So the technical definition of dinosaur, right now, is anything descended from the most recent common ancestor of triceratops, diplodocus, and the house sparrow.
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I mean, that is not how it works. Also, crocodiles don’t look like any dinosaur I can think of?
Classification is based on genetic relationships, not looks, so bats aren’t birds, for example.
Based on what?
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Various extinct crocodiles like Poposaurus were initially confused with dinosaurs due to some convergent evolution.
But modern crocs lack a lot of distinctive dinosaur traits, like having their legs directly under them.
More to the point, though, look at this fossil of caihong juji and tell me it doesn’t look more like a bird than a crocodile. Through a minor geologic miracle, the feathers were even preserved! It even seems like they were probably quite colorful.
Crocodiles are vastly different in appearance to any dinosaur that has been discovered
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Look at t-rex’s bird-like hips and feet. Compare them to the sprawling legs of a croc. Posture- wise, it looks way more like an ostrich than a croc.
And yeah, T-rex was almost certainly scaly, but evolved from feathered dinosaurs. Other earlier species in tyrannosauroidea like yutyrannus huali and dilong paradoxus had feathers.
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Not really. even for dinosaurs that are famous for being crocodile-like, its quite hard to see the resemblance
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