4 ms·

Yes, birds are feathered theropod dinosaurs.

jonny_eh 4y ago
If I'm not mistaken, we're still not sure how many species of dinosaurs were feathered. But it's likely at least many (all?) theropods (e.g. velociraptor, T-Rex) were.
- webwielder2 4y ago
  The new dinosaurs documentary on Apple TV+ portrays velociraptor as feathered, but T-Rex still looks like an old school "terrible lizard"
  - adrian_b 4y ago
    There are chances that this might be correct. It is likely that a dinosaur of the size of T-Rex would overheat if covered with feathers. It is still possible that T-Rex had feathers when very young and then lost them when growing large enough.
    - jonny_eh 4y ago
      Or had them ornamentally, like we (well, not me) have hair on the tops of our heads.
- adrian_b 4y ago
  There was a paper published this year about feathers identified in a fossil pterosaur. Previously it was believed that the pterosaurs were covered by some kind of hair (i.e. unbranched), not by feathers. (Most depictions of pterosaurs in movies are probably wrong, because they do not show even the hair, whose existence has been known for many years, much less that the hair was in fact some kind of bird-like down, which is a very recent discovery.) The pterosaurs are not dinosaurs, but they are related to dinosaurs, probably closer to them than to crocodiles. If it is true that the pterosaurs also had feathers, it is unlikely that feathers have evolved twice, as they are much more complex than hair. In that case, the ancestor of all dinosaurs already had feathers. We know that there are many kinds of large dinosaurs, especially most of the large herbivores, which did not have feathers. If the common ancestor had feathers, then all the large featherless dinosaurs have lost their feathers, like the elephants and the rhinoceroses, which have lost their hair, presumably for improved cooling.
  - mistrial9 4y ago
    not a specialist here, my first reaction is .. feathers are quite insulating.. so, not good for hot climates. Flying means that the creature is in wind all day, cool climate or not.. So put that together, I suspect that lots of the large reptiles just had to be in warm climates, and did not use insulating features each day. useful and interesting to see that everyone here is saying "yes" to the birds question
    - jonny_eh 4y ago
      Calling dinosaurs reptiles is fairly wrong at this point, since a dinosaurs were warm blooded, and being cold blooded is a defining characteristic of being a reptile. This does raise the question if it's worth considering birds and dinosaurs as different groups.
      - mistrial9 4y ago
        > dinosaurs were warm blooded hm? pointers please.. if they lay eggs then that is "reptile" no? I don't claim to know, I am asking..
        jonny_eh 4y ago
        https://earth.yale.edu/news/were-dinosaurs-warm-blooded-their-eggshells-say-yes https://earth.yale.edu/news/were-dinosaurs-warm-blooded-thei... Birds lay eggs and are definitely warm blooded. Not to mention the odd mammal that lays eggs like the platypus.
        SAI_Peregrinus 4y ago
        Birds lay eggs and are definitely not reptiles.

If I'm not mistaken, we're still not sure how many species of dinosaurs were feathered. But it's likely at least many (all?) theropods (e.g. velociraptor, T-Rex) were.

webwielder2 4y ago
The new dinosaurs documentary on Apple TV+ portrays velociraptor as feathered, but T-Rex still looks like an old school "terrible lizard"
- adrian_b 4y ago
  There are chances that this might be correct. It is likely that a dinosaur of the size of T-Rex would overheat if covered with feathers. It is still possible that T-Rex had feathers when very young and then lost them when growing large enough.
  - jonny_eh 4y ago
    Or had them ornamentally, like we (well, not me) have hair on the tops of our heads.
adrian_b 4y ago
There was a paper published this year about feathers identified in a fossil pterosaur. Previously it was believed that the pterosaurs were covered by some kind of hair (i.e. unbranched), not by feathers. (Most depictions of pterosaurs in movies are probably wrong, because they do not show even the hair, whose existence has been known for many years, much less that the hair was in fact some kind of bird-like down, which is a very recent discovery.) The pterosaurs are not dinosaurs, but they are related to dinosaurs, probably closer to them than to crocodiles. If it is true that the pterosaurs also had feathers, it is unlikely that feathers have evolved twice, as they are much more complex than hair. In that case, the ancestor of all dinosaurs already had feathers. We know that there are many kinds of large dinosaurs, especially most of the large herbivores, which did not have feathers. If the common ancestor had feathers, then all the large featherless dinosaurs have lost their feathers, like the elephants and the rhinoceroses, which have lost their hair, presumably for improved cooling.
- mistrial9 4y ago
  not a specialist here, my first reaction is .. feathers are quite insulating.. so, not good for hot climates. Flying means that the creature is in wind all day, cool climate or not.. So put that together, I suspect that lots of the large reptiles just had to be in warm climates, and did not use insulating features each day. useful and interesting to see that everyone here is saying "yes" to the birds question
  - jonny_eh 4y ago
    Calling dinosaurs reptiles is fairly wrong at this point, since a dinosaurs were warm blooded, and being cold blooded is a defining characteristic of being a reptile. This does raise the question if it's worth considering birds and dinosaurs as different groups.
    - mistrial9 4y ago
      > dinosaurs were warm blooded hm? pointers please.. if they lay eggs then that is "reptile" no? I don't claim to know, I am asking..
      - jonny_eh 4y ago
        https://earth.yale.edu/news/were-dinosaurs-warm-blooded-their-eggshells-say-yes https://earth.yale.edu/news/were-dinosaurs-warm-blooded-thei... Birds lay eggs and are definitely warm blooded. Not to mention the odd mammal that lays eggs like the platypus.
      - SAI_Peregrinus 4y ago
        Birds lay eggs and are definitely not reptiles.