Jingmai O'Connor

So it's a little bit semantics. When you say feather, do you mean even the earliest evolutionary stage of a feather all the way up to the very complex feathers we see today? Or do we restrict that term? That's why sometimes we'll call those primitive feathers proto-feathers. And then we'll refer to the modern, very complex feather as a panaceous feather.

Protofeathers basically just look like hair. They're very simple monofilamentous structures, right?

Protofeathers basically just look like hair. They're very simple monofilamentous structures, right?

Protofeathers basically just look like hair. They're very simple monofilamentous structures, right?

Developmentally, totally different than hair. But superficially, that's what they look like. And superficially, they probably both evolve for a similar purpose. Got it. Why are they so different? So basically the difference between a feather, a proto feather, which looks like a hair and hair is in their development.

Developmentally, totally different than hair. But superficially, that's what they look like. And superficially, they probably both evolve for a similar purpose. Got it. Why are they so different? So basically the difference between a feather, a proto feather, which looks like a hair and hair is in their development.

Developmentally, totally different than hair. But superficially, that's what they look like. And superficially, they probably both evolve for a similar purpose. Got it. Why are they so different? So basically the difference between a feather, a proto feather, which looks like a hair and hair is in their development.

Like feathers and hair, one of them starts by kind of folding inwards in the skin and then forming the follicle. And the other forms first as a projection out of the dermis and then becomes this complex structure. Yeah. Also feathers are the only keratinous structures that don't grow continuously throughout life.

Like feathers and hair, one of them starts by kind of folding inwards in the skin and then forming the follicle. And the other forms first as a projection out of the dermis and then becomes this complex structure. Yeah. Also feathers are the only keratinous structures that don't grow continuously throughout life.

Like feathers and hair, one of them starts by kind of folding inwards in the skin and then forming the follicle. And the other forms first as a projection out of the dermis and then becomes this complex structure. Yeah. Also feathers are the only keratinous structures that don't grow continuously throughout life.

When that actually evolved, we're not sure because modern feathers are so complex that they can't keep growing, right? They have very distinct distal end and proximal end that are morphologically, like the shape of them is very different. Whereas a hair or a beak or fingernails are all just the same, so they can just continuously grow.

When that actually evolved, we're not sure because modern feathers are so complex that they can't keep growing, right? They have very distinct distal end and proximal end that are morphologically, like the shape of them is very different. Whereas a hair or a beak or fingernails are all just the same, so they can just continuously grow.

When that actually evolved, we're not sure because modern feathers are so complex that they can't keep growing, right? They have very distinct distal end and proximal end that are morphologically, like the shape of them is very different. Whereas a hair or a beak or fingernails are all just the same, so they can just continuously grow.

Birds are dinosaurs.

Birds are dinosaurs.

Birds are dinosaurs.

Birds are one group of dinosaurs. And I think when we think of a dinosaur, we think of Triceratops or Stegosaurus. And these are dinosaurs that are not closely related to birds. Like, for example, if you looked at an artist's reconstruction of something like Velociraptor or Microraptor, a small feathered theropod dinosaur, very closely related to birds.

Birds are one group of dinosaurs. And I think when we think of a dinosaur, we think of Triceratops or Stegosaurus. And these are dinosaurs that are not closely related to birds. Like, for example, if you looked at an artist's reconstruction of something like Velociraptor or Microraptor, a small feathered theropod dinosaur, very closely related to birds.

Birds are one group of dinosaurs. And I think when we think of a dinosaur, we think of Triceratops or Stegosaurus. And these are dinosaurs that are not closely related to birds. Like, for example, if you looked at an artist's reconstruction of something like Velociraptor or Microraptor, a small feathered theropod dinosaur, very closely related to birds.

you would see that it pretty much looks the same as a bird. I mean, there's some structural, like, you know, differences in proportions and some, you know, minor differences in the skeleton. But in terms of the plumage, like the soft tissues covering the body, it would have looked very, very bird-like.