Jingmai O'Connor

In lakes, you have no scavengers and you have guaranteed burial. And so this leads to really exceptional preservation. And these fossils from China, the most common soft tissue they preserve are feathers.

In lakes, you have no scavengers and you have guaranteed burial. And so this leads to really exceptional preservation. And these fossils from China, the most common soft tissue they preserve are feathers.

In lakes, you have no scavengers and you have guaranteed burial. And so this leads to really exceptional preservation. And these fossils from China, the most common soft tissue they preserve are feathers.

But when feathers have pigment inside them, they have these pigment-bearing mono-organelles called melanosomes. They're in our eyes, they're in the ink sacs of squid, they're everywhere, right? So these organelles are extremely decay-resistant. So the keratin matrix of the feather is gone, but these pigment-containing mono-organelles get fossilized very easily.

But when feathers have pigment inside them, they have these pigment-bearing mono-organelles called melanosomes. They're in our eyes, they're in the ink sacs of squid, they're everywhere, right? So these organelles are extremely decay-resistant. So the keratin matrix of the feather is gone, but these pigment-containing mono-organelles get fossilized very easily.

But when feathers have pigment inside them, they have these pigment-bearing mono-organelles called melanosomes. They're in our eyes, they're in the ink sacs of squid, they're everywhere, right? So these organelles are extremely decay-resistant. So the keratin matrix of the feather is gone, but these pigment-containing mono-organelles get fossilized very easily.

And that's why we can now tell you, sort of, what color some feathered dinosaurs were by looking at these melanosomes.

And that's why we can now tell you, sort of, what color some feathered dinosaurs were by looking at these melanosomes.

And that's why we can now tell you, sort of, what color some feathered dinosaurs were by looking at these melanosomes.

So it's very likely that only smaller dinosaurs were feathered and theropods in particular. So basically, we know that the earliest dinosaur was a small, warm-blooded animal. And the earliest feathers evolved for the same reason as fur in mammals, in order to help with thermoregulation in a warm-blooded animal, right?

So it's very likely that only smaller dinosaurs were feathered and theropods in particular. So basically, we know that the earliest dinosaur was a small, warm-blooded animal. And the earliest feathers evolved for the same reason as fur in mammals, in order to help with thermoregulation in a warm-blooded animal, right?

So it's very likely that only smaller dinosaurs were feathered and theropods in particular. So basically, we know that the earliest dinosaur was a small, warm-blooded animal. And the earliest feathers evolved for the same reason as fur in mammals, in order to help with thermoregulation in a warm-blooded animal, right?

If you are small and you're warm-blooded and you don't have something to keep your body heat in, you're just shedding the body heat off your skin, it would take a ton of energy to maintain a high body temperature. So you need insulation.

If you are small and you're warm-blooded and you don't have something to keep your body heat in, you're just shedding the body heat off your skin, it would take a ton of energy to maintain a high body temperature. So you need insulation.

If you are small and you're warm-blooded and you don't have something to keep your body heat in, you're just shedding the body heat off your skin, it would take a ton of energy to maintain a high body temperature. So you need insulation.

Is that right? So not all dinosaurs would have been feathered. And also when we talk about feathers and dinosaurs, we're talking about these early evolutionary stages and feathers. When we think about a feather in the modern sense, that is restricted to a very narrow group of theropod dinosaurs. In fact, only three... Non-bird groups of dinosaurs had those types of feathers.

Is that right? So not all dinosaurs would have been feathered. And also when we talk about feathers and dinosaurs, we're talking about these early evolutionary stages and feathers. When we think about a feather in the modern sense, that is restricted to a very narrow group of theropod dinosaurs. In fact, only three... Non-bird groups of dinosaurs had those types of feathers.

Is that right? So not all dinosaurs would have been feathered. And also when we talk about feathers and dinosaurs, we're talking about these early evolutionary stages and feathers. When we think about a feather in the modern sense, that is restricted to a very narrow group of theropod dinosaurs. In fact, only three... Non-bird groups of dinosaurs had those types of feathers.

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.

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.