Off Topic: More dinosaurs had feathers than you may think

Look, y’all remember that I love PBS Eons, right? We did a whole post about it. So I wanted to make sure to point you to this video they did about dinosaurs and feathers. The reason I wanted to point you to that video is because it’s a nice primer on the subject of feathered non-avian dinosaurs. Basically, we still have this idea in our media (such as, say, the Jurassic World franchise) that most dinosaurs were scaly, reptilian creatures like their crocodillian cousins in the archosauria.

But we’ve been seeing more and more evidence for feathers in the dinosauria, to the point where we’re finding feathered ornithischians dating back to around 150 million years ago. This is an enormous find for a lot of reasons, including the fact that it establishes that feathers are not linked to theropods or even to the Saurischia, but rather appeared in both lineages of dinosaurs. In many species, such as Psittacosaurus, we find scales and feather-like quills in the same species.

The Ancient Quills

What this means is not that all dinosaurs were as brightly colored and thoroughly feathered as modern birds, but rather that feathers of various types were potentially present in any member of the dinosaur lineage and derive from their earliest ancestors. The argument is not that, as an example, an Argentinosaurus was covered in head to toe feathers — as we see today in large mammals like elephants and whales being sparse or even devoid of hair, the biggest dinosaurs may well have lived in biomes where full body feathers or quills simply wouldn’t be useful to them.

But they may have retained a few display patches, and animals like Kulindadromeus zabaikalicus provide us with evidence that feathers are an ancient and widespread part of the dinosaur lineage. Furthermore, since we  have evidence for feather-like structures on the related but non-dinosaurian pterosaurs, we now have evidence that the entirety of the Avemetatarsalia (a clade consisting of all Archosaurs more closely related to birds than crocodiles, including both dinosaurs and pterosaurs) were feathered, which would mean that feathers derive from an even more basal archosaurian ancestor of both dinosaus and pterosaurs. If the common ancestor of dinosaurs (including all modern birds) and pterosaurs had feathers, than literally any dinosaur could well have had them.

These Feathery Beasts

With feathered ceratopsians and other ornithischians being discovered, it would seem likely that feathers either convergently evolves at least twice or that the common ancestor of all dinosaurs had feathers. It’s an amazing find, and it makes me extremely excited and hopeful that we’ll find more dinosaur fossils with integument somewhat preserved so we can peel back more of the living animals, preserved in the rock. Feathered duckbills, feathered theropods, practically any dinosaur you can name, you can now imagine it with some version of feathers.

More research is of course needed, and again, this doesn’t mean that every dinosaur was covered in fuzz or pinions or long flight feathers or even quills. But it does mean that feathers go way, way back to perhaps even the common ancestors who predate dinosaurs themselves, and that we can now consider whether a dinosaur had feathers or not for basically any dinosaur you can think of, from the mighty sauropods towering over six stories tall to the smallest plant eater on the edge of an ancient riverbank.

Feathers were very much a dinosaur trait, as much as hair is for mammals today.