Trawdenia's Fossilized Brain

Publication Info:

Transcript:

Abigail M. Caron et al, Neural tissues and chondrostean traits in a Carboniferous actinopterygian, Proceedings of the National Academy of Sciences (2026). DOI: 10.1073/pnas.2610438123

When we talk about soft tissue, it's usually because paleontologists have found dinosaur skin or feathers, but in this insanely special case paleontologists have found a perfectly preserved, fossilized brain! Trawdenia was a small fish that lived in our world's oceans 300 million years ago, and now its brain may be changing everything we know about life on our planet!

Episode 303

Notes:

This is a fossilized brain and it's 300 million years old. Here's your most recent paleontology news almost daily or whenever I get around to it. So yeah, we talk about fossilized soft tissue from time to time. Stuff like skin and feathers and from dinosaurs or more modern with a few exceptions and it's super cool. It's super important. It lets us understand the animals that paleontologists are researching that much better. But this is on a whole different level because 300 million years ago life and evolution were experimenting a lot. These are the origins of most of the major groups of life we see on Earth today. the vertebrate life and it matters 'cause it helps us get a better understanding of how all the life on our planet formed including us. This is Trawdenia, a minnow-sized fish and 319 million years ago this individual died and was covered in sediment so fine that not only did it preserve its bones, but it preserved its soft tissue including its actual brain. To the point where the inner and outer membranes of the neural tissue are preserved along with the structures that help move cerebrospinal fluid through the brain. Yeah, especially in the case of fish, the brain cases preserve pretty well, but that doesn't necessarily mean they knew the size and shape of the brain. And it turns out the size and shape of the brain case mimics the brain pretty well, at least in these relatively early actinopterygians. Not only giving some new clues about the evolution of brains in vertebrates on our planet, but also letting paleontologists know that the new imaging techniques used to obtain this data may be able to get similar data from fossils that haven't been examined quite as closely yet. As usual, if you want more information, here's the source.