FEED ME, SEYMOURIA: PERMIAN SHENANIGANS

Seymouria baylorensis

Feed me, Seymouria!" No, not the man-eating plant from Little Shop of Horrors — though life in the Early Permian had its fair share of drama. 

Meet Seymouria baylorensis, an evolutionary troublemaker that spent decades confusing us by looking suspiciously reptilian while secretly being an amphibian.

Named for Seymour, Texas, where its fossils were first discovered in the famous Permian red beds of Baylor County, Seymouria baylorensis lived roughly 280 million years ago. 

At that time, North America sat much closer to the equator, and the landscape was a seasonally dry floodplain threaded with rivers and ponds. Dragonflies zipped through the warm air, sail-backed predators such as Dimetrodon prowled the landscape, and amphibians of every shape and size made the most of a world still finding its footing after life first ventured onto land.

At around 60 centimetres (two feet) in length, Seymouria was no giant, but it had presence. With sturdy limbs, a robust body, and well-developed vertebrae, it looked every bit like an early reptile striding confidently across the Permian countryside. For years, scientists classified it as exactly that — one of the first true reptiles.

Plot twist: it wasn't.

The answer came, as it so often does in paleontology, from the youngsters. Juvenile Seymouria fossils revealed evidence of aquatic beginnings, including features associated with external gills. While the adults may have spent much of their lives exploring the drier side of the floodplain, their early life stages still depended on water.

Seymouria baylorensis

Rather than being an early reptile, Seymouria turned out to be a close amphibian relative experimenting with a more terrestrial lifestyle. It was an evolutionary in-betweener — an amphibian dressed in reptilian clothing, testing out what life away from the pond might have to offer.

I have a soft spot for these wonderfully awkward creatures. We often imagine evolution as a neat procession: one group gives rise to another in a tidy, orderly fashion. The fossil record cheerfully disagrees. It is filled with experiments, side branches, doors that lead off to nowhere and organisms trying on new adaptations like last season's fashions.

Seymouria was one of those experiments.

Nature is less interested in our categories than we are. Evolution tinkers. It improvises. It throws ideas at the wall and occasionally comes up with something extraordinary.

So, should some little darling ask whether Seymouria was an amphibian or a reptile, you can smile knowingly and say, "Well, that's where things get interesting." 

Because 280 million years ago, on the sun-baked floodplains of what is now Texas, Seymouria baylorensis was busy blurring the lines.

And let's be honest, any fossil that gives people an excuse to mentally picture a two-foot-long Permian amphibian belting show tunes while trundling across a Texas floodplain is a win in my books. 

Evolution isn't always neat and tidy. Sometimes it's just 280 million years of Permian shenanigans.