#platyhystrix

Today's animal of the day is Platyhystrix rugosus!

Image credit: cisiopurple on DeviantArt

This adorable little (relatively speaking) amphibian lived from the late Carboniferous period to the early Permian in what is now the states of Utah, Colorado, Arizona, New Mexico, Kansas, and Texas. Its name means "flat porcupine" due to the series of tall neural spines that ran down its back, which in life supported a little sail similar to those of the mammal-like synapsids Dimetrodon and Edaphosaurus. This is what's known as convergent evolution, which is when different groups of animals evolve similar traits independently of each other.

Edaphosaurus with Platyhystrix (image credit: Dmitry Bogdanov)

While these three creatures may have evolved their sails independently, the thing they all have in common is that paleontologists aren't quite sure what their sails were for. One theory is that they were used for display. These sails may have been brightly colored and could've been used by males to attract females or intimidate rivals. Another theory is that they could've helped with thermoregulation, where the cold-blooded animals pumped cool blood into their sails, which had thinner skin that allowed the sun to more easily warm it up, before pumping it back down to the rest of their bodies. Then, to cool down, they could lie in the shade and pump hot blood into their sail, where the thin skin could allow the excess heat to more easily dissipate. In the case of Platyhystrix specifically, the sail could've helped stiffen its vertebral column to help this amphibian better adapt to a more terrestrial lifestyle. Since we don't have any living specimens to study, paleontologists will never know for certain. Personally, I think display is the best theory, but I also think that the sails could've been used for multiple purposes.

Image credit: Darren Pepper (prehistoric-wildlife.com)

While Platyhystric was definitely way bigger than any amphibians we have alive today, around 3.3 ft long, it was still tiny compared to the other creatures it shared its habitat with. It had a stout body with short, stubby legs, which would've made it hard for this adorable little critter to run away from larger predators like the aforementioned Dimetrodon as well as the semi-aquatic Eryops, which could've ambushed Platyhystrix when it came to the water to lay its eggs. Luckily, in addition to its sail, which probably made it a little harder to swallow it up whole, Platyhystrix also had thick plates on its back that served as armor.

Image credit: Charlie Worthington

The environment that Platyhystrix lived in was semi-arid, but still somewhat humid, with infrequent patches of conifer trees and ferns scattered about. During the rainy season, numerous rivers would flow through this region of Pangaea (which had not yet split up). These would've provided a place for Platyhystrix to return to lay its eggs, and were also home to many other types of prehistoric amphibians as well as numerous species of fish. It is believed, based on the size and shape of its teeth, that Platyhystrix would've fed on smaller creatures, such as lizards, insects, and even smaller species of amphibians.

Image credit: Gabriel N. U.

here's today's #Paleostream sketches!!! today we drew Gaiasia, Pelagornis, Platyhystrix, and Astrodon

Brutus, the dumb of ass