Creature of the Week #5: Euparkeria

Galvasean

At a glance Euparkeria (the name literally translated means "Parker's good animal") doesn't look very special. A small, but speedy predator less than a meter in lenght, it was about the size of a medium-large lizard and would have looked similar to one too as it roamed the early Triassic South African landscape.


So why so special? Euparkeria lived not long after the Permian extinction which occured some 250 million years ago and had a speciality which had not featured in any (known) reptile species before - bipedalism. While it would have spent most of it's time on all fours, it's back legs were somewhat longer than the front ones, which would have allowed it to dash on it's two back legs over short distances, either to pursue prey or evade it's own predators (as it was far from the largest carivore in it's habitat). While not a true biped, it certainly represents a sort of transitional form between quadrapedal (four legged) and bipedal (two legged) locomotion in reptiles.
Euparkeria also had teeth on the inside of it's palete, a very common feature among earlier reptiles, but significantly less common in later ones. This suggests that it was a fairly primitive form of reptile. It also had a row of small bony plates along it's back, which would have aided in defense. Curiously, it also posessed a prominent thumb claw not that unlike what is seen in later prosauropod dinosaurs. It's function was once considered as a defensive weapon, but it seems a bit redundant when you consider how close the little Euparkeria would have to be to it's predators in order to use it. It would surely be too late to be of any real use once in jabbing range. This has led some to speculate that the thumb may have been used for digging something, possibly for insects or perhaps even roots and tubors. Of course, the latter would suggest that Euparkeria was omnivorous as opposed to purely carnivorous, which might make sense considering it's relation to the dinosaurs of the late Triassic (which came in both meat eating and plant eating varieties).
There was once a time when Euparkeria was considered to be the ancestor of the dinosaurs, but this is no longer considered likely. However, it would not have bee too far off, a close relative of the creatues which did, so to speak.

Where have I seen you before?
Euparkeria featured in the final episode of the BBC's hit series Walking With Monsters.

https://www.youtube.com/watch?v=95ia1xUm7gk

Jako8

Very Interesting.

[It] would have periodically shed its teeth in order to keep them sharp

There's another bit of info I found.

Source: http://www.absoluteastronomy.com/topics/Euparkeria