Sunday, August 25, 2019

Adratiklit: Beast of the Week

This week we will be looking at a newly discovered dinosaur that also breaks a few records!  Let's check out Adratiklit boulahfa!

Adratiklit was a plant-eating dinosaur that lived in what is now Morocco, in Northern Africa, during the middle Jurassic period, about 168 million years ago.  The genus name translates from Berber to "Mountain Lizard" and the species name is for Boulahfa, the part of Morocco where it was found.  From snout to tail it could have measured roughly twenty feet long, but this is only based on fragmentary remains.

Life reconstruction of Adratiklit in watercolors by Christopher DiPiazza.  This is mostly educated guesswork since only a few bones are known.

Adratiklit is exciting because it is the oldest known member of the stegosaurid family, being from the middle Jurassic, 168 million years ago.  Stegosaurids, of which Stegosaurus is the most known member, were plant-eating dinosaurs that had proportionally tiny heads, bony plates on their backs, and spikes on their tails.  All other known members from this group lived several million years later, in the late Jurassic, around 150 million years ago give or take a few million years depending on the taxa.  The other interesting thing about Adratiklit is that it lived in what is now northern Africa, an area that no stegosaurid has ever been found in before.

A vertebra from Adratiklit.  Image from Maidment's paper listed below.

Adratiklit is only known from a few bones, including vertebrae and a humerus.  That being said, paleontologists were still able to identify these bones as being from a stegosaurid of some kind thanks to a number of diagnostic characteristics.  Based on the details of these bones, they were also able to deduct that Adratiklit was most likely most closely related to stegosaurids that lived in Europe, like includes the long-necked Miragaia and the slightly less mysterious Dacentrurus.  There were other stegosaurids that lived in Africa, like the extremely spiky Kentrosaurus, but its bones were found in what is now Tanzania, which despite being on the same continent, is geographically very far away from Morocco.  In fact, Morocco is actually a bit closer to Europe than it is to Tanzania.  (People often forget how gigantic Africa is.)

Since Adratiklit is only known from such fragmentary remains, a lot of the specifics of how it looked in life are a mystery.  Since it was a stegosaurid, we can assume it had plates and spikes growing out of its back and tail, but their shape, lengths, and arrangement, all of which vary depending on the taxa, we can only guess.  Did it have mostly plates and only four spikes on the tail like Stegosaurus?  Perhaps it had more spikes all the way up its back like Kentrosaurus?  Did it have a long neck, like Miragaia?  Maybe we'll find out one day if more of this amazing dinosaur is discovered?

References

Maidment, Susannah C. R.; Raven, Thomas J.; Ouarhache, Driss; Barrett, Paul M. (2019-08-16). "North Africa's first stegosaur: Implications for Gondwanan thyreophoran dinosaur diversity". Gondwana Research.