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The second known skull of Lemurosaurus. From Sidor and Welman, 2003.

Our Prehistoric Cousins Had Demonic Skulls

If there’s one conference I can’t bear to miss, it’s the Society of Vertebrate Paleontology annual meeting. Especially because there’s always at least one image presented during the talks that makes me sit bolt upright in my chair and think “What the hell is that?” A few years ago it was when the body of the mysterious Deinocheirus was unveiled. Last year it was when I popped into a session on the dome-snouted mammal Rusingoryx. And this year, in a darkened Dallas convention hall, it was when paleontologist Christian Sidor flashed an image of a very strange skull on the screen.

The creature wasn’t the focus of Sidor’s talk. His presentation was focused on new finds of protomammal cousins of ours called burnetiamorphs from Zambia and Tanzania. And given that paleontology is at its heart a comparative science, Sidor reviewed previous discoveries of related animals. Among them was a creature that immediately bit into my imagination. Flared, triangular crests poked up above each eye, and a pair of saber fangs jutted below the jaw at the end of the protomammal’s elongated snout. It looked downright demonic, and its name is Lemurosaurus.

Paleontologist Robert Broom named Lemurosaurus in 1949 from a single skull found in the Late Permian rock of South Africa. He was especially impressed by the protomammal’s cheek teeth. The “molars”, as Broom called them, had large serrations along the back edge. He could not recall seeing such teeth in any other reptile.

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The strange array of burnetiamorphs. Art by Mojcaj. CC BY-SA 3.0

That original skull remained the only known specimen of Lemurosaurus for decades. And given that protomammals aren’t as sexy as dinosaurs – rarely is there a child who exclaims “I want to study therapsids when I grow up!” – it’s not terribly surprising that a second skull was collected in 1974 but wasn’t recognized as Lemurosaurus until 2000. With that skull in hand, however, Sidor and Johann Welman were able to get a better look at our cousin over 254 million years removed.

While Lemurosaurus had been bumped around between various groups of protomammals in the past, Sidor an Welman were able to confirm its place among the burnetiamorpha. They were weirdos, all. Each species in the group had long canines and their own arrangement of knobs and bosses across the skull. Paired with names like Lobalopex and Bullacephalus, they seem like the perfect inspiration for science fiction or horror writers looking for made-to-order monsters.

Exactly what the rest of Lemurosaurus looked like, though, is still held secret by the fossil record. The two skulls are tantalizing reminders of how much else awaits discovery. And while I wish Lemurosaurus were as well-studied as some of the dinosaurs its brow horns remind me of, I’m still thrilled by the notion that such a creature existed at all. Since the very beginning life on Earth has been shaped by the opening and closing of evolutionary possibilities. Some were realized. Others not. For me, the saberfanged skull of Lemurosaurus is a reminder of the strange routes that life pioneered out of all the many potential options. A reason to ask “Why?” and wonder what else the fossil record might be hiding.


Broom, R. 1949. New fossil reptile genera from the Bernard Price collection. Annals of the Transvaal Museum. 21 (1): 187-194