Learning the fossil lexicon can be challenging. Not every name is as simple or sibilant as Stegosaurus. For example, the whaitsiids. My brain keeps wanting the word to read "what-is-it-ids", which actually wouldn't be far off. These ancient synapsids - or protomammals, if you like - aren't exactly rock stars. All the same, they are cousins of ours and a part of the long evolutionary story that mammals are carrying on today. So it seems only fair to take a moment away from the dinosaurs and other prehistoric celebrities to look at a new little whaitsiid found in South Africa.

Described by paleontologists Adam Huttenlocker and Roger Smith, the small creature is called Microwhaitsia mendrezi. The 260 million year old skull and isolated snout found so far have a superficially dog-like appearance about them, despite the fact that this animal lived over 200 million years before canines would come on the scene. 

What makes Microwhaitsia special, though, is how it and another animal named by Huttenlocker and Smith - called Ophidostoma tatarinovi - have added new context to a murky chapter in protomammal history.

The two protomammals lived around a time when life was changing. Paleontologists known this as the middle-to-late Permian transition, when the abundances and different groups of protomammals changed. So here's where Microwhaitsia comes in.

Not only does Microwhaitsia now stand as the oldest member of its lineage - the whaitsiids - in the southern continent of Gondwana, but its relation to other finds suggests that this group was widespread earlier than previously known. It was part of a rising tide of new forms of protomammals that were replacing previous ones, undergoing a radiation of their own. This pattern follows the long fuse model, Huttenlocker and Smith write, with the little whaitsiids originating alongside more archaic forms of protomammals and eventually outpacing them in evolutionary terms. How this happened is still a mystery, but this little synapsid is a sign of a much bigger change in life's story.

Stereopair images of the Microwhaitsia skull. Credit: Huttenlocker and Smith 2017

Fossil Facts

Name: Microwhaitsia mendrezi

Meaning: Microwhaitsia means "small whaitsiid", referring to a particular group of protomammals, while mendrezi honors paleontologist Christiane Mendrez-Carroll.

Age: Permian, about 260 million years ago.

Where in the world?: Karoo Basin, South Africa. 

What sort of organism?: A protomammal called a therocephalian.

How much of the organism’s is known?: A partial skull with jaws and a snout.


Huttenlocker, A., Smith, R. 2017. New whaitsioids (Therapsida: Therocephalia) from the Teeklook Formation of South African and therocephalian diversity during the end-Guadalupian extinction. PeerJ. doi: 10.7717/peerj.3868

Previous Paleo Profiles:

The Light-Footed Lizard
The Maoming Cat
Knight’s Egyptian Bat
The La Luna Snake
The Rio do Rasto Tooth
Bob Weir's Otter
Egypt's Canine Beast
The Vastan Mine Tapir
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The Pig-Footed Bandicoot
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The Tomatillo From the End of the World
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The Mighty Traveler from Egg Mountain
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Mexico's Ancient Horned Face
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