That’s newsworthy Diegoaelurus, left, and possible predecessor Patriofelis (not a sabertooth) right.
I saw that yesterday and just wanted to do a quick post to help you place these ancient critters in terms of sabertooths, from what I recall of notes taken in 2016 to roughly 2019.
Those notes are packed away at the moment because I’m covering a time some two billion years before these carnivorous sabertoothed mammals arrived. We will have to work our way up through the end-Cretaceous extinction (bye-bye, dinosaurs!) before we get to meet creodonts.
But creodonts are what really drew me into investigating the past history of cats, and not because cats are descended from them.
They aren’t, as far as anyone knows now, although paleontologists once thought they were, which is how Patriofelis up there got its name: “Father of cats.”
Granted, the image doesn’t look much like Fluffy, but consider the short legs and long body.
Creodonts also had carnassial teeth, although these evolved on different molars than those used by what is presently considered a sister group to Order Creodonta — the order Carnivora.
“Howdy!” — Carnivora (a few representative mugs), via Wikimedia
Dog-like and cat-like
To briefly sum up what I learned, the origins of Carnivora are unclear in that they might have been around in late Cretaceous times or else they appeared early in the Cenozoic (the official name for what most of us incorrectly think of as “the age of mammals” — actually, mammals and dinosaurs evolved at the same time back around Triassic times).
But carnivorans weren’t very impressive critters yet and continued to keep a low profile.
After the great mass extinction 66 million years ago, avian dinosaurs still ruled in places like South America (part of what had been south Pangea, the supercontinent) and the northern continents (formerly north Pangea).
As I understand it right now, a sister group to carnivorans — the creodonts — were the first mammals to have a go at the apex predator niche.
There’s still much to read up on, but essentially creodonts succeeded and developed two lines:
- Hyaenodonts, the “dog-like” group. (Dogs, by the way, are carnivorans.) Hyaenodonts were incredibly successful and lasted well into the Miocene.
- Oxyaenids, the “cat-like” group mentioned above. They did well, but they weren’t as longlived as the “dog-like” creodonts.
Per Antón, those with saberteeth have only been found in North America for some reason.
How did evolution go?
That basic split intrigues me, since today’s Order Carnivora also has two subgroups: caniforms and feliforms.
Was it something genetic in the last common ancestor of these two sister groups, or possibly something to do with the times they lived in?
This nimravid was quite small, but others could be much larger. (Image: Mauricio Antón)
What’s also fascinating is that, long before Family Felidae became a thing, the carnivorans came up with the very cat-like nimravids.
Nimravids used to be called “paleofelids,” but then some taxonomists found details that suggest nimravids were more closely related to caniforms!
Evolution is a strange thing.
Anyway, then either Family Felidae or a now extinct sister group took its shot at the sabertoothed predator niche with barbourofelids.
Only after all that did true sabertoothed cats evolve.
Is your head spinning?
Mine sure was at first, because I’d always thought sabercats were ancient relics that went all the way back to the dinosaur age.
The real story is that, somehow, life actually found more interesting ways to achieve this.
That’s cool!
I look forward to getting into all that in detail someday, after laying the foundation in posts covering earlier times and life.
In the meantime, field work goes on, obviously, and new discoveries are made quite often. Yay!
Featured image: Top: Diegoaelurus, San Diego Natural History Musem via Scientific American; Bottom: Patriofelis, American Museum of Natural History via Wikimedia.
Sources:
Antón, M. 2013. Sabertooth. Bloomington: Indiana University Press. Retrieved from https://books.google.com/books?id=dVcqAAAAQBAJ
Flight To Wonder 