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Party in the White Room!

Not. That’s actually a graph.

Spaghetti charts in 3D are even scarier than reconstructed sabercats.

Why share that graph?

Because very few fossils from the Early to Middle Miocene times that we’re headed for in this post are complete enough to reliably reconstruct their cats — some of the very first cats ever. (Antón, 2003)

So the feature image shown at the top of this page instead is a scientific picture of how cats and sabercats evolved.

Yep, the whole thing, according to Sakamoto and Ruta.

They put it together, as Figure 6 (CC BY-NC-ND-SA 4.0) in their paper, using morphometrics and phylogenetics, with time running up the vertical axis.

I don’t quite see it, either. The colors are pretty, though — black is for sabercats, red is for Panthera (the big cats), and all the rest represent other living feline lineages (for instance, those pink balloons and lines are the domestic-cat group Felis, among the youngest of lineages but still much older than us). (Johnson et al.; Sakamoto and Ruta)

That’s about all we need to know about Figure 6, except for two arrows: one black and the other one gray.

The gray arrow points at the last common ancestor of modern cats, as calculated by Sakamoto and Ruta.

A black arrow draws our attention to the last common ancestor of sabercats, according to these authors.

Neither of those two key ancestral kitties actually has been identified in the fossil record yet.

It’s all statistics and computer modeling based on systematics.

In other words, magic (for most of us laypeople, anyway).

Indiana-Jonesing it

Wait. That was archaeology, wasn’t it?

Anyway, in Academia such numerical studies give paleontologists something to work with as they head out to a fossil dig or rummage through museum collections that haven’t been examined yet.

It’s much easier to find something if you have a clue about what it is you seek and where it might be lurking.

And once you’ve found something, understanding what you’ve got is easier when there is a “big picture” to use as a reference.

Figure 6 is just one of the “big pictures” available to investigators of feline paleontology.

Sometimes your discovery fits in perfectly. Occasionally it is such a bad fit that you realize there was a problem with your concept of the “big picture,” which is cool, too.

My impression from reading is that often your find is so puzzling that you can only label it carefully and store it for future study when new knowledge is available.

🎉🎈🐾🎈🎊

What does any of this mean for us?

Mreow!

Some lucky and hard-working fossil-cat herder might recognize one, two, or more key Miocene cat ancestors someday.

For our series, this last post on sabercats (but not the last one on sabertooths!) also has to go deeper, toward the ancestors of those hypothetical last common ancestors of saber-tooths and cone-tooths shown in Figure 6.

Why? Without ancestors of the last common ancestors — boffins call them stem groups or stem lineages — there never would have been a Smilodon and we would not have any cats at all today.

We wouldn’t even know what we were missing.

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But what were these ancient founders of cathood? How and why did they come together and form what appears to be two subfamilies: sabertooth and conetooth? In terms of our series, how did the OGs turn into sabercats?

Sorry. It isn’t fair to raise questions that can’t yet be answered by Science. At least you now have some idea of what scientists themselves are trying to find out.

Let’s see if we can follow a little of what they have established thus far and learn a few basic facts about the ancestors of Machairodontinae, the “Knife-tooths.”

In brief

For all of Earth’s history, up to about 30 or so million years ago (Sakamoto and Ruta; Turner et al.; Werdelin et al.), there were never any cats.

Then there were.

Why? Who knows? The fossil record is silent on this point.

When they first appear in the planet’s known rocky archives, cats already have a Model-T classic feline shape — short face, teeth adapted to hypercarnivory, long back, short toes, and hind legs longer than front legs. (Slater and Van Valkenburgh; Turner and Antón; Van Valkenburgh: Werdelin et al.)

For that matter, so did the cat-like barbourofelids and nimravids that came before Family Felidae and then coexisted with true cats for a while (Agustí and Antón; Antón, 2013; Prothero), as we’ll see in the next two posts.

Like Felidae’s “Knife-tooths,” barbourofelids and nimravids also had several Ferrari highly evolved sabertooth modifications.

But, as far as I know, they never developed small forms as Felidae did with Fluffy’s wildcat clan and some other equally adorable cats who are even smaller.

Small, even without imaginative story-telling like this.

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🎉🎈🐾🎈🎊

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By the way, no one knows how the feline shape evolved (Werdelin et al.), but apparently it’s really good for some predators.

Several other groups besides cats have evolved it in the past. (Van Valkenburgh)

Once they get it, the predators don’t change very much over tens of millions of years (Van Valkenburgh) — to the dismay of fossil-cat herders who would like to sort them into species and figure out how they evolved.

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🎉🎈🐾🎈🎊

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Last common ancestor

Once Family Felidae was on the scene in Europe, there seems to have been what boffins call an adaptive radiation there (Werdelin et al.): from 17 to 16 Ma (million years ago), cats evolved in various ways rather quickly and they also expanded their range considerably.

Some of those cats became conetooths; some, sabertooths; and some, like Dinofelis and other metailurins were in between.

Small modern cats are undergoing such a radiation today in South America, which is why it sometimes is very hard to tell them apart as species.

This, even though they can be observed directly.

Imagine trying to understand a group of cats that’s radiating like los gatos sudamericanos when there is only indirect evidence of them, and very little of that!

This is why the last common ancestors of both Fluffy’s subfamily and Smilodon’s are currently hypothetical only.

Here is another way to view Felidae’s family history as Sakamoto and Ruta see it.

The coloring scheme here is still black for sabercats, red for big cats, etc.

A few specimens haven’t been identified yet, but the sabercat names will be familiar to readers of this post series.

For reasons explained in their paper (jargon alert), some sabercats, including Machairodus, aren’t labeled in this figure.

Machairodus (a/k/a as Miomachairodus or Machairodus _spp. to Werdelin (2024) and Werdelin et al.), is the first known sabercat.

According to all authors I’ve read, from Antón (2013) to Werdelin (2024), Machairodus fossils just suddenly show up, with all their superb Pleistocene-level cutlery, in Miocene rocks of the Greek-Iranian Province at ~12.5 Ma, without any indication of where the sabercat came from.

Metailurus, another mystery although it did make Sakamoto and Ruta’s list, first appears in the record around 11.6 Ma. (Slater and Van Valkenburgh)

How did that radiating brew of early cats come up with conetooths, Machairodus, Metailurus, and their last common ancestor? Where? And when?

That’s the tricky part.

Ancestors of the ancestors

Fossils from the earliest cats are rare. When found, they typically are in fragments — part of a mandible here, piece of a shin bone there, and so forth.

This makes interpretation very difficult.

So all I can cover here are some of the handles that paleontologists currently have on these ancient fossil cats.

The scientific names used, as well as various ideas about cat evolution — particularly for the really old cat groups — will likely change with time, as more discoveries are made and understanding grows.

What is known about Felidae’s founding felines is that, long before Machairodus, with its surprisingly advanced saberteeth, the early cats that we’re looking for now were present and became the first cats to walk into — or possibly OUT of — Africa after plate tectonics built a land bridge between that continent and Eurasia 18-20 million years ago, while forming the Mediterranean Sea. (Lyras et al.; Prothero; Rothwell, 2001; Werdelin, 2012)

During those Early and Middle Miocene days and nights, cats that are most widely known now as Pseudaelurus also spread across Eurasia.

And at the same time, similar-looking but apparently different pseudaelurines of some sort were in North America. (Rothwell, 2001; Werdelin et al.)

Some paleontologists call these American kitties Hyperailurictis while others, especially in older papers, still refer to them as Pseudaelurus.

One or more of them probably gave rise to the American sabercat Nimravides. (Werdelin et al., but see Antón, 2013; I follow Werdelin et al. in this post)

Somehow.

And then there are the African cats — if that’s what they were, cats and not cone-toothed barbourofelids.

This is very complicated. Asilifelis and friends are only just now starting to be studied. Also, the African Early to Middle Miocene cats make a nice crossover to the upcoming posts on barbourofelids, which probably originated in Africa.

For all those reasons, let’s save them for last.

🎉🎈🐾🎈🎊

For study purposes, Sakamoto and Ruta used Hyperailurictis for their early cat.

Another ancestral candidate, one closer geographically to Machairodus, would have been Pseudaelurus, who we have met before.

In this group was a species with rather long, moderately flattened upper canines and a square chin…

Pseudaelurus quadridentatus

You can’t really call P-Quad’s canines saberteeth, but they were headed in that direction (Antón, 2013) — a dental path that Metailurus went down a little farther, although without changing the body plan much.

Millions of years later, Paramachaerodus would still be built much like P-Quad, too. (Turner and Antón)

Even Antón’s doodles are beautiful!

That’s one of the Pseudaelurus cats on the left. Antón sketched out a comparison of its possible appearance and its skeleton with those of a cheetah (top right) and Smilodon (bottom right) — two VERY different cats but both advanced enough in evolution to be called Ferraris.

Their skeletons are parked next to the Pseudaelurus Model T, which wasn’t all that different even from most of today’s cats.

Sure, there were a few differences, according to my reading, but these were arcane and fairly minor ones.

Even the most noticeable difference that I can spot in this drawing is quite subtle — like the Dawn Cat, Proailurus, before it, Pseudaelurus was a little more flat-footed than modern cats are and probably spent most of its time in trees. (Antón, 2013; Turner and Antón; Werdelin et al.)

Cats being copycats, that physical resemblance doesn’t prove that metailurines and sabercats descended from P-Quad, which was about the size of a small cougar — and, until lion-sized Machairodus showed up, apparently the biggest cat in Middle Miocene Europe. (Agustí and Antón; Rothwell, 2004)

What makes paleontologists wonder about a sabercat connection to P-Quad are other, more esoteric dental details that only a scientist could love, as well as P-Quad’s slightly squared chin.

These are sabertooth signs, but if that’s what they really were in Pseudaelurus quadridentatus as a whole and not just individual variations in the few specimens that happen to have come down to us, then this was a very early stage of sabertooth development. (Antón, 2013; Turner and Antón)

Not much is known about any of the pseudaelurines, actually.

Their fossils are rare and, too, they were very much alike, except for size. (Ormsby; Rothwell, 2001; Werdelin et al.)

Of the four known Pseudaelurus species in Europe (and skipping current genus names, which are many), lorteti, almost as big as P-Quad, is a possible candidate for conetooth ancestor, and when all is said and done, quadridentatus — P-Quad — probably is close to the roots of all sabercats. (Antón, 2013; Salesa et al., 2012; Turner and Antón)

That is, if the sabercat origination story can also account for a surprise finding over in North America.

Hyperailurictis

Fossils found mostly in Nebraska show that North America hosted cats that were very similar to Europe’s Pseudaelurus during the Middle Miocene — robust and panther-sized. (Antón, 2013; Rothwell, 2001, 2004)

I haven’t come across mention of any saber-like canines, like P-Quad’s, but a couple of the American species did have prominent chins — a feature that would stand out even more in the later sabercat, Nimravides. (Antón, 2013)

As mentioned earlier, some experts refer to American pseudaelurines as the Hyperailurictis genus and we will, too.

It seems likely that at least one of their species was Nimravides’ ancestor (Jiangzuo et al.), but what were their ancestors? And where do they fit into the picture with Europe’s Pseudaelurus?

For quite a while, the most likely background story for Hyperailurictis seemed to be this:

1. Proailurus — the earliest named cat — appears first in the fossil record of Europe, and from it came the Pseudaelurus complex of cats.
2. Pseudaelurines wandered around, as cats do, and while there aren’t many Early to Middle Miocene sites in Asia yielding cat fossils, there are a few. Two additional Pseudaelurus species have been identified there, along with lorteti. (Rothwell, 2004)
3. Some of those pseudaelurines crossed over the Bering land bridge into North America around 18½ million years ago, along with mastodons and a variety of other critters.
4. These cats developed into Hyperailurictis and, eventually, Nimravides.

It made perfect sense until the day that someone found a very Proailurus-like cat skull, from around 17 to 16.5 Ma, in northwest Nebraska.

Not only is this the oldest known cat fossil in the New World, it also raises some sticky questions about how cats evolved. (Lyras et al.)

Those questions go far beyond the scope of a simple blog post.

While no one denies a connection to Hyperailurictis (as far as this layperson can tell, anyway), some researchers, including Antón, argue that the mystery cat — known to boffins as the Ginn Quarry specimen because of its location — was “proailurine-grade.”

I suppose that means that it somehow migrated into North America from Eurasia.

Some other paleontologists suggest that the mystery cat instead is evidence of an early Miocene lineage in North America, totally separate from Proailurus.

I think that makes it and all of its descendants also totally separate from Machairodontinae (the sabercats), as those have been defined thus far.

Since this American lineage gave rise to Nimravides, sabercats evolved independently at least twice, in different parts of the world.

That’s a radical change in perspective!

Lyras et al. took a close look at the nearly complete mystery-cat skull and report that:

• The Ginn Quarry cat likely was about the size of a modern clouded leopard, but its brain was 40% smaller:

  Could the Ginn Quarry mystery cat have done this?

• They can’t tell if it was a separate lineage, non-sabercat, non-conetooth, or whether it should be assigned to one or the other — as a sabercat, according to Antón’s group, but there appears to be no consensus on this.

I’m being unfair again: these are definitely still open questions. Much more research into the Nebraska mystery cat and the origin of sabercats still is needed.

Even more so, given recent discoveries in Africa!

Asilifelis

This section is short, both because research on these cats is just starting and also because, as far as I can tell, none of them (if they all were cats) was a sabercat.

We will take a closer look at them next time.

What this layperson has found through reading is that, basically, until the late 1990s, the only Middle Miocene cat found in Africa was one of the European pseudaelurines that had made it as far south and east as what is now Arabia. (Werdelin et al.).

After Machairodus first dropped its remains into the rocky record some 12½ million years ago, cats of all sorts can be found in Africa.

But before then? Nada, except those pseudaelurine fragments in Arabia from somewhere between 17 and 15.2 Ma.

Then, in 1998, two new cats were reported from Arrisdrift, in modern Namibia. (There aren’t enough fossils to reconstruct Diamantofelis and Namafelis, but check out Antón (2003) for some stunning artwork of the Arrisdrift region and its other diverse animals back in the day).

As we’ll see next time, it isn’t completely clear whether these two were cats or something else, but a THIRD Middle Miocene fossil predator — found on an island in 1949 and christened Asilifelis in 2012 — definitely belonged in Family Felidae. (Werdelin, 2012)

It must have been adorable, being the wee size of a rusty-spotted or blackfooted cat, but it was also 18 to 20 million years old, which was shocking.

You see, Asilifelis reportedly shows clear evidence of evolving from pseudaelurine to Felis grade.

And Pseudaelurus was thought to be brand new at that point, if it had even developed yet.

Also, Felis wasn’t even on the cat-evolution scene yet, as paleontologists have worked this out. Its first known fossil, Pristifelis attica, only dates back to around 11.6 Ma and comes from the Greek-Iranian Province, where it’s found along with Metailurus. (Agustí and Antón; Werdelin, 2012)

According to Wikipedia, a fourth cat — Katifelis — has since been found in Kenya. It reportedly was larger than Asifelis — almost the size of a caracal — and it, too, shows transitional features.

Perhaps Katifelis was also a true cat, but I could find no science papers discussing this yet, so let’s hold off on that for now.

Instead, let’s hear what Dr. Lars Werdelin — an international heavyweight in Paleontology — has to say about Asifelis (emphasis added):

…With only one specimen available, there are not enough data to evaluate this possibility. Nor can we know whether this African lineage migrated out of Africa to become the founder of the modern Felidae radiation – a possibility that does not militate against the reconstruction of the earliest Felidae ancestor as coming from Asia (Johnson et al., 2006), since this only refers to extant Felidae, not to any possible stem lineage taxa. An origin from African antecedents would at least explain why fully evolved Felidae of extant grade, such as P. attica and Machairodus, appear so abruptly in Eurasia near the beginning of the Tortonian. But again, without more material, this rapidly enters the realm of pure speculation…

Speculation for now, but even as we are checking it out, there are probably several research teams in the field and at the keyboard, focused on Africa’s Early to Middle Miocene cats and preparing to throw more parties in the White Room as they try to figure out anew just exactly where cats come from.

Featured image: Figure 6, Sakamoto and Ruta, CC BY-NC-ND-SA 4.0).

Disclosure: I have no personal, financial, or business connection with Mauricio Antón. I just think that readers of my blog should know about Sabertooth.

Sources:

• Agustí, J., and Antón, M. 2002. Mammoths, sabertooths, and hominids: 65 million years of mammalian evolution in Europe. New York and Chichester: Columbia University Press. Retrieved from https://play.google.com/store/books/details?id=O17Kw8L2dAgC
• Anton, M. 2003. Reconstructing fossil mammals from Arrisdrift (17-17.5 Ma), Namibia, in Memoir 19, Geology and Palaeobiology of the Central and Southern Namib, Vol. 2, Palaeontology of the Orange River Valley, Pickford, M., and Senut, B., eds. Geological Survey of Namibia. https://the-eis.com/elibrary/sites/default/files/downloads/literature/Reconstructing%20fossil%20mammals%20from%20Arrisdrift.pdf (PDF) (Reader note: Check this out, if you’re interested in paleoart — Antón goes into vivid detail on how he reconstructs fossil animals in general!)
• ___. 2013. Sabertooth. Bloomington: Indiana University Press. Retrieved from https://play.google.com/store/books/details?id=dVcqAAAAQBAJ
• Chatar, N.; Fischer, V.; and Tseng, Z. J. 2022. Many-to-one function of cat-like mandibles highlights a continuum of sabre-tooth adaptations. Proceedings of the Royal Society B, 289(1988), 20221627.
• Chatar, N.; Michaud, M.; Tamagnini, D.; and Fischer, V. 2024. Evolutionary patterns of cat-like carnivorans unveil drivers of the sabertooth morphology. Current Biology, 34(11): 2460-2473.
• Jiangzuo, Q.; Li, S.; and Deng, T. 2022. Parallelism and lineage replacement of the late Miocene scimitar-toothed cats from the old and New World. Iscience, 25(12).
• Johnson, W.E.; Eizirik, E.; Pecon-Slattery, J.; Murphy, W.J.; and others. 2006. The Late Miocene radiation of modern Felidae: a genetic assessment. Science, 311: 73-77.
• Juhn, M. S.; Balisi, M. A.; Doughty, E. M.; Friscia, A. R.; and others. 2024. Cenozoic climate change and the evolution of North American mammalian predator ecomorphology. Paleobiology, 50(3): 452-461.
• Lyras, G. A.; Giannakopoulou, A.; and Werdelin, L. 2019. The brain anatomy of an early Miocene felid from Ginn Quarry (Nebraska, USA). PalZ, 93(2): 345-355.
• Ormsby, C. 2021. Morphology and Paleoecology of Nimravides galiani (Felidae) and Barbourofelis loveorum (Barbourofelidae) from the Late Miocene of Florida. Electronic Theses and Dissertations, Paper 3902 https://dc.etsu.edu/etd/3902
• Prothero, D. R. 2006. After the Dinosaurs: The Age of Mammals. Bloomington and Indianapolis: Indiana University Press. Retrieved from https://play.google.com/store/books/details?id=Qh82IW-HHWAC.
• Rothwell, T. P. 2001. Phylogenetic systematics of North American Pseudaelurus (Carnivora: Felidae). Columbia University.
• ___. 2004. New felid material from the Ulaan Tologoi locality, Loh Formation (early Miocene) of Mongolia. Bulletin of the American Museum of Natural History, 2004(285): 157-165.
• Salesa, M. J.; Anton, M.: Turner, A.; Alcala, L.; and others. 2010. Systematic revision of the Late Miocene sabre‐toothed felid Paramachaerodus in Spain. Palaeontology, 53(6): 1369-1391.
• Salesa, M. J.; Antón, M.; Morales, J.; and Peigné, S. 2012. Systematics and phylogeny of the small felines (Carnivora, Felidae) from the Late Miocene of Europe: a new species of Felinae from the Vallesian of Batallones (MN 10, Madrid, Spain). Journal of Systematic Palaeontology, 10(1): 87-102.
• Shelbourne, C. D., and Lautenschlager, S. 2024. Morphological diversity of saber‐tooth upper canines and its functional implications. The Anatomical Record.
• Slater, G. J., and Van Valkenburgh, B. 2008. Long in the tooth: evolution of sabertooth cat cranial shape. Paleobiology, 34(3): 403-419.
• Turner, A., and Antón, M. 1997. The big cats and their fossil relatives: an illustrated guide to their evolution and natural history. Columbia University Press.
• Turner, A.; Antón, M.; Salesa, M. J.; and Morales, J. 2011. Changing ideas about the evolution and functional morphology of Machairodontine felids. Estudios Geológicos, 67(2): 255-276.
• Van Valkenburgh, B. 2007. Déjà vu: the evolution of feeding morphologies in the Carnivora. Integrative and Comparative Biology, 47(1): 147-163.
• Wang, X.; Carranza-Castañeda, O.; and Tseng, Z. J. 2023. Fast spread followed by anagenetic evolution in Eurasian and North American Amphimachairodus. Historical Biology, 35(5): 780-798.
• Werdelin, L. 2012. A new genus and species of Felidae (Mammalia) from Rusinga Island, Kenya, with notes on early Felidae of Africa. Estudios Geológicos, 67: 217-222.
• ___. 2024. Hypercanines: Not just for sabertooths. The Anatomical Record. https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.25510
• Werdelin, L.; Yamaguchi, N.; Johnson, W. E.; and O’Brien, S. J. 2010. Phylogeny and evolution of cats (Felidae), in Biology and Conservation of Wild Felids, eds. Macdonald, D. W., and Loveridge, A. J., 59-82. Oxford: Oxford University Press.
• Wikipedia. 2025. Asilifelis. https://en.m.wikipedia.org/wiki/Asilifelis Last accessed September 18, 2025.
• ___. 2025. Diamantofelis. https://en.m.wikipedia.org/wiki/Diamantofelis Last accessed September 18, 2025.
• ___. 2025. Katifelis. https://en.m.wikipedia.org/wiki/Katifelis Last accessed September 18, 2025.
• ___. 2025. Namafelis. https://en.m.wikipedia.org/wiki/Namafelis Last accessed September 18, 2025.

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