I came to possess a single toe fossil from something labeled Pseudaelurus, Miocene cat, found near Wikieup, Arizona in 2007. That area is known for a bounty of mammal fossils in the Big Sandy Formation¹. It is difficult to know from a single toe what species I am dealing with. The era and location can narrow it down, though.

Pseudaelurus was once a genus but in 2010² was possibly reclassified as a “grade” encompassing the genus Hyperailurictis North America and three others around the world such as Styriofelis. This adds one more layer of complexity to attempts to research these prehistoric felids because (for instance) Pseudaelurus validus and Hyperailurictis validus are the same thing, just with different names when accessing different papers.

Hyperailurictis fossils are rare. Jawbones are the most common specimens, but much has been gleaned from even partial skeletal examples³. These extinct felines came in a variety of sizes, comparable to everything from lynx to leopard.

Like the most reconstructions of prehistoric life, my choices on coat coloration are based on speculation. However, I’m trying to be realistic. Cats and even some of their relatives like hyenas and viverrids can have spots, so spots seem to be a pretty safe bet. Even when a cat has a plain, unmarked coat, the babies are usually born with spots. Therefore, it stands to reason that this ancestral cat could have had a spotted coat.

Although Hyperailurictis / Pseudaelurus does not wear the crown of “first cat” it does have a different and wondrous designation. It is the last cat known before the branches of the cat family tree split into all of the other types of cats, such as the big cats or Pantherae, smaller cats, and the now-extinct machairodonts or sabertooth cats.

So this cat sits squarely on the trunk of the cat family tree, before its divergence. Depending on how you look at it, this cat is the cat that contained all other cats.

1. Morgan, G.S.; White, R.S. 2005. Miocene and Pliocene vertebrates from Arizona. – New Mexico Museum of Natural History and Science Bulletin 29:115-136.

2.Werdelin, Lars; O’Brien, Stephen J.; Johnson, Warren; Yamaguchi, Nobuyuki (2010). “Phylogeny and evolution of cats (Felidae)”. In Macdonald, D.W.; Loveridge, A.J. (eds.). Biology and Conservation of Wild Felids. Oxford: Oxford University Press. ISBN9780199234455.

3.Rothwell, Tom (2001). “A partial skeleton of Pseudaelurus (Carnivora, Felidae) from the Nambé Member of the Tesuque Formation, Española Basin, New Mexico” (PDF). American Museum Novitates (3342): 1–31. doi:10.1206/0003-0082(2001)342<0001:APSOPC>2.0.CO;2. ISSN 0003-0082.