The New Origin of Cheetahs – Acinonyx kurteni
This article was retracted from PNAS by the original author in September 2012.
The undersigned author wishes to note the following: “After further examination, it was determined that the fossil used in the study was a composite specimen from the late Miocene laterite and not from the early Pleistocene loess. The article is hereby retracted.”
Ji H. Mazák
I have deleted information below in the original text of this post which was based off the original article.
The original blog post continues from this point
I’m hoping that this late-breaking 2008 science story is not drowned-out by the hogmanay hullabaloo. Why? Because cheetahs are just awesome, that’s why. And by the end of this entry, I hope that you too find their evolutionary history fascinating.
The late-breaking news (from various news sources  , including, most notably, the report at LiveScience.com) is that scientists Per Christiansena (from Zoological Museum, Denmark) and Ji Mazákb (from the Shanghai Science and Technology Museum) published details of a ~2,5 million year old cheetah fossil which calls into question the previous view that (1) cheetahs and pumas are closely related and (2) that because of their close lineage both evolved from a common ancestor somewhere in the Americas (based on fossil evidence from Texas). Christiansena and Mazákb named the new sub-species Acinonyx kurteni. The North American fossil evidence has been classified as an extinct species with some evidence of convergent adaptation with the same Late-Pliocene cheetah (a. kurteni). The North American fossils describe the separate species Miracinonyx.
Although our analysis of craniodental characters favors one evolutionary lineage of cheetah-like cats, and indicates a close relationship of Miracinonyx, at least M. trumani, to Acinonyx, A. kurteni has a number of primitive traits, notably more primitive dentition, that could indicate two separate lineages, each culminating in craniodentally highly derived predators, and thus, we would not at this time entirely rule out that the highly cheetah-like morphology of M. trumani evolved convergently in the Americas, as suggested by [Barnett R., et al (2005): Evolution of the extinct sabretooths and the American cheetahlike cat].
Christiansena and Mazákb studied this nearly complete skull from Gansu Province of China and concluded that it is the oldest cheetah fossil found to date. The skull shows fairly primitive tooth development indicating that the cheetah probably evolved gradually and that some tooth fossils previously found in Late-Pliocene layers, at sites across Africa and Eurasia and assumed to be the teeth of leopards, could also be from Acinonyx kurteni or it’s descendants. 2,5 MYA is roughly the same time as the other major cheetah fossil from North Africa from a sub-species called Acinonyx aicha, but kurteni pips aicha to the post being the oldest fossil because of a number of the cranial features of kurteni being more primitive. This evidence points towards modern cheetahs having their earliest ancestors in either Africa or Asia and being far more widely spread in the past than today.
But why is more fossil evidence more exciting? That’s because studying the history of cheetahs via other means (i.e. DNA) is far more difficult than other animals, that is because of a near-extinction event in their recent past. All cheetahs alive today are descended directly from a small group (estimated to be around seven individuals) a mere ten thousand years ago during the last ice age. That means that we do not have a diverse genetic spread between individual cheetahs that would allow us to compare genetic traits and discover similarities to other feline species. A genetic trait (such as a retro-virus which could have been shared with other species) indicating a common ancestry (if such a trait existed) was lost in the lineages which died-out during the ice age.
But the good news from the extremely shallow gene-pool of modern cheetahs, is that we have another defence against the inane challenges by creationists (such as the ridiculous Banana: The Atheist’s Nightmare). We can state (as DonExodus so eloquently does) that the Cheetah is the Creationist’s Nightmare. And that is yet another reason why I love the cheetah.
Here follows the same video from DonExodus for your convenience.