Acinonyx pardinensis

Acinonyx pardinensis, sometimes called the Giant cheetah, is an extinct felid species belonging to the genus Acinonyx, closely related to the cheetah, native to Eurasia during the Pliocene and Pleistocene epochs. It was substantially larger than the living cheetah.

Description
Acinonyx pardinensis was roughly twice the size of today's cheetahs, weighing around 60-121 kg, though A. pleistocaenicus was much larger. The morphology of the skull shows some similarities with those of pantherine cats and is not as short and deep as that of the modern cheetah. The teeth greatly resemble that of a modern cheetah. The limb bones, like those of a modern cheetah, were elongate relative to the animal's body size. The lumbar vertebrae were also elongate, suggesting the back was flexible. Compared to living cheetahs, the femur is more straight and the fibia is more robust and not fused to the tibia. The humerus is also more robust.

Classification
Acinonyx pardinensis is sometimes considered a macrospecies containing Acinonyx aicha, Acinonyx arvernensis, Acinonyx intermedius, Acinonyx pleistocaenicus, and Sivapanthera linxiaensis as subspecies.

Distribution and habitat
Acinonyx pardinensis is known from remains spanning from western Europe to China, spanning from the Late Pliocene to the Middle Pleistocene. The true number of species of Acinonyx in the Plio-Pleistocene of Eurasia is unclear.

Paleobiology
Like the modern cheetah, Acinonyx pardinensis is generally thought to have been adapted to running down prey. It probably took larger prey than living cheetahs, with estimated prey masses of 50-100 kg, though the idea that its ecology was similar to a modern cheetah has been contested by some authors, who suggest an ecology more similar to pantherine cats. Due to its larger body size, it probably did not reach the same speeds as modern cheetah. The morphology of its carnassial teeth suggest like modern cheetahs that it did not consume bone, and probably left large parts of carcasses to other carnivores. While a 2011 study suggested that it killed its prey by suffocation like a modern cheetah, a 2014 study alternatively suggested that Acinonyx pardinensis likely killed prey via a bite to the neck similar to pantherine cats.