Acinonyx pleistocaenicus

Content sourced from Wikipedia, licensed under CC BY-SA 3.0.

Acinonyx pleistocaenicus is an extinct big cat from Eurasia that lived during the Early to Middle Pleistocene, about 1.3 to 0.6 million years ago. It is the largest known member of the Acinonyx genus.

Classification and status
- First named Cynailurus pleistocaenicus in 1925. Later researchers often treated it as a subspecies of Acinonyx pardinensis.
- A 2024 study argues it is a separate species, with skull and tooth features that resemble modern cheetahs, suggesting A. pleistocaenicus and A. pardinensis are distinct.

Size and appearance
- One of the largest Acinonyx species. In East Asia, individuals were especially big.
- At Untermassfeld (Germany), males about 130 kg and females about 110 kg.
- At Zhoukoudian (China), males about 188 kg and females about 178 kg.
- Despite the large size, its limb bones suggest a body shape similar to the modern cheetah.

Evolutionary relationships
- Likely evolved from A. pardinensis in Eurasia during the Early Pleistocene.
- Replaced in the Middle Pleistocene by A. intermedius.
- It is probably not a direct ancestor of the modern cheetah or of A. intermedius.

Ecology and hunting
- A dominant carnivore in its ecosystems due to its large size.
- Its prey likely weighed 100–300 kg, such as big deer and horses.
- The ear region (ectotympanic chamber) was not enlarged like in modern cheetahs, suggesting it was not as specialized for living in very open habitats.

Coexisting predators
- In Jinyuan Cave, it lived alongside Xenocyon lycaonoides, Ursus, Pachycrocuta brevirostris sinensis, Megantereon, and Panthera gombaszogensis jinpuensis.
- In Zhoukoudian, it shared the area with Ursus arctos, Pachycrocuta brevirostris sinensis, Homotherium latidens, and tigers.