Quercylurus

Quercylurus major is an extinct, cat-like nimravid carnivora (or "false sabre-toothed cat") from the early Oligocene of France. Its fossils were found in Early Oligocene strata in Quercy. Q. major was possibly the largest nimravid ever known, as its fossils suggest it was similar in size to the modern-day lion.

Currently there is only one described species within this genus, the type species, Q. major. Q. major lived in the moist and humid forests of Oligocene Europe, alongside the much smaller, fellow nimravid Eofelis.

Description
Quercylurus is often considered one of the largest definitive nimravids known, with remains indicating individuals roughly comparable to modern lions with mass estimates around 140 kilograms (309 lbs). Only the larger members of Barbourofelidae, which more recent studies have considered nimravids, grew larger. Quercylurus somewhat resembled actual felines, with an elongated back and shortened snout, whilst having feet more resembling basal Feliformia members like civets, with partially retractable claws. It might have been scansorial, using trees as both vantage spots, retreats, and points of ambush for hunting prey.

As one of the largest predators in Europe during its existence, Quercylurus was almost certainly an apex predator in its ecosystem. The canine fangs were large and scimitar shaped, if less elongated and flattened as derived Machairodontini sabretoothed cats and Barbourofelidae. Because of its large build and dentition, Quercylurus likely preyed upon large herbivores, such as ungulate mammals, by use of ambush tactics instead of cursorial, prolonged chases.

Taxonomy
Quercylurus was named by Ginsburg (1979), and initially assigned to Felidae by Carroll in 1988. It would be placed as a member of Nimravidae, within the subfamily Nimravinae. Quercylurus was at one point classified as Nimravus intermedius major, and then classed within the Dinailurictis genus. More recent research typically places Quercylurus, Dinailurictis, and Eofelis as closely related, but distinct genera representing a European clade of nimravids. Quercylurus and Dinailurictis in particular share many similarities, with size being the chief distinguishing factor in some research.