The Evolution of Lynxes

The Lynx genus is composed of medium-sized felids distinguished by their tufted ears, large paws and long legs. They are a widespread genus with four existent species; L. lynx, L. rufus, L. canadensis and L. pardina or L. pardinus which is the critically endangered Iberian lynx (Werdelin 1981). The Lynx lineage is considered to be of African origin, with the oldest fossil being that of the ancestor species L. issiodorensis, dated at approximately 4 million years old (Werdelin 1981). L. issiodorensis skeletally resembled Felis but had lynx-like dentition, and as a result there was much debate over the  taxonomy of the species. Eventually L. issiodorensis migrated into the Northern Hemisphere, giving rise to many other species (Werdelin 1981). In Europe, L. pardina is a direct descendent to L. issiodorensis, a transition which resulted in the reduction of size through the intermediate species L. i. valdarensis and L. i. spalaea (see figure 1). Due to felid competition already present in Europe at the time, it had to exploit smaller prey and thus reduce its size. Soon after, the European descendents of  L. issiodorensis would have to reduce their size again to compensate for the competition brought on by the arrival of L. lynx (Werdelin 1981). 

 Figure 1. Suggested phylogeny of the Lynx genus (Werdelin 1981).


In Asia, L. issiodorensis gave rise to L. lynx which had a smaller skull and broader precarnassial teeth, most likely an adaption for crushing bones and a change in the type of prey (Werdelin 1981). L. lynx would then migrate into North America giving rise to the smaller L. canadensis. When L. lynx migrated into North America, snow shoe hare was the only prey similar, yet smaller, in size to its original prey from its previous habitat (Werdelin 1981). So it was seen as advantageous to reduce its size, given the smaller size of its available prey. L. issiodorensis would also give rise to L. rufus when it too migrated into North America, coinciding with the mammalian dispersal event that occurred around 2.6 million years ago (Werdelin 1981). Caracal caracal once thought to belong to the Lynx genus, can be distinguished from a lynx by the difference in the relative size of the postorbital constriction and phylogenetic analyses verify that there is no close relationship between the caracal and the lynx.

References:
  • Werdelin, L 1981, 'The evolution of lynxes', Annales Zoologici Fennici, vol. 18, no. 1, pp. 37-71.

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