Based on the name “snow leopard”, one would assume this big spotted cat was a species of leopard, and closely related to Panthera pardus.
However, this is not the case. In fact, snow leopards are more genetically linked to tigers!
Let’s back up to the snow leopard’s taxonomic classification. Since the 1930’s, this cat was known by the scientific name Uncia uncia, “uncia” being Latin for “ounce”, but this “ounce” comes from a word for lynx (yet, this cat is not related to lynx). It was in a genus all on its own. The big cat genus Panthera originally made up the four species (tiger, lion, jaguar, and leopard) that had similar skull features, and had the ability to roar. This ability is due to large vocal folds covered by a fibro-elastic pad in the larynx, and a partially ossified hyoid bone. In other words, they have unique larynx morphology in comparison to the other cat genera. Snow leopards lack this feature, so are one of three big cats that can’t roar (the other two species are cheetahs and pumas). They can, however, make a variety of other calls such as chuffs, growls, yowls, purrs, and groans. You can hear a snow leopard yowl here.
A genetics study by Davis, Li, & Murphy (2010) was conducted to compare the lineage of big cats through analyzing mitochondrial DNA (mtDNA). It discovered that tigers and snow leopards are actually “sister species”. This led to the snow leopard’s taxonomic name change to Panthera uncia.
So how and when did these species evolve in relation to each other? About 3.9 million years ago (mya), around the end of the Pliocene epoch, tigers and snow leopards split off from Panthera’s felid ancestor. By the time these two species had become separate species, jaguars, lions, and leopards were just starting to branch off from that same ancestor. Leopards and lions split into their own species around 3.1-1.95 mya, while jaguars split 3.6-2.5 mya.
What’s in a Name?
The word “leopard” derives from the Latin word “leopardus” and from the Greek word “leopardos”, translating to “lion-panther”. It was thought that the animal was a hybrid of a lioness and a male panther (a leopard or jaguar with a melanistic, or dark, coat color). I know what you’re thinking….you just heard me tell you how snow leopards aren’t related to leopards or jaguars, so how can they still have “leopard” in their common name?! The ancient Sanskrit word “prdakuh” translates to “panther, tiger”. See? It works out.
Davis, B.W.; Li, G.; Murphy, W.J. (2010).Supermatrix and species tree methods resolve phylogenetic relationships within the big cats, Panthera (Carnivora: Felidae). Molecular Phylogenetics and Evolution 56 (1): 64–76. doi:10.1016/j.ympev.2010.01.036.
Online Etymology Dictionary: Leopard http://www.etymonline.com/index.php?term=leopard&allowed_in_frame=0
Pocock, R. I. (1930). The panthers and ounces of Asia. Part II. The panthers of Kashmir, India, and Ceylon. Journal of the Bombay Natural History Society 34 (2): 307–36
Snow Leopard Trust. Behavior http://www.snowleopard.org/learn/cat-facts/behavior
Walker, M. (2010). Tigers evolved with snow leopards, gene study reveals http://news.bbc.co.uk/earth/hi/earth_news/newsid_8512000/8512455.stm
Wikipedia: Panthera. https://en.wikipedia.org/wiki/Panthera