Felidae
Felidae
Well-known felines: [A graph organizing various feline species labeled with common names ordered by genera (in order of which would win in a fight) on the y axis, and coolness of name on the x axis.] Smilodon (extinct): "Saber-toothed cat (scientific name: Smilodon fatalis) Panthera: "Jaguar", "Leopard", "Snow Leopard", "Tiger", "Lion" Puma: "Cougar", "Puma", "Panther", "Mountain Lion" Other felidae: "Ocelot", "Cheetah" Felis & Lynx: "Housecat", "Bobcat", "Wildcat", "Lynx" [Some elements are further connected using an unbranched acyclic digraph. The elements are connected thus: "Cheetah" -> "Puma" -> "Jaguar" -> "Panther" -> "Tiger" -> "Leopard" -> "Snow Leopard" -> "Lion" -> "Mountain Lion".] The OS X Problem

This comic shows a graph with three parts.
First, the names are sorted up by genera (plural of genus , a low-level taxonomic rank used in the biological classification of living and fossil organisms) from bottom to top of which animals would win in a fight. Secondly, the names within the genus are then sorted by coolness of name from left to right (the degree of "coolness" of the name is apparently determined in subjective manner by the author). Thirdly, in red you can see the direction that Apple has taken with nicknaming the versions of their OS X operating system. They started at v10.0 "Cheetah", and have moved through genera from there in no order that this chart can make out.
Please note that the second words in "Snow Leopard" and "Mountain Lion" are capitalized in the table because they are used as the proper names of the operating system versions. In their normal use, as species vernacular names , they are not capitalized and are written as "snow leopard" and "mountain lion".
Bobcats are a running XKCD joke, so their inclusion is to be expected. The genus Puma here only lists synonyms for the puma (see cougar ) instead of the actual genus . Of course, the three OS X versions named by three of these synonyms are not the same.
Since this comic was published, Apple has stopped naming versions of OS X after big cats, and now names them after Californian landmarks. OS X v10.8 "Mountain Lion" was followed by v10.9 "Mavericks", named after a surf spot , followed by v10.10 "Yosemite", named after a national park , and so on.
The title of the chart depicted on the comic ("OS X problem") is perhaps an allusion to the travelling salesman problem , as the directed arrows and graph nodes might appear as a possible path of the salesperson between the cities. The computational difficulty of the travelling salesman problem might echo with the difficulties that the author has with trying to figure out the underlying reason for naming the OS X versions in particular order. The chart thus looks like a parody on the scientific presentation.
In the title text, a Smilodon fatalis is a saber-tooth cat, a Dracorex hogwartsia is a dinosaur whose skull looks like that of a fairy tale dragon, and a Stygimoloch spinifer is one of the last dinosaurs before the K-T (Cretaceous-Paleogene) extinction about 66 million years ago. Notably, it's possible both Stygimoloch and Dracorex are in fact juvenile members of the genus Pachycepholosaurus who were wrongly identified as a separate species, meaning two of Randall's top four coolest extinct animal names would no longer be recognized. All of the animals mentioned in the title text are now extinct.
Well-known felines: [A graph organizing various feline species labeled with common names ordered by genera (in order of which would win in a fight) on the y axis, and coolness of name on the x axis.] Smilodon (extinct): "Saber-toothed cat (scientific name: Smilodon fatalis) Panthera: "Jaguar", "Leopard", "Snow Leopard", "Tiger", "Lion" Puma: "Cougar", "Puma", "Panther", "Mountain Lion" Other felidae: "Ocelot", "Cheetah" Felis & Lynx: "Housecat", "Bobcat", "Wildcat", "Lynx" [Some elements are further connected using an unbranched acyclic digraph. The elements are connected thus: "Cheetah" -> "Puma" -> "Jaguar" -> "Panther" -> "Tiger" -> "Leopard" -> "Snow Leopard" -> "Lion" -> "Mountain Lion".] The OS X Problem
