Sunday, 28 June 2020
It's been known for a long time that, at the highest level, mammals can be divided into three evolutionary groups based on their method of giving birth: marsupials, the egg-laying monotremes, and the placental mammals. That last group contains around 95% of all living mammal species, including everything from wolves to dolphins and moose to monkeys.
Given that wide variety, it's less obvious how we should divide up the placental mammals into smaller groups that genuinely reflect their evolutionary relationships. It's obvious that, say, cheetahs are members of the cat family and, at a slightly higher level, it's unsurprising that, for example, the dog and bear families are reasonably close relatives of one another. But once you get much higher than that, it becomes less so.
Sunday, 21 June 2020
The most famous of these sites are those connected with the evolution of our own species, but there are a number of sites that have yielded, for example, significant dinosaur fossils. When it comes to mammals other than humans (and whatever else was living alongside them), Kenya and South Africa have proved particularly rich sources - although, of course, there are others.
Sunday, 14 June 2020
Lynxes are readily identifiable animals, and the word "lynx" itself dates back to at least the Ancient Greeks. They were also one of the original seven species of cat identified by Linnaeus in 1758 when he created the modern system for scientific naming of animals. As early as 1792, they were split off from the other cats into a subgenus of their own, now considered a full genus. This was in Robert Kerr's translation of Linnaeus' original work into English, by which point, at least four different species of lynx had been scientifically named and described (including one by Kerr himself, in the book in question).
Sunday, 7 June 2020
Because of these primitive features, determining exactly where they fit in the pig family tree isn't a simple matter, but they are often placed with a group called the kubanochoerines. Assuming this is correct (and it's far from settled) they must have evolved fairly rapidly into much larger and more distinctive animals. The best-known member of the group is the giant "unicorn-pig" Kubanochoerus, which lived in China during the Late Miocene. This was an exceptionally large, long-legged animal, perhaps standing 120 cm (4 feet) high at the shoulder and - even more dramatically - sporting a long pointed horn that projected from the centre of its forehead.