mammals

The skeleton of Daeodon (Dinohyus), an entelodont. There are few fossil mammals that are as scary-looking as entelodonts. Justifiably called "Hell Pigs" in the book Cruisin' the Fossil Freeway, the long, toothy skulls of entelodonts are certainly imposing. This extinct group of pig relatives didn't just look fierce, though; the construction of their jaws and taphonomic evidence suggests that they had a taste for flesh as well as for plant foods. Although entelodonts were most likely omnivores, their skulls show a variety of features that seem to be convergent with carnivores, especially…
Giraffa camelopardalis
Presently only two genera of sloths exist, the two-toed sloths (Choloepus) and the three-toed sloth (Bradypus). They are the remaining vestiges of a much great past diversity, including many of the giant forms like Megatherium that occupied niches both in the trees and on the ground. As with most fossil mammals, though, the delicate inner ear bones of extinct ground sloths have rarely been preserved, but a new paper published in the Journal of Vertebrate Paleontology attempts to analyze what the fossil sloths Glossotherium robustum and Lestodon armatus could hear based upon some well-…
Tursiops truncatus
Charles R. Knight's Robert Bruce Horsfall's restoration of Thoatherium as it appeared in the book A History of Land Mammals In The Western Hemisphere (many thanks to Dan Varner for providing the image). Convergent evolution is an absolutely amazing phenomenon. Why do creatures, both closely and distantly related, sometimes develop the same body types or adaptations? Saber-teeth are my most favorite convergent character, but I recently found out about another case of convergence that is just as interesting. In South America there used to be a group of animals called Litopterns, the most…
Panthera uncia
One of Charles R. Knight's paintings of Smilodon fatalis, this one menacing a giant sloth stuck in tar (off panel). There are few fossil mammals that are as impressive as the saber-toothed cat Smilodon fatalis, but despite it's fearsome dentition some recent reports have suggested it was more of a pussycat when it came to bite strength. This seems to be counter-intuitive; how could such a fearsome-looking animal be associated with the term "weak"? Incredulity aside, it has become apparent that the bite of Smilodon wasn't as strong as that of some other carnivores (extinct and extant), yet…
Cheeta turns 76 today, continuing his run as the oldest living non-human primate. You can donate to the CHEETA sanctuary (which also cares for other ex-movie primates) here.
Panthera pardus orientalis
Melursus ursinus
Panthera leo
Between 2005 and 2007, USGS scientists studying black and grizzly bears captured video footage of the carnivores rubbing up against trees. Scent marking might be part of why the bears are exhibiting this behavior, but they probably just need a good scratch every now and then, too; LiveScience also covered this behavior in a new article, saying the bears are "dancing," although it's definitely not as elaborate as this; [ReBecca also covered this story in a bit more detail.]
Ailurus fulgens (See Darren's latest post about red pandas for more.)
Giraffa camelopardis
Did our ancestors exterminate the woolly mammoth? Well, sort of. According to a new study, humans only delivered a killing blow to a species that had already been driven to the brink of extinction by changing climates. Corralled into a tiny range by habitat loss, the diminished mammoth population became particularly vulnerable to the spears of hunters. We just kicked them while they were down. The woolly mammoth first walked the earth about 300,000 years ago during the Pleistocene period. They were well adapted to survive in the dry and cold habitat known as the 'steppe-tundra'. Despite the…
Although it started as part of holiday traditions in India, elephant polo has grown into a more regularly played sport, even having its own official association, the World Elephant Polo Association. Only Indian elephants (Elephas maximus) are used in the games, and the clip below shows the somewhat chaotic nature of the game;
Panthera uncia
A mother California sea lion (Zalophus californianus) lunges to bite her pup on the rear.
You might not be that impressed to receive a clump of grass or branches on a first date, but a boto dolphin might think differently. A new study suggests that these Amazonian dolphins wave bits of flotsam to attract mates. The boto is a freshwater river dolphin that swims through the currents of the Amazon and the Orinoco. They are elusive creatures that are difficult to study, so very little is known about their social lives. Tony Martin from the University of St Andrews spent three years in the Amazonian Mamiraua reserve studying the behaviour of botos. During this time, he spotted over…