Not all the fossils in the Western Science Center collection came from huge Ice Age mammals. In keeping with my post from a few days ago about possible modern rabbit traces on the WSC grounds, for this Fossil Friday we’ll look at an example of a fossil rabbit.
Most of the rabbit remains in the WSC collection are isolated teeth, recovered by screening sediment from Pleistocene sites. As you might expect, most of them are tiny; the partial cheek tooth in the image at the top is only about 3 mm long. Like many herbivorous mammals, rabbits have teeth in which the enamel is curved into folds, making a series of sharp ridges on the chewing surface as the tooth wears down. Rabbits have a particularly deep groove running along the lateral side of the tooth, visible in a different view of the same specimen:
This tooth is close to square in cross section, Suggesting that it’s probably a lower tooth (either the 4th premolar or the 1st or 2nd molar). The upper cheek teeth in rabbits are more rectangular in cross section, roughly twice as wide as they are long. This particular tooth is identified in the collection records as Sylvilagus sp., and while I’m not yet familiar enough with rabbit anatomy to confirm this, the size is consistent with Sylvilagus.
Sylvilagus, of course, is a rabbit that’s still widespread in California today, which brings up an important point about Pleistocene faunas. We have a tendency when describing the Ice Age of talking about big, impressive animals like mastodons, mammoths, and sabertooth cats (the “charismatic megafauna”), but most of the animals present during the Pleistocene are the same ones that are around today. It’s easy to forget that cottontail rabbits were grazing in the same meadows as Columbian mammoths.