SK 63

Drimolen dental analysis was published yesterday in Journal of Human Evolution, and in the class I’m TAing we’re talking about A. robustus. So I’ve been thinking about A. robustus lately. Here’s a picture of SK 63 I drew this summer. It’s a juvenile, with a nice molarized deciduous first molar, tall ascending ramus with posteriorly-pointing coronoid process.

SK 62 sketch

Copying John Hawks, here’s a picture I drew a few weeks ago while looking at some of the juvenile Australopithecus robustus material from Swartkrans. This cute little bugger is SK 62. On the left it preserves the deciduous (a.k.a. “baby”) left second incisor through the deciduous second molar; on the right are the deciduous canine and molars. The permanent (“adult”!) central incisors are in the process of erupting, and the left permanent first molar is visible in its crypt behind the dm2. What I like about its deciduous canines (I think most or all A. robustus juvenile canines are like this) is that they are quite asymmetrical, with the bulk of the crown displaced mesially, and a little lingual tubercle/ridge distally. Looks like a mitten. The corpus is tallest anteriorly but gets shorter as it runs posteriorly–this pattern is slightly less marked in adults. It appears to have a weak ‘chin,’ huh?