| Duke University
Lemur Center Division of Fossil Primates |
| KC Beard and RD MacPhee, Cranial Anatomy of Shoshonius...in Anthropoid Origins, p.62. |
| This specimen, a Shoshonius, is from the Wind River Basin, early Eocene of Wyoming. Within a very extensive discussion of relationships of Shoshonius to other omomyids, these authors conclude (p87) "Shoshonius appears to share most recent common ancestry with Tarsius." Since Shoshonius shows only rudimentary development of an external auditory meatus, and both plathyrrines and primate anthropoidea lack it altogether, their research demonstrates, among other things, the tubular ectotympanic meatus seen in both anthropoids and Tarsius is a convergent development. For example, both Plesiadapis and Megaladapis, which are neither related to each other, or to Shoshonius, Tarsius, or the old world anthropoidea, also have the auditory canal encased in a bony tube. Note in this figure how the external wings of the pterygoids extend backwards toward the front end of the bulla, as in Tarsius. |