Tupaiid

Some authors rank tupaiids in a separate order Tupaioidea (Martin, 1966), while others retain them among the Primates (Napier and Napier, 1967) or 1nsectivora (Hill, 1953b). The uncertainty surrounding tupaiid phylogeny is a consequence of an inadequate fossil record.

Dental characters have proven to be of little use as there is no Paleocene tree shrew, which would show more primitive tupaiid dental characters. From the dentition of living tupaiids, one would easily infer that all of them have derived characters that prevent them from being ancestral to primates, among which [are] specializations in their dentitions or molar characters in tupaiines (see Butler, 1980).

Figure 12.16 A typical tupaiid. This common treeshrew (Tupaia glis) superficially resembles a squirrel. Tupaiids have had a confused taxonomic history—at various times being placed in the Orders Primates and Insectivora, and currently within their own order, Scandentia.