Abstract
The skeletal composition of the lacrimal fossa, classifiable as a totally lacrimal lacrimal fossa (L-LF) or a maxillo-lacrimal lacrimal fossa (ML-LF), was observed in 1890 skulls of cercopithecids. The incidence of the L-LF is highly variable among cercopithecines, and is very low or non-existent in colobines as well as in hominoids. This finding, as well as the findings of Benefit and McCrossin (1993), negates Strasser and Delson (1987), who list the L-LF as a cercopithecine synapomoiphy with an ideally concordant distribution, and leads to a revised cladistic hypothesis of this character. The diversity of the L-LF among cercopithecine taxa cannot be wholly explained by a single factor such as facial elongation or terrestiality, but contains several patterns congruent with recent evolutionary hypotheses.
