ABSTRACT
The general pattern of bullar inflation may also differentiate tarsiiforms and anthropoids from adapids, most lemuriforms and plesiadapiforms. The fossilized brain of Rooneyia lacks a coronolateral sulcus, common to strepsirhines but replaced in anthropoids by the central sulcus, possibly signaling a close relationship of omomyids with anthropoids. The hypothesis advocated by Matt Cartmill and Richard F. Kay implies that anthropoids shared an immediate common ancestor with tarsiids sensu stricto rather than with some more primitive omomyid or haplorhine. Omomyids typically present an enlarged promontory artery, which enters the bulla posteromedially, and a relatively small stapedial artery branching from it. In haplorhines the inflated bulla is diagonalized and the hypotympanic sinus extends anteromedially before the promontorium. The carotid canal of platyrrhines retains its primitive haplorhine position. It courses laterad across the promontorium from a medial entry into the bulla at the carotid foramen, which lies opposite the ectotympanic meatus.
