The type specimen is relatively intact, missing only the
premaxillae, post orbital bars, zygomatic arches, and portions of the neurocranium. The natural
endocast of the braincase is largely undistorted as well. While only the skull of
Rooneyia has been recovered, much can be learned.
Rooneyia viejaensis preserves a funnel-shaped orbital fossa deeply recessed below the forebrain; located posteriorly in the face near the craniofacial junction.
Rooneyia’s orbits are highly convergent and forward facing. The frontal bone is relatively large in size with a fused metopic suture that extends like a roof above the orbit. The exterior surface of the frontal lacks any indication of longitudinal ridge or sagittal canal.
Rooneyia has a dorsoventrally and laterally extensive frontal process that forms a partial postorbital septum which implies the existence of a relatively large ascending processes of the zygomatic bone. Though the absence of the ascending process of the zygomatic makes it impossible to make an accurate reconstruction of the structure.
Rooneyia is more primitive than some tarsiiaforms it has been compared to, which typically had relatively small orbits. While the tip of the snout is missing from the
Rooneyia fossil, based on the premolar to molar layout, it can be inferred that the dental arcade was not bell-shaped
Rooneyia retains primitive features in its nasal region, but has a relatively large brain and what some have interpreted to be the beginnings of a post orbital closure. ==Paleobiology==