PanamacebusPanamacebus is an extinct genus of monkey known from the Early Miocene of central Panama. Panamacebus transitus is the only and type species of this genus.DescriptionTogether with Paralouatta marianae from Cuba, it is the oldest known New World monkey of North America. Fossils of Panamacebus, a left upper first molar and lower premolar, were uncovered from the Las Cascadas Formation, of which tuffs were analyzed providing an age of 20.93 ± 0.17 Ma, of the Panama Canal Zone.