Adapoidea: Order: Primates. One of the earliest groups of euprimates (true primates; earliest records from the early Eocene).
Adaptive radiations: Rapid diversifications of single lineages into many species which may present unique morphological features in response to different ecological settings.
Ancestral traits: Features that were inherited from a common ancestor and which remain (largely) unchanged.
Anthropoids:Group containing monkeys and apes, including humans.
Auditory bulla: The rounded bony floor of the middle ear cavity.
Bilophodonty: Dental condition in which the cusps of molar teeth form ridges (or lophs) separated from each other by valleys (seen, e.g., in modern catarrhine monkeys).
Catarrhines: Order: Primates; Suborder: Anthropoidea; Infraorder: Catarrhini. Group, with origins in Africa and Asia, that contains monkeys and apes, including humans.
Clade:Group containing all of the descendants of a single ancestor. A portion of a phylogenetic tree represented as a bifurcation (node) in a lineage and all of the branches leading forward in time from that bifurcation.
Convergent evolution: The independent evolution of a morphological feature in animals not closely related (e.g., wings in birds and bats).
Crown: Smallest monophyletic group (clade) containing a specified set of extant taxa and all descendants of their last common ancestor.
Diastema: Space between adjacent teeth.
Diffuse coevolution: The ecological interaction between whole groups of species (e.g., primates) with whole groups of other species (e.g., fruiting trees).
Ectotympanic: Bony ring or tube that holds the tympanic membrane (eardrum).
Euprimates: Order: Primates. True primates or primates of modern aspect.
Haplorhines: Group containing catarrhines, platyrrhines, and tarsiers.
Hominins: Modern humans and any extinct relatives more closely related to us than to chimpanzees.
Mandibular symphysis: Fibrocartilaginous joint between the left and right mandibular segments, located in the midline of the body.
Omomyoidea: Order: Primates; Superfamily: Omomyoidea. One of the earliest groups of euprimates (true primates; earliest record in the early Eocene).
Petrosal bone: The portion of the temporal bone that houses the inner ear apparatus.
Plagiaulacoid: Dental condition where at least one of the lower cheek-teeth (molars or premolars) is a laterally compressed blade.
Platyrrhines: Order: Primates; Suborder: Anthropoidea; Infraorder: Platyrrhini. Group containing monkeys found in the Americas.
Plesiadapiforms: Order: Plesiadapiformes. Archaic primates or primate-like placental mammals (Early Paleocene–Late Eocene).
Plesiomorphic: Having features that are shared by different groups which arose from a common ancestor.
Stem: Taxa that are basal to a given crown group but are more closely related to the crown group than to the closest living sister taxon of the crown group.
Strepsirrhines: Order: Primates; Suborder: Stresirrhini. Group containing lemurs, lorises, and galagos (does not include tarsiers).
Toothcomb: Dental condition found in modern strepsirrhines in which the lower incisors and canines are laterally compressed and protrude forward at a nearly horizontal inclination. This structure is used in grooming.
