Primate Origins and Evolution: The First 50 Million Years

A set of vocabulary flashcards based on lecture notes regarding primate evolution, covering the Paleocene through the Miocene, including key fossil species and evolutionary hypotheses.

Repenomamus robustus

An early mammal from the Mesozoic times (~$125\,mya$) that was approximately the size of a possum and is known for eating dinosaur hatchlings.

Vintana sertichi

A bizarre fossil skull from Madagascar dated to approximately $66\,mya$ representing a mammal that weighed about $20\,pounds$.

Arboreal Adaptation Hypothesis

The theory that primate characteristics like forward-facing eyes for stereoscopic vision, grasping hands and feet, and nails instead of claws evolved as adaptations for life in a three-dimensional tree environment.

Visual Predation Hypothesis

Proposed by Cartmill, this idea suggests primate traits like forward-facing eyes and grasping hands evolved for depth perception to hunt insect prey in the bushy undergrowth.

Angiosperm Radiation Hypothesis

Proposed by Sussman, this theory suggests that traits like color vision and grasping hands/feet evolved as adaptations for eating fruit, nectar, and pollen from flowering plants.

Plesiadapiforms

Primate-like mammals of the Paleocene that were anatomically more primitive than living primates, lacking a postorbital bar and convergent eyes.

Purgatorius

A generalized genus of plesiadapiform with less spiky teeth that might be ancestral to the first clear primates of the Eocene.

Carpolestes

A plesiadapiform from Wyoming ($58\,mya$) that possessed grasping feet and a nail on the big toe, but retained claws on most digits and nonconvergent eyes.

Euprimates

The first "true" primates that appeared in the Eocene epoch, characterized by having forward-facing eyes and a postorbital bar.

Omomyids

A group of Eocene euprimates that were nocturnal and characterized by a short snout.

Adapids

A group of Eocene euprimates that were diurnal and exhibited sexual dimorphism.

Adaptive Radiation

The process of diverse adaptations developing among the descendants of a single form, such as the various lemur types on Madagascar or anthropoids in the Oligocene.

Archicebus

The earliest known haplorhine, dated to $55\,mya$ from Hubei Province, China; it was small, diurnal, arboreal, and insectivorous.

Eosimias

A basal anthropoid from China dating to $42\,mya$ with anthropoid-like teeth and a short heel (calcaneus).

Aegyptopithecus

A genus of early catarrhine from the Fayum in Egypt ($29-37\,mya$) that weighed about $12\,pounds$ and had a dental formula of $2.1.2.3$.

Proconsulids

Early Miocene hominoids ($17-22\,mya$) characterized by Y-5 molars, honing canines, and the absence of a tail.

Morotopithecus bishopi

An early Miocene ape from Africa that showed postcranial adaptations for climbing and brachiation and could weigh up to $100\,pounds$.

Dryopithecids

A group of Miocene apes (~$15-18\,mya$) that expanded out of Africa into Europe, including countries like Spain, France, and Germany.

Sivapithecids

Miocene apes from Pakistan and India ($8-12\,mya$) that had thick tooth enamel for eating hard foods and skulls similar to modern orangutans.

Gigantopithecus

An extinct ape from Asia ($0.5-8.0\,mya$) that weighed over $660\,pounds$ and had massive jaws.

r-selection

A reproductive strategy based on population growth potential ($r$), involving many offspring, little parental investment, rapid maturity, and high mortality.

K-selection

A reproductive strategy based on the carrying capacity of a habitat ($K$), involving fewer offspring, high parental investment, slow maturity, and low mortality.