ANTRHO105 Exam 3 - Section 3 Ancient Environments, Fossils & First Primates - VOCAB ONLY

Continental drift

Movement of continents over geological time through plate tectonics.

Pangaea

The ancient supercontinent that later broke apart into today's continents.

Therapsids

a group of animals that includes mammals and their extinct relatives. Mammals evolved from earlier therapsids.

Mammal radiation

Diversification of mammals into many ecological roles, especially after non-avian dinosaur extinction.

Deep-sea cores

Columns of seafloor sediment containing a chronological environmental record.

Oxygen isotopes

Forms of oxygen with different neutron numbers; oxygen-18/oxygen-16 ratios help reconstruct past temperature and ice volume.

Fossilization

Processes preserving remains/traces, often through burial and mineralization.

Fossil

Preserved evidence of past organisms, including body remains or traces.

Fossil record

The discovered/preserved evidence of past life, which is incomplete and unevenly sampled.

Stratigraphy

Study of rock/sediment layers and their sequence.

Principle of superposition

In an undisturbed sequence, lower layers are older than layers above.

Carbon-14

A radioactive carbon isotope that decays with a half-life of about 5,730 years.

Radioactive decay

Predictable statistical breakdown of unstable isotopes into daughter products.

Carbon dating

Dating once-living material using remaining carbon-14; useful for relatively recent, not million-year-old, material.

Potassium-argon dating

Dating suitable volcanic rocks using decay of potassium-40 to argon-40, often to bracket fossil ages.

Plesiadapiforms

Early primate-like mammals lacking the full suite of true-primate traits in the course comparison.

Paleocene

Epoch preceding the Eocene, about 66-56 million years ago.

Eocene

Epoch about 56-34 million years ago, when true primates diversified in warm, widespread forests.

Adapids

An Eocene Primate. Associated strepsirrhines, especially lemurs.

Dinurnal (anti-nocturnal), quadrupedal, larger vs omoyids

Omomyids

Eocene primates associated in the course with tarsiers.

nocturnal & leaper

Angiosperm hypothesis

Primate traits evolved in connection with exploiting flowering plants and their foods.

Visual predation hypothesis

Grasping and forward-facing eyes evolved for visually guided capture of small prey.

Leaping hypothesis

Primate grasping hands and feet and improved depth perception evolved to help them judge distances and land securely when jumping between branches.

Generalized nocturnal hypothesis

UNVERIFIED COURSE DEFINITION: O21 names this hypothesis without explaining it. Obtain the assigned reading/lecture explanation before memorizing a specific formulation.

Terminal branch hypothesis

Primate grasping hands and feet evolved to help them move and feed on the thin outer branches of trees.