Early Hominins Overview

This set of flashcards encompasses key vocabulary terms and definitions related to early hominins, including species names, anatomical features, and evolutionary concepts.

Sahelanthropus tchadensis

An early hominin discovered in Chad, lived about 7 million years ago.

Ardipithecus ramidus

An early hominin that lived approximately 4.4 million years ago, discovered in Ethiopia.

Australopithecines

The earliest well-known hominins that first appeared around 4.2 million years ago.

Australopithecus afarensis

An early hominin that lived in East Africa from 4 to 3 million years ago, known for the fossil 'Lucy'.

Diastema

A gap between the teeth, often present in apes but less so in humans and some hominins.

Mosaic evolution

The concept where different traits appear at different rates in a species.

Laetoli footprints

Fossils from 3.75 million years ago showing bipedal characteristics.

Prognathic face

A facial structure where the jaw juts out, as seen in some Australopithecines.

Robust Australopithecines

A group of early hominins adapted for heavy chewing with large molars, including species like Paranthropus.

Gracile Australopithecines

Early hominins with smaller, less robust features than their 'robust' counterparts.

Sagittal crest

A bony ridge on the skull that serves as an attachment point for chewing muscles.

Paranthropus boisei

A species of robust Australopithecine known for its large cheek teeth.

Natural selection

The process where organisms better adapted to their environment tend to survive and produce more offspring.

Bipedalism

The ability to walk on two legs, a key trait distinguishing hominins from other primates.

Foramen magnum

The large opening at the base of the skull where the spinal cord enters, indicative of bipedalism.

Speciation

The formation of new and distinct species in the course of evolution.

Morphology

The study of the form and structure of organisms.

Holotype

The single type specimen upon which the description and name of a new species is based.

Paleoanthropology

The branch of anthropology concerned with the study of ancient humans and their relatives.

Hominin

A member of the biological family Hominidae, including modern humans, extinct human species, and all the immediate ancestors.

Ancient cranial traits

Characteristics of the skull that reflect ancestral forms, such as those seen in early hominins.

Evolutionary relationship

The connections and ancestry between different species based on shared traits.

Single Species Hypothesis

An outdated model stating that only one hominin species existed at any time during evolution.

Intrasexual competition

Competition among individuals of the same sex, often influencing traits related to mating.

Nuchal crest

A ridge at the back of the skull that provides an attachment for neck muscles.

Climbing ability

An adaptation seen in some early hominins indicating a lifestyle that included arboreal activity.

A./P. robustus

A robust Australopithecus species known from South Africa, lived around 1.8 to 1 million years ago.

Australopithecus africanus

A gracile Australopithecine species that lived in South Africa from 3 to 2.2 million years ago.

Taung Child

Fossil of an Australopithecus africanus child discovered by Raymond Dart.

Fossil record

The history of life on Earth as recorded by fossils.

Postcranial evidence

Fossils and anatomical features found in body parts other than the skull, providing insights into locomotion.

Subfossil

A fossil that is not fully fossilized, often found in a more recent geological layer.