Vertebrates

Myllokunmingia fengjiaoa

A slender, 3-cm-long animal that swam in the oceans during the early Cambrian period, closely related to vertebrates.

Vertebrates

Animals with a backbone, named for the series of bones called vertebrae that constitute the vertebral column.

Notochord

A longitudinal, flexible rod that provides skeletal support in all embryonic and some adult chordates.

Dorsal hollow nerve cord

A structure that develops from ectoderm and forms the central nervous system, distinguishing chordates from other animal phyla.

Pharyngeal slits

Grooves that develop into slits permitting water to exit without passing through the digestive tract; modified for gas exchange in vertebrates.

Amniotic egg

A key adaptation for life on land in amniotes, providing extraembryonic membranes for gas exchange, waste storage, and nutrient transfer.

Gnathostomes

Vertebrates that possess jaws, including sharks, rays, and various fish, amphibians, reptiles, and mammals.

Chondrichthyes

A clade including sharks and rays that have cartilaginous skeletons instead of bones.

Osteichthyes

A clade consisting of tetrapods and bony fishes, characterized by a hard matrix of calcium phosphate in their skeletons.

Tetrapods

Gnathostomes that have limbs adapted for life on land.

Amphibiann

A class of vertebrates that includes salamanders, frogs, and caecilians, characterized by their dual life cycle in water and on land.

Synapsids

A group of amniotes that mammals belong to, characterized by having a temporal fenestra out of the skull.

Primates

A mammalian order that includes lemurs, tarsiers, monkeys, and apes, characterized by grasping hands and a larger brain.

Homo sapiens

The species name for modern humans, distinguished by advanced cognitive abilities and bipedal locomotion.

Paleoanthropology

The study of human origins and the evolutionary history of hominins.

Australopiths

A paraphyletic group of early hominins related to modern humans, whose evolution remains complex and unresolved.

Homo erectus

The first hominin to migrate out of Africa, known for its larger brain and advanced tool use.

Homo floresiensis

An extinct species of hominin found in Indonesia, characterized by its small size and reduced brain volume.