The Paleontology of North America

Agnathans from North America

> Agnathans | Lobe-finned Fish | Placoderms and Acanthodians | Ray-finned Fish | Sharks and Relatives

What are Agnathans? The term agnatha means “no jaw,” and this group includes a wide variety of jawless fishes. Most extinct agnathans had thick bodies, paired fins, and body armor of some kind. Living agnathans, the lampreys, have elongated bodies, and lack body armor and paired fins. Agnathans arose in the Cambrian and were at their highest diversity during the Early to Middle Paleozoic. Note: While often grouped with agnathans, hagfish are more closely related to other chordates and are discussed in Hemichordates and Chordates.

First known fossil occurrence: Cambrian.

Last known fossil occurrence: Quaternary. This group has living relatives.

Fossils through time:
Choose a time period to see what life was like:

Quaternary
Tertiary
Cretaceous
Jurassic
Triassic
Permian
Carboniferous
Devonian
Silurian
Ordovician
Cambrian
Precambrian