Contains classification guide.

Features image of specimens from the Auburn University teaching collection.

Contains list of families.

Discusses unique features. Includes field identification key.

Discusses unique features. Includes anatomy.

Covers first page, citation, and abstract of article by Bigelow, Phillip K. Includes access and purchase links.

Contains descriptions of families. With photos.

Provides guide to families.

Discusses distinguishing features of the group.

Presents common names and etymology for order and class, sister order, first fossil record, families, and characteristics.

Abstract of the study by Adnet, Sylvain and Cappetta, Henri accompanies information on subjects and link to full article.

Shows images of fossils.

Provides classification guide.

Contains classification guide.