Pragian life

Pteraspis (from 'wing' or 'fin' and 'shield') is an extinct genus of pteraspidid heterostracan jawless fish. It existed from the Lochkovian to Eifelian epochs of the Devonian period in areas that are now the Americas and Europe.

Calymene is a genus of trilobites in the order Phacopida, suborder Calymenina, that are found throughout North America, North Africa, and Europe in primarily Silurian outcrops. Calymene is closely related to Flexicalymene, and both genera are frequently found enrolled. Calymene trilobites are small, typically 2 cm in length. The cephalon is the widest part of the animal and the thorax usually has 13 segments.

Boreaspis (meaning "Boreas's Shield") is an extinct genus of osteostracan agnathan vertebrate that lived in the Devonian period.