What is "pecopteris"

Pecopteris \Pe*cop"te*ris\, n. [NL., fr. Gr. ? to comb + ? a kind of fern.] (Paleon.) An extensive genus of fossil ferns; -- so named from the regular comblike arrangement of the leaflets.

n. Carboniferous fossil fern characterized by a regular arrangement of the leaflets resembling a comb

Pecopteris is a very common form genus of leaves. Most Pecopteris leaves and fronds are associated with the marattialean tree fern Psaronius. However, Pecopteris-type foliage also is borne on several filicalean ferns, and at least one seed fern. Pecopteris first appeared in the Devonian period, but flourished in the Carboniferous, especially the Pennsylvanian. Plants bearing these leaves became extinct in the Permian period.