Productida

Productida is an extinct order of brachiopods in the extinct class Strophomenata. Members of Productida first appeared during the Silurian. They represented the most abundant group of brachiopods during the Permian period, accounting for 45-70% of all species. The vast majority of species went extinct during the Permian-Triassic extinction event, though a handful survived into the Early Triassic. Many productids are covered in hollow tubular spines, which are characteristic of the group. A number of functions for the spines have been proposed, including as a defensive mechanism against predato

Chonetes is an extinct genus of brachiopods. It ranged from the Late Ordovician to the Middle Jurassic.

Gigantoproductus is a genus of extinct brachiopods in the order Productida and the family Monticuliferidae. The species were the largest of the carboniferous brachiopods, with the largest known species (Gigantoproductus giganteus) reaching in shell width. Such huge invertebrates appeared in the Mississippian as the proportion of oxygen in the atmosphere began to rise. The earliest members of the Productida date back to the Silurian period, and Gigantoproductus is known to have existed between 339.4 and 318.1 million years ago, during the Carboniferous period. As fossils, their shells occur wit