Hesperorthis sulcata 1.jpg

Hesperorthis sulcata Brachiopod

Bromide Formation, Oklahoma, USA
Ordovician Age (488.3 -443.7 million years ago)
Hesperorthis, extinct genus of brachiopods, or lamp shells, which as fossils are especially characteristic of Ordovician marine rocks (438 to 505 million years old). The plano-convex shell of Hesperorthis consists of two units (or valves), the brachial valve being flat and the pedicle valve convex. The shell has a radiating pattern of ribs and a relatively broad, triangular area at the dorsal shell margin.
Kingdom: Animalia
Phylum : Brachiopoda
Subphylum: Rhynchonelliformea
Class: Rhynchonellata
Order: †Orthida
Suborder: †Orthidina
Superfamily: †Orthoidea
Family: †Hesperorthidae
Genus: †Hesperorthis
Species: †sulcata