Leiorhynchus

Leiorhynchus is an extinct genus of brachiopod belonging to the order Rhynchonellida and family Leiorhynchidae.^[1] Specimens have been found in South America,^[2] North America, and Russia^[3] in beds of middle Devonian^[4] to Mississippian^[3] age (372 to 325 million years old).^[5] The genus may have been adapted to dysaerobic environments, colonizing areas of reduced oxygen concentrations rich in organic matter.^[6] The genus has been used as an index fossil in North America.^[7]

Leiorhynchus Temporal range: Devonian-Mississippian ~387–325 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Brachiopoda
Class:	Rhynchonellata
Order:	Rhynchonellida
Family:	†Leiorhynchidae
Subfamily:	†Leiorhynchinae
Genus:	†Leiorhynchus Hall 1860
Species
See text

Species

• L. carboniferum^[5]
• L. castanea Meek 1868^[8]
• L. hippocastanea Crickmay 1960^[8]
• L. kelloggi Hall 1867^[9]
• L. mesacostale Hall 1843^[8]
• L. miriam Johnson 1971^[4]
• L. quadracostatus Vanuxem 1842^[3]
• L. ripheicus Stepanov 1948^[10]
• L. rockymontanum Marcou 1858^[2]