''Emiliodonta'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

bivalve Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

in the

family Praenuculidae. The genus is one of three genera in the subfamily Concavodontinae. ''Emiliodonta'' is known solely from late Ordovician, Caradocian epoch, fossils found in South America. The genus contains a single accepted species, ''Emiliodonta cuerdai''.

Description

''Emiliodonta cuerdai'' is a bivalve first described in 1999 by Teresa M. Sánchez from fossils from sediments of the late Middle Ordovician, Caradocian-aged Don Braulio Formation. The formation outcrops on the flank of Sierra de Villicum in the

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

precordillera.The Paleobiology database "Sierra de Villicum" entry
accessed 17 January 2012 Generally the shells of ''Emiliodonta cuerdai'' are rounded and distinctly inflated. The shells have an umbo positioned on the anterior edge of the shell prosogyratly, with the beak curving towards the anterior side. The shell hinges have a series of twelve to fourteen concavodont teeth along the posterior edge and a series of five larger concavodont teeth on the anterior edge. The two series meet at the umbo with a group of four to five orthomorphic teeth. ''Emiliodonta'' ranges in shell length from and has a height between . As a member of Concavodontinae, the hinge displays the chevroning of teeth typical of the subfamily. The teeth have a concavity in the chevron, which faces away from the center of the hinge and the umbo. When first described, the genus name ''Emiliania'' was chosen by Sánchez in reference to her father Emiliano Sánchez. However the genus name '' Emiliania'' is a

homonym In linguistics, homonyms are words which are either; '' homographs''—words that mean different things, but have the same spelling (regardless of pronunciation), or '' homophones''—words that mean different things, but have the same pronunciat ...

already used by W.W. Hay & H.P. Mohler in 1967 for a genus of

coccolithophore Coccolithophores, or coccolithophorids, are single-celled organisms which are part of the phytoplankton, the autotrophic (self-feeding) component of the plankton community. They form a group of about 200 species, and belong either to the kingdom ...

. In a 2010 paper, Sánchez moved the species to the generic ''Emiliodonta'' name. The species epithet ''cuerdai'' was coined in honor of C. Cuerda, a professor at the Universidad de La Plata and friend of Teresa M. Sánchez.

References

{{Taxonbar, from=Q5371979 Praenuculidae Monotypic prehistoric bivalve genera Ordovician bivalves Fossil taxa described in 2010