''Clyomys'' is a

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...

genus in the family

Echimyidae Echimyidae is the family of neotropical spiny rats and their fossil relatives. This is the most species-rich family of hystricognath rodents. It is probably also the most ecologically diverse, with members ranging from fully arboreal to terr ...

. It contains two species, found in tropical savannas and grasslands from circa to elevation in central

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

and eastern

Paraguay Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...

. The term ''Clyomys'' derives from the two

ancient greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...

words (, or ''clyo''), meaning "to listen, to prick up one's ears", and (), meaning "mouse, rat". The ''Clyomys '' species are as follows: * Broad-headed spiny rat (''Clyomys laticeps'') * † ''Clyomys riograndensis''

Phylogeny

''Clyomys'' is the sister genus to ''Euryzygomatomys''. Both taxa are closely related to the genus ''Trinomys''. In turn, these three genera — forming the clade of

Euryzygomatomyinae Euryzygomatinae is a subfamily of rodents, proposed in 2017, and containing three extant genera of spiny Echimyidae: '' Clyomys'', '' Euryzygomatomys'', and ''Trinomys''. Members_of_this_echimyid_subfamily_all_share_an_origin_in_the_eastern_part ...

— share phylogenetic affinities with a clade containing ''

Carterodon Owl's spiny rat (''Carterodon sulcidens'') is a rodent species in the family Echimyidae found in Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and ...

'' and members of the family Capromyidae. Analyses of craniodental characters proposed that ''Clyomys'' — and also ''Euryzygomatomys'' — may be associated with ''Carterodon''. However, molecular data suggest the polyphyly of this assemblage of fossorial genera.

References

Echimyidae Rodent genera Taxa named by Oldfield Thomas {{Echimyidae-stub