The

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 ...

''Kerodon'' (vernacular name mocos; rock cavies) contains two

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

n rock cavies, related to

capybara The capybara or greater capybara (''Hydrochoerus hydrochaeris'') is the largest living rodent, native to South America. It is a member of the genus '' Hydrochoerus''. The only other extant member is the lesser capybara (''Hydrochoerus isthmi ...

s and

guinea pig The guinea pig or domestic guinea pig (''Cavia porcellus''), also known as the cavy or domestic cavy ( ), is a species of rodent belonging to the genus ''Cavia'', family Caviidae. Animal fancy, Breeders tend to use the name "cavy" for the ani ...

s. They are found in semiarid regions of northeast

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

known as the

Caatinga Caatinga () is a type of semi-arid tropical vegetation, and an ecoregion characterized by this vegetation in interior northeastern Brazil. The name "Caatinga" comes from the Tupi word '' ka'atinga'', meaning "white forest" or "white vegetat ...

. This area has a rocky terrain with large granite boulders that contain rifts and hollows where ''Kerodon'' species primarily live.

Characteristics

They are hystricomorph

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

s, medium-sized, with bodies, a face, and heavily padded feet. Their nails are blunt on all digits except a small grooming claw on the outermost digit of the foot. Fully grown adults weigh around 1000 g or 31–35 oz, and range in length from 200 to 400 mm or 7.5 to 16 in. They forage for mostly leaves, grasses, seeds, and tree bark. They breed year round, usually having one to three litters per year and one to three young per pregnancy. Gestation last around 76 days and the young are weaned from the mother within 33 days. They reach sexual maturity at 133 days.

Behavior

Like their relatives, the capybaras and the maras, members of the genus ''Kerodon'' are highly social.Rowe, D. L. and R. L. Honeycutt. 2002. Phylogenetic relationships, ecological correlates, and molecular evolution within the Cavioidea (Mammalia, Rodentia). Molecular Biology and Evolution, 19:263-277. ''Kerodon'' species, like capybaras, are

polygynous Polygyny () is a form of polygamy entailing the marriage of a man to several women. The term polygyny is from Neoclassical Greek πολυγυνία (); . Incidence Polygyny is more widespread in Africa than in any other continent. Some scholar ...

, with males forming

harem A harem is a domestic space that is reserved for the women of the house in a Muslim family. A harem may house a man's wife or wives, their pre-pubescent male children, unmarried daughters, female domestic Domestic worker, servants, and other un ...

s. They are very vocal creatures and produce various whistles, chirps, and squeaks. Males establish ownership over one or several rock piles and defend their territories. Within each group, a hierarchical structure exists. They are primarily active during late hours of the day.

Classification

Traditionally, the genus ''Kerodon'' has been considered a member of the subfamily

Caviinae Caviinae is a subfamily uniting all living members of the family Caviidae with the exception of the maras, capybaras, and '' Kerodon''. The subfamily traditionally contained the guinea pig or cavy-like forms along with the cursorially adapted ...

along with the guinea pigs and other cavies.

Molecular A molecule is a group of two or more atoms that are held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, ...

results have consistently suggested ''Kerodon'' is most closely related to the capybara, and the two evolved from within the Caviidae. This led Woods and Kilpatrick (2005) to unite the two into the subfamily

Hydrochoerinae Hydrochoerinae is a subfamily of Caviidae, consisting of two living genera, ''Hydrochoerus'', the capybaras, and '' Kerodon'', the rock cavies. In addition, a number of extinct genera related to capybaras should also be placed in this subfamily. ...

within the Caviidae. Using a

molecular clock The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. The biomolecular data used for such calculations are usually nucleot ...

approach, OpazoOpazo, J. C. 2005. A molecular timescale for Caviomorph rodents (Mammalia, Hystricognathi). Molecular Phylogenetics and Evolution, 37:932-937. suggested ''Kerodon'' diverged from ''Hydrochoerus'' (the capybara) in the late Middle

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

Species

*''

Kerodon acrobata The acrobatic cavy (''Kerodon acrobata'') also known as the acrobatic moco and climbing cavy is a Caviidae, cavy species native to Brazil. It is found from Goiás state to Tocantins state, west of the Espigão Mestre, Serra Geral de Goiás, and is ...

'' Moojen, Locks & Langguth, 1997 – climbing cavy *'' Kerodon rupestris'' Wied-Neuwied, 1820 – rock cavy

Characteristics

Behavior

Classification

Species

References

Further reading