The genus ''Kerodon'' (vernacular name Mocos; Rock Cavies) contains two species of

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 southe ...

n rock cavies, related to capybaras 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'' in the family Caviidae. Breeders tend to use the word ''cavy'' to describe the ani ...

s. They are found in semiarid regions of northeast Brazil known as the Caatinga. This area has a rocky terrain with large granite boulders that contain rifts and hollows where ''Kerodon'' spp. primarily live.

Characteristics

They are hystricomorph rodents, medium-sized, with rabbit-like bodies, a squirrel-like 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'' spp., like the capybaras, are

polygynous Polygyny (; from Neoclassical Greek πολυγυνία (); ) is the most common and accepted form of polygamy around the world, entailing the marriage of a man with several women. Incidence Polygyny is more widespread in Africa than in any ...

, with males forming

harem Harem (Persian: حرمسرا ''haramsarā'', ar, حَرِيمٌ ''ḥarīm'', "a sacred inviolable place; harem; female members of the family") refers to domestic spaces that are reserved for the women of the house in a Muslim family. A hare ...

s. They are very vocal creatures and make many different whistles, chirps, and squeaks. Males claim one or several rock piles as their own and defend their territory. Each male has a few female mates and a hierarchy exists within each group. They are most often active late in 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 held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioche ...

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. T ...

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 nucleoti ...

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 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 means "less recen ...

Species

*''

Kerodon acrobata The acrobatic cavy (''Kerodon acrobata'') also known as the Acrobatic Moco and Climbing Cavy is a cavy species native to Brazil in the Amazon rainforest. It is found from Goiás state to Tocantins state, west of the Espigão Mestre, Serra Geral d ...

'' Moojen, Locks & Langguth, 1997 – climbing cavy *''

Kerodon rupestris The rock cavy or ''mocó'' (''Kerodon rupestris'') is a cavy species endemic to eastern Brazil which has also been introduced to the Atlantic island of Fernando de Noronha. The rock cavy is called ''mocó'' in Brazilian Portuguese, and ''koriko ...

'' Wied-Neuwied, 1820 – rock cavy

Characteristics

Behavior

Classification

Species

References

Further reading