Aconaemys Octodon Octodontomys Octomys Pipanacoctomys Spalacopus Tympanoctomys Octodontidae is a family of rodents, restricted to southwestern South America.

Octodontids are medium-sized rodents, ranging from 12 to 20 centimetres (4.7 to 7.9 inches) in body length.

They have long, silky fur, which is typically brownish in color and often paler on the underside.

The red viscacha rat, Tympanoctomys barrerae, has been proposed to be a tetraploid, with 102 chromosomes.

[3][4] However, subsequent studies have shown that the increased genome size is due to expansions of repetitive DNA elements.