List of octodontids

Common degu (Octodon degus)

Octodontidae is a family of mammals in the order Rodentia and part of the Caviomorpha parvorder. Members of this family are called octodontids and include degus, rock rats, and viscacha rats. They are found in southern South America, primarily in forests, shrublands, and rocky areas, though some species can be found in savannas, grasslands, and wetlands. They range in size from the coruro, at 11 cm (4 in) plus a 4 cm (2 in) tail, to the mountain viscacha rat, at 33 cm (13 in) plus a 18 cm (7 in) tail. Octodontids are herbivores, and eat a variety of plant matter and fruit, with some species also eating dung. No octodontids have population estimates, but three species—the Pacific degu, golden viscacha rat, and Chalchalero viscacha rat—are categorized as critically endangered.

The 14 extant species of Octodontidae are divided into seven genera, which range in size from one to four species. Several extinct prehistoric octodontid species have been discovered, though due to ongoing research and discoveries, the exact number and categorization is not fixed. ^[1]

Conventions

IUCN Red List categories

Conservation status
EX	Extinct (0 species)
EW	Extinct in the wild (0 species)
CR	Critically endangered (3 species)
EN	Endangered (0 species)
VU	Vulnerable (1 species)
NT	Near threatened (2 species)
LC	Least concern (5 species)
Other categories
DD	Data deficient (3 species)
NE	Not evaluated (0 species)

The author citation for the species or genus is given after the scientific name; parentheses around the author citation indicate that this was not the original taxonomic placement. Conservation status codes listed follow the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. Range maps are provided wherever possible; if a range map is not available, a description of the octodontid's range is provided. Ranges are based on the IUCN Red List for that species unless otherwise noted.

Classification

Octodontidae is a family consisting of fourteen extant species in seven genera. This does not include hybrid species or extinct prehistoric species.

Family Octodontidae

• Genus Aconaemys (rock rats): three species
• Genus Octodon (degus): four species
• Genus Octodontomys (mountain degu): one species
• Genus Octomys (mountain viscacha rat): one species
• Genus Pipanacoctomys (golden viscacha rat): one species
• Genus Spalacopus (coruro): one species
• Genus Tympanoctomys (viscacha rats): three species

Octodontidae [2] Aconaemys Spalacopus Octodon Octodontomys Octomys Pipanacoctomys Tympanoctomys

Octodontids

The following classification is based on the taxonomy described by the reference work Mammal Species of the World (2005), with augmentation by generally accepted proposals made since using molecular phylogenetic analysis, as supported by both the IUCN and the American Society of Mammalogists. ^[3]

Genus Aconaemys – Ameghino, 1891 – three species

Common name	Scientific name and subspecies	Range	Size and ecology	IUCN status and estimated population
Chilean rock rat	A. fuscus (Waterhouse, 1842)	Eastern Chile	Size: 15–17 cm (6–7 in) long, plus 5–8 cm (2–3 in) tail [4] Habitat: Forest [5] Diet: Roots, fruit, and other vegetation [6]	LC  Unknown [5]
Porter's rock rat	A. porteri Thomas, 1917	Eastern Chile and western Argentina	Size: 14–20 cm (6–8 in) long, plus 6–9 cm (2–4 in) tail [4] Habitat: Forest and rocky areas [7] Diet: Roots, fruit, and other vegetation [6]	DD  Unknown [7]
Sage's rock rat	A. sagei Pearson, 1984	Central Chile	Size: 14–16 cm (6 in) long, plus 5–7 cm (2–3 in) tail [4] Habitat: Forest and rocky areas [8] Diet: Roots, fruit, and other vegetation [6]	DD  Unknown [8]

Genus Octodon – Bennett, 1823 – four species

Common name	Scientific name and subspecies	Range	Size and ecology	IUCN status and estimated population
Bridges's degu	O. bridgesii Waterhouse, 1845	Central Chile	Size: 15–20 cm (6–8 in) long, plus 10–17 cm (4–7 in) tail [9] Habitat: Forest and shrubland [10] Diet: Grass, leaves, bark, herbs, seeds, and fruit, as well as dung [11]	VU  Unknown [10]
Common degu	O. degus (Molina, 1782)	Central Chile	Size: 16–21 cm (6–8 in) long, plus 8–14 cm (3–6 in) tail [9] Habitat: Shrubland [12] Diet: Grass, leaves, bark, herbs, seeds, and fruit, as well as dung [11]	LC  Unknown [12]
Moon-toothed degu	O. lunatus Osgood, 1943	Central Chile	Size: 16–22 cm (6–9 in) long, plus 15–17 cm (6–7 in) tail [9] Habitat: Shrubland and rocky areas [13] Diet: Grass, leaves, bark, herbs, seeds, and fruit, as well as dung [11]	NT  Unknown [13]
Pacific degu	O. pacificus R. Hutterer, 1994	Mocha Island in Chile	Size: 12–20 cm (5–8 in) long, plus 16–17 cm (6–7 in) tail [9] Habitat: Forest [14] Diet: Grass, leaves, bark, herbs, seeds, and fruit, as well as dung [11]	CR  Unknown [14]

Genus Octodontomys – Palmer, 1903 – one species

Common name	Scientific name and subspecies	Range	Size and ecology	IUCN status and estimated population
Mountain degu	O. gliroides (Gervais & d'Orbigny, 1844)	Northern Chile, southwestern Bolivia, and northwestern Argentina	Size: 16–19 cm (6–7 in) long, plus 10–19 cm (4–7 in) tail [9] Habitat: Shrubland, grassland, and rocky areas [15] Diet: Acacia seed pods and cactus fruits [11]	LC  Unknown [15]

Genus Octomys – Thomas, 1920 – one species

Common name	Scientific name and subspecies	Range	Size and ecology	IUCN status and estimated population
Mountain viscacha rat	O. mimax Thomas, 1920	Western Argentina	Size: 14–33 cm (6–13 in) long, plus 10–18 cm (4–7 in) tail [9] Habitat: Rocky areas [16] Diet: Roots, bark, and cactus [17]	LC  Unknown [16]

Genus Pipanacoctomys – Mares, Braun, Barquez, & Díaz, 2000 – one species

Common name	Scientific name and subspecies	Range	Size and ecology	IUCN status and estimated population
Golden viscacha rat	P. aureus Mares, Braun, Barquez, & Díaz, 2000	Northwestern Argentina	Size: 16–18 cm (6–7 in) long, plus 12–15 cm (5–6 in) tail [9] Habitat: Inland wetlands [18] Diet: Leaves and stems [19]	CR  Unknown [18]

Genus Spalacopus – Wagler, 1832 – one species

Common name	Scientific name and subspecies	Range	Size and ecology	IUCN status and estimated population
Coruro	S. cyanus (Molina, 1782) Three subspecies S. c. cyanus S. c. maulinus S. c. poeppigii	Central Chile	Size: 11–17 cm (4–7 in) long, plus 4–6 cm (2 in) tail [4] Habitat: Forest, savanna and grassland [20] Diet: Tubers and stems of Leucocoryne and other plants [21]	LC  Unknown [20]

Genus Tympanoctomys – Yepes, 1942 – three species

Common name	Scientific name and subspecies	Range	Size and ecology	IUCN status and estimated population
Chalchalero viscacha rat	T. loschalchalerosorum Mares, Braun, Barquez, & Díaz, 2000	Northern Argentina	Size: 14–16 cm (6 in) long, plus 11–12 cm (4–5 in) tail [9] Habitat: Wetlands and shrublands [22] Diet: Leaves and stems [19]	CR  Unknown [22]
Kirchner's viscacha rat	T. kirchnerorum Teta, Pardiñas, Sauthier, & Gallardo, 2014	Southern Argentina	Size: 11–14 cm (4–6 in) long, plus 11–12 cm (4–5 in) tail [9] Habitat: Shrubland, grassland [23] Diet: Leaves and stems [19]	DD  Unknown [23]
Plains viscacha rat	T. barrerae (B. Lawrence, 1941)	Western Argentina	Size: 12–16 cm (5–6 in) long, plus 9–15 cm (4–6 in) tail [9] Habitat: Shrubland [24] Diet: Leaves and stems [19]	NT  Unknown [25]

References

1. "Fossilworks: Octodontidae". Paleobiology Database . University of Wisconsin–Madison. Archived from the original on December 7, 2024. Retrieved July 19, 2025.
2. Kelt; Lessa; Salazar-Bravo, pp. 694–719
3. Wilson; Reeder, pp. 1570-1573
4. Chernasky; Motis; Burgin, p. 366
5. Roach, N. (2016). "Aconaemys fuscus". IUCN Red List of Threatened Species . 2016: e.T278A78318793. doi: 10.2305/IUCN.UK.2016-2.RLTS.T278A78318793.en .
6. Nowak, p. 1685
7. Roach, N. (2016). "Aconaemys porteri". IUCN Red List of Threatened Species . 2016: e.T136331A22239645. doi: 10.2305/IUCN.UK.2016-2.RLTS.T136331A22239645.en .
8. Roach, N. (2016). "Aconaemys sagei". IUCN Red List of Threatened Species . 2016: e.T279A78318855. doi: 10.2305/IUCN.UK.2016-2.RLTS.T279A78318855.en .
9. Chernasky; Motis; Burgin, p. 365
10. Roach, N. (2017) [errata version of 2016 assessment]. "Octodon bridgesi". IUCN Red List of Threatened Species . 2016: e.T15087A115124772. doi: 10.2305/IUCN.UK.2016-3.RLTS.T15087A78321197.en .
11. Nowak, p. 1682
12. Roach, N. (2016). "Octodon degus". IUCN Red List of Threatened Species . 2016: e.T15088A78321302. doi: 10.2305/IUCN.UK.2016-2.RLTS.T15088A78321302.en .
13. Roach, N. . (2016). "Octodon lunatus". IUCN Red List of Threatened Species . 2016: e.T15089A78321388. doi: 10.2305/IUCN.UK.2016-2.RLTS.T15089A78321388.en .
14. Roach, N. (2016). "Octodon pacificus". IUCN Red List of Threatened Species . 2016: e.T15090A78321512. doi: 10.2305/IUCN.UK.2016-2.RLTS.T15090A78321512.en .
15. Weksler, M. (2016). "Octodontomys gliroides". IUCN Red List of Threatened Species . 2016: e.T15091A22240265. doi: 10.2305/IUCN.UK.2016-2.RLTS.T15091A22240265.en .
16. Roach, N. (2016). "Octomys mimax". IUCN Red List of Threatened Species . 2016: e.T15093A78321632. doi: 10.2305/IUCN.UK.2016-2.RLTS.T15093A78321632.en .
17. Nowak, p. 1681
18. Roach, N. (2016). "Tympanoctomys aureus". IUCN Red List of Threatened Species . 2016: e.T136557A78324400. doi: 10.2305/IUCN.UK.2016-2.RLTS.T136557A78324400.en .
19. Nowak, p. 1683
20. Roach, N. (2016). "Spalacopus cyanus". IUCN Red List of Threatened Species . 2016: e.T20427A78323110. doi: 10.2305/IUCN.UK.2016-2.RLTS.T20427A78323110.en .
21. Nowak, p. 1684
22. Roach, N. (2016). "Tympanoctomys loschalchalerosorum". IUCN Red List of Threatened Species . 2016: e.T136714A78324608. doi: 10.2305/IUCN.UK.2016-2.RLTS.T136714A78324608.en .
23. Roach, N. (2016). "Tympanoctomys kirchnerorum". IUCN Red List of Threatened Species . 2016: e.T86051353A86051372. doi: 10.2305/IUCN.UK.2016-2.RLTS.T86051353A86051372.en .
24. Roach, N. (2016). "Tympanoctomys barrerae". IUCN Red List of Threatened Species . 2016: e.T22586A78323698. doi: 10.2305/IUCN.UK.2016-2.RLTS.T22586A78323698.en .
25. Roach, N. (2016). "Tympanoctomys barrerae". IUCN Red List of Threatened Species . 2016: e.T22586A78323698. doi: 10.2305/IUCN.UK.2016-2.RLTS.T22586A78323698.en . Retrieved December 26, 2024.

Sources

• Chernasky, Amy; Motis, Anna; Burgin, Connor, eds. (2023). All the Mammals of the World . Lynx Nature Books. ISBN   978-84-16728-66-4.
• Kelt, Douglas A.; Lessa, Enrique P.; Salazar-Bravo, Jorge (2007). The Quintessential Naturalist: Honoring the Life and Legacy of Oliver P. Pearson. University of California Press. doi:10.1525/california/9780520098596.003.0019. ISBN   978-0-520-09859-6.
• Nowak, Ronald M. (1999). Walker's Mammals of the World. Vol. 2 (6th ed.). Johns Hopkins University Press. ISBN   978-0-8018-5789-8.
• Woods, Charles A.; Kilpatrick, C. William (2005). Wilson, Don E.; Reeder, DeeAnn M. (eds.). Mammal Species of the World . Vol. 2 (3rd ed.). Johns Hopkins University Press. ISBN   978-0-8018-8221-0.