The spiny rats are a group of hystricognath rodents in the family Echimyidae. They are distributed from central Central America through much of South America. They were also found in the West Indies until the 19th century. Some authorities consider the nutria from southern and central South America to be a part of this family.

Characteristics

In general form, most spiny rats resemble rats, although they are more closely related to guinea pigs and chinchillas. Most species have stiff pointed hairs, or spines, that presumably serve for protection from predators.

Many echimyids can break off their tails when attacked. This action may confuse predators long enough for the spiny rat to escape. Unlike the tails of some species of lizards, however, the tails of spiny rats do not regenerate. Therefore the tactic cannot be used more than once in each individual's lifetime.

Most spiny rats are rare and poorly known, but a few are extremely abundant. Various species are respectively terrestrial, arboreal, or fossorial. In general, the arboreal forms are most rat-like in appearance, whilst the burrowing species are more gopher-like, with stocky bodies and short tails. Most species do poorly in conditions of high heat and aridity and are restricted to regions with abundant water. They are almost exclusively herbivorous.

The Thin-spined Porcupine, Chaetomys subspinosus, is often included in the Echimyidae due to similarities in the premolar.

Genera

• Family Echimyidae - spiny rats
  • †Cercomys
  • †Maruchito
  • †Paulacoutomys
  • †Willidewu
  • Subfamily †Adelphomyinae
    • †Adelphomys
    • †Deseadomys
    • †Paradelphomys
    • †Stichomys
    • †Xylechimys
  • Subfamily Dactylomyinae
    • Dactylomys - coro-coros
    • Kannabateomys - Rato de Taquara
    • Olallamys
  • Subfamily †Heteropsomyinae - extinct West Indian echimyids
    • †Boromys
    • †Brotomys
    • †Heteropsomys
    • †Puertoricomys
  • Subfamily Eumysopinae
    • †Acarechimys
    • †Chasichimys
    • †Eumysops
    • Hoplomys Armored rat
    • Lonchothrix
    • Mesomys
    • †Palaeoechimys
    • †Pampamys
    • †Pattersomys
    • †Protacaremys
    • †Protadelphomys
    • †Sallamys
    • Proechimys - spiny rats
    • Thrichomys - punaré
    • Trinomys
    • Tribe Euryzygomatomyini
      • Carterodon
      • Clyomys
      • Euryzygomatomys - guiara
  • Subfamily Echimyinae
    • Callistomys
    • Diplomys
    • Echimys - arboreal spiny rats
    • Isothrix - toros
    • Makalata
    • Pattonomys
    • Phyllomys
    • Santamartamys
    • Toromys

References

• Emmons, L.H. 2005. A Revision of the Genera of Arboreal Echimyidae (Rodentia: Echimyidae, Echimyinae), With Descriptions of Two New Genera. pp. 247–310 in Lacey, E.A. & Myers, P. 2005. Mammalian Diversification: From Chromosomes to Phylogeography (A Celebration of the Career of James L. Patton). University of California Publications in Zoology.
• Nowak, R. M. 1999. Walker's Mammals of the World, Vol. 2. Johns Hopkins University Press, London.