Evolution and systematics

Although both Old World and New World porcupines exist, the New World family Erethizontidae is actually more closely related to pacas, agoutis, and other cavy-like rodents than to the Old World porcupine family Hystricidae.

This family requires additional research before its placement is clear. Until that work is completed, however, this chapter will use the following classification of genera and species:

• Chaetomys—C. subspinosus (this species was thought to be extinct until it was rediscovered in 1986)

• Coendou—C. bicolor, C. ichillus (described as new species in 2001), C. koopmani (described as new species in 1992), C. melanurus (sometimes identified as Sphiggurus insidiosus), C. pallidus, C. paragayensis (sometimes identified as S. spinosus), C. prehensilis, C. pruinosus (sometimes classified as S. vestitus), C. roos-malenorum (described as new species in 2001), C. rothschildi, and C. sneiderni

• Echinoprocta—E. rufescens

A North American porcupine (Erethizon dorsatum) foraging. (Photo by Animals Animals ©Richard Kolar. Reproduced by permission.)
A North American porcupine (Erethizon dorsatum) adult and baby. (Photo by D. Robert Franz. Bruce Coleman, Inc. Reproduced by permission.)

• Sphiggurus—S. insidiosus, S. mexicanus (sometimes classified under the genus Coendou), S. spinosus, S. vestitus, and S. villosus

Scientists are still grappling with this family's phylogeny and taxonomy, particularly since some of the species listed above are known from only one or a few specimens. Some of the questions involve the genus Chaetomys, which has at times been placed in the family Erethizontidae or the family Echimyidae; the genus Sphiggurus, which is often grouped as a subgenus of Coendou; and C. rothschildi, which is considered by some to be a subspecies of C. bicolor. Many other questions also remain. Phylogenists tend to agree that the erethizontids likely spread from South America to North America, but they continue to puzzle over whether the Erethizon genus branched from the Coendou genus or a now-extinct species, known as Steiromys.

0 0

Post a comment