Article · Wikipedia archive · Last revised Jun 17, 2026

Planetetherium

Planetetherium is an extinct genus of herbivorous plagiomenid mammal endemic to North America during the Paleogene living from 56.8 to 55.4 mya, existing for approximately 1.4 million years.

Last revised
Jun 17, 2026
Read time
≈ 1 min
Length
192 w
Citations
3
Source
Planetetherium
Temporal range:
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Placentalia
Order: Dermoptera
Family: Plagiomenidae
Genus: Planetetherium
Simpson, 1928
Species:
P. mirabile
Binomial name
Planetetherium mirabile
Simpson, 1928

Planetetherium is an extinct genus of herbivorous plagiomenid mammal endemic to North America during the Paleogene living from 56.8 to 55.4 mya, existing for approximately 1.4 million years.1

Fossils have been discovered in strata formed from ancient cypress forests, suggesting that this was the animal's preferred habitat.

Morphology

Plantetherium is estimated to reach around 25 centimetres (10 in) in length, and its known materials closely resembled that of its modern relatives. Its teeth already included the comb-like structure distinctive to modern colugos. Since no postcranial materials have been described for any plagiomenid,2 there is no direct evidence that Planetetherium had the membrane of skin that allows modern colugos to glide.3

References

References

  1. PaleoBiology Database: Planetetherium, basic info
  2. Rose, Kenneth D. (2008-01-01), "Plagiomenidae and Mixodectidae", Evolution of Tertiary Mammals of North America: Volume 2: Small Mammals, Xenarthrans, and Marine Mammals, Cambridge University Press, pp. 198–206, retrieved 2025-02-24
  3. Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 210. ISBN 1-84028-152-9.