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Temporal range: Early Eocene–Middle Eocene
Trogosus hyracoides - National Museum of Natural History - IMG 2009.JPG
Trogosus hyracoides skull at the National Museum of Natural History
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cimolesta
Suborder: Tillodontia
Family: Esthonychidae
Subfamily: Trogosinae
Genus: Trogosus
Leidy 1871
Species [1]
  • T. castoridens (type)
  • T. gazini
  • T. grangeri
  • T. hillsii
  • T. hyracoides
  • T. latidens

Trogosus is an extinct genus of tillodont mammal. Fossils have been found in Wyoming and British Columbia, [2] and date from the Eocene between 54.8 and 33.7 million years ago. Trogosus was a bear-like herbivore with a large, short skull and flat feet, and had a skull 35 cm (14 in) long with an estimated body weight of 150 kg (330 lb). [3] It had large, rodent-like incisors, which continued growing throughout the creature's life. Judging from the heavily worn molar teeth, Trogosus fed on rough plant material, such as roots and tubers. [4]


  1. Trogosus in the Paleobiology Database. Retrieved July 2013.
  2. Russell 1935
  3. Kemp 2005 , p. 240
  4. Palmer 1999 , p. 236

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