Science and conservation for the world’s 2800 small mammal species

Rodents: Family Bathyergidae

holding_imgThe family Bathyergidae contains African mole rats and is within the suborder Hystricomorpha of the order Rodentia. Evidence shows that members of this family belong to the Old World Hystricognathi lineage and are closely related to Petromuridae, Thyronomyidae, and Hystricidae. The divergence of the Old World and New World lineages occurred during the Eocene in Africa. Bathyergids originate in sub-Saharan Africa and are small to medium sized. Bathyergidae consists of 5 genera and 16 species. The genera are Georychus, Heterocephalus, Heliophobius, and Bathyergus. These five genera are further separated into two subfamilies. The first subfamily, Bathyerginae, includes the genus Bathyergus and its two species. This subfamily is characterized by large front claws and a groove in their upper incisors. The second subfamily, Heterocephalinae, includes the genera Georychus, Heliophobius, Cryptomys, and Heterocephalus. This subfamily lacks the large claws and groove in their upper incisors. Species within this family include the naked mole-rat and the silvery mole-rat.

All members of the family live fossorial lifestyles and have physical characteristics to accommodate such a living. These characteristics include short legs, a tapered body, small ears and eyes, and large incisors. In order to burrow, bathyergids utilize their powerful incisors to loosen dirt and then move said dirt away from their path with their short arms. This is true for all members of the family apart from the genus Bathyergus, which uses its arms to burrow. Due to the presence of small eyes, bathyergids do not use sight frequently, if at all, when underground. The sense of touch, however, is vital to the family. When underground, bathyergids feel for their surroundings by using their short tails and long hairs made specifically for such purpose. Members also have hypsodont dentition, which reflects their herbivorous diet. Compared to other rodents, bathyergids have a much longer lifespan, which is often between 12 and 26 years. The genera Heterocephalus and Cryptomys are unique based on their social systems, which can include one mating female along with several males and non-mating female helpers.

 

 

Work Cited
Kingdon et al. (2013). Mammals of Africa, Volumes 1-6. Retrieved from http://www.books.google.com/
Myers, P. 2000. “Bathyergidae blesmoles and mole rats.” (Online). Animal Diversity Web. Accessed April 15, 2015 at http://animaldiversity.org/accounts/Bathyergidae/

Author: Anna Cole