Short characteristic of the genera Chersobius and Homopus
The genus Chersobius consists of three and the genus Homopus of two species:
All are small, relatively flattened tortoise species (maximum shell length 10-17 cm), and the group includes the world's smallest tortoise C. signatus. Males are smaller than females and have concave plastrons in Chersobius species. The genus Homopus derives its name from the fact that the front and hind limbs both have four claws. Chersobius species have five claws on the front limbs. The genera are endemic to South African and Namibia. They are poorly studied and all live secretive lives in the wild. All species are uncommon in captivity.
- Chersobius boulengeri (Karoo dwarf tortoise)
- Chersobius signatus (speckled dwarf tortoise)
- Chersobius solus (Nama dwarf tortoise)
- Homopus areolatus (parrot-beaked dwarf tortoise)
- Homopus femoralis (greater dwarf tortoise)
Since early in the twentieth century, all dwarf tortoises have been considered to represent a single genus, Homopus. However, a recent study in 2018 demonstrated that Homopus species represent two genera, Chersobius and Homopus. Other recent taxonomic changes are the formal description of C. solus in 2007, and the synonimisation of two subspecies previously distinguished in C. signatus in 2010. One extinct fossil Homopus species is known as H. fenestratus.
Conservation and threats
The IUCN Red List of Theatened Species has categorised all Chersobius and Homopus species. The three Chersobius species categorise Near Threatened and Vulnerable, but recent assessments will elevate the conservation status of C. boulengeri and C. signatus to Endangered. Both Homopus species are Least Concern. Main treats to the survival of Chersobius and Homopus species are overgrazing, climate change, mining, road casualties, and poaching for the pet trade. Dwarf Tortoise Conservation is actively involved in raising awareness on the worsening conservation status of the dwarf tortoises, among locals, policy makers and law enforcers.
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