The dwarf crocodile is one of the world’s smallest crocodilians, rarely exceeding 2 metres in length. The taxonomy, distribution, population size and conservation status of dwarf crocodiles remains unclear.
Originally considered to be a single species, Osteolaemus tetraspis, there are now thought to be three distinct species of dwarf crocodile: O. tetraspis is restricted to the populations found between Nigeria and the Democratic Republic of Congo; O. osborni is found in the Democratic Republic of Congo; and a currently undescribed species, O. cf. tetraspis, encompasses all populations west of Nigeria.
Each of these lineages diverged from one another more than eight million years ago, which means they are more distantly related than we are to chimpanzees! Together, dwarf crocodiles diverged from their closest relatives, the slender-snouted crocodiles, more than 20 million years ago.
Central African dwarf crocodiles are heavily impacted by hunting for meat and trade by local people and, in terms of weight, are one of the most abundant sources of bushmeat found across the region. However, it is likely populations in West Africa are now below economically viable levels for such exploitation. All three species are also under threat from habitat loss.
At the time of writing, the existing IUCN Red List assessment for this group of species is more than 10 years out-of-date. The assessment considers all dwarf crocodiles as a single species and, therefore, almost certainly underestimates the extinction risk of the three species when considered separately.
- Order: Crocodylia
- Family: Crocodylidae
- Population: Unknown
- Trend: decreasing
- Size: 1.6m (?)
- Weight: 80kg (?)
Dwarf crocodiles are found throughout West and Central Africa, from Senegal to the Democratic Republic of Congo. However, there are multiple cryptic species comprising this range and species boundaries are yet to be clearly delimited.
Habitat and Ecology
Dwarf crocodiles inhabit a wide range of water bodies, from small streams in closed canopy rainforest and dense swamps to savanna pools and coastal lagoons. They are nocturnal and unusually terrestrial, and can be found tens of metres from the nearest water following heavy rains. Their diet largely consists of invertebrates, particularly as juveniles. Dwarf crocodiles build mound nests, in which they lay 10-14 eggs early in the wet season.