Evolution and systematics
African Sideneck Turtles ( Pelomedusidae ) is most intently associated to Podocnemidae, however diverged from that household not less than by the Cretaceous (not less than 110 million years in the past). Fossils are identified from the Miocene to the Recent, however all belong to the 2 dwelling genera. No subfamilies are acknowledged.
These turtles are usually small to medium in measurement, often lower than 12 in (30 cm), with a comparatively in depth plastron which will (in Pelusios) or might not (in Pelomedusa) have a hinge current between the pectoral and belly scutes. The neural collection is extremely variable (with 4 to eight current), and the pleural bones nearly all the time meet on the midline posterior to the neurals. A pair of mesoplastral bones are current between the hyoand hypoplasta, and should (in Pelusios) or might not (in Pelomedusa) keep up a correspondence. Five claws are current on the hind ft.
Africa up to not less than 10,200 ft (3,100 m) elevation, Madagascar, and the Seychelles Islands.
As a gaggle, these turtles occupy practically any freshwater aquatic system, from everlasting lakes or rivers to ephemeral swimming pools which can comprise water only some weeks at a time.
Surprisingly little is thought concerning the conduct of these sideneck turtles. They incessantly bask on the water’s edge, and several other species make in depth overland actions throughout the moist season. During the dry season, many species estivate underground. In the temperate climates of southern Africa, they’ll hibernate terrestrially or aquatically. When captured, they produce a pungent musk from glands placed close to the bridges (bony constructions that join the plastron and carapace).
Feeding ecology and weight-reduction plan
These sideneck turtles are all primarily carnivorous, feeding primarily on annelids, mollusks, crustaceans, bugs, fish, amphibians, and carrion. Some are not less than partly herbivorous, consuming water lettuce, aquatic grasses, or fruits.
No species on this household has been properly studied; most of what’s identified is predicated on anecdotal reviews. Most species apparently nest in late spring or summer time, from October to January. The eggs are elongate with leathery shells, and clutch sizes vary from six to 48. Multiple annual clutches haven’t been confirmed for any species, however appear probably contemplating the size of the potential nesting season. All species which have been studied exhibit temperature-dependent intercourse willpower, with heat temperatures producing females, intermediate temperatures producing principally males, and nonetheless cooler temperatures once more producing females.
The precise subject standing of a lot of the species on this household has not been adequately assessed. The solely two species listed as Vulnerable on the IUCN Red List are the 2 with essentially the most restricted distributions: Pelusios broadleyi in Lake Turkana in Kenya, and P. seychellensis within the Seychelles.
Significance to people
These turtles are sometimes eaten by indigenous people, however their foul-smelling musk secretions most likely serve to discourage extra common consumption. They are additionally in low demand for the pet commerce.