African elephant

The African elephant (Loxodonta) is a genus comprising two living elephant species, the African bush elephant (L. africana) and the smaller African forest elephant (L. cyclotis). Loxodonta is one of two existing genera of the family Elephantidae. The name refers to the lozenge-shaped enamel of their molar teeth. Fossil remains of Loxodonta species have been excavated in Africa, dating to the middle Pliocene. Both living species have grey skin. They differ in size, and in the shape and size of their skulls, large ears and tusks. They are both herbivores and live in groups. They are listed as Vulnerable species on the IUCN Red List since 2004, and are threatened by habitat loss and fragmentation. Poaching for the illegal ivory trade is a threat in several range countries as well. The first scientific description of the African elephant was written by Johann Friedrich Blumenbach in 1797 who proposed the scientific name Elephas africanus.Loxodonte was proposed as generic name for the African elephant by Georges Cuvier in 1824. This name refers to the lozenge-shaped enamel of the molar teeth, which differs significantly from the shape of the Asian elephant's molar enamel.An anonymous author used the latinized spelling Loxodonta in 1827. Anonymous was recognized as authority by the International Code of Zoological Nomenclature in 1999. Elephas (Loxodonta) cyclotis was proposed by Paul Matschie in 1900 who described three African elephant zoological specimens from Cameroon whose skulls differed in shape from elephant skulls collected elsewhere in Africa. In 1936, Glover Morrill Allen considered this elephant to be a distinct species and called it 'forest elephant'. Later authors considered it to be a subspecies. Morphological and genetic analyses provided evidence for species-level differences between the African bush elephant and the African forest elephant. In 1907, Richard Lydekker proposed six African elephant subspecies based on the different sizes and shapes of their ears. They are all considered synonymous with the African bush elephant. Between the late 18th and 20th centuries, the following extinct African elephants were described on the basis of fossil remains: Analysis of nuclear DNA sequences indicates that the genetic divergence between African bush and forest elephants dates 2.6 – 5.6 million years ago. The divergence between the Asian elephant and the woolly mammoths is estimated 2.5 – 5.4 million years ago, which strongly supports their status as distinct species. The African forest elephant was found to have a high degree of genetic diversity, perhaps reflecting periodic fragmentation of their habitat during the climatic changes in the Pleistocene. Gene flow between the two African elephant species was examined at 21 locations. The analysis revealed that several African bush elephants carried mitochondrial DNA of African forest elephants, which indicates that they hybridised in the savanna-forest transition zone also in ancient times.