The Seychelles Islands are genuine Gondwanan fragments, cast adrift millions of years ago as India drifted north toward Asia. They are the only mid-oceanic granitic islands in the world. Isolated for 75 million years, the Seychelles now host a unique assemblage of flora and fauna, many of them extremely primitive. Among the 233 or so endemic plant species, there is one endemic family, 12 endemic genera, and 72 endemic species. The palms are a particularly unique group, with 6 endemics classified into 6 monotypic genera. The pandans are also unusually diverse, with the granitic islands hosting 8 species, of which 5 are endemic. Unfortunately, many of the unique plants of the Seychelles have such small populations and restricted distributions that their eventual survival is unlikely. For example, the jellyfish tree (Medusagyne oppositifolia) has a total population of fewer than 30 plants scattered over three hilltops on Mahé. It is the sole representative of the endemic family, Mesdusagynaceae, and is currently one of the rarest plant species in the world. It was thought to be extinct until it was rediscovered in 1970.
Most of the lowland forests of the Seychelles granitic islands have been disturbed or destroyed to make way for coconut, vanilla and cinnamon plantations. The Vallée de Mai on Praslin Island provides the best example of intact native forest and has been declared a World Heritage Site. The Morne Seychellois N.P. (35 km2) contains important mountain mist forest. Other important reserves are Aride Special Reserve (0.7 km2), Cousin Special Reserve (0.3 km2), La Digue Veuve Special Reserve (0.1 km2) and Curieuse National Park (15 km2). Although extremely small, these reserves make an important contribution to the protection of critically endangered species. For example, an intensive recovery program has helped increase the total population of the Seychelles warbler from 30 to 500 individuals. Intense management efforts have helped build up the populations of the Seychelles magpie robin on Frégate Island, and to translocate it to other islands.
The flora shows affinities with that of nearby islands, Madagascar and the Mascarenes, as well as with mainland Africa and Asia. The Seychellian species of Impatiens, Pseuderanthemum, and Rothmannia are more closely related to species found on the African continent than they are to species that live on Madagascar and the Mascarenes. And although Asia is twice as far away as mainland Africa, several species are found also in Indo-Malaysia and Polynesia. Unlike many other mid-oceanic island groups, the Seychelles are inhabited by a diverse herpetofauna of which most striking are two species of giant land tortoise, Dipsochelys arnoldi and D. dussumieri. In addition there are several native terrapins, 7 species of legless caecilians, 4 native frogs, 3 native snakes, an endemic chameleon, and several species of geckos and skinks. Only one endemic mammal species is found here, the critically endangered Seychelles sheath-tailed bat (Coleura seychellensis).