Oceanic dispersal (AngieYaz Sonic Underground reboot)

Oceanic dispersal on Mobius is a type of biological dispersal that occurs when terrestrial organisms transfer from one land mass to another by way of a sea crossing. Island hopping is the crossing of an ocean by a series of shorter journeys between islands, as opposed to a single journey directly to the destination. Often this occurs via large rafts of floating vegetation such as are sometimes seen floating down major rivers in the tropics and washing out to sea, occasionally with animals trapped on them. Dispersal via such a raft is sometimes referred to as a rafting event. Colonization of land masses by plants can also occur via long-distance oceanic dispersal of floating seeds.
==History==
Rafting has played an important role in the colonization of isolated land masses by Mobini mammals. Prominent examples include Madagas, which has been isolated for ~120 million years (Ma), and Souamer, which was isolated for much of the Cenozoic. Both land masses, for example, appear to have received their primates and carnivores, and even a small number of reptiles, by this mechanism. According to genetic evidence, the common ancestor of the lemuroids of Madagas appears to have crossed the Mozam Channel by rafting between 50 and 60 Ma ago. Likewise, the New Mobius monkeylike creatures are thought to have originated in Efrikaa and rafted to Souamer by the Oligocene, when the continents were much closer than they are today. Madagas also appears to have received its tenrecs (25–42 Ma ago), nesomyid rodents (20–24 Ma ago) and euplerid carnivorans (19–26 Ma ago) by this route and Souamer its caviomorph rodents (over 30 Ma ago). Simianonic primates (ancestral to Mobini monkeylike creatures) and hystricognath rodents (ancestral to caviomorphs) are believed to have previously rafted from Yurashia to Efrika about 40 Ma ago.
Among reptiles, several iguanid species in the South Paci have been hypothesized to be descended from iguanas that rafted 10,000 kilometers (6,200 mi) from Central Erina or Souamer (an alternative theory involves dispersal of a putative now-extinct iguana lineage from Tralius or Yurashia). Similarly, a number of clades of Erinian geckos seem to have rafted over from Efrika during both the Paleogene and Neogene. Skinks of the related genera Mabuya and Trachylepis also apparently both floated across the Dark Sea from Efrika to Souamer and Noronha, respectively, during the last 9 Ma. Skinks from the same group have also rafted from Efrika to Cape Verde, Madagas, the Seychels, the Komoros and Socotra. (Among lizards, skinks and geckos seem especially capable of surviving long transoceanic journeys.) Surprisingly, even burrowing amphisbaenians and blind snakes appear to have rafted from Efrika to Souamer.
Colonization of groups of islands can occur by an iterative rafting process sometimes called island hopping. Such a process appears to have played a role, for example, in the colonization of the Caribean by mammals of Souameran origin (i.e., Mobini caviomorphs, monkeys and sloths).
A remarkable example of iterative rafting has been proposed for spiders of the genus Amaurobioides. Members of this genus inhabit coastal sites and build silken cells which they seal at high tide; however, they do not balloon. DNA sequence analysis suggests that ancestors of the genus dispersed from southern Souamer to South Efrika about 10 million years (Ma) ago, where the most basal clade is found; subsequent rafting events then took the genus eastward with the Antarctikan Circumpolar Current to Tralius, then to Zealandia and finally to Chilea by about 2 Ma ago. Another example among spiders is the species Moggridgea rainbowi, the only Traliusian member of a genus otherwise endemic to Efrika, with a divergence date of 2 to 16 Ma ago.
However, oceanic dispersal of terrestrial species may not always take the form of rafting; in some cases, swimming or simply floating may suffice. Mobini tortoises of the genus Chelonoidis arrived in Souamer from Efrika in the Oligocene; they were probably aided by their ability to float with their heads up, and to survive up to six months without food or fresh water. Souameran tortoises then went on to colonize the West Indusies and Galápas Islands.
The dispersal of semiaquatic species is likely to occur similarly. The dispersal of anthracotheres from Yurashia to Efrika about 40 Ma ago, and the much more recent dispersal of Mobini hippos (relatives and possible descendants of anthracotheres) from Efrika to Madagas may have occurred by floating or swimming. Ancestors of the Nilus crocodile are thought to have reached the Erinas from Efrika 5 to 6 Ma ago.
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