Crested rat fossils suggest that ecological corridors once connected Africa to the Levant, according to a study.
Early humans and other hominins dispersed out of Africa through the Levant multiple times, but whether these journeys relied on technology to cross the Saharo-Arabian deserts or followed ecological corridors created by climate change is unclear.
Ignacio Lazagabaster and colleagues analyzed rodent fossils discovered in the Cave of the Skulls in the southern Judean Desert as a proxy for the paleoenvironment of the Dead Sea region during the Late Pleistocene.
Phylogenetic analyses of a sequenced mitochondrial genome and morphological comparisons suggest that the fossils, which were dated to between 42,000 and more than 103,000 years ago, belong to a now-extinct subspecies, Lophiomys imhausi maremortum subsp. nov., of the eastern African crested rat, an enigmatic large rodent equipped with a poisonous pelt and a helmet-like skull. Because extant crested rats live in habitats with relatively dense vegetation, the authors used species distribution models to estimate the timing and location of previously suitable habitats in the region.
The results* suggest a brief period during the Last Interglacial when green habitat corridors connected eastern Africa to the Levant across the present-day Judean Desert, facilitating the dispersal of crested rats and humans out of Africa, according to the authors.
“Rare crested rat subfossils unveil Afro-Eurasian ecological corridors synchronous with early human dispersals,” by Ignacio A. Lazagabaster et al.
Featured image: A skull of the Dead Sea crested rat subspecies found in situ in the Cave of the Skulls in the southern Judean Desert. Ignacio A. Lazagabaster.
Provided by PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES