A revision of Testudo honanensis (Testudinidae) and the biogeographical history of Palearctic tortoises

• In 1930, Carl Wiman named a series of tortoise species based on fossils recovered from the Late Miocene (Baodean: Tortonian-Messinian equivalent) 'red-beds' of Shaanxi in northern China. The most complete of these specimens, an articulated skeleton including skull and carapace/plastron, was dubbed Testudo honanensis and has been considered a potential sister taxon of the currently extant Russian or Steppe tortoise Testudo horsfeldii; a species occasionally distinguished as a separate genus, Agrionemys, although recent molecular analyses advocate nesting within Testudo spp. A phylogenetic reassessment of Wiman’s original holotype using a combined morphological/DNA sequence data set suggests that T. honanensis is distinct from T. (Agrionemys) horsfeldii, and might be related to larger-bodied African taxa including Stigmochelys. Testudo honanensis could thus form part of a parallel radiation of Palearctic testudinids that migrated out of Africa, alongside the broader testudonan clade (= greater Testudo group), into Europe (via Anatolia) and Asia following the spread of dry savannah grasslands around 10 Ma. A Late Miocene influx of 'African' tortoises into Eastern Asia is consistent with the distribution of coeval Hipparion Fauna mammals, and supports interpretations of the modern Testudo spp. as vicariant remnants of what was once a much more widely geographically dispersed series of Eurasian lineages.

Subject headings

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Annan geovetenskap och miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Other Earth and Related Environmental Sciences (hsv//eng)

Keyword

Earth Science with specialization in Historical Geology and Palaeontology

Geovetenskap med inriktning mot historisk geologi och paleontologi

Publication and Content Type

vet (subject category)

kon (subject category)