Biostratigraphy, palaeogeography and palaeoenvironmental significance of Sorex runtonensis Hinton, 1911 (Mammalia, Soricidae): First record from the Iberian Peninsula

Abstract

Sorex runtonensis (Mammalia, Soricidae) is a well-known Pleistocene taxon with a broad distribution in Europe. However, no record of the species had been reported from the Iberian Peninsula up to now. Here we present nearly two hundred specimens of S. runtonensis recovered from the Lower Red Unit (levels TE7-14) of Sima del Elefante (Sierra de Atapuerca, Burgos, Spain), dated to ~1.1-1.5 Ma. Rigorous morphometrical and morphological analyses allowed the assignation of the items from Sima del Elefante confidently to this taxon, distinguishing them from the several other Pleistocene species of similar size that inhabited Europe. Sorex runtonensis survived all through the Pleistocene (and maybe more), but the remains from Sima del Elefante exhibit some traits that appear to be particular to the Early Pleistocene, which agrees with the pre-Jaramillo chronology inferred for the lower levels of the site. Western Palearctic S. runtonensis has been regarded as a proxy of patchy and relatively arid, open past biotopes due to its similarity to recent Eastern Palearctic S. tundrensis. In light of this fact, and given the high relative quantities of this taxon at the site, previous palaeoenvironmental reconstructions proposed for the lowermost unit of Sima del Elefante should be revised to present a more ecologically diverse scenario than previously thought.

Evolutionary history and phylogeographic relationships of shrews from Sorex araneus group

“…The oldest representative of this group may be: (1) S . runtonensis known from the Early (MN17, 2.6–1.9 Mya) to the Late Pleistocene in Europe and Caucasus Mountains [ 86 , 89 , 90 ], or (2) an earlier Sorex form Pliocene of Europe (MN15-MN16, 4.2–2.6 Mya), resembling S . runtonensis [ 86 ].…”

“…They may represent ancestors or old remains of the lineages leading to current species. Other detailed studies are required to solve the taxonomic position of these two taxa [ 89 ].…”

Contribution to the validity and taxonomic status of the European fossil shrew Sorex subaraneus and the origin of Sorex araneus (Soricidae, Eulipotyphla, Insectivora, Mammalia)

“…Despite individual variability, S. runtonensis can be easily distinguished from S. subaraneus and S. araneus. Therefore, the suggestion of Rofes et al (2016) on the unity of the S. subaraneus and S. runtonensis does not seem justifiable.…”

“…On the other hand, Rofes et al (2016) thought that two fossil taxa, S. subaraneus and S. runtonensis Hinton, 1911, described from the Early Pleistocene of West Runton (England) could be regarded as "a morphological continuum of the same species" and the name "runtonensis" would have priority. This study also questioned the validity of S. subaraneus species and in consequence its probability as the ancestor of S. araneus.…”

Sorex (Mammalia, Soricidae) remains from the late Early Pleistocene Somssich Hill 2 locality (Villány Hills, Southern Hungary)

“…Both of the species were described from Valerots, France and from Deutsch-Altenburg 2C, Austria. Th ere were some transitional specimens found in Untermassfeld, Germany, and those are considered (2013,2015); Garcia et al (2014);Huguet et al (2017); Rofes et al (2016) Fragmenta Palaeontologica Hungarica 33, 2016 as S. margaritodon-savini. In Figure 6 is visible that the areas of the two species do not separate from each other in time and space (Fig.…”