Evolutionary history of saber-toothed cats based on ancient mitogenomics

Saber-toothed cats (Machairodontinae) are among the most widely recognized representatives of the now largely extinct Pleistocene megafauna. However, many aspects of their ecology, evolution, and extinction remain uncertain. Although ancient-DNA studies have led to huge advances in our knowledge of these aspects of many other megafauna species (e.g., mammoths and cave bears), relatively few ancient-DNA studies have focused on saber-toothed cats, and they have been restricted to short fragments of mitochondrial DNA. Here we investigate the evolutionary history of two lineages of saber-toothed cats (Smilodon and Homotherium) in relation to living carnivores and find that the Machairodontinae form a well-supported clade that is distinct from all living felids. We present partial mitochondrial genomes from one S. populator sample and three Homotherium sp. samples, including the only Late Pleistocene Homotherium sample from Eurasia. We confirm the identification of the unique Late Pleistocene European fossil through ancient-DNA analyses, thus strengthening the evidence that Homotherium occurred in Europe over 200,000 years later than previously believed. This in turn forces a re-evaluation of its demography and extinction dynamics. Within the Machairodontinae, we find a deep divergence between Smilodon and Homotherium ( 18 million years) but limited diversity between the American and European Homotherium specimens. The genetic data support the hypothesis that all Late Pleistocene (or post-Villafrancian) Homotherium should be considered a single species, H. latidens, which was previously proposed based on morphological data

Results of the CERPOLEX/Mammuthus Expeditions on the Taimyr Peninsula, Arctic Siberia, Russian Federation

During a series of expeditions organized by CERPOLEX/Mammuthus to the Taimyr region in northern Siberia several mammoth (Mammuthus primigenius) carcasses were discovered and subsequently excavated and studied. The oldest specimen is the Arilakh Mammoth (ca. 55,800 BP). Much younger are the Jarkov Mammoth (ca. 20,380 BP) and the Fishhook Mammoth (ca. 20,620 BP), and still much younger are well-preserved Holocene mammoth remains (<10,000 BP). Some paleobotanical data and descriptions of accompanying fauna provide insight into the ecology of the region during Late Pleistocene times. The faunal collapse at the end of the Pleistocene seems to be the result of increasing temperatures, greater humidity, increased snow cover, formation of insulating plant layers, later thawing of the soil, and a lower herbivore density amplifying the climatic effects.

Revision and new data on the Early and Middle Miocene soricids (Soricomorpha, Mammalia) from Central and South-Eastern France

International audienceNew or poorly known Soricids from the Early Miocene of Central France (Limagne d'Allier) and from the Middle Miocene of South-Eastern France (near Lyon) are studied; one new genus (Viretia) and a newspecies (Carposorex burkarti) are described. The soricid assemblages of the Early and late Early/Middle Miocene localities are totally different from each other and new information about appearance and evolution of the taxa are introduced. The following are lists of studied taxa for the beginning of the EarlyMiocene: Clapasorex bonisi, Clapasorex aff. sigei, Carposorex burkarti nov. sp., Soricella cf. discrepans, Oligosorex aff. antiquus and Crocidosoricinae indet, and for the late Early/Middle Miocene Dinosorex sansaniensis, Dinosorex pachygnathus, Heterosorex delphinensis, Miosorex desnoyersianus, Miosorex grivensis, Lartetium dehmi, Lartetium ziegleri, Turiasorex pierremeini, Viretia nov. gen. gracilidens, Paenelimnoecus micromorphus, Paenelimnoecus crouzeli and Hemisorex robustus