Raef Minwer-Barakat

EVOLUTIONARY HISTORY OF THE AFRICAN SORICID MYOSOREX (INSECTIVORA, MAMMALIA) OUT OF AFRICA

Abstract The species Myosorex meini Jammot, 1977 was a nomen nudum because it was named in an unpublished dissertation. The species is here revised using the new material found in the Late Pliocene fissure infillings of Almenara-Casablanca 1 and 4 (province of Castelló, East of Spain) and from the Tollo de Chiclana localities 1B, 3, 10, and 10B in the Guadix Basin (province of Granada, Southeastern Spain). A new diagnosis is given with some differential characters to identify the species within the family. The species definitively belongs to the genus Myosorex. A definitive new allocation for the genus into the subfamily Crocidosoricinae is proposed as an alternative to the classical assignment to the Crocidurinae. This is justified by available data coming from different fields of research, such as genetics, reproductive biology, morphology, and paleontology. Within the Crocidosoricinae, the tribe Myosoricini Kretzoi, 1965 is resurrected, and two other ones, the Crocidosoricini and the Oligosoricini, are redefined. From the paleobiogeographical point of view, the occurrence of the African genus Myosorex constitutes a new striking evidence of the faunal exchange between Eurasia and Africa that took place during the Messinian Salinity Crisis.

MURIDAE (RODENTIA) FROM THE PLIOCENE OF TOLLO DE CHICLANA (GRANADA, SOUTHEASTERN SPAIN)

Abstract In the continental deposits of the area of Tollo de Chiclana (Guadix Basin, south-eastern Spain), several new fossiliferous Pliocene localities yield a rich rodent and insectivore fauna. Of the various rodent families that occur in these sites, Muridae are the most abundant and diversified. Eleven species belonging to seven different genera (Occitanomys, Stephanomys, Castillomys, Paraethomys, Apodemus, Rhagapodemus, and Micromys) have been recognized. In this paper we describe the Muridae from these localities, which have great biostratigraphical and paleoecological interest. The presence of certain taxa and the changes in the abundance of the various taxonomic groups indicate a decrease in temperature and a change in the biotopes from Late Ruscinian through Middle Villafranchian in the area of Tollo de Chiclana.

The Latest Ruscinian and Early Villanyian Arvicolinae from Southern Spain Re-Examined: Biostratigraphical Implications

Abstract The Arvicolinae from the latest Ruscinian and early Villanyian sites of the section of Tollo de Chiclana (Southern Spain) are re-examined in the light of new material and exhaustive comparisons with other European populations. The uppermost Ruscinian population from TCH-1B, previously assigned to Mimomys stehlini, is now ascribed to M. hassiacus, cited for the first time from southern Spain. The populations from the lower Villanyian localities of TCH-3 and 13, assigned to M. minor, are considered to belong to M. stehlini. In addition, the material from the uppermost Ruscinian karstic level of Mo1-A, assigned to “Mimomys” occitanus is ascribed to M. hassiacus. The presence of different species of Arvicolinae is key for delimiting the Ruscinian–Villanyian boundary in the continental deposits of southern Spain and correlating them with European biochronological schemes. In this paper we discuss the problems associated with specific identifications of upper Ruscinian and lower Villanyian arvicolines from Spain, pointing out the invalidity of many citations, and demonstrating the need for an extensive revision of these faunas.

Micromys Caesaris, A New Murid (Rodentia, Mammalia) from the Late Pliocene of the Guadix Basin, Southeastern Spain

The genus Micromys includes a single extant species, Micromys minutus (Pallas, 1771), which lives in Europe and North Asia. This genus is known in the fossil record since the late Miocene; eight fossil species have been described in Europe and Asia, most of them of late Miocene and early Pliocene age. The evolution of this genus during the late Pliocene is barely known. Although it is present in numerous localities of this age, remains of Micromys are usually scarce and generally assigned to the species M. minutus or M. praeminutus Kretzoi, 1959.nnOn the contrary, Micromys is the most abundant genus of Muridae in the late Pliocene locality of Tollo de Chiclana-13 (TCH-13). In a previous paper (Minwer-Barakat et al., 2005), a sample of Micromys from this locality was described, demonstrating its differences from all species of the genus Micromys known until then. Nevertheless, the scarcity of material at that time did not allow the description of a new species. After renewed sampling of this fossiliferous level carried out by the same authors, a more numerous collection is available (41 molars), in which the distinctive features of the new species Micromys caesaris can be observed clearly.nnThe type locality of this new species, Tollo de Chiclana-13, is situated in the central part of the Guadix Basin, an intramontane basin established in the late Miocene. The oldest sedimentary infilling of this basin was deposited in a phase of marine sedimentation during the Tortonian. The upper part of the infilling represents a stage of exclusively continental sedimentation that lasted from latest Tortonian until Late Pleistocene (Viseras, 1991; Fernandez et al., 1996). In the section of Tollo de Chiclana, six fossiliferous localities were described in previous publications (Minwer-Barakat et al., 2004, 2005). These fossiliferous levels, ranging in age from late …

The primate remains from Roc de Santa (Late Eocene, NE Spain) revisited: New taxonomic allocation

The scarce primate remains from the late Eocene locality of Roc de Santa (Central Pyrenees, NE Spain) were first documented in 1975. This material included a mandibular fragment with P3-M2 and a maxillary fragment with P3-M3 assigned to Adapis magnus (later transferred to the genus Leptadapis), and an isolated M3 attributed to Necrolemur antiquus. However, these specimens were never described in detail. We have thoroughly studied these specimens, with the exception of the mandibular fragment, which has been lost. The maxillary fragment is much smaller than in Leptadapis magnus and shows clear morphological differences from that species; this specimen is assigned to Microchoerus hookeri. Similarly, the isolated M3 resembles that of M.xa0hookeri in size and morphology, and can therefore be attributed to this taxon. In addition, we describe an upper incisor never reported previously, which can also be allocated to M.xa0hookeri, representing the first description of this tooth for the species. Therefore, we conclude that the previous taxonomic determinations were mistaken and all the available primate specimens from Roc de Santa can be confidently assigned to the species M.xa0hookeri, previously described from the same-age localities of Sossís, Spain, and Eclépens-B, Switzerland.