Antonio García-Alix

The Micromammal Fauna from Negratín-1 (Guadix Basin, Southern Spain): New Evidence of African-Iberian Mammal Exchanges during the Late Miocene

Abstract A rich and diverse micromammal fauna from the late Turolian (MN13) locality of Negratín-1 (Guadix Basin, southern Spain) is described. The faunal list of this site includes Apodemus gudrunae, Occitanomys alcalai, Stephanomys dubari, Paraethomys meini, Myocricetodon jaegeri, Debruijnimys almenarensis, Apocricetus alberti, Ruscinomys sp., Eliomys sp., Atlantoxerus sp., Parasorex ibericus, and Soricidae indet. This is the most nearly complete mammal fauna from the Miocene of the Guadix Basin and allows precise correlations with localities from other Iberian areas. In addition, some of the taxa identified in Negratín-1 are useful as palaeoecological indicators (Myocricetodon, Debruijnimys, Atlantoxerus), evidencing warm and dry climatic conditions. But the principal interest of the fauna from Negratín-1 is the presence of several species of African origin, the gerbillids Debruijnimys almenarensis and Myocricetodon jaegeri, which are recognized for the first time in Europe. We also ascribe to M. jaegeri the population from the upper Turolian karst infilling of Almenara-M. This finding constitutes new evidence for faunal exchanges between North Africa and the Iberian Peninsula during the Messinian Salinity Crisis.

Muridae (Rodentia, Mammalia) from the Mio-Pliocene boundary in the Granada Basin (southern Spain). Biostratigraphic and phylogenetic implications.

The record of Mio-Pliocene continental sediments is very complete in the Granada Basin (southern Spain), and many fossiliferous localities have yielded material of Rodentia, Lipotyphla and Lagomorpha. The most diversified and numerous are rodents, more specifically the family Muridae. Seventeen murid species, belonging to eight genera (Castromys, Occitanomys, Stephanomys, Apodemus, Paraethomys, Castillomys, Micromys, and Muridae gen. et sp. indet.), have been identified. New data on these genera have been used to propose and corroborate some phylogenetic hypotheses. The studied localities range in age from middle Turolian to early Ruscinian, and the variation of the relative abundance of the faunas through time show a faunistic replacement between the middle-late Turolian transition and the late Turolian-early Ruscinian.

Late Turolian micromammals from Rambla de Chimeneas-3: considerations on the oldest continental faunas from the Guadix Basin (Southern Spain)

The fauna from Rambla de Chimeneas-3 (RCH-3), a new uppermost Miocene micro- mammal site from the Guadix Basin, is described. This level has yielded remains of Paraethomys meini, Occitanomys alcalai, Stephanomys cf. dubari, Cricetinae indet., Erinaceidae indet., and Soricidae indet. This faunal assemblage can be assigned to the upper Turolian (MN13). The section of Rambla de Chimeneas is situated in the lower part of the oldest exclusively continental stratigraphic unit distinguished in the filling of the Guadix Basin. Other rodent faunas from this unit were previously assigned to the middle Turolian (MN12). In this paper we reconsider the age of the oldest mammal localities from the Guadix Basin, concluding that none of them can be clearly assigned to MN12. Therefore, there is no evidence of the continentalization of the basin before the late Turolian.

Muscardinus meridionalis sp. nov., a new species of Gliridae (Rodentia, Mammalia) and its implications for the phylogeny of Muscardinus.

The Granada Basin is situated in the central sector of the Betic Cordillera (southern Spain). Its Neogene and Quaternary sediments cover the contact between the internal and external zones of the Cordillera, and the continental deposits extend from the latest Tortonian (middle Turolian) to the Quaternary (GarcíaAlix, 2006). A new Muscardinus from the Mio–Pliocene transition is described from the localities Purcal-4 (PUR-4; UTM 30 SVG 456218) and Purcal-24A (PUR-24A; UTM 30SVG462219), situated about 5 km north of the city of Granada (Fig. 1). According to García-Alix (2006), PUR-24A is late Turolian (upper Miocene), and PUR-4 is earliest Ruscinian (lower Pliocene). This new species of Muscardinus allows us to reinterpret the phylogeny of this genus proposed by Aguilar (1982).

A late Ruscinian (Pliocene) rodent fauna from the Granada Basin (SE Spain)

The Granada basin is situated in the central sector of the Betic Cordillera in southern Spain (Fig. 1). Its Neogene and Quaternary sediments cover the contact between the Internal and External Zones of the Cordillera. After a marine phase, in the latest Tortonian (middle Turolian) a large continental lake, occupying almost the whole basin, was established; it was fed by the fluvial courses, which drained the surrounding relief (GarciaAlix, 2006). This configuration is broken up in the early Pliocene, and two independent alluvial systems with associated fluviolacustrine facies developed: one in the eastern sector and the other one in the western sector (Garcia-Alix, 2006). In the west of the basin we find the paleo-Cacin braided system occupying the same position as the actual Cacin River (Fig. 1) (Fernandez and Soria, 1987). The sediments come from the southern Betic reliefs (Sierra Almijara, Sierra Tejeda) and have a south-north direction, turning west near the village of Moraleda (Fernandez and Soria, 1987). These deposits are usually attributed to the Plio-Pleistocene, but we now show that they correspond to the lower Pliocene (upper Ruscinian). It is the first evidence of a typical Pliocene mammal fauna in the Granada basin.

Dating the change from endorheic to exorheic conditions in the drainage system of the Granada Basin (southern Spain)

Abstract The drainage system of the Granada Basin in southern Spain has evolved from endorheic to exorheic since the basin emerged and became continental in the latest Tortonian (late Miocene). The age of implementation for the recent exorheic, east-west drainage can now be identified by small mammal dating. This drainage configuration began in the latest Pliocene–earliest Pleistocene due to the capture of the Genil River by a Cacín River tributary. It represented an important change in the behavior of the basin and therefore in the geomorphology, as depositional forms and processes were replaced by erosive ones. While the basin was endorheic, sedimentation was active throughout the basin. Afterward the change to exorheic and up to the present, erosion dominates and sedimentation occurs only in some small, fault-controlled depositional depocenters.

Validation of the Species Stephanomys progressus, a Murid (Rodentia) from the Early Pleistocene of Spain

THE GENUS Stephanomys (Muridae, Rodentia) is one of the most common elements in the late Miocene to Early Pleistocene mammal faunas from the Ibero-Occitan region. Its geographic distribution is limited to this area with only two mentions in the late Miocene of Italy (de Giuli, 1989) and Algeria (Coiffait et al., 1985). The genus has been subject of numerous studies, some of them suggesting different interpretations on the phylogenetic relationships between the various described species (Gmelig-Meyling and Michaux, 1973; Cordy, 1978; Adrover, 1986; Bachelet and Castillo-Ruiz, 1990; Aguilar et al., 1993). The most extensive and significant study of the genus is the Ph.D. dissertation of Cordy (1976), who studied in detail several samples of Stephanomys , analyzed the changes observed in successive populations and defined four species ( S. medius , S. michauxi , S. thaleri and S. progressus ), which are considered as nomina nuda because this work was never published. Only one of these species, S. thaleri from the French locality of Seynes, was validated later by Lopez-Martinez et al. (1998).nnAlthough invalid, the name Stephanomys progressus has been used by many authors (Gil and Sese, 1984, 1985; Agusti and Galobart, 1986; Agusti et al., 1993a, 1993b; Aguilar et al., 1993; Vianey-Liaud and Michaux, 2003; Furio et al., 2005; Madurell-Malapeira et al., 2009), only some of them referring specifically to it as a nomen nudum (Minwer-Barakat et al., 2005; Laplana and Blain, 2008). This species was considered by Lopez-Martinez et al. (1998) to be a synonym of S. balcellsi . On the contrary, other studies differentiate S. balcellsi from S. progressus , this latter representing the last step of the continuous lineage Progonomys-Stephanomys , an example of increase in size and morphological specialization in relation …