Description: Eight rodent species from the Upper Oligocene of Pareja are described. The Theridomyidae are represented by Issiodoromys minor and Archaeomys (A.) gervaisi and the Eomyidae by Eomys cf. molassicus. Four cricetid species are described: Heterocricetodon landroveri sp. nov., Eucricetodon margaritae sp. nov., Eucricetodon cf. atavus, and Eucricetodon sp. One new glirid species, Gliravus caracensis, is recognized. The fauna of Pareja is considered to be somewhat older than that of Carrascosa del Campo, and considerably younger than that of Montalb\xc3\xa1n.

Description: This paper is the first fundamental study on Spanish Eomyidae. The flourishing time of this family in Europe was the Late Oligocene and Early Miocene. Four genera are recognized in this time span: Rhodanomys Dep\xc3\xa9ret & Douxami, 1902, Ritteneria Stehlin & Schaub, 1951, Pseudotheridomys Schlosser, 1926, and Ligerimys Stehlin & Schaub,1951. The study is based on more than 8000 dental elements from 32 localities, which are situated in the following basins: Ebro Basin (provinces of La Rioja and Huesca), Almaz\xc3\xa1n Basin (province of Zaragoza), Calatayud-Teruel Basin (provinces of Zaragoza and Teruel), Loranca Basin (province of Cuenca), and the Bu\xc3\xb1ol Basin (province of Valencia). The following, anteriorly described species are recognized: Rhodanomys transiens Hugueney, 1969, Rh. schlosseri Dep\xc3\xa9ret & Douxami, 1902; Ritteneria manca Stehlin & Schaub, 1951; Pseudotheridomys schaubi Lavocat, 1951, P. parvulus (Schlosser, 1884), P. fejfari Alvarez & Daams, 1987; Ligerimys antiquus Fahlbusch, 1970, L. florancei Stehlin & Schaub, 1951, L. ellipticus Daams, 1976. Seven new species are described: Rhodanomys oscensis sp. nov.; Ritteneria molinae sp. nov.; Pseudotheridomys lacombai sp. nov.; Ligerimys freudenthali sp. nov., L. fahlbuschi sp. nov., L. magnus sp. nov., L. palomae sp. nov. The evolutionary lineage of Rhodanomys transiens - Rhodanomys schlosseri - Rhodanomys oscensis - Ritteneria molinae - Ritteneria manca is characterized by a simplification of the dental pattern and a reduction of size. The biochronological value of this lineage for the Late Oligocene and Early Miocene is confirmed, and a subdivision of this time interval is made on the basis of the various evolutionary stages. Zone W is characterized by Rhodanomys transiens, zone X by Rhodanomys schlosseri and Rhodanomys oscensis, zone Yl by Ritteneria molinae, and zone Y2 by Ritteneria manca. Fahlbusch (1970) proposed the following phylogenetic model for the Pseudotheridomys - Ligerimys group: Pseudotheridomys parvulus - Pseudotheridomys-Ligerimys transitional assemblages - Ligerimys antiquus - Ligerimys florancei. We think, on the contrary, that two lineages are present in the German material. On the one hand there is a lineage composed of P. parvulus - L. antiquus - L. florancei, characterized by a simplification of the dental pattern and size increase. On the other hand, parallel to this lineage, P. parvulus continues without any apparent changes during the Early Miocene. For that matter P. parvulus is is not considered to be a good biochronological marker for MN zone 2, as it has been found in localities as high as zone MN 4 (Alvarez, Daams & van der Meulen, 1987). In Spain we propose the lineage Pseudotheridomys schaubi - P. parvulus - P. lacombai - Ligerimys antiquus - L. palomae, characterized also by a simplification of the dental pattern, and - contrary to the German situation - by a size decrease. Concurrently, during the early Miocene there is a second lineage, represented by Pseudotheridomys fejfari, characterized by a stable morphology and size increase. Considerable fluctuations are observed in the relative frequency of Eomyidae during the Late Oligoc\xc3\xa8ne and the Early Miocene. These fluctuations are attributed to ecological changes. A high frequency of Ligerimys appears to indicate a relatively humid environment. Se ha realizado por primera vez en Espana una revision de la fam\xc3\xadlia Eomyidae, abord\xc3\xa1ndose el est\xc3\xbadio de los representantes espanoles en el per\xc3\xadodo de mayor abund\xc3\xa2ncia e import\xc3\xa2ncia de la fam\xc3\xadlia en Europa (Oligoceno superior - Mioceno inferior). Cuatro g\xc3\xa9neros est\xc3\xa1n representados para este intervalo: Rhodanomys Dep\xc3\xa9ret & Douxami, 1902, Ritteneria Stehlin & Schaub, 1951, Pseudotheridomys Schlosser, 1926, and Ligerimys Stehlin & Schaub, 1951. Despues dei est\xc3\xbadio sistem\xc3\xa1tico dei material de 32 localidades, que han proporcionado m\xc3\xa1s de 8.000 piezas dentarias, se han determinado las siguientes esp\xc3\xa9cies: Rhodanomys transiens Hugueney, 1969, Rh. schlosseri Dep\xc3\xa9ret & Douxami, 1902, Rh. oscensis sp. nov.; Ritteneria molinae sp. nov., R. manca Stehlin & Schaub, 1951; Pseudotheridomys schaubi Lavocat, 1951, P. parvulus (Schlosser, 1884), P. lacombai sp. nov., P. fejfari Alvarez & Daams, 1987; Ligerimys antiquus Fahlbusch, 1970, L. freudenthali sp. nov., L. fahlbuschi sp. nov., L. magnus sp. nov., L. palomae sp. nov., L. florancei Stehlin & Schaub, 1951, L. ellipticus Daams, 1976. En determinados casos se han establecido las hipot\xc3\xa9ticas relaciones filogen\xc3\xa9ticas entre los distintos taxones diferenciados. Tambien se ha podido constatar el valor biocronol\xc3\xb3gico de la l\xc3\xadnea Rhodanomys - Ritteneria y se han precisado, para Espana, los rangos y distribuciones estratigr\xc3\xa1ficos de las esp\xc3\xa9cies estudiadas.

Description: This work gives preliminary information on the taxonomic determinations for the micromammal fossil material from the locality of exceptional preservation of Casa Montero (Madrid). The proposed taxonomic assignations have allowed the correlation of this fossil material with localities belonging to the biozone E (middle Aragonian, middle Miocene) of Daams et al. (1999). Finally, several taphonomic considerations are made aiding to understand how this fossiliferous locality of exceptional richness and quality formed.\n\nEste trabajo aporta informaci\xc3\xb3n preliminar sobre las determinaciones taxon\xc3\xb3micas del material f\xc3\xb3sil de micromam\xc3\xadferos del yacimiento de preservaci\xc3\xb3n excepcional de Casa Montero (Madrid). Las determinaciones taxon\xc3\xb3micas realizadas han permitido la correlaci\xc3\xb3n del material con yacimientos pertenecientes a la biozona E (Aragoniense medio, Mioceno medio) de Daams et al. (1999). Por \xc3\xbaltimo se aportan algunas consideraciones tafon\xc3\xb3micas que ayudan a entender la formaci\xc3\xb3n de este yacimiento de excepcional riqueza y calidad.

Description: The Cerro de los Batallones (Los Batallones Butte) is located in the central-northern area of the Madrid Basin, central Spain. Nine vertebrates localities containing a large variety of mammals of Upper Vallesian Age (Late Miocene) have been found associated with the sediments forming the butte. From bottom to top, these sediments consist of magnesian lutite beds (Unit I), paleosols formed of sepiolite and opal (Unit II), and siliclastic, marlstone and carbonate beds (Unit III). The set of ERT profiles developed in Los Batallones Butte have demonstrate that electrical imaging techniques are an estimable tool for the characterization and prospecting of fossil sites developed in fine-grained siliciclastic sequences. These localities contain an exceptionally rich, varied and well-preserved vertebrate fauna together with invertebrate and plant fossils. Carnivore species are strikingly well represented at Batallones 1 and 3, and large herbivore species, such as mastodons, rhinoceros and giraffes, at Batallones 2, 4, 5 and 10. The taphonomical studies, together with the morphological features shown by the sedimentary fills of the mammal localities, permit an overall interpretation of these deposits as vertebrate traps. The study of these localities should offer a significant contribution to our understanding of the formation pattern of trap-like paleontological sites - which so far have been typically reported in karstic-type systems -, as well as an important source of paleobiological information about numerous vertebrate groups.

Description: The micromammal fauna from the Middle Miocene (Middle Aragonian) of La Retama, eastern central Spain, is described. It is a relatively poor rodent fauna composed by ten species only, associated to a highly diverse bat fauna, which includes five genera. The insectivores are represented by two species. This fossil assemblage has been correlated to zone Db (MN 5). The palaeoenvironmental reconstruction based on micromammals indicates open and dry conditions for this locality.\n\nSe describen los micromam\xc3\xadferos del Mioceno medio (Aragoniense medio) de La Retama, sector centro-oriental espa\xc3\xb1ol. La fauna de roedores es relativamente pobre y est\xc3\xa1 compuesta \xc3\xbanicamente por diez especies. Sin embargo, cabe destacar la elevada diversidad de los quir\xc3\xb3pteros, representados por cinco g\xc3\xa9neros. Se describe tambi\xc3\xa9n dos taxa de insect\xc3\xadvoros. Esta asociaci\xc3\xb3n f\xc3\xb3sil ha sido correlacionada con la zona Db (MN5). La reconstrucci\xc3\xb3n paleoambiental de La Retama inferida a partir de la fauna de micromam\xc3\xadferos corresponde a un ambiente abierto y seco. Palabras clave: Roedores, Insect\xc3\xadvoros, Murci\xc3\xa9lagos, Sistem\xc3\xa1tica, Biocronolog\xc3\xada, Paleoecolog\xc3\xada.

Description: This paper, the third one in a series of monographs on the mammal faunas from the type areas of the Aragonian and Ramblian in the provinces of Zaragoza and Teruel, deals with the description of a new species of the Eomyidae, Pseudotheridomys fejfari.

Description: In this paper the micromammals from three localities in the Oligocene/Miocene boundary interval and the Lower Miocene of the Ebro Basin in the Province of Huesca (northern Spain) are described. Twenty-five species are recognized, two of which are new (Quercomys daamsi de Visser and Peridyromys turbatus Alvarez Sierra et al.; Gliridae). One new subspecies belonging to the Ochotonidae (Prolagus vasconiensis fortis L\xc3\xb3pez Mart\xc3\xadnez & Ses\xc3\xa9) is described. The biostratigraphy, palaeoecological implications and palaeobiogeography are discussed.