New Species of Rotundomys (Cricetinae) from the Late Miocene of Spain and Its Bearing on the Phylogeny of Cricetulodon and Rotundomys

The material of Rotundomys (Rodentia, Cricetinae) from the Late Miocene fossiliferous complex of Cerro de los Batallones (Madrid, Spain) is described and compared with all species currently placed in the genera Rotundomys and Cricetulodon. Both the morphology and size variation encompassed in the collection of specimens from Batallones suggest they belong to a single taxon different from the other known species of these genera. A new species Rotundomys intimus sp. nov. is, therefore, named for it. A cladistic analysis, which is the first ever published concernig these taxa, has been conducted to clear up the phylogenetic position of the new species. Our results suggest that Rotundomys intimus sp. nov. inserts between R. mundi and R. sabatieri as a relatively primitive taxon inside the clade Rotundomys. The new taxon is more derived than R. mundi in having a transversal connection between the metalophulid and the anterolophulid on some m1 but more primitive than R. sabatieri and the most evolved species of Rotundomys (R. montisrotuni +R.bressanus) in its less developed lophodonty showing distinct cusps, shallower valleys, and the presence of a subdivided anteroloph on the M1. The species of Cricetulodon do not form a monophyletic group. As a member of Rotundomys, Rotundomys intimus sp. nov. is more derived than all of these taxa in its greater lophodonty and the complete loss of the anterior protolophule, mesolophs, and mesolophid.Ministerio de Economía y Competitividad (MINECO)Universidad Complutense de MadridDepto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Primeras faunas de micromamíferos del Paleógeno de La Cuenca del Duero

Se estudian cinco yacimientos de micromamiferos del Eoceno de la Cuenca del Duero, región de Zamora y Salamanca (Jambrina, Santa Clara, Babilafuente y Sanzoles) y de la región de Almazán (Miñana). Las faunas de micromamíferos aparecidas en ellos nos han permitido situar sus asociaciones en la escala cronológica del Paleógeno europeo (SCHMIDT-KITTLER, 1987) y datar asi con relativa precisión los tramos en los que se encuentran. Los yacimientos de Zamora corresponderfan al Neustriense -Rhenaniense, siendo el de Santa Clara Rhenaniense Medio (Eoceno Medio). El de Salamanca correspondería al Rhenaniense Superior (Eoceno Medio final) y el de Almazán al Eoceno Superior. La similitud de algunos elementos faunísticos hallados en Zamora con faunas asiáticas. [ABSTRACT] Five gisements of Eocene micromammals of Duero Basin in the Zamora (Jambrina, Santa Clara, Babilafuente and Sanzoles) and Almazán (Miñana) areas are studied. The associations of micromammals found can be placed in the Chronologic scale for the European Paleogene (as stablished by SCHMIDT-KITTLER, 1987) and, as a consequence, the deposits they occur in have been dated with certain accuracy. The deduced ages are: Zamora: Neusttian-Rhenanian; Santa Clara: Middle Rhenanian (Middle Eocene); Salamanca: Upper Rhenanian (Uppemrost Middle Eocene) and Almazán: Upper Eocene. The similitude of some faunistic elements found in Zamora with asiatic faunas are thought to be of biogeographical importance as far as the relationships between Europe and Asia during the Eocene times are concerned

The earliest mammal of the european paleocene: the multituberculate hainina.

A new species of multituberculate mammal, Hainina pyrenaica n. sp. is described from Fontllonga-3 (Tremp Basin, Southern Pyrenees, Spain), correlated to the later part of chron C29r just above the K/T boundary. This taxon represents the earliest European Tertiary mammal recovered so far, and is related to other Hainina species from the European Paleocene. A revision of the species of Hainina allows recognition of a new species, H. vianeyae n. sp. from the Late Paleocene of Cernay (France). The genus is included in the family Kogaionidae Ra˜dulescu and Samson, 1996 from the Late Cretaceous of Romania on the basis of unique dental characters. The Kogaionidae had a peculiar masticatory system with a large, blade-like lower p4, similar to that of advanced Ptilodontoidea, but occluding against two small upper premolars, interpreted as P4 and P5, instead of a large upper P4. The endemic European Kogaionidae derive from an Early Cretaceous group with five premolars, and evolved during the Late Cretaceous and Paleocene. The genus Hainina represents a European multituberculate family that survived the K/T boundary mass extinction event

New Cricetodontini from the middle Miocene of Europe: An example of mosaic evolution

A new species of Cricetodontini (Cricetidae, Rodentia, Mammalia), Cricetodon nievei sp. nov. from the Toril section (Toril 3A, Toril 3B, Toril 2) and Las Planas 5H is described. All this sites belong to the local biozone G3 (late Aragonian, late middle Miocene) from the Calatayud-Daroca Basin (Zaragoza, Spain). The new species displays a mosaic pattern consisting in a combination of primitive and derived characters: the upper molars have a basal Cricetodon-like pattern –short and not complete ectolophs –, whereas the lower molars share several derived features with the older representatives of Hispanomys – absence of metalophulid II. The generic assignation of the new taxon is further discussed and it is compared with all the species of Cricetodon and Hispanomys described until date. This mosaic evolutionary pattern of dental characters is also recognized in other species of Cricetodontini from Europe during the late Aragonian, although involving different combination of morphological characters. At this time, the diversity of the tribe increases, including species with complex morphology and higher intraspecific variability than the older representatives. The new species proposed here is morphologically close to Cricetodontini recorded outside the Calatayud-Daroca Basin, especially C. albanensis and H. decedens from France. Finally, the palaeoecological context of the new species is discussed; the stratigraphical distribution of Cricetodon nievei sp. nov. coevals changes in the faunal assemblages which are possibly related to an increase of humidity detected in the Calatayud-Daroca Basin

General palaeontology, systematics and evolution (Vertebrate palaeontology) Early Late Miocene insectivores (Eulipotyphla, Mammalia) from the Cañada section (Province of Zaragoza, east Central Spain).

Vallesian (early Late Miocene) strata from the recently introduced Ca˜nada section (province of Zaragoza, east Central Spain) have yielded fairly large insectivore assemblages. These show that, after the generally dry Aragonian, the Vallesian gave rise to more humid conditions that were favourable to insectivores, both in number of taxa, and in overall number of specimens. The assemblage of Ca˜nada 8 (Biozone H) is dominated by shrews, whereas the assemblage of Ca˜nada 10 (uppermost Biozone H) contains the oldest record of Desmanella in the area. This seems to signify a bioevent in which after millions of years of absence, talpids return to the area. In addition to the Vallesian assemblages, a small Turolian insectivore fauna has been recovered. On the basis of the rodents, Ca˜nada 12 was assigned to Biozone L, and the insectivore assemblage is very similar to the assemblages from the Teruel basin of that zone. This implies that the discovery of Postpalerinaceus in Ca˜nada 12 is the youngest published record of this large spiny hedgehog

Virtual cranial reconstruction of Hispanomys moralesi (Rodentia, Mammalia) from Cerro de los Batallones (upper Miocene, Spain)

El Cerro de los Batallones is one of the most important fossil sites of the Miocene. The quantity and preservation of its fossil remains have allowed us to describe many new mammal species. One of these is Hispanomys moralesi, a derived species of the Tribe Cricetodontini, a wide group of rodents with great importance in the faunal assemblage during the Miocene. Unlike most fossil micromammals in this fossil site, we have obtained skull remains that preserve never recorded anatomical structures in this time interval. Due to the fragility of the material, it could only be studied in detail using X-ray micro-computed tomography (µ-CT Scan). With this technique, we obtained three-dimensional models of 12 skulls of Hispanomys moralesi, in which different osteological parts have been described. In this way, we compared the morphological variation of the skull with other fossil cricetids and concluded that Batallones’ species is an opisthodont rodent, with a relatively elongated rostrum, a robust base of zygomatic arches and big-sized tooth rows. Opisthodont incisor characterises omnivore and herbivore diets in rodents. Therefore, these new findings of Hispanomys moralesi could allow us to describe the dietary affinities of this extinct species

Ecomorphological characterization of Murinae and hypsodont “Cricetidae” (Rodentia) from the Iberian Plio-Pleistocene

In order to make inferences on the climatic range of extinct rodent genera, cluster analysis using dental morphological variables is performed. The goal of this study is to obtain rodent groupings which relate extinct an extant rodent genera on the basis of the ecomorphology of the dentition. The method is applied to two rodent groups, Murinae and hypsodont “Cricetidae” from the Iberian Plio- Pleistocene. The results show that dental morphology of the Plio-Pleistocene Murinae from the Iberian Peninsula shows similar patterns to those found in extant genera inhabiting tropical forested biomes. The hypsodont “Cricetidae” show a close relationship in dental pattern to that of Phillotini genera, which are inhabitants of herbaceous biomes mainly. The coexistence of both studied groups in the Spanish Plio-Pleistocene could imply an ecological segregation between them. The Murinae would preferably occupy the forested areas and the hypsodont “Cricetidae” the areas with open landscapes. Nevertheless, both groups contain genera that could occupy both types of ecosystems (Huerzelerimys and Ruscinomys). [RESUMEN] Con el objetivo de inferir el rango de climas ocupados por géneros de roedores extintos, se han realizado análisis de conglomerados jerárquicos en los que se han introducido variables morfológicas dentales. Con este análisis se pretenden obtener agrupaciones que relacionen géneros fósiles con actuales sobre la base de la ecomorfología de la dentición. Esta metodología es aplicada a dos grupos de roedores, Murinae y “Cricetidae” hipsodontos, del Plio-Pleistoceno ibérico. Los resultados muestran que la morfología dental de los Murinae Plio-Pleistocenos de la Península Ibérica presenta patrones similares a los encontrados en géneros actuales habitantes principalmente de biomas forestales tropicales. Por otro lado, los “Cricetidae” hipsodontos presentan patrones más parecidos a los de habitantes de biomas predominantemente herbáceos. La coexistencia de ambos grupos en los yacimientos españoles del Plio-Pleistoceno podría implicar, posiblemente, una segregación ecológica entre ellos. Los Murinae ocuparían preferentemente las áreas forestales y los “Cricetidae” hipsodontos las áreas con medios abiertos. No obstante, en ambos grupos aparecen géneros (Huerzelerimys y Ruscinomys) que podrían ocupar ambos tipos de ecosistemas

The bioclimatic model: a method of palaeoclimatic qualitative inference based on mammal associations

Aim The bioclimatic model is a new method for palaeoclimatic reconstruction built on the assumption of a significant correlation between climate and mammal community composition. The goal of this approach is to infer past climatic conditions using mammal fossil associations as source data. Location The study used mammal faunas from all over the world to develop the bioclimatic model. As an example of the potential of the model, we have applied it to Quaternary faunas from Eurasia. Methods The proposed model was constructed by applying multivariate discriminant analysis to modern mammal faunas and climates from throughout the world. The model was validated with a different set of modern faunas than those used in the discriminant analysis, including some from transitional zones between different climates (ecotones). To test the reliability of the method in the Pleistocene, the results have been compared to those obtained with data from other disciplines, such as palaeobotany. Results The results obtained in the validation of the model show that more than 90% of the localities have been classified correctly. Comparisons of results in the late Pleistocene-Holocene of Barová between a palaeobotanical study and the bioclimatic analysis show the latter to be highly accurate. The results for early Pleistocene faunas show somewhat drier and more open climatic conditions for Europe than the present day, with larger areas of steppe environments. Main Conclusions The bioclimatic model could be used to infer climatic conditions from mammal faunas. The results presented in this work provide a preliminary example of the potential that bioclimatic analysis has as a tool for palaeoclimatic inference. Finally, this method offers the opportunity to standardize data coming from vertebrate palaeontology for use in the construction and evaluation of climatic models

Revision of medium-sized Cricetidae from the Miocene of the Daroca-Villafeliche area in the Calatayud-Teruel basin (Zaragoza, Spain)

Revision of Democricetodon (excluding D. sulcatus and D. cf gaillardi), Fahlbuschia, Pseudofahlbuschia and Renzimys from the Aragonian type area (Spain) results in the synonymization of the four genera, Democricetodon prevailing according to the rules of priority. Democricetodon decipiens is synonymized with D. corcolesi, D. darocensis with D. larteti, and Renzimys bilobatus with D. crusafonti. One new species of Democricetodon (D. moralesi n.sp.) is defined.Two partly contemporaneous evolutionary lineages are recognized: the Democricetodon hispanicus - D. lacombai lineage (D. hispanicus-D. moralesi n.sp.-D. jordensi-D. lacombai) and the Democricetodon franconicus - D. crusafonti lineage (D. franconicus-D. koenigswaldi-D. larteti- D. crusafonti). [RESUMEN] La revisión realizada del material de los géneros Democricetodon (excluidos D. sulcatus y D. cf gaillardi), Fahlbuschia, Pseudofahlbuschia and Renzimys del área tipo del Aragoniense (España) ha dado como resultado la sinonimia de los cuatro géneros, siendo Democricetodon el que tiene la prioridad. Democricetodon decipiens se ha sinonimizado con D. corcolesi, D. darocensis con D. larteti, y Renzimys bilobatus con D. crusafonti. Una nueva especie de Democricetodon (D. moralesi n.sp.) ha sido definidas. Dos líneas evolutivas, parcialmente contemporáneas han sido reconocidas: La línea Democricetodon hispanicus - lacombai (D. hispanicus-D. moralesi n.sp.-D. jordensi-D. lacombai) y la línea Democricetodon franconicus - D. crusafonti (D. franconicus-D. koenigswaldi-D. larteti- D. crusafonti)