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Hitherto, only the Proterotheriidae Ameghino, 1887 litopterns from the Cerro Azul Formation (Chasicoan-­Huayquerian Stages/Ages; Late Miocene-Early Pliocene) in LaPampa Province had been studied, recognizing Proterotheriidae indet. at Cerro LaBota, Diplasiotherium pampa Soria, 2001 at several localities, Eoauchenia primitiva Ameghino, 1887 at El Guanaco, and cf.Brachytherium cuspidatum Ameghino,1883 at Salinas Grandes de Hidalgo, which added to Epecuenia thoatherioides Cabrera, 1939 from Laguna Epecuén in Buenos Aires Province; this locality also yielded the Macraucheniidae Gervais, 1855 Huayqueriana cristata (Rovereto, 1914). Now, we enlarge the study to both litoptern families and to the outcrops of the Cerro Azul Formation in Buenos Aires Province. Concerning Macraucheniidae, we recognize: Scalabrinitherium bravardi Ameghino, 1883 at Salinas Grandes de Hidalgo, Telén, and Guatraché (LaPampa), and Laguna Epecuén (Buenos Aires); Paranauchenia denticulata Ameghino, 1891, Promacrauchenia sp., and Cullinia sp. at Salinas Grandes de Hidalgo and Laguna Chillhué (LaPampa); cf.Oxyodontherium zeballosi Ameghino, 1883b at Laguna del Monte (Buenos Aires); and Promacrauchenia sp. at Cantera Relleno Sanitario (Buenos Aires). Referring to Proterotheriidae, new results reveal the first record of Diplasiotherium pampa in Buenos Aires (Arroyo El Venado) and Neobrachytherium sp. at Laguna Epecuén and Laguna La Paraguaya (Buenos Aires). The litoptern diversity is close to that from the Lower Member of the Ituzaingó Formation, Late Miocene, Entre Ríos Province. The litoptern record does not provide confident data to support or reject the established relative biostratigraphic succession of localities of the Cerro Azul Formation, which is mainly based on some rodent lineages.

Studies focused on deciduous dentition, ontogenetic series, and tooth eruption and replacement patterns in fossil mammals have lately increased due to the recognized taxonomic and phylogenetic weight of these aspects. A study of the deciduous and permanent dentition of Interatherium and Protypotherium (Interatheriinae) is presented, based mainly on unpublished materials. Deciduous cheek teeth are brachydont and placed covering the apex of the respective permanent tooth; in addition, some morphological and metrical differences are observed along the crown height. Five dental ontogenetic stages are distinguished among the juvenile specimens on the basis of the degree of wear, the replacement of the deciduous premolars, and the eruption of the molars. The crown height and the wear degree of different Interatheriinae taxa show: (1) eruption pattern of molars in an anterior–posterior direction (M/m1 to M/m3); (2) pattern of replacement of deciduous premolars and eruption of permanent premolars in a posterior–anterior direction (dP/dp4 to dP/dp2 and P/p4 to P/p2); and (3) eruption of M/m3 before the replacement of dP/dp4. Results allow evaluating the diagnostic dental characteristics used to describe some interatheriines, as well as reinterpreting some taxonomic assumptions: the holotype of Protypotherium diversidens Ameghino, 1891 is recognized as a juvenile of another species of the genus, and the species is not validated, considering it as Protypotherium sp.; the holotype of Eudiastatus lingulatus Ameghino, 1891 falls in the variability of Protypotherium, becoming P. lingulatus new combination, tentatively maintaining the species and implying the synonymy between Eudiastatus and Protypotherium; and the holotype of Eopachyrucos ranchoverdensis Reguero, Ubilla, and Perea, 2003 is reinterpreted as bearing deciduous premolars.

Arenas Blancas is a poorly known fossiliferous site located in the lower reach of the Chasicó creek (Buenos Aires Province, Argentina), with great relevance from a biostratigraphic viewpoint. The Macrochorobates scalabrinii Biozone was defined in this site, proposed as the biostratigraphic basis of the early Huayquerian Stage/Age (Late Miocene); however, the geological context and faunal record of this site have never been studied in detail. In this work, we perform a multi-proxy analysis of the Arenas Blancas site, as well as a nearby site here called Curva de la Vaca, and provide new interpretations on their origin, age, and biostratigraphy. Sedimentological, stratigraphic, and geomorphological characteristics of both sites suggest that the sequences include fluvial/alluvial deposits that represent Quaternary terraces. The taxonomic analysis of the Arenas Blancas faunal assemblage evidences the presence of 14 mammal taxa, together with some fishes, reptiles, and birds; the assemblage is correlated with the assemblage from the Cerro Azul Formation assigned to the Chasicoan Stage/Age (Late Miocene), also recovered from the lower reach of the Chasicó creek. The use of the taxa proposed in previous works to characterize the Macrochorobates scalabrinii Biozone (including this species) is not supported due to their taxonomic status and/or temporal distribution. Taphonomic evaluation indicates that the assemblage is constituted by reworked specimens; in this frame, it is proposed that fluvio/alluvial events, occurred during the Late Pleistocene-Holocene, eroded the Upper Miocene substrate and reworked fossil remains. Based on the present evidence, the Macrochorobates scalabrinii Biozone is here rejected as a valid biostratigraphic unit.

We describe a new toxodontid species, Nesodon taweretus sp. nov., from the Aisol Formation in Mendoza Province, central-west Argentina. Nesodon is a frequently found Toxodontidae, member of the Notoungulata, an extinct endemic group of Cenozoic South American mammals that are ecologically similar to current hoofed ungulates. The holotype of N. taweretus sp. nov. is a skull, and we tentatively assign some mandibular fragments and postcranial bones. N. taweretus sp. nov. differs from the other Nesodon species in several cranial and dental features, and close comparisons were made with the Patagonian Nesodon imbricatus, common in the Santa Cruz Formation (Santacrucian Age, Early Miocene). The material is of a similar size to N. imbricatus, with a body mass estimation of about 550 kg. The phylogenetic analysis groups N. taweretus sp. nov. with other species of Nesodon. The absolute age of the Aisol Formation has been established at ca 19.480 ± 0.025 Ma (Burdigalian; Early Miocene) by means of U–Pb zircon dating. The vertebrate association is encompassed by the Santacrucian Age. Latitudinal separation between Mendoza and Patagonia in the south would have favored taxonomic differences, as reflected in the species of Nesodon., Facultad de Ciencias Naturales y Museo

En el yacimiento de La Roma 2 (Alfambra, Teruel), localidad casi desconocida del Vallesiense Superior, han sido hallados restos de tres especies distintas de rinocerótidos. Una de ellas la identificamos con Dicerorhinus schleiermacheri. Algunos restos corresponden a Aceratherium incisivum. La tercera constituye una nueva forma de Aceratherium, A. alfambrense sp.n., cuyo estudio es el objeto de este trabajo. Todos los restos asignados a la nueva especie corresponden al esqueleto postcraneal, principalmente tarsales y metatarsales. Llama la atención la gran escasez de piezas dentarias, no sólo de rinoceronte (únicamente seis dientes de D. schleiermacheri) sino también de otros taxones (carnívoros, proboscídeos, Hipparion). Aceratherium alfambrense sp.n. es una especie directamente relacionada con A.simorrense, de la cual difiere por su mayor talla y robustez.

Interatheriinae is one of the most derived subfamilies of South American notoungulates. Several interatheriines have been described since the 19th century, but most of them have not been revised, o...

Premise Two Bignoniaceae stems with the distinctive anatomy of a liana are described from the Miocene of South America. They are the first fossil evidence of climbing habit in Bignoniaceae. Methods The fossil lianas are siliceous permineralizations. Transverse, tangential, and radial thin sections of the woods were prepared for study using standard petrographic techniques and observed under both light and scanning electron microscopy. Results The stems consist of wood and presumably bark (peripheral tissues). They exhibit phloem wedges, a cambial variant associated with the climbing habit in Bignoniaceae. The wood is diffuse-porous; solitary and in radial multiples vessels; alternated intervessel pitting; ray-vessel pitting with distinct borders; simple perforation plates; rays 1-3 seriate, composed of procumbent cells or body ray cells procumbent with one or two-row of upright or square marginal cells; fibers septate and non-septate, with simple to minutely bordered pits; axial parenchyma scanty paratracheal, vasicentric, septate; perforated ray cells; prismatic crystals in rays, and rays and fibers irregularly storied. The fossil stems are related to extant Dolichandra unguis-cati (L.) Miers. Conclusions The fossils represent a new taxon, Dolichandra pacei sp. nov., which confirms the presence of a neotropical Bignoniaceae liana from the Miocene and provides the first and oldest evidence of the climbing habit in the family. Paleobotanical studies in the Marino Formation, with the record of Bignoniaceae and Verbenaceae, and phylogenetic and biogeographical studies have great importance to understand plant evolution and diversification in South American Andes.

The vertebrate fossil record of the Pampean Region of Argentina occupies an important place in South American vertebrate paleontology. An abundance of localities has long been the main basis for constructing the chronostratigraphical/geochronological scale for the late Neogene–Quaternary of South America, as well as for understanding major patterns of vertebrate evolution, including the Great American Biotic Interchange. However, few independently-derived dates are available for constraining this record. In this contribution, we present new 40Ar/39Ar dates on escorias (likely the product of meteoric impacts) from the Argentinean Atlantic coast and statistically-based biochronological analyses that help to calibrate Late Miocene–Pliocene Pampean faunal successions. For the type areas of the Montehermosan and Chapadmalalan Ages/Stages, our results delimit their age ranges to 4.7–3.7 Ma and ca. 3.74–3.04 Ma, respectively. Additionally, from Buenos Aires Province, dates of 5.17 Ma and 4.33 Ma were recovered for “Huayquerian” and Montehermosan faunas. This information helps to better calibrate important first appearances of allochthonous taxa in South America, including one of the oldest records for procyonids (7.24–5.95 Ma), cricetids (6.95–5.46 Ma), and tayassuids (> 3.74 Ma, oldest high-confidence record). These results also constrain to ca. 3 Ma the last appearances of the autochthonous sparassodonts, as well as terror birds of large/middle body size in South America. South American faunal turnover during the late Neogene, including Late Pliocene extinctions, is interpreted as a consequence of knock-on effects from global climatic changes and initiation of the icehouse climate regime. Fil: Prevosti, Francisco Juan. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Rioja. Secretaria de Ciencia y Tecnología; Argentina Fil: Romano Muñoz, Cristo Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Forasiepi, Analia Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Hemming, Sidney. Columbia University; Estados Unidos Fil: Bonini, Ricardo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; Argentina Fil: Candela, Adriana Magdalena. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina Fil: Cerdeño Serrano, Maria Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Madozzo Jaén, María Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Correlación Geológica. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Departamento de Geología. Cátedra Geología Estructural. Instituto Superior de Correlación Geológica; Argentina. Museo Paleontológico Egidio Feruglio; Argentina Fil: Ortiz, Pablo Edmundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Correlación Geológica. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Departamento de Geología. Cátedra Geología Estructural. Instituto Superior de Correlación Geológica; Argentina Fil: Pujos, François Roger Francis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Rasia, Luciano Luis. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina Fil: Schmidt, Gabriela Ines. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina Fil: Taglioretti, Matias Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Geología de Costas y del Cuaternario. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Geología de Costas y del Cuaternario; Argentina. Litoral Atlántico Norte. Observatorio Patrimonio Arqueológico y Paleontológico; Argentina Fil: Macphee, Ross Douglas Earle. American Museum of Natural History; Estados Unidos Fil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentina. Instituto Nacional de Biodiversidad; Ecuador

Late Oligocene caviomorphs represent one of the most important early adaptive radiations of this group of rodents. They show a high taxonomic diversity and a wide geographic distribution, with those found in the upper Oligocene of Salla (Bolivia) and Patagonia (Argentina) being particularly diverse. However, caviomorphs from the Deseadan South American Land Mammal Age in other latitudes are still scarcely known. In this contribution, we describe new caviomorph rodents from the Deseadan levels of Quebrada Fiera locality (Mendoza Province; central-western Argentina) and evaluate their systematic and paleobiogeographic significance. The taxonomic composition of the caviomorphs from Quebrada Fiera reveals a complex biogeographic history, as we recognize one endemic Cavioidea (Asteromys puelche sp. nov.) and two Chinchilloidea: one with Patagonian affinities (Cephalomys sp.) and another with a wide distribution in South America (Incamys bolivianus). Asteromys puelche sp. nov., shows closer phylogenetic affinities with the Bolivian A. bolivianus than with the Patagonian A. punctus. These rodents, in common with the whole mammalian association from Quebrada Fiera, show a mix of endemic taxa and others shared with higher and lower latitudes.

The apparently regular and favourable climate that characterizes the Holocene as an interglacial period shows, however, important climatic instability well documented in the Northern Hemisphere. These fluctuations from colder to warmer or wetter to drier affected both biodiversity and human societies in the last 12,000 years, although the impact in Southern America is still poorly known. We are here investigating the biodiversity of small mammal faunas, more sensitive to climatic changes than large mammals, combining taphonomic and palaeoecological data in the Argentine Pampas to better understand the global nature and effect of these Holocene climatic fluctuations. This paper is pioneering applying in this region palaeoecological methodologies practised in European sites, such as the chorotype classification and biomes overlap analyses. The Pampean Region is an ecotone with a confluence of three climatic regions where any change in climatic conditions should be easily detected. Our results, based on the palaeoecological requirements of small mammals, do not indicate severe changes, and most of the sites show climatic stability except for one of them, in which a possible trend towards present conditions (temperate/humid) can be inferred., This work was supported by the Ministerio de Ciencia, Innovación y Universidades (Project CGL2016-79334P); the Consejo Superior de Investigaciones Científicas de Cooperación Internacional (Project i-COOPB-20287); the Facultad de Ciencias Exactas y Naturales, Universidad Nacional de La Pampa (Project 05-G) and the Secretaría General de Ciencia y Tecnología, Universidad Nacional del Sur (PGI 24/H154); SGM and ACDG have a predoctoral grant funded by the Universidad Complutense de Madrid (UCM) and Banco Santander (CT42/18-CT43/18 and CT17/17-CT18/17, respectively). LD acknowledges to the Ministerio de Ciencia, Innovación y Universidades for the project PGC2018-094955-A-I00.

We revise the mammal fossils from the Fray Bentos Formation previously assigned to Notoungulata, as well as some new remains recovered from levels cropping out in Corrientes Province (Argentina). In some cases, previous determinations have been completed to the species level, but others have been substantially modified, identifying different families. At present, identified taxa are: “Prohegetotherium” schiaffinoi (Hegetotheriidae), an undetermined interatheriid that is hypothesized as representing the upper teeth of Eopachyrucos ranchoverdensis, and Argyrohyrax proavus (Interatheriidae), cf. Archaeohyrax suniensis (Archaeohyracidae), cf. Mendozahippus fierensis (“Notohippidae”), a Leontiniidae indet., and some undetermined Notoungulata. The presence of Leontiniidae is based on the specimen CTES-PZ 7871, but those previously assigned to this family are herein discarded as such and reinterpreted (notohippid and undetermined taxon). The Mesotheriidae are discarded among the revised materials, but they are present in the Fray Bentos Formation in Corrientes Province with Trachytherus spegazzinianus (= Ameghinotherium curuzucuatiense). The revised sample presents affinities with the fauna from the type locality of the Fray Bentos Formation, in Uruguay, and the Deseadan assemblages from Quebrada Fiera (Mendoza Province, Argentina), Patagonia (Argentina), and Salla (Bolivia). These similarities are important from a paleobiogeographic point of view, especially by the recognition of cf. M. fierensis, a species only known from Mendoza up to now. Only the finding of new material from Fray Bentos Formation in Corrientes Province will allow us to corroborate these tentative determinations and a possible eastward extension of up-to-now exclusive taxa from Quebrada Fiera.

Hegetotheriidae is one of the most derived families of South American notoungulates, which are known from the late Oligocene to Pliocene. Several genera of hegetotheriids have been described; most of them have been recently re-examined, but the Miocene taxa Hegetotherium and Pachyrukhos have not been revised for more than a century. Numerous species of both genera were described mainly from the Santa Cruz Formation, Santa Cruz Province, but also from the Colhuehuapian beds in Chubut Province, and the Colloncuran beds in Neuquén and Río Negro provinces, Argentina. Recently, Hegetotherium was recorded in Bolivia and Chile. Sinclair was the first reviewer to postulate some synonymies, in the first decade of the twentieth century. The present contribution provides a re-evaluation of these genera, including the study of previously unpublished materials. We conclude that Hegetotherium mirabile and Pachyrukhos moyani are the only hegetotheres in the Santa Cruz Formation (Santacrucian SALMA) with Hegetotherium novum and Pachyrukhos politus in the Colhuehuapian SALMA. Additionally, H. convexum, H. anceps, H. minum and H. andinum are proposed as synonyms of H. mirabile; H. novum is removed from Prohegetotherium; and Hegetotherium arctum is excluded from Hegetotheriidae. This taxonomic revision led to a new phylogenetic analysis of Hegetotheriidae, based on a previous data matrix, but enlarged and corrected, as some taxonomic issues concerning other genera were revealed. The analysis supports the monophyly of Hegetotheriidae and the subfamily Pachyrukhinae, as well as the monophyly of the genera Hemihegetotherium and Paedotherium, if the proposed removal of Pd. kakai from the latter is admitted. In contrast, Hegetotheriinae and Hegetotherium appear to be paraphyletic. The position of H. novum supports its removal from the genus Prohegetotherium, in which it was recently included. Fil: Seoane, Federico Damián. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geologicas. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Cerdeño Serrano, Maria Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina

Se describen los restos de rinocerótido procedentes del yacimiento de Cerro de los Batallones (Madrid, España). Se confirma su identificación preliminar como Aceratherium incisivum Kaup. La mayor parte de los restos pertenece al mismo individuo y su estudio comparativo muestra que tiene la sínfisis mandibular relativamente más larga y la altura de la rama ascendente algo más corta que otras poblaciones de la especie; además, el escafoides presenta tres facetas de articulación con el semilunar, lo cual no es común en Aceratherium y géneros afines. En general, las dimensiones de los restos son menores que las del material tipo de Eppelsheim (Alemania), pero entran en el rango de variación establecido para la especie en diversas localidades europeas. Cerro de los Batallones se considera de edad Vallesiense superior (Mioceno superior). A. incisivum se conoce bien a lo largo del Vallesiense y Turoliense en Europa, pero esta poco representado en España, salvo en la cuenca del Valles-Penedes. Este nuevo material aumenta el conocimiento de la especie en las cuencas centrales de España.

Old and new specimens from the early Miocene middle member of the Mariño Formation (Mendoza, Argentina) allow for a reinterpretation of a controversial Mesotheriidae taxon. Earlier known remains come from the Divisadero Largo locality and were, depending on the specimen, either previously described as Trachytherus? mendocensis or referred to a coeval taxon from Chile, Altitypotherium chucalensis. Based on new specimens, here described in detail for the first time, we propose that all mesotheriid material from Divisadero Largo, as well as new material from the Potrerillos locality belong to a new mesotheriid taxon. Recognition of the same taxon from these two localities establishes a sound biostratigraphic correlation. The combination of morphological characters leads to the proposal of a new generic name, Rusconitherium, for Trachytherus? mendocensis, establishing Rusconitherium mendocense New genus and New Combination. This nomenclatural act is due to the fact that T.? mendocensis, formerly thought as a Trachytheriinae from the Paleogene Divisadero Largo Formation, actually comes from the Mariño Formation and belongs to the same taxon as the new material. The missing holotype of T.? mendocensis prompts us to propose a neotype and a new diagnosis for this species, which better characterize the Santacrucian mesotheriids from Mendoza. A phylogenetic analysis does not support a close relationship between this species and Altitypotherium (or any other mesotheriine genus) counter to a previous hypothesis. An unnamed new taxon from the Chinches Formation (San Juan Province) could belong to Rusconitherium, but its full description is pending, as well as a thorough revision of most Mesotheriinae members. Sediments at Potrerillos reveal two paleoenvironmental scenarios: dune fields, influenced by volcanic events, and capillary water that provided humid conditions encouraging vegetation and fauna. Fil: Cerdeño Serrano, Maria Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Vera, Bárbara Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Combina, Ana María. Universidad Nacional de La Rioja; Argentina

The Neogene outcrops in Northwestern Argentina have provided many fossil mammals, particularly notoungulates. However, the fossil record of the early stages of the late Miocene is scarce. The present study describes two mesotheriine specimens from Las Arcas Formation (underlying the Chiquimil Formation dated at 9.14 ± 0.09 Ma; Catamarca Province) and Saladillo Formation (dated at 10 ± 0.3 Ma; Tucumán Province), represented by a left maxillary fragment with complete M1–3 and a right isolated M3, respectively. The main feature of these pieces is their small size, significantly smaller than that of the Miocene genera Eutypotherium, Typotheriopsis, and Pseudotypotherium, recorded in Argentina. In contrast, these mesotheriines are closer to specimens known from Bolivia. The comparative analysis allows us to refer the material herein described to Plesiotypotherium aff. P. achirense and Mesotheriinae indet., with all cautions inherent to the incompleteness of the material. In turn, the paleobiogeographic implication of these new records is approached. A relationship concerning phylogenetic aspects, size, temporal range, and distribution pattern is proposed, taking into account the small size of the studied material in a temporal context of medium to large-sized mesotheriines. Fil: Armella, Matías Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Correlación Geológica. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Departamento de Geología. Cátedra Geología Estructural. Instituto Superior de Correlación Geológica; Argentina Fil: Nasif, Norma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Correlación Geológica. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Departamento de Geología. Cátedra Geología Estructural. Instituto Superior de Correlación Geológica; Argentina Fil: Cerdeño Serrano, Maria Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Museo de Historia Natural de San Rafael - Ianigla | Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Museo de Historia Natural de San Rafael - Ianigla | Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Museo de Historia Natural de San Rafael - Ianigla; Argentina

Remains of Proterotheriidae (Litopterna) recovered from different localities in La Pampa Province, Argentina, are described. The fossiliferous levels in these localities correspond to the Cerro Azul Formation (late Miocene), where Chasicoan and Huayquerian faunal associations are known. The specimens of Proterotheriidae herein studied are assigned to Diplasiotherium pampa, Eoauchenia primitiva, cf. Brachytherium cuspidatum, Neobrachytherium sp. and Proterotheriidae indet. Although the holotype of D. pampa (left mandibular fragment with p3-m2) was defined in a previous paper, it is figured and fully described here, and its m3 is now known among the new collected specimens. Eoauchenia, Brachytherium and Neobrachytherium are registered in La Pampa Province for the first time, and the record of E. primitiva extends back to late Miocene its temporal distribution. Proterotheriids from the Cerro Azul Formation gather exclusive elements and others related to taxa represented in different Argentinean geological units corresponding to late Miocene-early Pliocene period. Fil: Schmidt, Gabriela Ines. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina Fil: Montalvo, Claudia Inés. Universidad Nacional de la Pampa. Facultad de Cs.exactas y Naturales. Departamento de Cs.naturales. Pabellon de Geología; Argentina Fil: Sostillo, Renata. Universidad Nacional de La Pampa; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Cerdeño Serrano, Maria Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina

En este trabajo, se describen los restos postcraneale s de un hegetotérid o (Notoungulata) hallados en e1 yacimiento de Puchuzum, situado en el valle de Calingasta, en la provincia de San Juan, Argentina. La asociación de mamíferos encontrada en Puehuzum permite atribuirla a la edad Huayqueriense (Mioceno superior). Se confirma la determinación genérica preliminar de los restos estudiados y se completa a nivel específico, identificándolos con Hemihegetotherium achathaleptum Rovereto, 1914. Existen muy pocas descripciones del esqueleto postcraneal de los hegetotéridos, ya que la mayoría de las especies se basan principalmente en restos dentarios. Por el1o, algunos de los huesos postcraneales de Hemihegetotherium se describen aquí por primera vez. La revisión de otros materiales de este género nos lleva a establecer la sinonimia de las tres especies Huayqueriense H. achathaleptum H Asimismo se confirma la pertenencia de género Hemihegetotherium de la especie chaquiquense, H. Torresi, H. achathaleptum se distribuye en provincias argentinas de Catamarca, San Juan, Mendoza y La Pampa, mientras que la especie más antigua, H. torres i, se conoce de la provincia de Buenos Aires.

Se describen más de 180 restos de Mesotheriidae Mesotheriinae (Notoungulata) del Mioceno Superior de la provincia de La Pampa (Argentina). Proceden básicamente de la Formación Cerro Azul, pero también se ha incluido material de la Formación El Palo, y se identifican como Typotheriopsis silveyrai Cabrera, 1937 y Pseudotypotherium subinsigne (Rovereto, 1914). El carácter principal para diferenciar ambas especies es la ausencia o presencia de surco lingual en el P4. El material procede de 18 localidades diferentes que han proporcionado un rico conjunto de mamíferos atribuible a la edad Huayqueriense (Mioceno Superior). La revisión de los datos existentes sobre los mesoterinos nos lleva a proponer la sinonimia de las especies Typotheriopsis silveyrai, T. jachalensis y T. vanhoullei, así como la de Pseudotypotherium carhuense y P. subinsigne, correspondiendo la prioridad a T. silveyrai y P. subinsigne, respectivamente. El análisis cladístico de la subfamilia Mesotheriinae ha proporcionado un úinico cladograma en el que todos los géneros considerados están justificados como taxones monofiléticos. Las únicas relaciones no resueltas son las existentes entre las especies de Pseudotypotherium.

Se describe en detalle un esqueleto bastante completo de rinoceronte hallado en el yacimiento plioceno superior (Villafranquiense, MN 16-17) de Crespià (Cuenca de Banyoles-Besalu, Gerona, España). Se confirma su atribución preliminar a Stephanorhinus etruscus Falconer. Se establecen comparaciones con yacimientos comprendidos en el área de distribución bioestratigráfica de la especie y con algunos situados en los niveles inferiores del Pleistoceno medio donde aparece S. hundsheimensis Toula. El esqueleto corresponde a un individuo adulto, con una masa corporal estimada en 1200 kg. A nivel morfométrico, presenta claras semejanzas con otros restos españoles de la especie, como los de La Puebla de Valverde o El Rincón-1. Comparado con otros restos europeos, las dimensiones en general están por debajo de la media establecida para la especie y la serie premolar inferior es relativamente larga. Como detalles morfologicos característicos, destaca la sínfisis mandibular acortada y las ramas ascendentes relativamente bajas con respecto a algunos ejemplares coetáneos; dentición superior con gancho menos desarrollado que los ejemplares del Pleistoceno inferior; y huesos largos más gráciles que los de La Puebla de Valverde, aunque los metápodos mantienen epífisis relativamente anchas.

We describe new remains of notoungulates from the Cerro Azul Formation (late Miocene) in La Pampa Province and reassign others previously studied, helping to precise the taxonomic diversity of 25 fossiliferous localities of this formation. Geomorphological context previously described for the area provides data to place some localities in a temporal sequence. The following Notoungulata are recognised: Protypotherium minutum (Interatheriidae), Paedotherium minor, Tremacyllus impressus, Hemihegetotherium achataleptum, H. torresi, and Hemihegetotherium sp. (Hegetotheriidae), Typotheriopsis silveyrai, T. chasicoensis, and Pseudotypotherium subinsigne (Mesotheriidae), and Pisanodon nazari, Hemixotodon chasicoensis, and cf. Stenotephanos plicidens (Toxodontidae). This study allows adding new localities to the biochronological sequence previously proposed based on the evolutionary pattern of the octodontoid rodents. Chasicoan and early Huayquerian (as herein considered) faunal assemblages present higher diversity of notoungulates than those assigned to late Huayquerian. Some localities lack a representation of taxa significant enough to precise their biochronological position within the late Miocene. The difference in the notoungulates representation along the Chasicoan–Huayquerian ages may be due to climatic changes that affected the centre of Argentina from late Miocene to early Pliocene. Fil: Sostillo, Renata. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; Argentina Fil: Montalvo, Claudia Inés. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; Argentina Fil: Cerdeño Serrano, Maria Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Schmidt, Gabriela Ines. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina Fil: Folguera, Alicia. Instituto de Geología y Recursos Minerales. Servicio Geológico Minero Argentino; Argentina Fil: Cardonatto, María Cristina. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; Argentina

Several systematic revisions of the Hegetotheriidae have been published in the last twenty years, but some important taxonomic work remains limited to unpublished studies. In one such thesis, the late Oligocene genera Prosotherium and Propachyrucos were revised, so that Prosotherium garzoni and Propachyrucos smithwoodwardi were considered the only valid species for each genus. Later authors loosely accepted these informal revisions, but recent phylogenetic coding has yet to accurately reflect these revisions, with character states often at odds with the known material for these genera. This study re-examines most of the fossil material assigned to Propachyrucos and Prosotherium, including both published and unpublished fossils, and contributes to a better understanding of the systematics, taxonomic diversity and early morphological evolution of the pachyrukhines. We conclude that Prosotherium garzoni and Propachyrucos smithwoodwardi are indeed the only valid species for each genus, confirming the influential but unpublished revisions that have become widely accepted. The known material for these species is clarified to aid future phylogenetic studies. At the same time, Propachyrucos aequilatus and Pr. robustus are herein considered nomina dubia. Additionally, Miocene species originally ascribed to Propachyrucos, along with unpublished material loosely assigned to the same genus, are here synonymized with other genera. Finally, several fossils previously recognized as Prosotherium sp. are here recognized as P. garzoni. Au cours des vingt dernières années, des révisions systématiques de plusieurs genres d’Hegetotheriidae ont été publiées, mais quelques autres sont restées inédites. C’est le cas d’une thèse de doctorat où les genres Prosotherium et Propachyrucos de l’Oligocène supérieur ont été étudiés et plusieurs synonymies ont été proposées. Néanmoins, des auteurs ultérieurs ont accepté ces synonymies informelles, ce qui a conduit à considérer Propachyrucos smithwoodwardi et Prosotherium garzoni comme les seules espèces valables pour les genres respectifs. Les analyses phylogénétiques d’Hegetotheriidae ont codifié certains caractères pour ces taxons, mais ils ne correspondaient pas au matériel fossile connu pour chaque espèce. Nous avons réétudié la plupart des matériaux attribués à Propachyrucos et Prosotherium, y compris des restes inédits. Nos résultats indiquent que Prosotherium garzoni et Propachyrucos smithwoodwardi sont vraiment les seules espèces valables pour chaque genre. En même temps, Propachyrucos aequilatus and Pr. robustus sont ici considérés comme nomina dubia. En outre, les espèces du Miocène précédemment attribuées à Propachyrucos, ainsi que le matériel non publié intitulé Propachyrucos sp., ont été synonymisés avec d’autres genres. Enfin, le matériel identifié comme Prosotherium sp. a été reconnu comme P. garzoni. Fil: Seoane, Federico Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina Fil: Cerdeño Serrano, Maria Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Henderson, Hayley. Amherst College; Estados Unidos

This contribution discusses the interatheriids from Quebrada Fiera, a Late Oligocene locality in the south of Mendoza Province. In addition, the taxonomic status of the Deseadan interatheres Plagiarthrus clivus, Argyrohyrax proavus, Argyrohyrax proavunculus, ?Argyrohyrax acuticostatus, Progaleopithecus fissurelatus, Progaleopithecus tournoueri, and Notohyrax conicus is discussed. We recognise in Quebrada Fiera A. proavus and Progaleopithecus sp. A possible third taxon is represented by one specimen that shows a combination of features that do not permit accurate assignment. These new remains, in combination with a systematic study of Deseadan interatheres, allow for a better definition of each recognised taxon, extended diagnoses, and clarification of some long-standing taxonomic misconceptions. Indeed, the priority of A. proavus over P. clivus is established, and the latter is proposed as a nomen dubium. Associated deciduous and permanent dentition and some limb bones provide new data on the ontogenetic variation and postcranial morphology of Argyrohyrax. Phylogenetic analysis supports the taxonomic determinations and places A. proavus in a basal position with respect to Archaeophylus or Progaleopithecus. Documented fossil records of Argyrohyrax and Progaleopithecus in Mendoza extend the known range to middle latitudes in central west Argentina; these taxa expand the list of mammals from Quebrada Fiera with Patagonian affinities. Fil: Vera, Bárbara Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Cerdeño Serrano, Maria Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Reguero, Marcelo Alfredo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Se realiza una revisión sistemática de los materiales referidos a Toxodontidae (Notoungulata) provenientes del Lujanense (Pleistoceno tardío-Holoceno temprano) de las Provincias de Corrientes y Chaco, Argentina. Previamente, diversos autores habían reconocido en esta área la presencia de los siguientes Toxodontidae: Toxodon gezi, T. cf. T. gezi, T. aguirrei, T. cf. T. platensis, T. gracilis y Toxodon sp. Los resultados obtenidos sugieren que las especies presentes en la Provincia de Corrientes son T. platensis y T. gracilis. En la Provincia de Chaco, los materiales originalmente referidos a T. cf. T. gezi se reconocen como T. platensis. En este sentido, la evidencia indica que T. gezi y T. aguirrei no son especies válidas y deben ser consideradas sinónimos posteriores de T. platensis. Además, en este trabajo, se da a conocer un cráneo bastante completo de T. platensis procedente del Lujanense (Pleistoceno tardío-Holoceno temprano) de la Provincia de Santa Fe.

Thomas H. Huxley (1870) mentioned as Homalodotherium some fossils sent to him by Dr. Robert O. Cunningham, and sent these remains to William H. Flower to be described. Flower presented at the same time at the Royal Society of London (reception May 30, and presentation June 19, 1873) a short abstract (Flower, 1873) and a full description (Flower, 1874), which were, however, published with different date, being the abstract previous to the complete work. This fact gave place to subsequent nomenclatural changes because the author used a different generic name in the paper published in 1874, Homalodontotherium instead of Homalodotherium. Besides, Flower’s complete work is often referred to 1873 due to the date of presentation, but it was published in 1874. The abstract included a general comparison of the fossil, and the taxonomic name Homalodotherium cunninghami appears in the title. Fil: Seoane, Federico Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos ; Argentina Fil: Hernández del Pino, Santiago Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Scioscia, Cristina Luisa. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina Fil: Cerdeño Serrano, Maria Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina

The subfamily Scelidotheriinae (Xenarthra, Folivora) is a clade of extinct sloths recorded from the middle Miocene to the Pleistocene/Holocene transition in South America, namely Argentina, Bolivia, Brazil, Colombia, Chile, Peru, Ecuador, Uruguay, and Paraguay. Quaternary taxa are the best known, but the knowledge of the late Neogene representatives has been greatly improved in recent years, particularly in Argentina. New materials of Scelidotheriinae recovered from the Cerro Azul Formation (late Miocene; Huayquerian) in La Pampa and Buenos Aires provinces are here described and identified as Proscelidodon gracillimus Rovereto, and ontogenetic variations are established for the first time in this group of sloths. The comparative study has led to the taxonomical revision of other species such as P. almagroi Rovereto (from Catamarca Province) and Elassotherium altirostre Cabrera (from western Buenos Aires Province), whose type specimens are reinterpreted as subadult and juvenile individuals, respectively, of P. gracillimus; thus, the former two become synonymous names of the latter. As the type material from Mendoza, the remains of P. gracillimus from Buenos Aires and La Pampa provinces have been recovered from Huayquerian levels, being absent from the older Chasicoan levels, within the late Miocene. In turn, the materials from Catamarca (type of P. almagroi) have less chronological precision, and could range from late Miocene to early Pliocene.

The first known Interatheriinae (Interatheriidae, Notoungulata) were described by Florentino Ameghino based on fossils collected by his brother Carlos in diverse Argentinean early Miocene outcrops in the Santa Cruz Province, which are housed at different institutions. In order to perform a systematic study of the subfamily, it is essential to revise as much specimens as possible, but first of all the type material of the species under study. Due to the fact that Florentino Ameghino never referred to any type specimens with a collection number in any of his publications, their identification becomes a complex task. In consequence, when studying the species erected by Ameghino within the genera Interatherium and Icochilus, we identified a lack of correspondence between some materials catalogued as type specimens and the original descriptions. In this contribution, we present the type specimens of 18 out of the 21 Santacrucian species of Interatherium (4) and Icochilus (14) within the paleontological collection of the Museo de La Plata and Ameghino National Collection at the Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”. Four case studies are presented: a) specimens correctly identified; b) materials erroneously catalogued as type specimens; c) specimens catalogued as type, whose status cannot be evaluated because they are lost; and d) specimens not catalogued as types, but herein recognised as such. As the selection of the type species of Icochilus was pending, Ic. extensus is herein designated as such. The lectotypes of Ic. extensus and Ic. multidentatus are selected among their identified syntypes.

A new hydrochoerine rodent, Cardiatherium calingastaense sp. nov. (Caviidae), is described based on the specimen INGEO-PV 87. It was recovered from the late Miocene Las Flores Formation, cropping out at the Puchuzum locality, San Juan Province, Argentina. The new species is based on a particular combination of characters, among which the following can be highlighted: p4 with internal fissures equally deep as in Cardiatherium paranense, secondary external fissure as in Cardiatherium patagonicum, and lacking the fifth internal fissure and supernumerary internal fissure, as in C. paranense; m3 with a conspicuous labial column in the posterior ramus of the second prism; very deep primary and secondary external fissures in upper cheek teeth, the former producing a labial strong step-shaped profile in M2; sagittal crest on the parietals; bullae small in ventral view; scars of the origin of the masseter medialis muscle with an anterior projection up to the level of the incisive foramen and the maxilla-premaxilla suture. The phylogenetic analysis supports the taxonomic proposal of creating a new species of Cardiatherium and shows C. calingastaense sp. nov. as the sister group of the other species of the genus. The lineage leading to the clade Cardiatherium + largest capybaras would have originated at least during the Chasicoan SALMA (early late Miocene). Cardiatherium calingastaense sp. nov. adds to the previous record of Cardiatherium chasicoense and Cardiatherium paranense in the late Miocene of San Juan and Mendoza provinces, respectively, thus increasing the diversity of capybaras in central-west Argentina. Fil: Cerdeño Serrano, Maria Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Pérez, María Encarnación. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Deschamps, Cecilia Marcela. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina Fil: Contreras, Victor Hugo. Universidad Nacional de San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Geología "Dr. Emiliano Aparicio"; Argentina

Fil: Vera, Bárbara. Centro de Investigación Esquel de Montaña y Estepa Patagónica (CIEMEP), CONICET-UNPSJB; Argentina. Fil: Tunik, Maisa. Universidad Nacional de Río Negro. Instituto de Investigación en Paleobiología y Geología. Río Negro, Argentina. Fil: Cerdeño, Esperanza. Paleobiología y Paleoecología, Instituto de Nivología, Glaciología y Ciencias Ambientales, CONICET; Argentina. We present two new Paleogene fossiliferous sites that provide the first mammal remains for the Malargüe Group in the Neuquén basin of southeastern Mendoza Province, Argentina. Identified taxa from Agua de Flores-Agua de Isaac: Kibenikhoria sp., Oldfieldthomasiidae indet., ?Henricosborniidae indet., and a large Notoungulata probably related to the Isotemnidae. Taxa from Liu Malal: cf. Kibenikhoria and Notopithecidae gen. et sp. nov. Based on facies composition and geological distribution, we consider that the Cenozoic deposits from these fossiliferous localities correspond to the already defined Puesto Fortunata Formation. This unit is correlated to the Coihueco Formation, the top of the Malargüe Group in the northern Neuquén basin, and its mammal content supports the proposed hiatus between the ~40 Ma and 20 Ma based on chronostratigraphy. The presence of Kibenikhoria in the local faunas of southeastern Mendoza extends the geographic range of this genus so far known in Patagonia to central-west areas of Argentina and supports an early-middle Eocene age for the fossil-bearing levels of the Puesto Fortunata Formation.

More than 40 remains of Tremacyllus Ameghino (Notoungulata, Hegetotheriidae, Pachyrukhinae) from the Province of La Pampa (Argentina) are analyzed. They were recovered from different outcrops of the late Miocene Cerro Azul Formation at Laguna Chillhué, Quehué, Telén, Salinas Grandes de Hidalgo, Estancia Ré, Bajo Giuliani, Barrancas Coloradas and Caleufú. During the late Miocene, pachyrukhines are represented by two genera, Tremacyllus and Paedotherium Burmeister. The present sample of Tremacyllus allows for the dental morphological variation to be evaluated, especially in lower and upper premolars. This study shows high variability in the diagnostic characters of two recognized species, T. impressus Ameghino (Pliocene-Pleistocene of the Pampean Region) and T. incipiens Rovereto (late Miocene of Catamarca). We interpret these differences to actually correspond to intraspecific variation and, consequently, propose their synonymy. T. impressus has priority over T. incipiens, and an emended diagnosis is provided. This nomenclatural action implies, in turn, the extension of the biochron of Tremacyllus impressus from the late Miocene to the Pleistocene. T. impressus differs from Paedotherium in its smaller size, post-incisive impressions extended beyond the level of P2 (even reaching the anterior margin of P3), M3 shorter or equal to M2, relatively shorter mandibular symphysis, and lower premolars not molariform and more imbricated. Within the studied sample, we identify several juvenile specimens that confirm the dental eruption pattern previously proposed for Tremacyllus based on fewer remains. Se analizan más de 40 restos de Tremacyllus Ameghino (Notoungulata, Hegetotheriidae, Pachyrukhinae) de la Provincia de La Pampa (Argentina). Se colectaron en diferentes afloramientos de la Formación Cerro Azul (Mioceno tardío) en Laguna Chillhué, Quehué, Telén, Salinas Grandes de Hidalgo, Estancia Ré, Bajo Giuliani, Barrancas Coloradas y Caleufú. Durante el Mioceno tardío, los paquiruquinos están representados por dos géneros, Tremacyllus y Paedotherium Burmeister. La muestra estudiada permite definir variaciones morfológicas dentales dentro de la muestra de Tremacyllus, especialmente en los premolares inferiores y superiores. El resultado muestra una amplia variabilidad en los caracteres previamente asumidos como diagnósticos en las dos especies reconocidas, T. impressus Ameghino (Plioceno-Pleistoceno de la Región Pampeana) y T. incipiensRovereto (Mioceno tardío de Catamarca). Se interpreta que las diferencias entre ellas corresponden a variaciones intraespecíficas y, por lo tanto, se propone su sinonimia, teniendo la prioridad de nombre T. impressus, y se proporciona una diagnosis enmendada. Esto implica, a su vez, la extensión del biocrón de Tremacyllus impressus, desde el Mioceno tardío hasta el Pleistoceno. Tremacyllus impressus difiere de Paedotherium en su menor tamaño, la presencia de impresiones postincisivas que exceden el nivel del P2 (alcanzando incluso la cara anterior del P3), el M3 igual o más corto que el M2, la sínfisis mandibular relativamente más corta y los premolares inferiores no molariformes y más imbricados. Dentro de la muestra estudiada, identificamos varios especímenes juveniles que confirman el patrón de erupción dentaria propuesto previamente para Tremacyllus a partir de pocos ejemplares. Fil: Sostillo, Renata. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina Fil: Cerdeño Serrano, Maria Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Montalvo, Claudia Inés. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; Argentina

Daura, J. et al, © 2015 Elsevier Ltd. The Cova del Rinoceront, a site in NE Iberia, contains a thick sedimentary fill preserving a faunal archive from the penultimate glacial and the the last interglacial periods. Layers I to III have been dated to between 74 and 147ka, coinciding with MIS 5a to 5e, a period poorly represented in the Mediterranean terrestrial record. The results from Cova del Rinoceront are of broader interest for the reconstruction of ecological dynamics during warm stages and the understanding of the evolution and geographical variation of several taxa. The palaeoecological evidence suggests a landscape dominated by mixed wooded vegetation with mild climatic conditions, slightly more humid than today. Several vertebrate taxa, including Haploidoceros mediterraneus, Stephanorhinus hundsheimensis and Glis glis, are documented for the first time in the early Upper Pleistocene of Europe, showing that these species persisted across the region for longer than previously thought. In addition, the recovery of a small lithic assemblage indicates human presence in the surroundings of the site. The 11m-thick stratigraphic section also provides an ideal setting in which to compare several geochronological methods. U-Th dating of the flowstones that cap the deposit, of speleothems formed along the cave walls, and of speleothems buried by the deposit at different elevations provides minimum and maximum ages of 74 and 175ka, respectively, for the accumulation. The ages obtained by luminescence, electron spin resonance (ESR), amino acid racemisation (AAR), palaeomagnetism and U-series dating of bone are in good agreement with each other and are stratigraphically consistent. This well-dated faunal succession presents a unique opportunity to assess changes in the Pleistocene fauna of the Mediterranean coast over an interval of more than 100ka., This paper is an output of the archaeological research project El Plistocé Superior a la costa central catalana: paleoambients i ocupació dels neandertals (2014/100639) sponsored by Servei d'Arqueologia i Paleontologia e Generalitat de Catalunya (G.C.) and Castelldefels City Council. Sampling and laboratory analyses were funded by Catalan (2014SGR-00108) and Spanish (HAR2011-26193, HAR2011-26193, CGL2010-18616, CGL2012-38358, CGL2012-38434-C03-03 and CGL2013-48441-P) MICINN Projects. J. Daura has been supported by a postdoctoral grant (Juan de la Cierva Subprogram JCI-2011-09543), J.M. López-García by a postdoctoral fellowship (2011BP-A00272) from the G.C. a grant co-funded by the European Union through the Marie Curie Actions of the 7th Framework Program for R.D. We are also grateful to R. Alvarez (UB) for lithics'photos. J. Mangope, Williams College, prepared and measured the ESR sample. D. Lawrence, Wadsworth Laboratories of the New York State Public Health Service provided access to the source for the ESR irradiations. Funding for the ESR spectrometer came from NSF grant ILI 9151111; other funding was provided by Williams College. L.Arnold and M. Demuro were supported by MINECO grant G2010- 16821, Australian Research Council Future Fellowship F130100195, and Marie Curie International Reintegration grant PIRG08-GA-2010-276810. Thanks to the Paleomagnetism Laboratory of Barcelona (CCiTUB-CSIC) where the paleomagnetic analyses were carried out.

The first collections of Interatheriinae (Interatheriidae, Notoungulata) were created by the brothers Florentino and Carlos Ameghino, based on fossil specimens collected from diverse outcrops of Argentina and housed at different national institutions. In order to perform a systematic study of the subfamily, it is essential to revise as much specimens as possible, but first of all those that were used to establish the respective species, that is, the type material. Florentino Ameghino never referred to the collection number of the type specimens of the species he erected in any of his publications; this fact added to the occasional absence of illustrations and adequate descriptions, all of which make their identification a complex task. Thus, when studying the species erected by Florentino Ameghino within Protypotherium and Patriarchus, we recognised a lack of correspondence between some specimens that appeared labelled as types in the collections and the original descriptions of these species. In this contribution, we identify the type specimens of the eleven species of Protypotherium and eight of Patriarchus founded by Florentino Ameghino, housed in the Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" (Buenos Aires, Argentina) and the Zoological Museum of the University of Copenhagen (Denmark). Three case studies are presented: a) specimens correctly identified; b) specimens erroneously catalogued as type material; and c) specimens not established as types in Ameghino's catalogue, but herein recognised as such. Lectotype and paralectotype of P. antiquum are herein designated. Fil: Fernández, Mercedes. Universidad Nacional de Luján. Departamento de Ciencias Básicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina Fil: Fernicola, Juan Carlos. Universidad Nacional de Luján. Departamento de Ciencias Básicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina Fil: Cerdeño Serrano, Maria Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Reguero, Marcelo Alfredo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico de Paleontología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

The study of juvenile remains of Paedotherium Burmeister from Cerro Azul Formation (La Pampa Province, Argentina; late Miocene) is presented. Upper and lower deciduous dentition (or permanent molars supposed to be associated with non-preserved deciduous teeth) are recognised. Several ontogenetic stages are distinguished among juveniles, according to the degree of wear and the replaced deciduous teeth. Besides, some morphological and metrical differences are observed along the crown height. Deciduous cheek teeth are high-crowned and placed covering the apex of the corresponding permanent tooth. The height of the crown and the degree of wear allow establishing the pattern of dental replacement of deciduous and permanent premolars in a posterior–anterior direction (DP/dp4–2 and P/p4–2), as well as the eruption of M/m3 before DP/dp4 is replaced. Some of the studied remains are recognised as young individuals of Tremacyllus Ameghino, but with complete permanent dentition, which leads to propose a different timing in the dental replacement with respect to Paedotherium; they also allow the establishment of an opposite premolar eruption pattern, from P/p2 to P/p4. This knowledge of the deciduous dentition of Paedotherium suggests the need of revising the morphological and metrical characters previously used for defining species within this taxon. Fil: Cerdeño Serrano, Maria Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Montalvo, Claudia Inés. Universidad Nacional de La Pampa; Argentina Fil: Sostillo, Renata. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina