Presence of Amphimachairodus coloradensis (Cook, 1922) (Felidae: Machairodontinae) in the Neogene of Hidalgo, Central Mexico

The Neogene Amphimachairodus coloradensis appears to be one of the most abundant species of Machairodontine in Mexico. However, its fossil record is composed of scarce, fragmented, and poorly studied material. New remains discovered in La Plegaria locality (late Hemphillian), in the State of Hidalgo, in Central Mexico, offers the opportunity to review some morphological aspects and phylogenetic relationships of this species within the subfamily Machairodontinae. Our observations allow us to recognize that the material from La Plegaria looks like the paratype of A. coloradensis (DMNH EPV 207, from the Ogallala Fm. in the western United States); this means, m1 with reduced talonid and paraconid almost as large as protoconid, and p4 with posterior cingulum. Phylogenetic analysis confirms the relationship of La Plegaria felid with A. coloradensis and A. alvarezi; although the last one presents autapomorphies that differentiate it from others Amphimachairodus: highly developed mandibular flange. We concluded that the material from La Plegaria corresponds to the southernmost record of an A. coloradensis. This work made it possible to review variation within this species and its morphological relationship with M. catocopis.Fil: Ruiz Ramoni, Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; Argentina. Universidad Nacional Autónoma de México; MéxicoFil: Montellano Ballesteros, Marisol. Universidad Nacional Autónoma de México; MéxicoFil: Rincón Rincón, Ascanio Daniel. Instituto Venezolano de Investigaciones Científicas; VenezuelaFil: Solórzano, Andrés. Universidad Nacional Autónoma de México; MéxicoFil: Guzmán, Germán. Universidad Nacional Autónoma de México; Méxic

Cánidos (caninae) derl pasado de Venezuela

There are three extant species of wild canids in Venezuela: Urocyon cinereoargenteus, Cerdocyon thous, and Speothos venaticus, excluding the feral domestic dog (Canis familiaris). However, a review of paleontological material that was published previously, along with newly reported ancient specimens, reveals a distinct historical diversity for the same region. The gray fox, U. cinereoargenteus, is the only small-sized taxon and the only Vulpini (true fox) identified to date in the fossil record of Venezuela; its presence is limited to the late Pleistocene of the Mene de Inciarte site, Zulia State. In contrast, large canids are more abundant. Aenocyon dirus (subtribe Canina), the dire wolf from the late Pleistocene, was reported from the sites El Mene de Inciarte, Muaco in Falcón State, and for the first time in El Breal de Orocual (ORS20) in Monagas State. The genus Protocyon, a native South American canid (subtribe Cerdocyonina), is recognized in the country from late Pleistocene Inciarte (Protocyon troglodytes sensu lato), and late Pliocene-early Pleistocene Orocual (ORS16) (Protocyon orocualensis sp. nov.). Finally, we report a possible genus Theriodictis from the late Pleistocene Orocual; this is a Cerdocyonina not previously mentioned for the northern region of South America. These records present broader diversity and suggest a more complex evolutionary history than previously thought for South American canids.En Venezuela existen tres especies vivientes de cánidos: Urocyon cinereoargenteus, Cerdocyon thous y Speothos venaticus. Sin considerar al perro domestico asilvestrado (Canis familiaris), estos cánidos corresponden a formas de pequeño tamaño. La revisión del material paleontológico hasta ahora reportado para el país, más nuevos elementos fósiles, muestran una diversidad distinta para el pasado de la región. El zorro gris, U. cinereoargenteus es la única especie de tamaño pequeño y el único Vulpini (zorro real) identificado en el registro fósil de Venezuela; su presencia se limita al Pleistoceno tardío del sitio Mene de Inciarte, Estado Zulia. Por su lado, los grandes cánidos son más abundantes. Aenocyon dirus (subtribu Canina), el lobo terrible del Pleistoceno tardío, fue reportado en los sitios El Mene de Inciarte, Muaco en el Estado Falcón y por primera vez en El Breal de Orocual (ORS20) en el Estado Monagas. El género Protocyon, que pertenece a los cánidos nativos suramericanos (subtribu Cerdocyonina), está reconocido en el país para el Pleistoceno tardío de Inciarte, con la especie P. troglodytes (sensu lato) y para el Plioceno tardío–Pleistoceno temprano de Orocual (ORS16), por P. orocualensis sp. nov. Finalmente, se reporta la presencia del género Theriodictis en el Pleistoceno tardío de Orocual, un Cerdocyonina no antes mencionado para la región norte del continente. Estos registros muestran una amplia diversidad y una evolución más compleja de lo que se pensaba para los cánidos suramericanos.Fil: Ruiz Ramoni, Damián. Universidad Nacional de La Rioja; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Wang, Xiaoming. Natural History Museum Of Los Angeles County; Estados UnidosFil: Rincón Rincón, Ascanio Daniel. Instituto Venezolano de Investigaciones Científicas; Venezuel

Taxonomic review of two fossil crocodylians from the Cenozoic of South America and its implications for the crocodylian fauna of the continent

Cidade, Giovanne M., Fortier, Daniel, Rincón, Ascanio Daniel, Hsiou, Annie Schmaltz (2019): Taxonomic review of two fossil crocodylians from the Cenozoic of South America and its implications for the crocodylian fauna of the continent. Zootaxa 4656 (3): 475-486, DOI: https://doi.org/10.11646/zootaxa.4656.3.

A preliminary assessment of the mammalian fauna from the Pliocene-Pleistocene El Breal de Orocual locality, Monagas State, Venezuela

Preliminary collections from a new asphalt seep deposit in northeastern Venezuela produced a diverse vertebrate faunal assemblage of latest Pliocene or early Pleistocene age. This unique taxonomic assemblage includes 24 mammalian taxa described herein. Seven taxa represent new records for Venezuela (including Pachyarmatherium cf. P. leiseyi, Hoplophorus sp., Erethizontidae, Hippidion sp., and Platygonus sp.), and two of these represent the first definitive records for South America (a new tapir similar to Tapirus webbi and a homotheriine cat). The fauna represents the first diverse biota of Pliocene-early Pleistocene age from northern South America and fills an important geographical gap in our knowledge of faunal dynamics associated with the Great American Biotic Interchange.Fil: Rincón Rincón, Ascanio Daniel. Instituto Venezolano de Investigaciones Científicas; VenezuelaFil: Parra, Gilberto E.. Petróleos de Venezuela S.A.; VenezuelaFil: Prevosti, Francisco Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Alberdi, María Teresa. Consejo Superior de Investigaciones Científicas. Museo Nacional de Ciencias Naturales; EspañaFil: Bell, Christopher J.. University of Texas at Austin; Estados Unido

A new Mourasuchus (Alligatoroidea, Caimaninae) from the late Miocene of Venezuela, the phylogeny of Caimaninae and considerations on the feeding habits of Mourasuchus

Mourasuchus (Alligatoroidea, Caimaninae) is one of the most peculiar crocodyliforms due to the skull morphology consisting of a long, wide, dorsoventrally flat rostrum with long, slender mandibular rami. Despite these peculiarities, the systematics, phylogeny and feeding habits of this taxon have not been properly studied. In this paper, we describe a new species of the genus, Mourasuchus pattersoni sp. nov., from the late Miocene of the Urumaco Formation of Venezuela. The new species differs from the other Mourasuchus species in having a lateromedially wide, dorsoventrally high jugal bone and a circular incisive foramen, which both represent autapomorphies of the new taxon. Phylogenetically, M. pattersoni sp. nov. is more closely related to M. amazonensis and the specimen UFAC-1424 (formely attributed to M. nativus) than to M. arendsi or M. atopus, whilst Mourasuchus is recovered once more as a monophyletic group. Furthermore, the cladistic analysis performed in this contribution offers a new phylogenetic assessment of Caimaninae, including many taxa described recently for the group. In this study, we also discuss the crocodylian diversity of the Urumaco Formation as well as how paleoenvironment may have contributed toward its evolution. In addition, we provide a discussion of the potential feeding habits of Mourasuchus. In this contribution, Mourasuchus is regarded as a taxon that likely preferred to prey on small animals. The unusual skull morphology of this group may have evolved to cover a large area with the rostrum, allowing for a more efficient prey capture, while the prey may have consisted predominantly of large amounts of small animals