Killer animals in films: Reality vs fiction

Among horror, drama, action, and scifi films, the subgenre of killer animals has been exploited since the very beginnings of cinema. A thorough search of horror/drama/action/sci-fi films with killer animals as the main antagonists was performed, and the data was confronted with the number of human deaths per year caused by animals. A review of movies involving killer animals shows that the animals that causes thousands of human deaths each year do not inspire fear or concern in movies and hence, in the public. This may be in part reverted by educating about diseases transmitted by these animals and the real danger that some animals represent.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; Argentin

Los Chinchillidae (Rodentia, Caviomorpha) fósiles de la República Argentina: sistemática, historia evolutiva y biogeográfica, significado bioestratigráfico y paleoambiental

Tesis presentada para optar al Grado de Doctor en Ciencias NaturalesFil: Rasia, Luciano Luis. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin

Systematic and biostratigraphic significance of a chinchillid rodent from the Pliocene of eastern Argentina

Two species of chinchillid rodents, Lagostomus (Lagostomopsis) incisus and “Lagostomus (Lagostomopsis) spicatus”, have been recorded from the Monte Hermoso Formation (Montehermosan–Lower Chapadmalalan, Early Pliocene) of southern Buenos Aires Province, eastern Argentina. L. (L.) incisus is based on skull remains,while “L. (L.) spicatus” is based on mandible remains and fragmentary skulls. Detailed study of specimens recovered from the upper section of the Monte Hermoso Formation, from the Irene “Formation”, and the Chapadmalal Formation (late Early–early Late Pliocene, Buenos Aires Province), some of them represented by associated skull and mandible remains, indicates that L. (L.) incisus and “L. (L.) spicatus” are synonymous, with the valid name being L. (L.) incisus. The differences between both nominal species are here attributed to different ontogenetic states and sexual dimorphism. The stratigraphic provenance of the fossil material of L. (L.) incisus indicates a temporal distribution of this species restricted to the Montehermosan?–Chapadmalalan (Early–early Late Pliocene), instead of the Montehermosan (Early Pliocene).Facultad de Ciencias Naturales y Muse

Tooth morphology of Echimyidae (Rodentia, Caviomorpha): Homology assessments, fossils, and evolution

Echimyidae constitute the most important radiation of caviomorph rodents in the Neotropical region, represented by 20 extant genera and several extinct species. Both in extant and fossil forms, this diversity is reflected by a significant morphological variation found in crown structures of the cheek teeth. Different hypotheses of primary homology have been proposed for these structures, which, in turn, support diverse dental evolutionary hypotheses. In this contribution we inspect the main structures (cusps and lophids) of the lower deciduous teeth and molars in extinct and extant Echimyidae, and establish their topological correspondences. Comparisons with cusps and lophids of Erethizontidae are emphasized. We explore the testing of alternative primary hypotheses of lophid correspondences in a cladistic context. Following a 'dynamic' approach, we select the hypothesis of primary homology, which produced the more parsimonious results, and evaluate the evolutionary transformations of the dental characters analysed. In this context, the phylogenetic relationships of living Myocastor coypus (Molina, 1782) with the extinct Tramyocastor and Paramyocastor are tested. Our results indicate that pentalophodonty is the derived condition for the lower molars in Echimyidae, that trilophodonty evolved independently at least three times during the evolutionary history of these rodents, and that tetralophodonty represents the plesiomorphic condition. This study shows that dental evolution in echimyids can be better understood when occlusal structures are expressed as reliably comparable characters, and when fossils are taken into account.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; ArgentinaFil: 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; Argentin

Tooth morphology of Echimyidae (Rodentia, Caviomorpha): homology assessments, fossils, and evolution

Echimyidae constitute the most important radiation of caviomorph rodents in the Neotropical region, represented by 20 extant genera and several extinct species. Both in extant and fossil forms, this diversity is reflected by a significant morphological variation found in crown structures of the cheek teeth. Different hypotheses of primary homology have been proposed for these structures, which, in turn, support diverse dental evolutionary hypotheses. In this contribution we inspect the main structures (cusps and lophids) of the lower deciduous teeth and molars in extinct and extant Echimyidae, and establish their topological correspondences. Comparisons with cusps and lophids of Erethizontidae are emphasized. We explore the testing of alternative primary hypotheses of lophid correspondences in a cladistic context. Following a 'dynamic' approach, we select the hypothesis of primary homology, which produced the more parsimonious results, and evaluate the evolutionary transformations of the dental characters analysed. In this context, the phylogenetic relationships of living Myocastor coypus (Molina, 1782) with the extinct Tramyocastor and Paramyocastor are tested. Our results indicate that pentalophodonty is the derived condition for the lower molars in Echimyidae, that trilophodonty evolved independently at least three times during the evolutionary history of these rodents, and that tetralophodonty represents the plesiomorphic condition. This study shows that dental evolution in echimyids can be better understood when occlusal structures are expressed as reliably comparable characters, and when fossils are taken into account.Facultad de Ciencias Naturales y Muse

Reappraisal of the giant caviomorph rodent <i>Phoberomys burmeisteri</i> (Ameghino, 1886) from the late Miocene of northeastern Argentina, and the phylogeny and diversity of Neoepiblemidae

Phoberomys is a giant caviomorph rodent included in the extinct Neoepiblemidae. It is recorded in the late Miocene-Pliocene of South America (Argentina, Venezuela, Brazil and Peru), and is one of the largest rodents that have ever lived. In this contribution we study specimens of Phoberomys from the ‘Mesopotamiense’, late Miocene of Entre Ríos Province (Argentina), including several unpublished specimens and the holotypes of the five nominal species (Ph. burmeisteri, Ph. praecursor, Ph. insolita, Ph. lozanoi and Ph. minima) previously recognised for this unit. Our study indicates that all Mesopotamian specimens belong to Phoberomys burmeisteri, and that the differences among them reveal individual and ontogenetic variation. Our phylogenetic analysis indicates that Neoepiblemidae is monophyletic and includes Phoberomys, Neoepiblema, and Perimys. Phoberomys species are recovered as a clade, which is more closely related to Neoepiblema than to the Patagonian Perimys. In addition, our study shows that Eusigmomys is not a Neoepiblemidae, but a Dinomyidae.Facultad de Ciencias Naturales y Muse

Systematic and biostratigraphic significance of a chinchillid rodent from the Pliocene of eastern Argentina

Two species of chinchillid rodents, Lagostomus (Lagostomopsis) incisus and “Lagostomus (Lagostomopsis) spicatus”, have been recorded from the Monte Hermoso Formation (Montehermosan–Lower Chapadmalalan, Early Pliocene) of southern Buenos Aires Province, eastern Argentina. L. (L.) incisus is based on skull remains,while “L. (L.) spicatus” is based on mandible remains and fragmentary skulls. Detailed study of specimens recovered from the upper section of the Monte Hermoso Formation, from the Irene “Formation”, and the Chapadmalal Formation (late Early–early Late Pliocene, Buenos Aires Province), some of them represented by associated skull and mandible remains, indicates that L. (L.) incisus and “L. (L.) spicatus” are synonymous, with the valid name being L. (L.) incisus. The differences between both nominal species are here attributed to different ontogenetic states and sexual dimorphism. The stratigraphic provenance of the fossil material of L. (L.) incisus indicates a temporal distribution of this species restricted to the Montehermosan?–Chapadmalalan (Early–early Late Pliocene), instead of the Montehermosan (Early Pliocene).Facultad de Ciencias Naturales y Muse

Revisión sistemática de las vizcachas (Rodentia, Caviomorpha, Chinchillidae) de la formación Chapadmalal, Plioceno tardío de la provincia de Buenos Aires, Argentina

Lagostomine rodents (Caviomorpha, Chinchillidae) are very abundant in late Cenozoic vertebrate associations of the Pampean area but the study of their systematics has been mostly limited to a handful of works from the late 19th Century and early 20th Century. Although seven species of Lagostomus were described for the Chapadmalal Formation (late Pliocene; Buenos Aires Province, Argentina), the holotypes of these species do not present precise stratigraphic provenance and have not been studied since their original description. This study of lagostomines from the Chapadmalal Formation with precise stratigraphic provenance gives way to the recognition of at least three species: Lagostomus incisus, L. compressidens and L. euplasius. The comparative study of the holotypes of the previously recognized species in this unit indicates that ‘Viscaccia indefinita’ is a junior synonym of L. compressidens while ‘V. loberiaense’, ‘V. definita’ and ‘V. chapalmalense’ are junior synonyms of L. euplasius. The validity of ‘Viscaccia arcuata’ and its inclusion in the Chapadmalalan fauna has to be re-evaluated. This work clarifies part of the systematics of the genus Lagostomus, thus contributing to the comprehension of the taxonomic diversity of chinchillids during their most recent evolutionary history.Los roedores lagostominos (Caviomorpha, Chinchillidae) son muy abundantes en las asociaciones de vertebrados en el Cenozoico tardío del área pampeana, pero su estudio sistemático se limita mayormente a algunos trabajos de fines del Siglo XIX y principios del Siglo XX. Se describieron siete especies de Lagostomus para la Formación Chapadmalal (Plioceno tardío; provincia de Buenos Aires, Argentina), pero los holotipos de estas especies no tienen procedencia estratigráfica precisa y no han sido estudiados desde su descripción original. Este estudio de lagostominos de la Formación Chapadmalal con procedencia estratigráfica precisa permitió reconocer al menos tres especies: Lagostomus incisus, L. compressidens y L. euplasius. El análisis comparativo de los holotipos de las especies previamente reconocidas en esta unidad indica que ‘Viscaccia indefinita’ es un sinónimo junior de L. compressidens; y que ‘V. loberiaense’, ‘V. definita’ y ‘V. chapalmalense’ son sinónimos junior de L. euplasius. La validez de ‘Viscaccia arcuata’ y su inclusión en la fauna Chapadmalalense debe ser re-evaluada. Este trabajo permite esclarecer parte de la sistemática del género Lagostomus, contribuyendo así a la comprensión de la diversidad taxonómica de los chinchíllidos durante su historia evolutiva más reciente.Facultad de Ciencias Naturales y Muse

Evolution of the cheek teeth occlusal structures in caviomorph rodents, with special reference to octodontoids and erethizontids

Caviomorphs are representative of the oldest rodent radiation in South America, with a rich fossil record, known since the late Eocene-early Oligocene. They reached an important taxonomic diversity expressed by the existence of 12 extant families and several extinct taxa. Both in extant and fossil forms, this diversity is reflected by a significant morphological variation found in crown structures of the cheek teeth. Different hypotheses of primary homology have been proposed for these structures, which, in turn, supported diverse dental evolutionary hypotheses in caviomorphs. The identification of homologies in crown structures of the oldest fossil caviomorphs became protagonists in this context. In spite of the research generated, for most of the main clades of caviomorphs, there is not a unified nomenclature of the crown structures. In the case of octodontoids and Erethizontidae, certain fossil taxa reveal the presence of cusps, which are not so well differentiated in living species, pointing out the essential role of fossils in the identification of homologous structures. In this contribution, we examine the occlusal morphology of these rodents and evaluate alternative primary homology hypotheses for occlusal structures in the cheek teeth of caviomorphs. On this base, we explore the testing of alternative primary hypotheses of lophs / lophids correspondences in a phylogenetic context. Following a dynamic approach, we select the best primary homologies and evaluate the evolutionary transformations of the analyzed dental characters. Our results indicate that pentalophodonty is the derived condition for the lower molars in caviomorphs; the trilophodonty evolved independently at least two times during the evolutionary history of octodontoids, and pentalophodonty represents the primitive condition in erethizontids and octodontoids. Pentalophodonty emerges as the derived condition in the upper molars, from a "prepentalophodont" pattern. This study shows that the dental evolution in caviomorphs can be better understood when their occlusal structures are expressed as characters reliably comparable, and when fossils are taken into account.Simposio V: Los mamíferos oligocenos de América del Sur: explosión evolutiva de los mamíferos nativos y llegada de los emigrantes africanosFacultad de Ciencias Naturales y Muse

Systematic revision of the vizcachas (Rodentia, caviomorpha, chinchillidae) from the Chapadmalal Formation, Late Pliocene of Buenos Aires province, Argentina

Fil: Rasia, Luciano Luis. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; ArgentinaFil: Candela, Adriana Magdalena. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentin