Late pleistocene carnivores (Carnivora: Mammalia) from a cave sedimentary deposit in northern Brazil

The Brazilian Quaternary terrestrial Carnivora are represented by the following families: Canidae, Felidae, Ursidae, Procyonidae Mephitidae and Mustelidae. Their recent evolutionary history in South America is associated with the uplift of the Panamanian Isthmus, and which enabled the Great American Biotic Interchange (GABI). Here we present new fossil records of Carnivora found in a cave in Aurora do Tocantins, Tocantins, northern Brazil. A stratigraphical controlled collection in the sedimentary deposit of the studied cave revealed a fossiliferous level where the following Carnivora taxa were present: Panthera onca, Leopardus sp., Galictis cuja, Procyon cancrivorus, Nasua nasua and Arctotherium wingei. Dating by Electron Spinning Resonance indicates that this assemblage was deposited during the Last Glacial Maximum (LGM), at least, 22.000 YBP. The weasel, G. cuja, is currently reported much further south than the record presented here. This may suggest that the environment around the cave was relatively drier during the LGM, with more open vegetation, and more moderate temperatures than the current Brazilian Cerrado.Facultad de Ciencias Naturales y Muse

A peculiar new Pampatheriidae (Mammalia: Xenarthra: Cingulata) from the Pleistocene of Argentina and comments on Pampatheriidae diversity

Pampatheriidae are a group of cingulates native to South American that are known from the middle Miocene to the lower Holocene. Two genera have been recognized between the lower Pleistocene and the lower Holocene: Pampatherium Gervais and Ameghino (Ensenadan, Bonaerian and Lujanian, lower Pleistocene-lower Holocene) and Holmesina Simpson (Blancan, Irvingtonian, upper Pliocene-lower Holocene). They have been mainly differentiated by their osteoderm morphology and cranio-dental characters. These taxa had a wide latitudinal distribution, extending from the southern part of South America (Península Valdés, Argentina) to North America (Florida, USA). In this contribution, we describe a new genus and species of Pampatheriidae for the lower and middle Pleistocene of Buenos Aires Province and for the upper Pleistocene of Santa Fe Province (Argentina).The new taxon is represented by disarticulated osteoderms, one skull element, two thoracic vertebrae and a right femur and patella. It has extremely complex osteoderm ornamentations and particular morphological characters of the cranial element and femur that are not found in any other species of the family. This new taxon, recorded in the lower-middle Pleistocene (Ensenadan Stage/Age) and in the upper Pleistocene-early Holocene (Lujanian Stage/Age), is incorporated to the Pleistocene mammal assemblage of South America. Finally, the Pampatheriidae diversity is greater during the Lujanian Stage/Age than the Ensenadan Stage/Age.Facultad de Ciencias Naturales y Muse

Late pleistocene carnivores (Carnivora: Mammalia) from a cave sedimentary deposit in northern Brazil

The Brazilian Quaternary terrestrial Carnivora are represented by the following families: Canidae, Felidae, Ursidae, Procyonidae Mephitidae and Mustelidae. Their recent evolutionary history in South America is associated with the uplift of the Panamanian Isthmus, and which enabled the Great American Biotic Interchange (GABI). Here we present new fossil records of Carnivora found in a cave in Aurora do Tocantins, Tocantins, northern Brazil. A stratigraphical controlled collection in the sedimentary deposit of the studied cave revealed a fossiliferous level where the following Carnivora taxa were present: Panthera onca, Leopardus sp., Galictis cuja, Procyon cancrivorus, Nasua nasua and Arctotherium wingei. Dating by Electron Spinning Resonance indicates that this assemblage was deposited during the Last Glacial Maximum (LGM), at least, 22.000 YBP. The weasel, G. cuja, is currently reported much further south than the record presented here. This may suggest that the environment around the cave was relatively drier during the LGM, with more open vegetation, and more moderate temperatures than the current Brazilian Cerrado.Facultad de Ciencias Naturales y Muse

A peculiar new Pampatheriidae (Mammalia: Xenarthra: Cingulata) from the Pleistocene of Argentina and comments on Pampatheriidae diversity

Pampatheriidae are a group of cingulates native to South American that are known from the middle Miocene to the lower Holocene. Two genera have been recognized between the lower Pleistocene and the lower Holocene: Pampatherium Gervais and Ameghino (Ensenadan, Bonaerian and Lujanian, lower Pleistocene-lower Holocene) and Holmesina Simpson (Blancan, Irvingtonian, upper Pliocene-lower Holocene). They have been mainly differentiated by their osteoderm morphology and cranio-dental characters. These taxa had a wide latitudinal distribution, extending from the southern part of South America (Península Valdés, Argentina) to North America (Florida, USA). In this contribution, we describe a new genus and species of Pampatheriidae for the lower and middle Pleistocene of Buenos Aires Province and for the upper Pleistocene of Santa Fe Province (Argentina).The new taxon is represented by disarticulated osteoderms, one skull element, two thoracic vertebrae and a right femur and patella. It has extremely complex osteoderm ornamentations and particular morphological characters of the cranial element and femur that are not found in any other species of the family. This new taxon, recorded in the lower-middle Pleistocene (Ensenadan Stage/Age) and in the upper Pleistocene-early Holocene (Lujanian Stage/Age), is incorporated to the Pleistocene mammal assemblage of South America. Finally, the Pampatheriidae diversity is greater during the Lujanian Stage/Age than the Ensenadan Stage/Age.Facultad de Ciencias Naturales y Muse

Conical and sabertoothed cats as an exception to craniofacial evolutionary allometry

Among evolutionary trends shaping phenotypic diversity over macroevolutionary scales, CREA (CRaniofacial Evolutionary Allometry) describes a tendency, among closely related species, for the smaller-sized of the group to have proportionally shorter rostra and larger braincases. Here, we used a phylogenetically broad cranial dataset, 3D geometric morphometrics, and phylogenetic comparative methods to assess the validity and strength of CREA in extinct and living felids. To test for the influence of biomechanical constraints, we quantified the impact of relative canine height on cranial shape evolution. Our results provided support to CREA at the family level. Yet, whereas felines support the rule, big cats, like Pantherinae and Machairodontinae, conform weakly if not at all with CREA predictions. Our findings suggest that Machairodontinae constitute one of the first well-supported exceptions to this biological rule currently known, probably in response to the biomechanical demands and developmental changes linked with their peculiar rostral adaptations. Our results suggest that the acquisition of extreme features concerning biomechanics, evo-devo constraints, and/or ecology is likely to be associated with peculiar patterns of morphological evolution, determining potential exceptions to common biological rules, for instance, by inducing variations in common patterns of evolutionary integration due to heterochronic changes under ratchet-like evolution

Catálogo de mamíferos marinos de la Colección Mastozoológica del Museo de La Plata, Argentina.

This catalogue lists the materials of marine mammals housed in the Mammalogical collection of Museo de La Plata. This contribution is an update of the unpublished catalogue made by R. Bastida, J.B. Desojo, and L.H. Soibelzon in 1997. It includes all the specimens deposited in this collection, belonging to the Superorder Cetartilodactyla, order Cetacea, suborders Mysticeti and Odontoceti, the order Carnivora, suborder Caniformia, and the order Sirenia. The Mammalogical collection of the División Zoología Vertebrados of Museo de la Plata holds 185 specimens of 37 species of marine mammals.El presente catálogo lista los materiales de mamíferos marinos depositados en la colección de Mastozoología del Museo de La Plata. Esta contribución es una actualización del catálogo inédito realizado por R. Bastida, J.B. Desojo y L.H. Soibelzon en 1997. Se incluyen todos los materiales del superorden Cetartilodactyla, orden Cetacea, subórdenes Mysticeti y Odontoceti, orden Carnivora, suborden Caniformia y orden Sirenia. La colección de Mastozoología de la División Zoología Vertebrados del Museo de La Plata cuenta con 185 especímenes referidos a 37 especies de mamíferos marinos

Descubrimos nuestro subsuelo: paleontología y patrimonio en el aula

Entre gliptodontes, tigres dientes de sable y perezosos gigantes, transcurría la vida en la Región Pampeana durante los últimos 2,5 millones de años (Cuaternario). Estos animales, al igual que muchos otros, como toxodontes, macrauquenias, osos y mastodontes, se encuentran actualmente extintos y podemos conocerlos solo a través de sus restos fósiles. El estudio de estos organismos, que comenzó hace unos 200 años con los primeros viajeros científicos que arribaron a nuestro país (como Charles Darwin), nos permite conocer la historia natural de nuestra región durante los últimos dos millones y medio de años.Facultad de Ciencias Naturales y Muse

Descubrimos nuestro subsuelo: paleontología y patrimonio en el aula

Entre gliptodontes, tigres dientes de sable y perezosos gigantes, transcurría la vida en la Región Pampeana durante los últimos 2,5 millones de años (Cuaternario). Estos animales, al igual que muchos otros, como toxodontes, macrauquenias, osos y mastodontes, se encuentran actualmente extintos y podemos conocerlos solo a través de sus restos fósiles. El estudio de estos organismos, que comenzó hace unos 200 años con los primeros viajeros científicos que arribaron a nuestro país (como Charles Darwin), nos permite conocer la historia natural de nuestra región durante los últimos dos millones y medio de años.Facultad de Ciencias Naturales y Muse