Leonardo S. Avilla

The South American Gomphotheres (Mammalia, Proboscidea, Gomphotheriidae): Taxonomy, Phylogeny, and Biogeography

The taxonomic history of South American Gomphotheriidae is very complex and controversial. Three species are currently recognized: Amahuacatherium peruvium, Cuvieronius hyodon, and Notiomastodon platensis. The former is a late Miocene gomphothere whose validity has been questioned by several authors. The other two, C. hyodon and N. platensis, are Quaternary taxa in South America, and they have distinct biogeographic patterns: Andean and lowland distributions, respectively. South American gomphotheres became extinct at the end of the Pleistocene. We conducted a phylogenetic analysis of Proboscidea including the South American Quaternary gomphotheres, which resulted in two most parsimonious trees. Our results support a paraphyletic Gomphotheriidae and a monophyletic South American gomphothere lineage: C. hyodon and N. platensis. The late Miocene gomphothere record in Peru, Amahuacatherium peruvium, seems to be a crucial part of the biogeography and evolution of the South American gomphotheres.

Distributional patterns of herbivore megamammals during the Late Pleistocene of South America

The geographic distribution of 27 species of the South American megafauna of herbivore mammals during the Late Pleistocene was analyzed in order to identify their distributional patterns. The distribution of the species was studied using the panbiogeographical method of track analysis. Six generalized tracks (GTs) and two biogeographic nodes were obtained. The GTs did not completely superpose with the areas of open savanna present in Pleistocene, nor with the biotic tracks of some arthropods typical of arid climate, indicating that these animals avoided arid environment. Overall, the GTs coincided with some biogeographic provinces defined on the basis of living taxa, indicating that certain current distributional patterns already existed in Pleistocene. The biogeographic nodes coincided with the borders between the main vegetal formations of the Pleistocene, showing that the type of vegetation had great influence in the distribution of the mammalian megafauna. The node 1 confirmed the existence of contact zones between paleobiogeographic regions near Argentina-Uruguay border. The node 2 connects the Brazilian Intertropical regions.

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.

The Systematics of South American Quaternary Mammals with Holarctic Origins – an Introduction to the I FOGEMI Proceedings Volume

This special issue of the Journal of Mammalian Evolution represents the proceedings from a meeting held in conjunction with the VII Brazilian Symposium on Vertebrate Paleontology, entitled “First Forum of the Group of Specialists on Immigrant Mammals” (I FOGEMI). This meeting gathered researchers on the systematics of South American Quaternary mammals with holarctic origins. In this brief introduction to the meeting proceedings, we discuss the justification for the meeting, quote its main results, and introduce the contents of the present volume. The intent of the First Forum of the Group of Specialists on Immigrant Mammals (I FOGEMI, I Fórum do Grupo de Especialistas em Mamíferos Invasores) was to join scientists conducting research on the systematics of South American Quaternary mammals with holarctic origins. Most of these studies were theses and dissertations, mainly conducted by Brazilian paleontologists. Therefore, the I FOGEMI was one of the special events of the VII Simpósio Brasileiro de Paleontologia de Vertebrados (VII SBPV, Seventh Brazilian Symposium on Vertebrate Paleontology), which occurred from the 18th to 23rd July of 2010, at the Universidade Federal do Estado do Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil. All researchers invited for the I FOGEMI attended the event (Fig. 1), and we gathered during three days, from the 19th to 21st of July, 2010. The I FOGEMI was an open event for the participants of the VII SBPV, and it was composed of a series of oral presentations. At the end of the third day, all participants (including the audience) were invited to debate about the main issues highlighted during the event. The oral presentations of the I FOGEMI became the papers in this special volume. These papers present taxonomic revisions and biogeographical inferences, mostly based on new phylogenetic studies for Gomphotheriidae (Proboscidea), Camelidae, Tayssuidae (Artiodactyla), and Tapiridae (Perissodactyla). Furthermore, another paper demonstrates new ideas about the controversial issue on the ecological displacement and consecutive extinction of the Sparassodonta (Metatheria), a South American native carnivorous group, by the holarctic Carnivora. Moreover, there is a paper on new absolute datings for Brazilian Pleistocene mammals. The main results of these papers suggest that the ingression of holarctic mammals in South America occurred in several independent pulses on each of the lineages. Also, probably, these ingressions happened from the upper Miocene on, and not only after the imposition of the Panamanian Isthmus. The ingression of holarctic Carnivora is not related to the extinction of the South American native mammalian carnivores, the Sparassodonta. The southern Brazilian Pleistocene mammals were represented by a mixture of “Brazilian” and Pampean Quaternary mammals, and they occurred throughout the Pleistocene. However, some Pampean faunal elements apparently went extinct earlier in Argentina and Uruguay. Apart from the papers present here, the main conclusions of the I FOGEMI were: 1) some other groups of South American Pleistocenemammals with holarctic origins, such as Cervidae, Equidae, and Sigmodontinae, require taxonomic revisions; in consequence, this would stimulate phylogenetical and L. dos Santos Avilla (*) Departamento de Zoologia, Instituto de Biociências, Laboratório de Mastozoologia, Universidade Federal do Estado do Rio de Janeiro, Avenida Pasteur, 458, Urca, 22290-240, Rio de Janeiro, Brazil e-mail: leonardo.avilla@gmail.com

The Dance of Tusks: Rediscovery of Lower Incisors in the Pan-American Proboscidean Cuvieronius hyodon Revises Incisor Evolution in Elephantimorpha.

The incisors of proboscideans (tusks and tushes) are one of the most important feature in conservation, ecology and evolutionary history of these mammals. Although the absence of upper incisors is rare in proboscideans (occurring only in deinotheres), the independent losses of lower incisors are recognized for most of its lineages (dibelodont condition). The presence of lower incisors in the Pan-American gomphothere Cuvieronius hyodon was reported a few times in literature, but it was neglected in systematic studies. We analyzed several specimens of Cuvieronius hyodon from the Americas and recognized that immature individuals had lower incisors during very early post-natal developmental stages. Subsequently, these are lost and lower incisors alveoli close during later developmental stages, before maturity. Moreover, for the first time in a formal cladistic analysis of non-amebelodontine trilophodont gomphotheres, Rhynchotherium and Cuvieronius were recovered as sister-taxa. Among several non-ambiguous synapomorphies, the presence of lower incisors diagnoses this clade. We recognize that the presence of lower incisors in Cuvieronius and Rhynchotherium is an unique case of taxic atavism among the Elephantimorpha, since these structures are lost at the origin of the ingroup. The rediscovery of the lower incisors in Cuvieronius hyodon, their ontogenetic interpretation and the inclusion of this feature in a revised phylogenetic analysis of trilophodont gomphotheres brought a better understanding for the evolutionary history of these proboscideans.

Didelphidae marsupials (Mammalia, Didelphimorphia) from the Late Pleistocene deposit of the Gruta dos Moura Cave, northern Brazil

The present study acknowledges the diversity of fossil marsupials from the Gruta dos Moura cave, as well as environmental and climatic aspects during the Quaternary. The results show that this is the largest diversity of Pleistocene marsupials recorded in a single cave: Didelphis albiventris, D. aurita, Gracilinanus agilis, G. microtarsus, Marmosa murina, Monodelphis brevicaudata, M. domestica and Sairadelphys tocantinensis. Furthermore, the described specimens are also part of the only fossil assemblage unequivocally referable to the late Pleistocene. Paleontological studies suggest an intimate association with dry and open environments with high abundance of water sources. Since most of the identified taxa are characteristic of open forests and gallery forests, this could represent the actual environment around the Gruta dos Moura cave. Recent studies identified sympatric occurrences between species from open and dry environments and species from humid forests that were identified among our material and are characteristic of humid regions. Therefore, these species could inhabit gallery forests and capons, or even ecotones, inside a dry and open environment. Moreover, the extinction of Sairadelphys could also indicate that the climatic and environmental conditions changed or that the past environment was more heterogeneous than the current environment of the region.

New record of Furipterus horrens (Cuvier, 1828) (Mammalia, Chiroptera) from the Cerrado of Tocantins state with a compilation of the known distribution within Brazil

Furipterus horrens is an insectivorous bat that occurs from Costa Rica to southeastern Bolivia and southern Brazil, with records in the Amazon, Caatinga, Cerrado and Atlantic Forest biomes. Despite this broad distributional range across South America, the species is currently known from few localities, and its habitat preferences are poorly known. We report the first record of Furipterus horrens for the Tocantins state, northern Brazil, based on four individuals collected in two caves surrounded by Neotropical savanna (Cerrado) in the Aurora do Tocantins municipality.

Rostral reconstruction of South American hippidiform equids: New anatomical and ecomorphological inferences

The Pleistocene Equus (Amerhippus) and hippidiforms frequently occur together in the South American fossil record, suggesting a possible case of sympatry and syntopy. Although resembling each other in their overall morphology, their rostra show distinct differences. While Equus (Amerhippus) resembles extant horses, hippidiforms are characterised by slender nasal bones, a retracted nasal notch at the level of M2–M3 or posterior to M3, and the presence of dorsal preorbital fossae of variable depth. Here we present an anatomical reconstruction of the muzzle of hippidiforms based on homologous patterns in the extant horse Equus caballus, together with a morphofunctional analysis of their rostra and a comparative analysis of premaxillary shape. The rostral morphology of hippidiforms suggests the presence of a developed upper lip with prehensile function, as occurs in extant black rhinoceros. This prehensile structure could be ecomorphologically related to browsing, thus reducing niche overlap with Equus (Amerhippus), and hence competitive pressure.

A Quaternary very young juvenile Tapirus Brisson, 1762 (Mammalia, Perissodactyla) from a cave deposit in northern Brazil: taxonomy and taphonomy

During fieldworks carried out from 2009 to 2013 in Aurora do Tocantins (northern Brazil), three isolated deciduous teeth of Tapirus were recovered. Those fossils come from a sedimentary deposit of presumed Late Pleistocene–early Holocene age in a karstic cave. This contribution aims to present a new locality of fossil Tapirus from northern Brazil, describe for the first time deciduous fossil teeth for South American Tapirus and evaluate the taphonomic aspects of those fossils. The specimens probably belong to the same individual due to there are no repeated teeth and they have the same wear pattern. Furthermore, the crowns of those teeth show no evidence of abrasion produced by transport. However, some abrasion is observed on the borders of the pulp chamber of teeth. These polishing are probably resulting of a very short transport (parautochthonous). These specimens are the only record of Tapiridae in Gruta do Urso cave; due to correspond to isolated and deciduous teeth, its identification to species level was not possible. There is not yet clear evidence that may indicate the kind of death of the individual studied here.

First record of two molossid bats (Chiroptera: Molossidae) from Piauí state and distributional review for Brazil

The Family Molossidae has a cosmopolitan distribution; it is common in urban areas as well as in agricultural and forested environments. In Brazil, the group comprises seven genera with 25 species. In spite of the representative number of taxa, Molossidae is insufficiently documented in biological inventories. Thus, there is a gap in knowledge about the actual distribution of most species. Here we present new records of tow molossids, Cynomops planirostris and Neoplatymops mattogrossensis , for the state of Piaui, Northeastern Brazil, and review locality records for species throughout the Brazilian territory.