A historical vertebrate collection from the Middle Miocene of the Peruvian Amazon

The Miocene aquatic and terrestrial fossil record from western Amazonia constitute a clear evidence of the palaeoenvironmental diversity that prevailed in the area, prior to the establishment of the Amazon River drainage. During the Miocene, the region was characterized by a freshwater megawetland basin, influenced by episodic shallow-marine incursions. A fossil vertebrate collection from the middle Miocene strata of the Pebas Formation is here studied and described. This historical collection was recovered in 1912 along the banks of the Itaya River (Iquitos, Peru), during a scientific expedition led by two scientists of the University of Zurich, Hans Bluntschli and Bernhard Peyer. Our findings include a total of 34 taxa, including stingrays, bony fishes, turtles, snakes, crocodylians, and lizards. Fishes are the most abundant group in the assemblage (~ 23 taxa), including the first fossil record of the freshwater serrasalmids Serrasalmus, and Mylossoma, and the hemiodontid Hemiodus for the Pebas system, with the latter representing the first fossil be discovered for the entire Hemiodontidae. The presence of a representative of Colubroidea in the middle Miocene of Iquitos supports the hypothesis of arrival and dispersal of these snakes into South America earlier than previously expected. This fossil assemblage sheds light on the palaeoenvironments, and the geographical/temporal range of several aquatic/terrestrial lineages inhabiting the Amazonian region

A New Clevosaurid from the Triassic (Carnian) of Brazil and the Rise of Sphenodontians in Gondwana

The early evolution of lepidosaurs is marked by an extremely scarce fossil record during the Triassic. Importantly, most Triassic lepidosaur specimens are represented by disarticulated individuals from high energy accretion deposits in Laurasia, thus greatly hampering our understanding of the initial stages of lepidosaur evolution. Here, we describe the fragmentary remains of an associated skull and mandible of Clevosaurus hadroprodon sp. nov., a new taxon of sphenodontian lepidosaur from the Late Triassic (Carnian; 237–228 Mya) of Brazil. Referral to Sphenodontia is supported by the combined presence of a marginal dentition ankylosed to the apex of the dentary, maxilla, and premaxilla; the presence of ‘secondary bone’ at the bases of the marginal dentition; and a ventrally directed mental process at the symphysis of the dentary. Our phylogenetic analyses recover Clevosaurus hadroprodon as a clevosaurid, either in a polytomy with the Late Triassic to Early Jurassic Clevosaurus and Brachyrhinodon (under Bayesian inference), or nested among different species of Clevosaurus (under maximum parsimony). Clevosaurus hadroprodon represents the oldest known sphenodontian from Gondwana, and its clevosaurid relationships indicates that these sphenodontians achieved a widespread biogeographic distribution much earlier than previously thought.Fil: Hsiou, Annie S.. Universidade de Sao Paulo; BrasilFil: Nydam, Randall L.. Midwestern University; Estados UnidosFil: Simões, Tiago R.. University of Alberta; Canadá. Harvard University; Estados UnidosFil: Pretto, Flávio A.. Universidade Federal de Santa Maria; BrasilFil: Onary, Silvio. Universidade de Sao Paulo; BrasilFil: Martinelli, Agustín Guillermo. Universidade Federal do Rio Grande do Sul; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Liparini, Alexandre. Universidade Federal de Sergipe; BrasilFil: Romo de Vivar Martínez, Paulo Rodrigo. Universidade Federal do Rio Grande do Sul; BrasilFil: Soares, Marina. Universidade Federal do Rio Grande do Sul; BrasilFil: Schultz, Cesar. Universidade Federal do Rio Grande do Sul; BrasilFil: Caldwell, Michael Wayne. University of Alberta; Canad

Why we shouldn’t blame women for gender disparity in academia : perspectives of women in zoology

The following letter, from a network of women zoologists, is a reply to the article of AlShebli et al. (2020), which suggests that female protégés reap more benefits when mentored by men and concludes that female mentors hinder the success of their female protégés and the quality of their impact. This contribution has two parts. First, we highlight the most relevant methodological flaws which, in our opinion, may have impacted the conclusions of AlShebli et al. (2020). Second, we discuss issues pertaining to women in science, bring a perspective of Women in Zoology and discuss how current diversity policies are positively changing our field

Lepidosaurs from Gondwana: An Introduction

Lepidosaurian reptiles (squamates and rhynchocephalians) comprise one of the world's most diverse groups of tetrapods, with most of that diversity found in regions of the world that once formed the supercontinent of Gondwana. In this special section of the Journal of Herpetology, we present both review and original studies on the evolution of lepidosaurs from Gondwana. In this contribution, we provide a brief introduction to those studies and also present metadata collected from the Web of Science on the progress of the study of lepidosaurian evolution. The latter indicate a substantial increase of research interest in multiple aspects of lepidosaur evolution worldwide, with special increase for lepidosaurs from Gondwanan continents. We conclude by setting some of the main goals we hope to achieve in the study of lepidosaurs from Gondwana in the near future.Fil: Simões, Tiago R.. University of Alberta; CanadáFil: Apesteguía, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; ArgentinaFil: Hsiou, Annie S.. Universidade de Sao Paulo; BrasilFil: Daza, Juan D.. Sam Houston State University; Estados Unido

New Quaternary Teiid (Lepidosauria, Squamata) Lizard Remains From Gruta Do Urso, Tocantins, Brazil

Here we present teiid lizard fossils from Gruta do Urso, Aurora do Tocantins, Tocantins State, northern Brazil. We describe a left lower jaw of a Cnemidophorinae indet. and a right dentary attributed to Tupinambis sp. These materials share with extant Teiidae a heterodont dentition with subpleurodont tooth implantation, and are assigned to Teiinae and Tupinambinae based on dental characteristics. The paleofaunal assemblage from Gruta do Urso suggests a late Pleistocene/early Holocene age. These records add to our knowledge of the Quaternary fauna of northern Brazil

New lower jaw and teeth referred to Maxakalisaurus topai (Titanosauria: Aeolosaurini) and their implications for the phylogeny of titanosaurid sauropods

Sauropod dinosaurs compose a diversified, well known, and worldwide distributed clade, with a stereotyped body plan: deep trunk, elongated neck and tail, columnar limbs and very small skull. In Brazil, the group is represented by ten formally described Cretaceous species, mostly titanosaurs. This is the case of Maxakalisaurus topai, known based on an incomplete and disarticulated skeleton, unearthed from deposits of the Adamantina Formation in Minas Gerais. Here, we report a partial right dentary, including five isolated teeth, collected from the same site as the type-series of M. topai and tentatively referred to that taxon. The bone is gently curved medially, the functional teeth are set on an anterolingual position, and two replacement teeth are seen per alveoli. New morphological data gathered from that specimen was employed to conduct a comprehensive phylogenetic analysis of Titanosauria (with 42 taxa and 253 characters), based on previous studies. The Aeolosaurini clade was recovered, with Gondwanatitan and Aelosaurus as sister taxa, and Maxakalisaurus, Panamericansaurus, and Rinconsaurus forming a basal polytomy

A new fossil rodent assemblage from the Solimões Formation (upper Miocene), Acre, Brazil

International audienceCaviomorpha is a South American hystricognath clade with great taxonomic and phenotypic diversity. Their stratigraphic distribution ranges from the middle Eocene to the present times. In the Solimões Formation, northern Brazil, a rich Neogene fossil record has been documented over the last years. Here, we report preliminary data about a new fossiliferous assemblage recovered in recent fieldwork in the Envira River, State of Acre, Brazil. The specimens were recovered in 2010 and 2019 from Neogene sedimentary strata exposed in this river. The fossils were found using a screen-washing method with an aqueous hydrogen peroxide solution and subsequent screening in a stereoscopic magnifying glass. After these procedures, the specimens are being scanned with a micro-CT. The preliminary analysis identified a mandible with premolar and molars and many isolated molariform teeth. Our results suggest the presence of Octodontoidea (including Acarechimys-like), Erethizontoidea, Chinchilloidea (Scleromys-like dinomyids and a potamarchine; and Neoepiblemidae), and Cavioidea (Hydrochoerinae). Based on previous records of Solimões Formation, the presence of potamarchines, neoepiblemids, and hydrochoerines is in accordance with a late Miocene age for these strata (typical Acre fauna). Although fossils have not yet been identified at a less inclusive level, it is possible to observe that this is the most diverse assemblage of Neogene rodents from the Brazilian Amazon

A new fossil rodent assemblage from the Solimões Formation (upper Miocene), Acre, Brazil

International audienceCaviomorpha is a South American hystricognath clade with great taxonomic and phenotypic diversity. Their stratigraphic distribution ranges from the middle Eocene to the present times. In the Solimões Formation, northern Brazil, a rich Neogene fossil record has been documented over the last years. Here, we report preliminary data about a new fossiliferous assemblage recovered in recent fieldwork in the Envira River, State of Acre, Brazil. The specimens were recovered in 2010 and 2019 from Neogene sedimentary strata exposed in this river. The fossils were found using a screen-washing method with an aqueous hydrogen peroxide solution and subsequent screening in a stereoscopic magnifying glass. After these procedures, the specimens are being scanned with a micro-CT. The preliminary analysis identified a mandible with premolar and molars and many isolated molariform teeth. Our results suggest the presence of Octodontoidea (including Acarechimys-like), Erethizontoidea, Chinchilloidea (Scleromys-like dinomyids and a potamarchine; and Neoepiblemidae), and Cavioidea (Hydrochoerinae). Based on previous records of Solimões Formation, the presence of potamarchines, neoepiblemids, and hydrochoerines is in accordance with a late Miocene age for these strata (typical Acre fauna). Although fossils have not yet been identified at a less inclusive level, it is possible to observe that this is the most diverse assemblage of Neogene rodents from the Brazilian Amazon

New records of marsupials from the Miocene of Western Amazonia, Acre, Brazil

The Amazonian region covers a significant part of the South American continent and harbors outstanding biodiversity. However, much of its history is still unknown. This situation has begun to change with paleontological field efforts over the last decades, which have been proving that fossils can be common in this region. Despite their great current species richness and abundance in the area today, marsupials have a sparse fossil record, restricted to a few specimens from handful Cenozoic Amazonian localities. Here we present new records of fossil marsupial teeth from the Solimões Formation (lower Eocene–Pliocene), on the Juruá and Envira riverbanks (Acre, Northwestern Brazil). The localities investigated yield at least four distinct didelphid didelphimorphians at PRE 06 (Ponto Rio Envira: Marmosini ?Marmosa sp., Didelphis cf. D. solimoensis, Thylamys? colombianus, plus unidentified didelphids), and two paucituberculatans from the Juruá River localities (Ponto Rio Juruá: the palaeothentid Palaeothentinae indet. at PRJ 25 and PRJ 33’, and Abderitidae indet. from PRJ 33). In agreement with the associated mammalian faunas, most of the didelphids, except for Thylamys? colombianus from PRE 06, indicate a (?early) Late Miocene age for this locality. Conversely, the abderitid specimens found in situ at PRJ 33 would match a Middle Miocene age. The palaeothentids found at PRJ 25 and PRJ 33’ localities cannot be considered for biostratigraphic inferences, since they were found outside a stratigraphic context. Nevertheless, these paucituberculatans considerably add to our knowledge, as they are the first ever recorded in Brazilian Amazonia