31 Works

Southern elephant seals (Mirounga leonina L.) in the Antarctic Treaty Area

Marthán Bester, Horst Bornemann, Gustavo A. Daneri & John van den Hoff
Despite the wholesale slaughter of southern elephant seals for the commercial extraction of blubber-oil during the mid and late 1800’s, their populations have persisted at almost all historical breeding locations There are presently an estimated 749,000 southern elephant seals in the Southern Ocean, about 2% (14,500) of which live permanently in the Antarctic Treaty Area south of 60º South Although these southernmost permanent breeding populations are relatively small, a large (yet to be determined) proportion...

A new faunistic component of the Lower Triassic Panchet Formation of India increases the continental non-archosauromorph neodiapsid record in the aftermath of the end-Permian mass extinction

Martin Ezcurra, Saswati Bandyopadhyay & Kasturi Sen
The fossil record of Early Triassic diapsids is very important to understand how the end-Permian mass extinction affected ecosystems and the patterns and processes involved in the subsequent biotic recovery. Vertebrate fossil assemblages of continental deposits in current-day South Africa, China and Russia are the best source of information of this clade during the aftermath of the extinction event. Although considerably less sampled, the Induan continental rocks of the Panchet Formation of the Damodar Basin...

Data from: Phylogenetic relationships of toads of the Rhinella granulosa group (Anura: Bufonidae): a molecular perspective with comments on hybridization and introgression

Martín O. Pereyra, Diego Baldo, Boris L. Blotto, Patricia P. Iglesias, Maria T. C. Thomé, Célio F. B. Haddad, César Barrio-Amorós, Roberto Ibáñez & Julián Faivovich
The Rhinella granulosa group consists of 13 species of toads distributed throughout open areas of South America and Panama. In this paper we perform a phylogenetic analysis considering all but one species of the group, employing five nuclear and four mitochondrial genes, for up to 7910 bp per specimen. Separate phylogenetic analyses under direct optimization (DO) of nuclear and mitochondrial sequences recovered the R. granulosa group as monophyletic and revealed topological incongruence that can be...

Data from: Do the historical biogeography and evolutionary history of the digenean Margotrema spp. across central Mexico mirror those of their freshwater fish hosts (Goodeinae)?

Andrés Martínez-Aquino, Fadia Sara Ceccarelli, Luis E. Eguiarte, Ella Vázquez-Domínguez & Gerardo Pérez-Ponce De León
Host-parasite systems provide an ideal platform to study evolution at different levels, including codivergence in a historical biogeography context. In this study we aim to describe biogeographic and codivergent patterns and associated processes of the Goodeinae freshwater fish and their digenean parasite (Margotrema spp.) over the last 6.5 Ma (million years), identifying the main factors (host and/or hydrogeomorphology) that influenced the evolution of Margotrema. We obtained a species tree for Margotrema spp. using DNA sequence...

Phylogenomics of scorpions reveal contemporaneous diversification of scorpion mammalian predators and mammal-active sodium channel toxins

Carlos Santibanez, Shlomi Aharon, Jesús Ballesteros, Guilherme Gainett, Caitlin Baker, Edmundo González-Santillán, Mark Harvey, Mohamed Hassans, Ali Abu-Almaaty, Shorouk Aldeyarbi, Lionel Monod, Andrés Ojanguren-Affilastro, Ricardo Pinto Da Rocha, Yoram Zvik, Efrat Gavish-Regev & Prashant Sharma
Scorpions constitute a charismatic lineage of arthropods and comprise more than 2,500 described species. Found throughout various tropical and temperate habitats, these predatory arachnids have a long evolutionary history, with a fossil record that began in the Silurian. While all scorpions are venomous, the asymmetrically diverse family Buthidae harbors nearly half the diversity of extant scorpions, and all but one of the 58 species that are medically significant to humans. However, the lack of a...

Data from: Palynology of a short sequence of the Lower Devonian Beartooth Butte Formation at Cottonwood Canyon (Wyoming): Age, depositional environments and plant diversity

Alexandru Tomescu, Sol Noetinger & Alexander Bippus
The Beartooth Butte Formation hosts the most extensive Early Devonian macroflora of western North America. The age of the flora at Cottonwood Canyon (Wyoming) has been constrained to the Lochkovian-Pragian interval, based on fish biostratigraphy and unpublished palynological data. We present a detailed palynological analysis of the plant-bearing layers at Cottonwood Canyon. The palynomorphs comprise 32 spore, five cryptospore, two prasinophycean algae and an acritarch species. The stratigraphic ranges of these palynomorphs indicate a late...

Biometric conversion factors as a unifying platform for comparative assessment of invasive freshwater bivalves

Neil Coughlan, Eoghan Cunningham, Ross Cuthbert, Patrick Joyce, Pedro Anastacio, Filipe Banha, Nicolás Bonel, Stephanie Bradbeer, Elizabeta Briski, Vincent Butitta, Zuzana Čadková, Jaimie Dick, Karel Douda, Lawrence Eagling, Noé Ferreira-Rodríguez, Leandro Hünicken, Mattias Johansson, Louise Kregting, Anna Labecka, Deliang Li, Florencia Liquin, Jonathan Marescaux, Todd Morris, Patrycja Nowakowska, Małgorzata Ożgo … & Francisco Sylvester
1. Invasive bivalves continue to spread and negatively impact freshwater ecosystems worldwide. As different metrics for body size and biomass are frequently used within the literature to standardise bivalve related ecological impacts (e.g. respiration and filtration rates), the lack of broadly applicable conversion equations currently hinders reliable comparison across bivalve populations. To facilitate improved comparative assessment amongst studies originating from disparate geographic locations, we report body size and biomass conversion equations for six invasive freshwater...

Genetic variation in Neotropical butterflies is associated with sampling scale, species distributions, and historical forest dynamics

Natalí Attiná, Ezequiel Núñez Bustos, Darío A. Lijtmaer, Paul D. N. Hebert, Pablo L. Tubaro & Pablo D. Lavinia
Prior studies of butterfly diversification in the Neotropics have focused on Amazonia and the tropical Andes, while southern regions of the continent have received little attention. To address the gap in knowledge about the Lepidoptera of temperate South America, we analyzed over 3,000 specimens representing nearly 500 species from Argentina for a segment of the mitochondrial COI gene. Representing 42% of the country’s butterfly fauna, collections targeted species from the Atlantic and Andean forests, biodiversity...

Data from: A new Upper Cretaceous titanosaur nesting site from La Rioja (NW Argentina), with implications for titanosaur nesting strategies

E. Martin Hechenleitner, Lucas E. Fiorelli, Gerald Grellet-Tinner, Léa Leuzinger, Giorgio Basilici, Jeremías R. A. Taborda, Sergio R. De La Vega & Carlos A. Bustamante
Cretaceous titanosaur nesting sites are currently known only from Europe, Asia and South America. In the latter, only the Auca Mahuevo and Sanagasta nesting sites have been confidently assigned to this clade of sauropod dinosaurs. Here we report the discovery of the first eggs and egg clutches found at Tama, a new Upper Cretaceous fossiliferous locality in the Los Llanos Formation, Sierra de Los Llanos (La Rioja, NW Argentina). At least five egg clutches, several...

Data from: Biases with the Generalized Euclidean Distance in disparity analyses with high levels of missing data

Oscar E.R. Lehmann, Martin D. Ezcurra, Richard J. Butler & Graeme T. Lloyd
The Generalized Euclidean Distance (GED) has been extensively used to conduct morphological disparity analyses based on palaeontological matrices of discrete characters. This is in part because some implementations allow the use of morphological matrices with high percentages of missing data without needing to prune taxa for a subsequent ordination of the data set. Previous studies have suggested that this way of using the GED may generate a bias in the resulting morphospace, but a detailed...

A test of the riverine barrier hypothesis in the largest subtropical river basin in the neotropics

Leonardo Campagna, Cecilia Kopuchian, Darío A. Lijtmaer, Gustavo S. Cabanne, Natalia C. García, Pablo D. Lavinia, Pablo L. Tubaro, Irby Lovette & Adrián S. Di Giacomo
The riverine barrier hypothesis proposes that large rivers represent geographic barriers to gene flow for terrestrial organisms, leading to population differentiation and ultimately allopatric speciation. Here we asses for the first time if the subtropical Paraná-Paraguay River system in the Del Plata basin, second in size among South American drainages, acts as a barrier to gene flow for birds. We analyzed the degree of mitochondrial and nuclear genomic differentiation in seven species with known subspecies...

Morphologic-phylogenetic analysis of the late Cenozoic Chlamydini von Teppner (Bivalvia: Pectinidae) of southern South America

María Belén Santelli, Maximiliano J. Alvarez & Claudia J. Del Río
The tribe Chlamydini was highly diversified in the marine Neogene of southern South America, reaching its maximum taxonomic diversity during the Miocene. However, the evolutionary relationships of South American taxa remain uncertain. This is the first phylogenetic analysis based on a large morphological matrix on Pectinidae, which is focusing on South American taxa and species related to Chlamys s. The phylogenetic analysis is based on a matrix composed of 145 shell characters scored for 48...

Data from: A new global palaeobiogeographical model for the late Mesozoic and early Tertiary

Martín D. Ezcurra & Federico L. Agnolín
Late Mesozoic palaeobiogeography has been characterized by a distinction between the northern territories of Laurasia and the southern landmasses of Gondwana. The repeated discovery of Gondwanan lineages in Laurasia has led to the proposal of alternative scenarios to explain these anomalous occurrences. A new biogeographical model for late Mesozoic terrestrial ecosystems is here proposed, in which Europe and ‘Gondwanan’ territories possessed a common Eurogondwanan fauna during the earliest Cretaceous. Subsequently, following the Hauterivian, Europe severed...

Data from: A new species of Allophryne (Anura: Allophrynidae) from the Atlantic Rain Forest biome of eastern Brazil

Ulisses Caramaschi, Victor G. D. Orrico, Julián Faivovich, Iuri R. Dias & Mirco Solé
A new species of the genus Allophryne is described and, in contrast to its congeners that occur in the Amazon Basin, is based on specimens obtained in Uruçuca, State of Bahia, in the Atlantic Rain Forest of eastern Brazil. Allophryne relicta sp. nov. is characterized by a medium body size for the genus (snout–vent length range 19.9–21.9 mm in males); large head (head width about 35% of SVL); large, red-orange eyes, with a large black...

Data from: Calculating structural complexity in phylogenies using ancestral ontologies

Martín J. Ramírez & Peter Michalik
Complexity is an important aspect of evolutionary biology, but there are many reasonable concepts of complexity, and its objective measurement is an elusive matter. Here we develop a simple measure of complexity based on counts of elements, incorporating the hierarchical information as represented in anatomical ontologies. Neomorphic and transformational characters are used to identify novelties and individuated morphological regions, respectively. By linking the characters to terms in an anatomical ontology a node-driven approach is implemented,...

Data from: Endocranial anatomy and life habits of the Early Triassic archosauriform Proterosuchus fergusi

Emily Brown, Richard Butler, Martin Ezcurra, Bhart-Anjan Bhullar & Stephan Lautenschlager
Proterosuchids are an important group of carnivorous basal archosauriforms characterised by a bizarre and enigmatic downturned premaxilla that overhangs the lower jaw. They are particularly significant because they radiated in the immediate aftermath of the Permian–Triassic mass extinction, and represent one of the best known ‘disaster taxa’ following that event. While traditionally considered semi-aquatic, recent histological studies and geological data have suggested that they more likely inhabited terrestrial environments. By utilising computed tomographic (CT) data,...

Is Cyclocardia (Conrad) a wastebasket taxon? Exploring the phylogeny of the most diverse genus of the Carditidae (Archiheterodonta, Bivalvia)

Damian Perez & Luciana Giachetti
The carditid genus Cyclocardia is currently the most diverse genus of the family, including nearly 180 nominal species from a wide stratigraphical (Cretaceous–Recent) and geographical range (Antarctica, South and North America, Europe, Africa, Alaska, Russia, Japan, and New Zealand). Due to the lack of autapomorphies in the diagnosis of the genus and its large account of species, we re-evaluated the systematic and phylogenetic status of Cyclocardia. We carried out three approaches: bibliographic revision, phylogenetic analysis,...

Data from: Deciduous dentition and dental eruption sequence in Interatheriinae (Notoungulata, Interatheriidae): implications in the systematics of the group

Mercedes Fernández, Juan Fernicola & Esperanza Cerdeño
Studies focused on deciduous dentition, ontogenetic series, and tooth eruption and replacement patterns in fossil mammals have lately increased due to the recognized taxonomic and phylogenetic weight of these aspects. A study of the deciduous and permanent dentition of Interatherium and Protypotherium (Interatheriinae) is presented, mainly based on unpublished materials. Deciduous cheek teeth are brachydont and placed covering the apex of the respective permanent tooth; in addition, some morphological and metrical differences are observed along...

Data from: Diet composition of reintroduced Red-and-Green Macaws (Ara chloropterus) reflects gradual adaptation to life in the wild

Noelia Volpe, Bettina Thalinger, Elisabet Vilacoba, Thomas W.A. Braukmann, Adrián S. Di Giacomo, Igor Berkunsky, Darío A. Lijtmaer, Dirk Steinke & Cecilia Kopuchian
Over the last two centuries, the Red-and-Green Macaw (Ara chloropterus) has become locally extinct in Argentina. In an attempt to restore its key ecosystem functions as both disperser and regulator of large-seeded plants, a reintroduction project was initiated at the Iberá National Park in northeastern Argentina. The ability of released individuals to find food is crucial, especially when working with captive-bred animals, as long-term establishment of a self-sustaining population depends on their short-term ability to...

Data from: The grass was greener: repeated evolution of specialized morphologies and habitat shifts in ghost spiders following grassland expansion in South America

Fadia Sara Ceccarelli, Nicolas Mongiardino Koch, Eduardo M. Soto, Mariana L. Barone, Miquel A. Arnedo & Martin J. Ramirez
While grasslands, one of Earth’s major biomes, are known for their close evolutionary ties with ungulate grazers, these habitats are also paramount to the origins and diversification of other animals. Within the primarily South American spider subfamily Amaurobioidinae (Anyphaenidae), several species are found living in the continent’s grasslands, with some displaying putative morphological adaptations to dwelling unnoticed in the grass blades. Here, a dated molecular phylogeny provides the backbone for analyses revealing the ecological and...

Data from: Systematics of spiny-backed treefrogs (Hylidae: Osteocephalus): an Amazonian puzzle

Karl-Heinz Jungfer, Julián Faivovich, José M. Padial, Santiago Castroviejo-Fisher, Mariana M. Lyra, Bianca Von Muller Berneck, Patricia P. Iglesias, Philippe J. R. Kok, Ross T. Macculloch, Miguel Trefaut Rodrigues, Vanessa K. Verdade, Claudia P. Torres Gastello, Juan Carlos Chaparro, Paula H. Valdujo, Steffen Reichle, Jiří Moravec, Václav Gvoždík, Giussepe Gagliardi-Urrutia, Raffael Ernst, Ignacio De La Riva, Donald Bruce Means, Albertina P. Lima, J. Celsa Señaris, Ward C. Wheeler & Célio F. B. Haddad
Spiny-backed tree frogs of the genus Osteocephalus are conspicuous components of the tropical wet forests of the Amazon and the Guiana Shield. Here, we revise the phylogenetic relationships of Osteocephalus and its sister group Tepuihyla, using up to 6134 bp of DNA sequences of nine mitochondrial and one nuclear gene for 338 specimens from eight countries and 218 localities, representing 89% of the 28 currently recognized nominal species. Our phylogenetic analyses reveal (i) the paraphyly...

Data from: Description and phylogenetic position of a new species of Oreobates (Anura: Craugastoridae) from northwestern Argentina

Martín O. Pereyra, Darío E. Cardozo, Jorge Baldo & Diego Baldo
We describe a new species of Oreobates from Jujuy, Argentina. The new species is clearly diagnosable from other species of Oreobates by a combination of morphological characters and supported by molecular evidence (genetic distance and phylogenetic analysis). We also provide taxonomic comments about O. discoidalis and O. barituensis, emphasizing the need for an exhaustive revision of these species

Phylogeny of the Eocene Antarctic Tapetinae Gray, 1851 (Bivalvia: Veneridae) from the La Meseta and Submeseta formations

Maximiliano Jorge Alvarez
Systematic analysis shows that the Southern Hemisphere bivalve genus Retrotapes includes the Antarctic species R. antarcticus, R. newtoni, and R. robustus and recognizes for the first time the presence of Katelysia represented by K. florentinoi. Two new genera were erected in this study: Marciachlys new genus to include M. inflata new combination, and Adelfia new genus, which includes A. austrolissa new combination and A. omega new species from the Eocene of Antarctica, and the late...

Unexpected high accuracy of landscape genetics inference with convolutional neural networks

Marcelo Kittlein, Matías Mora, Fernando Mapelli & Ailin Austrich
During the last decade convolutional neural networks (CNNs) have revolutionized the application of machine learning methods to classification tasks and object recognition.

Data from: Contrasting evolutionary histories in Neotropical birds: divergence across an environmental barrier in South America

Pablo D. Lavinia, Ana S. Barreira, Leonardo Campagna, Pablo L. Tubaro & Dario A. Lijtmaer
Avian diversity in the Neotropics has been traditionally attributed to the effect of vicariant forces promoting speciation in allopatry. Recent studies have shown that phylogeographic patterns shared among co-distributed species cannot be explained by a single vicariant event, as species responses to a common barrier depend on the biological attributes of each taxon. The open vegetation corridor (OVC) isolates Amazonia and the Andean forests from the Atlantic Forest, creating a notorious pattern of avian taxa...

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  • Bernardino Rivadavia Natural Sciences Museum
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