Data from: Diversity, phylogeny and biogeography of the South American ‘cardiomyine’ rodents (Hystricognathi, Cavioidea) with a description of two new speciesMaría E. Pérez, Cecilia M. Deschamps & María G. Vucetich
‘Cardiomyine’ rodents are extinct large terrestrial Caviidae closely related to capybaras, that inhabited large parts of South America during the middle Miocene and Pliocene. They are mostly preserved as isolated teeth, but also as skull and jaw fragments. Here we revise the taxonomy of this group and describe two new species, each pertaining to one of the two main late Miocene groups, represented by the genera Caviodon and Cardiomys. This suggests that the diversity of...
Data from: The role of trait combination in the conspicuousness of fruit display among bird-dispersed plantsMariano Ordano, Pedro G. Blendinger, Silvia B. Lomáscolo, Natacha P. Chacoff, Mariano S. Sánchez, María G. Núñez-Montellano, Julieta Jiménez, Román A. Ruggera & Mariana Valoy
In visually-driven seed dispersal mutualisms, natural selection should promote plant strategies that maximize fruit visibility to dispersers. Plants might increase seed dispersal profitability by increasing conspicuousness of fruit display, understood as a plant strategy to maximize fruit detectability by seed dispersers. The role of different plant traits in fruit choice and consumption by seed dispersers has been broadly studied. However, there is no clear evidence about the importance of the traits that increase conspicuousness of...
Data from: Detecting hybridization by likelihood calculation of gene tree extra lineages given explicit modelsMelisa Olave, Luciano J. Avila, , Mariana Morando & Jack W. Sites
Explanations for gene tree discordance with respect to a species tree are commonly attributed to deep coalescence (also known as incomplete lineage sorting [ILS]), as well as different evolutionary processes such as hybridization, horizontal gene transfer and gene duplication. Among these, deep coalescence is usually quantified as the number of extra lineages and has been studied as the principal source of discordance among gene trees, while the other processes that could contribute to gene tree...
Data from: Climate and sea-level changes across a shallow marine Cretaceous–Palaeogene boundary succession in Patagonia, ArgentinaJohan Vellekoop, Femke Holwerda, Mercedes B. Prámparo, Verónica Willmott, Stefan Schouten, Nestor R. Cúneo, Roberto A. Scasso & Henk Brinkhuis
Upper Maastrichtian to lower Paleocene, coarse-grained deposits of the Lefipán Formation in Chubut Province, (Patagonia, Argentina) provide an opportunity to study environmental changes across the Cretaceous–Palaeogene (K–Pg) boundary in a shallow marine depositional environment. Marine palynological and organic geochemical analyses were performed on the K–Pg boundary interval of the Lefipán Formation at the San Ramón section. The palynological and organic geochemical records from the San Ramón K–Pg boundary section are characteristic of a highly dynamic,...
Highly specialized diving birds display substantial dichotomy in neck length with, for example, cormorants and anhingas having extreme necks, while penguins and auks have minimized necks. We attached acceleration loggers to Imperial cormorants Phalacrocorax atriceps and Magellanic penguins Spheniscus magellanicus, both foraging in waters over the Patagonian Shelf, to examine the difference in movement between their respective heads and bodies in an attempt to explain this dichotomy. The penguins had head and body attitudes and...
Data from: Phylogenomic reclassification of the world’s most venomous spiders (Mygalomorphae, Atracinae), with implications for venom evolutionMarshal Hedin, Shahan Derkarabetian, Martín J. Ramírez, Cor Vink & Jason E. Bond
Here we show that the most venomous spiders in the world are phylogenetically misplaced. Australian atracine spiders (family Hexathelidae), including the notorious Sydney funnel-web spider Atrax robustus, produce venom peptides that can kill people. Intriguingly, eastern Australian mouse spiders (family Actinopodidae) are also medically dangerous, possessing venom peptides strikingly similar to Atrax hexatoxins. Based on the standing morphology-based classification, mouse spiders are hypothesized distant relatives of atracines, having diverged over 200 million years ago. Using...
Sharks are a diverse group of mobile predators that forage across varied spatial scales and have the potential to influence food web dynamics. The ecological consequences of recent declines in shark biomass may extend across broader geographic ranges if shark taxa display common behavioural traits. By tracking the original site of photosynthetic fixation of carbon atoms that were ultimately assimilated into muscle tissues of 5,394 sharks from 114 species, we identify globally consistent biogeographic traits...
1. Stable isotope analyses have become an important tool in reconstructing diets, analyzing resource use patterns, elucidating trophic relations among predators and understanding the structure of food webs. 2. Here, we use stable carbon and nitrogen isotope ratios in bone collagen to reconstruct and compare the isotopic niches of adult South American fur seals (Arctocephalus australis); n = 86) and sea lions (Otaria flavescens); n = 49) –two otariid species with marked morphological differences– in...
Data from: Sexual dimorphism, phenotypic integration, and the evolution of head structure in casque-headed lizardsGregory W. Taylor, Juan C. Santos, Benjamin J. Perrault, Mariana Morando, Carlos Roberto Vásquez Almazán, & Jack W. Sites
Sexes can differ in features associated with differential reproduction, which can be used during courtship or aggressive encounters. Some traits tend to evolve independently between sexes and emerge as sexually dimorphic within the organismal phenotype. We characterize such a relationship by estimating the phenotypic integration of the head morphology and modularity of the crest in the casque-headed lizards (Corytophanidae). In this clade, some species show extreme sexual dimorphism (e.g., head crests in the genus Basiliscus)...
Data from: Increasing the fish diversity of the Triassic faunas of Gondwana: a new redfieldiiform (Actinopterygii) from the Middle Triassic of Argentina and its palaeobiogeographical implicationsSoledad Gouiric-Cavalli, Ana María Zavattieri, Pedro Raúl Gutierrez, Bárbara Cariglino & Lucía Balarino
A new actinopterygian, Calaichthys tehul gen. et sp. nov. is described on the basis of a few, well-preserved specimens from the Anisian Cerro de Las Cabras Formation, Cuyo Basin in Mendoza Province. The new genus shows a combination of primitive characters (e.g. deep posterior region of the maxilla contacting the preopercle, a suspensorium backwardly oriented) and more advanced characters (e.g. distally segmented fin rays, hemiheterocercal caudal fin) and is thus considered to be a ‘subholostean’...
Data from: Vertical gradients in species richness and community composition across the twilight zone in the North Pacific Subtropical GyreStephanie A. Sommer, Lauren Van Woudenberg, Petra H. Lenz, Georgina Cepeda & Erica Goetze
Although metazoan animals in the mesopelagic zone play critical roles in deep pelagic food webs and in the attenuation of carbon in midwaters, the diversity of these assemblages is not fully known. A metabarcoding survey of mesozooplankton diversity across the epipelagic, mesopelagic and upper bathypelagic zones (0-1500m) in the North Pacific Subtropical Gyre revealed far higher estimates of species richness than expected given prior morphology-based studies in the region (4,024 OTUs, 10-fold increase), despite conservative...
National Scientific and Technical Research Council11
National University of La Plata2
University of Barcelona2
Brigham Young University2
University of Buenos Aires1
National Oceanography Centre1
St. John's University1
University of Newcastle Australia1
Spanish Institute of Oceanography1