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Cement Creek and Haystack caves in Colorado have produced a diverse record of high-elevation late Quaternary mammals. Intermixed with the abundant mammalian remains were rare occurrences of amphibian and reptile fossils reported here. Cement Creek Cave (2860 m elevation) contained the fossils of only a few anurans and a limited number of snakes, whereas Haystack Cave, at a substantially lower elevation (2450 m), contained the fossils of a salamander, a larger number of snakes, and an extensive number of lizard remains, yet no anurans. The 2 faunas are overall distinct in composition, and, although not diverse or abundant in terms of species or number of faunal remains, they provide a rare and exceptional record of a late Pleistocene high-elevation herpetofauna from the Intermountain West. Las cuevas Cement Creek y Haystack en Colorado han producido un diverso registro de mamíferos de gran altitud del Cuaternario tardío. Entre los abundantes restos de mamíferos, se registraron raros casos de anfibios y reptiles, los cuales reportamos a continuación. En la cueva Cement Creek (2860 m de elevación) se encontraron solo unos pocos anuros y un número limitado de serpientes. Mientras que, en la cueva Haystack, a una elevación sustancialmente más baja (2450 m de elevación), se encontraron una salamandra, una mayor cantidad de serpientes y una gran cantidad de restos de lagartos, pero no anuros. Las dos faunas son distintas en su composición en general y, aunque no son diversas ni abundantes en términos de especies o número de restos de fauna, proporcionan un registro único y excepcional de una herpetofauna de alta elevación del Pleistoceno tardío del oeste intermontañoso.

The new conodont genus Magnigondolella is recognized based on specimens recovered from the Anisian (Middle Triassic) of British Columbia in Canada, and Nevada in the USA. This new genus encompasses problematic specimens with high carinas, which have recently been collectively referred to as Neogondolella ex gr. regalis Mosher. Ten species from North America are herein assigned to Magnigondolella n. gen., including the eight new species M. alexanderi, M. cyri, M. julii, M. nebuchadnezzari, M. salomae, M. n. sp. A, M. n. sp. B, and M. n. sp. C, as well as the two existing species M. regalis (Mosher) and M. dilacerata (Golding and Orchard). Other species from the Tethys region are also tentatively assigned to Magnigondolella n. gen. Based on published records, the genus appears to range from the Spathian to the upper Anisian in North America. The recognition of eight new species from the Anisian significantly increases the conodont biodiversity of this period, which has previously been regarded as a time of low diversity. Although some of the species included within Magnigondolella n. sp. have relatively long stratigraphic ranges, many have been identified in both British Columbia and Nevada, and therefore show potential for biostratigraphic correlation on a regional scale.

In recent years several studies have been carried out to test the validity of Bergmann’s rule for amphibians, and have generated varying results. Due to the lack of agreement on this topic, here we examine the relationship between climate and body size for one anuran species (Bufo calamita, commonly known as the natterjack toad) with a new methodological approach that uses the fossil record as the data source. We analysed bones from two archaeo-paleontological sites located close to each other in the Sierra de Atapuerca (Burgos, Spain) that together encompass more than one million years from Early to Late Pleistocene. We used ordinary least squares (OLS) simple regression models to integrate body size and palaeoclimatic data (temperature and precipitation) and describe the relationship between the amphibian’s body size and climate along the entire temporal gradient. We found the body size of B. calamita to be negatively related to the mean annual temperature and the mean temperature of the coldest month, and positively related to December-to-February precipitation. The climatic influence was stronger in females, which were smaller than males in most cases, and therefore an inverse sexual size dimorphism pattern was found. Juvenile individuals or the limited sexual size dimorphism of this species may be causes of this unusual pattern. Bufo calamita populations showed a clear Bergmann cline during the Pleistocene period, and winter stands out as the most influential season. Although this new methodology can only be used to describe patterns, we discuss several mechanisms that could explain our results. We propose that starvation resistance and delayed maturation are the main causes for this increase in size in periods with cooler winters, and a fecundity-related hypothesis to explain why climate has a greater influence on female body size.

The use of ecological models enables determining the current distribution of species, but also their past distribution when matching climatic conditions are available. In specific cases, they can also be used to determine the likelihood of fossils to belong to the same species—under the hypothesis that all individuals of a species have the same ecological requirements. Here, using environmental modeling, we reconstructed the distribution of the Mongolian toad, Strauchbufo raddei , since the Last Glacial Maximum and thus covering the time period between the Late Pleistocene and the Holocene. We found the range of the species to have shifted over time, with the LGM population clustered around the current southern range of the species, before expanding east and north during the Pleistocene, and reaching the current range since the mid-Holocene. Finally, we determined that the ecological conditions during the life-time of the mid-Pleistocene fossils attributed to the species in Europe were too different from the one of the extant species or fossils occurring at the same period in Asia to belong to the same species.

The species-rich family of true toads (Anura: Bufonidae) has been the focus of several earlier studies investigating the biogeography of geographically widespread taxa. Herein, we employ newly developed Bayesian divergence estimate methods to investigate the biogeographical history of this group. Resulting age estimates are used to test several key temporal hypotheses including that the origin of the bufonid clade pre-dates Gondwanan vicariance (~105 million years ago, Ma). Area cladograms are also invoked to investigate the geographical origin of the family. Worldwide, except the Australia-New Guinea plate, Madagascar and the Antarctic. A phylogenetic hypothesis of the relationships among true toads was derived from analysis of 2521 bp of DNA data including fragments from three mitochondrial (12S, tRNAval, 16S) and two nuclear (RAG-1, CXCR-4) genes. Analysis of multiple, unlinked loci with a Bayesian method for estimating divergence times allowed us to address the timing and biogeographical history of Bufonidae. Resulting divergence estimates permitted the investigation of alternative vicariance/dispersal scenarios that have been proposed for true toads. Our area cladogram resulting from phylogenetic analysis of DNA data supports a South American origin for Bufonidae. Divergence estimates indicate that the family originated earlier than had been suggested previously (78-99 Ma). The age of the enigmatic Caribbean clade was dated to the late Palaeocene-early Eocene. A return of bufonids to the New World in the Eocene was followed by rapid diversification and secondary expansion into South America by the early Oligocene (Rupelian). The South American origin of Bufonidae in the Upper Cretaceous was followed by relatively rapid expansion and radiation around the globe, ending with a return to the Americas via a Eurasian/North American land bridge in the Eocene. Though the exact route of this dispersal (Beringia or North Atlantic) remains unclear, an argument is made for the less frequently invoked North Atlantic connection. The origin of the enigmatic Caribbean lineage was found to be consistent with colonization following the bolide impact at the K/T boundary. These findings provide the first, firm foundation for understanding true toad divergence times and their truly remarkable and global radiation.

A new tick species of the genus Ornithodoros (Acari: Argasidae) was described from larvae collected on the toad Rhinella arenarum in a locality from Argentina belonging to the Monte Biogeographic Province. Ornithodoros montensis n. sp. was described based on morphological traits and sequences of the mitochondrial 16S rRNA gene. The diagnostic characters for this species are a combination of idiosoma oval, dorsal plate pyriform with posterior margin slightly concave, dorsal surface with 17 pairs of setae (7 anterolateral, 4 to 5 central and 5 to 6 posterolateral), ventral surface with 6 pairs of setae and 1 pair on anal valves, three pairs of sternal setae, postcoxal setae absent, and hypostome pointed apically with dental formula 3/3 in the anterior half and 2/2 posteriorly almost to base. Phylogenetic analysis of 16S rDNA sequences and a principal component analysis based on morphometric characters provided additional support to the description of O. montensis as an independent lineage within the genus Ornithodoros. Larvae of O. montensis are phylogenetically closely related to O. puertoricensis, O. rioplatensis, O. talaje s.s., O. guaporensis, O. hasei and O. atacamensis, all of them belonging to the “O. talaje group”.

Fossils are indispensible in understanding the evolutionary origins of the modern fauna. Crown-group spadefoot toads (Anura: Pelobatoidea) are the best-known fossorial frog clade to inhabit arid environments, with species utilizing a characteristic bony spade on their foot for burrowing. Endemic to the Northern Hemisphere, they are distributed across the Holarctic except East Asia. Here we report a rare fossil of a crown-group spadefoot toad from the late Paleocene of Mongolia. The phylogenetic analysis using both morphological and molecular information recovered this Asian fossil inside the modern North American pelobatoid clade Scaphiopodidae. The presence of a spade and the phylogenetic position of the new fossil frog strongly support its burrowing behavior. The late Paleocene age and other information suggestive of a mild climate cast doubt on the conventional assertion that burrowing evolved as an adaptation to aridity in spadefoot toads. Temporally and geographically, the new fossil provides the earliest record of Scaphiopodidae worldwide and the only member of the group in Asia. Quantitative biogeographic analysis suggests that Scaphiopodidae, despite originating in North America, dispersed into East Asia via Beringia in the Early Cenozoic. The absence of spadefoot toads in East Asia today is a result of extinction.

Although many amphibian populations around the world are declining at alarming rates, the cause of most declines remains unknown. Environmental contamination is one of several factors implicated in declines and may have particularly important effects on sensitive developmental stages. Despite the severe effects of maternal transfer of contaminants on early development in other vertebrate lineages, no studies have examined the effects of maternal transfer of contaminants on reproduction or development in amphibians. We examined maternal transfer of contaminants in eastern narrow-mouth toads (Gastrophryne carolinensis) collected from a reference site and near a coal-burning power plant. Adult toads inhabiting the industrial area transferred significant quantities of selenium and strontium to their eggs, but Se concentrations were most notable (up to 100 µg/g dry mass). Compared with the reference site, hatching success was reduced by 11% in clutches from the contaminated site. In surviving larvae, the frequency of developmental abnormalities and abnormal swimming was 55-58% higher in the contaminated site relative to the reference site. Craniofacial abnormalities were nearly an order of magnitude more prevalent in hatchlings from the contaminated site. When all developmental criteria were considered collectively, offspring from the contaminated site experienced 19% lower viability. Although there was no statistical relationship between the concentration of Se or Sr transferred to eggs and any measure of offspring viability, our study demonstrates that maternal transfer may be an important route of contaminant exposure in amphibians that has been overlooked.