Yale Peabody Museum of Natural History
Yale Peabody Museum of Natural History
Stabile F.A.,Yale University |
Watkins-Colwell G.J.,Yale Peabody Museum of Natural History |
Moore J.A.,Florida Atlantic University |
Vecchione M.,National Oceanic and Atmospheric Administration |
Burtt E.H.,Ohio Wesleyan University
Wilson Journal of Ornithology | Year: 2017
Ornithologists have observed migratory landbirds from offshore ships for over a century. These birds are often in poor condition and thrown off course by storms. We report observations of migratory landbirds on a research vessel that was 320 km offshore in the western North Atlantic Ocean, shortly after Hurricane Gonzalo moved through the area. Between 19 and 25 October 2014, we observed nine passerine species and one falcon species. Two of these passerine species have not previously been observed on offshore ships. We also describe passerine and falcon foraging behaviors that have not been reported before. We examined six passerine birds found dead on the ship and concluded that they likely died of starvation and exhaustion. The passerines we observed may have been disturbed by Hurricane Gonzalo, forcing birds in poor condition to land on the ship. We encourage ornithologists to publish offshore accounts of migratory landbirds to improve our understanding of avian migration.
Brazaitis P.,Yale Peabody Museum of Natural History |
Watanabe M.E.,Naugatuck Valley Community College
Historical Biology | Year: 2011
Modern crocodilians and birds are the only living representatives of the Archosauria, a group that also includes non-avian dinosaurs and pterosaurs. Modern crocodilians originated during the early Cretaceous period and dispersed globally. Examples of physiological similarities between living crocodilians and birds include similar amino acids in b-keratins among crocodiles, turtles and birds; oviduct homologies between crocodilians and birds; similar forelimb structures in crocodiles and other archosaurs and similarities in gene expression in limb development in alligators and chickens. While individual crocodilian species have adapted their behaviours to meet specific strategies for survival in specific habitats, core reproductive behaviours are universal among modern crocodilians and transcend speciation, morphology and geographic distribution. Hard-wired core behaviours include social signals that incorporate chemosensory, auditory and mechanoreception modalities; construction of a temperature-stabilising nest chamber to incubate eggs; and parental care of their young. Parental care may reflect a primitive character for archosaurs, including dinosaurs. Crocodilians use integumentary sense organs (ISOs) during courtship and in parental care, and similar structures may have had similar functions in dinosaurs. The presence of numerous foramina (possible ISOs) in the skulls of saurischians, along with the findings of fossilised nests with adults, may indicate similar complex behaviours, including parental care, in dinosaurs. © 2011 Taylor & Francis.
Joyce W.G.,University of Tübingen |
Parham J.F.,California State University, Fullerton |
Lyson T.R.,Yale Peabody Museum of Natural History |
Lyson T.R.,Smithsonian Institution |
And 4 more authors.
Journal of Paleontology | Year: 2013
Turtles have served as a model system for molecular divergence dating studies using fossil calibrations. However, because some parts of the fossil record of turtles are very well known, divergence age estimates from molecular phylogenies often do not differ greatly from those observed directly from the fossil record alone. Also, the phylogenetic position and age of turtle fossil calibrations used in previous studies have not been adequately justified. We provide the first explicitly justified minimum and soft maximum age constraints on 22 clades of turtles following best practice protocols. Using these data we undertook a Bayesian relaxed molecular clock analysis establishing a timescale for the evolution of crown Testudines that we exploit in attempting to address evolutionary questions that cannot be resolved with fossils alone. Some of these questions, such as whether the turtle crown originated in the Triassic or Jurassic, cannot be resolved by our analysis. However, our results generate novel age-of-origination estimates for clades within crown Testudines. Finally, we compare our fossil calibrations and posterior age estimates to those from other studies, revealing substantial differences in results and interpretation.Copyright © 2013, The Paleontological Society.
PubMed | University of British Columbia, New York University, Yale Peabody Museum of Natural History, Yale University and 6 more.
Type: Journal Article | Journal: PloS one | Year: 2015
The taxonomy of giant Galapagos tortoises (Chelonoidis spp.) is currently based primarily on morphological characters and island of origin. Over the last decade, compelling genetic evidence has accumulated for multiple independent evolutionary lineages, spurring the need for taxonomic revision. On the island of Santa Cruz there is currently a single named species, C. porteri. Recent genetic and morphological studies have shown that, within this taxon, there are two evolutionarily and spatially distinct lineages on the western and eastern sectors of the island, known as the Reserva and Cerro Fatal populations, respectively. Analyses of DNA from natural populations and museum specimens, including the type specimen for C. porteri, confirm the genetic distinctiveness of these two lineages and support elevation of the Cerro Fatal tortoises to the rank of species. In this paper, we identify DNA characters that define this new species, and infer evolutionary relationships relative to other species of Galapagos tortoises.
News Article | March 17, 2016
The Tully monster likely used its long tail to propel it forward in the water. More In 1958, amateur fossil collector Francis Tully found a prehistoric creature so strange that even scientists called it a monster. The beast has perplexed researchers ever since, with some calling the so-called "Tully monster" a worm and others classifying it as a shell-less snail. But now, an analysis of more than 1,200 Tully monster (Tullimonstrum gregarium) fossils has uncovered the monster's true identity. It's a 307-million-year-old jawless fish, a creature in the lineage leading to modern-day lampreys, the researchers found. "It's a very unusual animal," study co-author Scott Lidgard, curator of invertebrate paleontology at the Field Museum of Natural History in Chicago, told Live Science. [See Images of the Bizarre Tully Monster] The roughly foot-long (0.3 meters) monster had a narrow body with eyes like a hammerhead's on the top of its head and a long, slender snout ending in a toothy jaw. Scientists formally described it in 1966, and in 1989, Illinois designated it as the official state fossil. But experts still couldn't make heads or tails of it. They couldn't even place it in a phylum, a big-picture category that includes about 30 broad subcategories, and explains the origins of almost every living thing on Earth. Researchers have found thousands of Tully monster specimens in Illinois over the years. Many of them were digitally scanned into The Field Museum's electronic database, so scientists had plenty of samples to examine while undertaking the new study. "Basically, nobody knew what it was,” study co-author Derek Briggs, a professor of geology and geophysics at Yale University and a curator of invertebrate paleontology at the Yale Peabody Museum of Natural History, said in a statement. "The fossils are not easy to interpret, and they vary quite a bit. Some people thought it might be this bizarre, swimming mollusk. We decided to throw every possible analytical technique at it." The researchers combed through the database and also used synchrotron elemental mapping, a technique that uses a powerful light source to determine the chemistry within a fossil. Although soft-bodied, the Tully monster is a vertebrate that likely used its tail to propel itself forward in the water. Moreover, analyses showed that "the monsters are related to the jawless fishes that are still around today by a unique combination of traits, including primitive gills [and] rows of teeth," Paul Mayer, The Field Museum's fossil invertebrates collections manager, said in the statement. It also has "traces of a notochord, the flexible rodlike structure along the back that's present in chordate animals — including vertebrates like us," Mayer said. The big-eyed and pointy-toothed fish was likely a predator, said study lead author Victoria McCoy, who conducted the research as a Yale graduate student and is now at the University of Leicester in the United Kingdom. However, it's unclear when the animal first developed and when it went extinct, she said. The study was published online today (March 16) in the journal Nature. Copyright 2016 LiveScience, a Purch company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Lyson T.R.,Yale University |
Lyson T.R.,Marmarth Research Foundation |
Bercovici A.,Wuhan University |
Chester S.G.B.,Yale University |
And 4 more authors.
Biology Letters | Year: 2011
Modern debate regarding the extinction of nonavian dinosaurs was ignited by the publication of the Cretaceous-Tertiary (K-T) asteroid impact theory and has seen 30 years of dispute over the position of the stratigraphically youngest in situ dinosaur. A zone devoid of dinosaur fossils reported from the last 3 m of the Upper Cretaceous, coined the '3 m gap', has helped drive controversy. Here, we report the discovery of the stratigraphically youngest in situ dinosaur specimen: a ceratopsian brow horn found in a poorly rooted, silty, mudstone floodplain deposit located no more than 13 cm below the palynologically defined boundary. The K-T boundary is identified using three criteria: (i) decrease in Cretaceous palynomorphs without subsequent recovery, (ii) the existence of a 'fern spike', and (iii) correlation to a nearby stratigraphic section where primary extraterrestrial impact markers are present (e.g. iridium anomaly, spherules, shocked quartz). The in situ specimen demonstrates that a gap devoid of non-avian dinosaur fossils does not exist and is inconsistent with the hypothesis that non-avian dinosaurs were extinct prior to the K-T boundary impact event. © 2011 The Royal Society.
Hart J.A.,Lukuru Wildlife Research Foundation |
Detwiler K.M.,Florida Atlantic University |
Gilbert C.C.,York College - The City University of New York |
Burrell A.S.,New York University |
And 8 more authors.
PLoS ONE | Year: 2012
In June 2007, a previously undescribed monkey known locally as "lesula" was found in the forests of the middle Lomami Basin in central Democratic Republic of Congo (DRC). We describe this new species as Cercopithecus lomamiensis sp. nov., and provide data on its distribution, morphology, genetics, ecology and behavior. C. lomamiensis is restricted to the lowland rain forests of central DRC between the middle Lomami and the upper Tshuapa Rivers. Morphological and molecular data confirm that C. lomamiensis is distinct from its nearest congener, C. hamlyni, from which it is separated geographically by both the Congo (Lualaba) and the Lomami Rivers. C. lomamiensis, like C. hamlyni, is semi-terrestrial with a diet containing terrestrial herbaceous vegetation. The discovery of C. lomamiensis highlights the biogeographic significance and importance for conservation of central Congo's interfluvial TL2 region, defined from the upper Tshuapa River through the Lomami Basin to the Congo (Lualaba) River. The TL2 region has been found to contain a high diversity of anthropoid primates including three forms, in addition to C. lomamiensis, that are endemic to the area. We recommend the common name, lesula, for this new species, as it is the vernacular name used over most of its known range. © 2012 Hart et al.
Reese A.T.,Yale Peabody Museum of Natural History |
Reese A.T.,Yale University |
Lanier H.C.,University of Michigan |
Sargis E.J.,Yale Peabody Museum of Natural History |
Sargis E.J.,Yale University
Journal of Morphology | Year: 2013
Pika species generally fall into two ecotypes, meadow-dwelling (burrowing) or talus-dwelling, a classification that distinguishes a suite of different ecological, behavioral, and life history traits. Despite these differences, little morphological variation has previously been documented to distinguish among ecotypes. The aim of this study was to test whether postcranial features related to burrowing are present in meadow-dwelling species and whether talus-dwelling species exhibit postcranial modifications related to frequent leaping between rocks. To test this, the scapula, humerus, ulna, radius, innominate, femur, tibia, and calcaneus of 15 species were studied and measured. Twenty-three measurements were taken on 199 skeletons, and 19 indices were constructed from these measurements. Indices were compared between the two ecotypes using Student's t-test. Comparisons among ecotypes, species, and subgenera were made using one-way ANOVA with the Tukey honest significant difference post hoc test. Multivariate results were generated using principal components analyses. Thirteen forelimb and hind limb indices proved significant in distinguishing the meadow-dwelling, talus-dwelling, and intermediate forms. A number of these indices are associated with burrowing or leaping in other mammals, providing some support for the hypothesis that postcranial modifications in pika are related to locomotor differences. This evidence of morphological responses to ecological specialization will be useful for reconstructing the paleobiology of extinct taxa, assessing the behavioral variability of extant species, and improving our understanding of the evolutionary history of pikas. © 2013 Wiley Periodicals, Inc.
Ague J.J.,Yale University |
Nicolescu S.,Yale Peabody Museum of Natural History
Nature Geoscience | Year: 2014
The balance between the subduction of carbonate mineral-bearing rocks into Earth's mantle and the return of CO2 to the atmosphere by volcanic and metamorphic degassing is critical to the carbon cycle. Carbon is thought to be released from subducted rocks mostly by simple devolatilization reactions. However, these reactions will also retain large amounts of carbon within the subducting slab and have difficulty in accounting for the mass of CO2 emitted from volcanic arcs. Carbon release may therefore occur via fluid-induced dissolution of calcium carbonate. Here we use carbonate δ18O and δ13C systematics, combined with analyses of rock and fluid inclusion mineralogy and geochemistry, to investigate the alteration of the exhumed Eocene Cycladic subduction complex on the Syros and Tinos islands, Greece. We find that in marble rocks adjacent to two fluid conduits that were active during subduction, the abundance of calcium carbonate drastically decreases approaching the conduits, whereas silicate minerals increase. Up to 60-90% of the CO2 was released from the rocks - far greater than expected via simple devolatilization reactions. The δ18O of the carbonate minerals is 5-10‰ lighter than is typical for metamorphosed carbonate rocks, implying that isotopically light oxygen was transported by fluid infiltration from the surroundings. We suggest that fluid-mediated carbonate mineral removal, accompanied by silicate mineral precipitation, provides a mechanism for the release of enormous amounts of CO2 from subduction zones. © 2014 Macmillan Publishers Limited.
News Article | April 5, 2016
Scientists at Yale University reported the discovery of a prehistoric species of arthropod that employed a unique but already extinct form of parenting strategy. The ancient animal known as Aquilonifer spinosus moved around carrying its young in pouches tethered to its body resembling the appearance of swirling kites. Derek Briggs, from Yale Peabody Museum of Natural History, said that they have nicknamed the ancient animal "The Kite Runner," from the 2003 bestselling novel written by Khalid Hosseini, because of the resemblance of the creature's juvenile to kites. The researchers initially considered that the young may have been parasites feeding off a host but eventually decided that this was not likely given that the attachment position would not have been favorable for accessing nutrients. "Here we report a new arthropod with 10 tiny arthropods tethered to its tergites by long individual threads," Briggs and colleagues reported. "The evidence suggests that the tethered individuals are juveniles and the association represents a complex brooding behavior." Briggs explained that how the A.spinosus has carried its young like kites attached to it shows that arthropods went through different brooding strategies over the course of their evolution. Arthropods during this period may still be experimenting on how to best brood their young and the strategy used by the eyeless and flat-bodied creature may have been less successful and eventually became extinct. "Modern crustaceans employ a variety of strategies to protect their eggs and embryos from predators - attaching them to the limbs, holding them under the carapace, or enclosing them within a special pouch until they are old enough to be released - but this example is unique," Briggs said. The creature measured less than 0.5 inches and featured a shield that protected its head topped by antenna-like structures. The creature used its 12 pairs of legs to navigate across the sea bottom of what is now Herefordshire in England about 430 million years ago. The region is no longer underwater today but fossils of small ancient creatures such as the A. spinosus that once lived in the oceans were preserved in hardened volcanic ash. The findings were published in the journal Proceedings of the National Academy of Sciences on April 4.