A5034233218- Subterranean biodiversity and taxonomy
- Paleontology and Stratigraphy of Fossils
- Evolution and Paleontology Studies
- Marine Biology and Ecology Research
- Amphibian and Reptile Biology
- Paleontology and Evolutionary Biology
- Ichthyology and Marine Biology
- Fossil Insects in Amber
- Geology and Paleoclimatology Research
- Spider Taxonomy and Behavior Studies
- Protist diversity and phylogeny
- Genomics and Phylogenetic Studies
- Lepidoptera: Biology and Taxonomy
- Insect and Arachnid Ecology and Behavior
- Marine and environmental studies
- Parasite Biology and Host Interactions
- Cephalopods and Marine Biology
- Collembola Taxonomy and Ecology Studies
- Venomous Animal Envenomation and Studies
- Plant and animal studies
- Geochemistry and Geologic Mapping
- Study of Mite Species
- Morphological variations and asymmetry
- Geological Studies and Exploration
- Fish biology, ecology, and behavior
West Virginia University
2016-2025
Alibaba Group (China)
2023
American Museum of Natural History
2016-2017
Yale University
2014-2016
Whitney Museum of American Art
2015-2016
University of Kansas
2010-2014
Samueli Institute
2011
University of Bristol
2009-2010
Abstract Xiphosurids are an archaic group of aquatic chelicerate arthropods, generally known by the colloquial misnomer ‘horseshoe crabs’. Known from marine environments as far back early O rdovician, horseshoe crabs considered ‘living fossils’ – descendants a bradytelic lineage exhibiting little morphological or ecological variation throughout geological time. However, xiphosurids freshwater sediments in P alaeozoic and M esozoic; furthermore, contention that show has never been tested...
Abstract Implied weighting, a method for phylogenetic inference that actively seeks to downweight supposed homoplasy, has in recent years begun be widely utilized palaeontological datasets. Given the method's purported ability at handling widespread homoplasy/convergence, we investigate effects of implied weighting on modelled data. We generated 100 character matrices consisting 55 characters each using M arkov C hain morphology model evolution based known tree. Rates these datasets were...
The monophyly of the class Xiphosura is critically re-examined. For first time a phylogenetic analysis number synziphosurine and xiphosurid taxa performed together with representatives other chelicerate orders also included as ingroup taxa. currently defined shown to be paraphyletic, revised classification presented. Previous characteristics used unite xiphosurids (possessing fused thoracetron) paraphyletic grade synziphosurines (retaining freely articulating opisthosomal tergites) include...
Gigantism is widespread among Palaeozoic arthropods, yet causal mechanisms, particularly the role of (abiotic) environmental factors versus (biotic) competition, remain unknown. The eurypterids (Arthropoda: Chelicerata) include largest arthropods; gigantic predatory pterygotids (Eurypterina) during Siluro-Devonian and bizarre sweep-feeding hibbertopterids (Stylonurina) from Carboniferous to end-Permian. Analysis family-level originations extinctions vertebrates show that diversity...
Abstract Background Eurypterids are a diverse group of chelicerates known from ~250 species with sparse Ordovician record currently comprising 11 species; the oldest fully documented example is Sandbian Avalonia. The Middle (Darriwilian) fauna Winneshiek Lagerstätte includes new eurypterid represented by more than 150 specimens, including some juveniles, preserved as carbonaceous cuticular remains. This taxon represents described eurypterid, extending range back 9 million years. Results...
Mass extinctions have altered the trajectory of evolution a number times over Phanerozoic. During these periods biotic upheaval different selective regime appears to operate, although it is still unclear whether consistent survivorship rules apply across extinction events. We compare variations in diversity and disparity evolutionary history major Paleozoic arthropod group, Eurypterida. Using data, we explore group's transition from successful, dynamic clade stagnant persistent lineage,...
Xiphosurans are aquatic chelicerates with a fossil record extending into the Early Ordovician and known from total of 88 described species, four which extant. Known for their apparent morphological conservatism, they have gained notoriety as supposed 'living fossils', recent analyses demonstrated xiphosurans to an ecologically diverse evolutionary history, several groups moving non-marine environments developing morphologies markedly different those modern species. The combination long...
Eurypterids-Palaeozoic marine and freshwater arthropods commonly known as sea scorpions-repeatedly evolved to remarkable sizes (over 0.5 m in length) colonized continental aquatic habitats multiple times. We compiled data on the majority of eurypterid species explored several previously proposed explanations for evolution giant size group, including potential role habitat, surface temperature dissolved oxygen levels, using a phylogenetic comparative approach with new tip-dated tree. There is...
Abstract The Vicissicaudata, a group of artiopods, originated and reached their highest diversity during the Cambrian period. However, relatively few vicissicaudatan species are known from Paleozoic. Here we report new arthropod, sister to cheloniellids, Late Carboniferous Mazon Creek Lagerstätte. two specimens preserve small eyeless head, trunk comprising seven tergites with wide pleural lobes, narrower postabdomen bearing long, posteriorly directed caudal appendages, short, shield-shaped...
Pterygotid eurypterids have traditionally been interpreted as active, high-level, visual predators; however, recent studies of the system and cheliceral morphology pterygotid Acutiramus contradict this interpretation. Here, we report similar analyses pterygotids Erettopterus, Jaekelopterus Pterygotus, sister taxon Slimonia. Representative species all these genera more acute vision than A. cummingsi. The systems rhenaniae Pterygotus anglicus are comparable to that modern predatory arthropods....
Few studies on eurypterids have taken into account morphological changes that occur throughout postembryonic development. Here two species of eurypterid are described from the Pragian Beartooth Butte Formation Cottonwood Canyon in Wyoming and included a phylogenetic analysis. Both comprise individuals number instars, this allows for their ontogeny to be documented, how ontogenetically variable characters can influence analysis tested. The as Jaekelopterus howelli (Kjellesvig-Waering Størmer,...
Two new specimens of the xiphosuran Kasibelinurus yueya Lamsdell, Xue & Selden, 2013 are described, from same horizon and locality as type. The conspecific with type, but show ventral morphology, which considerably alters interpretation species. It can no longer be referred to Pickett, 1993, a genus, Houia n. gen., is erected. shows unique combination xiphosurid chasmataspidid/eurypterid characteristics such lack opisthosomal pleura possession large, metastomal plate. Phylogenetic...
Abstract The chemical composition of fossil soft tissues is a potentially powerful and yet underutilized tool for elucidating the affinity problematic organisms. In some cases, it has proven difficult to assign even invertebrates or vertebrates (more generally chordates) based on often incompletely preserved morphology alone, may help resolve such questions. Here, we use in situ Raman microspectroscopy investigate chemistry diverse array invertebrate vertebrate fossils from Pennsylvanian...
Abstract The occupation of new environments by evolutionary lineages is frequently associated with morphological changes. This covariation ecotype and phenotype expected due to the process natural selection, whereby environmental pressures lead proliferation variants that are a better fit for prevailing abiotic conditions. One primary mechanism which phenotypic known arise through changes in timing or duration organismal development resulting alterations adult morphology, as heterochrony....
Abstract A relatively uncommon arthropod of the Waukesha lagerstätte, Parioscorpio venator , is redescribed as an bearing a combination characters that defy ready classification. Diagnostic features include sub‐chelate ‘great appendages’, lack antennae, multiramous anterior trunk appendages, filamentous fan‐like rear and apparently thin poorly preserved pleural fields. Phylogenetic analysis resolves this organism basal to crown‐group Mandibulata Chelicerata, but its exact placement...
The first well-resolved phylogeny of stylonurine eurypterids (30 taxa, 58 characters) is presented, prompting a taxonomic revision at the familial and superfamilial levels. monophyletic suborder Stylonurina consists four superfamilies: Rhenopteroidea, Stylonuroidea, Kokomopteroidea Hibbertopteroidea. enigmatic hibbertopterids – large sweep-feeding forms from Carboniferous to end-Permian are therefore demonstrated be an in-group clade, within Eurypterida, in contrast some earlier hypotheses....