A new Triassic decapod, Platykotta akaina , from the Arabian shelf of the northern United Arab Emirates: earliest occurrence of the Anomura

A Triassic decapod crustacean is described here for the first time from the Norian-Rhaetian Ghalilah Formation of the Musandam Peninsula, United Arab Emirates. The single specimen Platykotta akaina n. gen n. sp. is referred to a new family Platykottidae. The studied crustacean, initially with only the ventral exposure preserved, was collected from shallow-water, burrowed limestones. Using a chemical preparation, the dorsal view revealed a well-preserved, chitinous, granular carapace exhibiting characteristic carapace morphology and groove pattern of the Eocarcinoidea, the superfamily to which the new family is assigned. The dorsal view together with the ventral surface, rarely seen in the fossil record, provide new insight into the morphology of representatives of the Eocarcinoide

Industrial Resources - Fulton County - Fulton

Resources for Economic Development: Fulton County, Kentucky” prepared by the Kentucky Department of Economic Development, Division of Research, and the Fulton County Economic Development Partnership, 1995. The report includes, but is not limited to, information about: population, labor market, local manufacturing, transportation, utilities, fuel, water, sewage, industrial sites, local government and services, taxes, educational and health facilities, housing, communication, recreation, natural resources, markets, and climate

Eocene decapod crustacea (thalassinidea and brachyura) from Patagonia, Argentina

Rocks of the Rio Turbio Formation, exposed in southern Patagonia, Argentina, represent one of very few occurrences of Eocene rocks in the region. Decapod crustaceans collected from the unit include one species of thalassinidean mud shrimp; Turbiocheir minutospinata, new genus, new species; and three species of brachyurans; Raninoides rioturbiensis, new species; Megokkos patagoniensis, new species; and Nitotacarcinus antipodes, new species. The three brachyuran genera are also known from species in the Northeast Pacific, suggesting an amphitropical distributional pattern.Fil: Schweitzer, Carrie E.. Kent State University; Estados UnidosFil: Feldmann, Rodney M.. Kent State University; Estados UnidosFil: Casadio, Silvio Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: Rodriguez Raising, Martin Eduardo. Universidad Nacional de La Pampa; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

New Decapoda (Crustacea) from the Middle and Late Eocene of Pakistan and a revision of Lobonotus A. Milne Edwards, 1864

p. 89-118http://deepblue.lib.umich.edu/bitstream/2027.42/41256/2/C31-4.pd

Redescription of Americlus rankini (Woodward, 1868) (Pancrustacea: Cyclida: Americlidae) and interpretation of its systematic placement, morphology, and paleoecology

The best-preserved Scottish species of a cyclidan is reinterpreted, based upon recent advances in cyclidan paleobiology. Americlus rankini (Woodward, 1868) is one of the best-preserved members of this crustacean group, and its morphology suggests that it and related forms exhibited a unique and distinct morphology within Multicrustacea. Paleoecological evidence suggests that the animal was most likely free living, possibly as a scavenger, in a marginal marine environment. Americlus lived in Laurentia during the Middle Mississippian (Visean) to Middle Pennsylvanian (Moscovian)

A comprehensive and integrative reconstruction of evolutionary history for Anomura (Crustacea: Decapoda).

BACKGROUND: The infraorder Anomura has long captivated the attention of evolutionary biologists due to its impressive morphological diversity and ecological adaptations. To date, 2500 extant species have been described but phylogenetic relationships at high taxonomic levels remain unresolved. Here, we reconstruct the evolutionary history-phylogeny, divergence times, character evolution and diversification-of this speciose clade. For this purpose, we sequenced two mitochondrial (16S and 12S) and three nuclear (H3, 18S and 28S) markers for 19 of the 20 extant families, using traditional Sanger and next-generation 454 sequencing methods. Molecular data were combined with 156 morphological characters in order to estimate the largest anomuran phylogeny to date. The anomuran fossil record allowed us to incorporate 31 fossils for divergence time analyses. RESULTS: Our best phylogenetic hypothesis (morphological + molecular data) supports most anomuran superfamilies and families as monophyletic. However, three families and eleven genera are recovered as para- and polyphyletic. Divergence time analysis dates the origin of Anomura to the Late Permian ~259 (224-296) MYA with many of the present day families radiating during the Jurassic and Early Cretaceous. Ancestral state reconstruction suggests that carcinization occurred independently 3 times within the group. The invasion of freshwater and terrestrial environments both occurred between the Late Cretaceous and Tertiary. Diversification analyses found the speciation rate to be low across Anomura, and we identify 2 major changes in the tempo of diversification; the most significant at the base of a clade that includes the squat-lobster family Chirostylidae. CONCLUSIONS: Our findings are compared against current classifications and previous hypotheses of anomuran relationships. Many families and genera appear to be poly- or paraphyletic suggesting a need for further taxonomic revisions at these levels. A divergence time analysis provides key insights into the origins of major lineages and events and the timing of morphological (body form) and ecological (habitat) transitions. Living anomuran biodiversity is the product of 2 major changes in the tempo of diversification; our initial insights suggest that the acquisition of a crab-like form did not act as a key innovation

Exceptional Preservation of Mid-Cretaceous Marine Arthropods and the Evolution of Novel Forms via Heterochrony

Evolutionary origins of novel forms are often obscure because early and transitional fossils tend to be rare, poorly preserved, or lack proper phylogenetic contexts. We describe a new, exceptionally preserved enigmatic crab from the mid-Cretaceous of Colombia and the United States, whose completeness illuminates the early disparity of the group and the origins of novel forms. Its large and unprotected compound eyes, small fusiform body, and leg-like mouthparts suggest larval trait retention into adulthood via heterochronic development (pedomorphosis), while its large oar-like legs represent the earliest known adaptations in crabs for active swimming. Our phylogenetic analyses, including representatives of all major lineages of fossil and extant crabs, challenge conventional views of their evolution by revealing multiple convergent losses of a typical “crab-like” body plan since the Early Cretaceous. These parallel morphological transformations may be associated with repeated invasions of novel environments, including the pelagic/necto-benthic zone in this pedomorphic chimera crab

A new millipede (Diplopoda, Helminthomorpha) from the Middle Triassic Luoping biota of Yunnan, Southwest China

AbstractA new helminthomorph millipede,Sinosoma luopingensenew genus new species, from the Triassic Luoping biota of China, has 39 body segments, metazonites with lateral swellings that bear a pair of posterolateral pits (?insertion pits for spine bases), and sternites that are unfused to the pleurotergites. This millipede shares a number of characters with nematophoran diplopods, but lacks the prominent dorsal suture characteristic of that order. Other “millipede” material from the biota is more problematic. Millipedes are a rare part of the Luoping biota, which is composed mainly of marine and near-shore organisms. Occurrences of fossil millipedes are exceedingly rare in Triassic rocks worldwide, comprising specimens from Europe, Asia, and Africa, and consisting of juliform millipedes and millipedes that are either nematophorans or forms very similar to nematophorans.</jats:p

Exceptional appendage and soft-tissue preservation in a Middle Triassic horseshoe crab from SW China

Abstract Horseshoe crabs are classic “living fossils”, supposedly slowly evolving, conservative taxa, with a long fossil record back to the Ordovician. The evolution of their exoskeleton is well documented by fossils, but appendage and soft-tissue preservation is extremely rare. Here we analyse details of appendage and soft-tissue preservation in Yunnanolimulus luopingensis, a Middle Triassic (ca. 244 million years old) horseshoe crab from Yunnan Province, SW China. The remarkable preservation of anatomical details including the chelicerae, five pairs of walking appendages, opisthosomal appendages with book gills, muscles, and fine setae permits comparison with extant horseshoe crabs. The close anatomical similarity between the Middle Triassic horseshoe crabs and their recent analogues documents anatomical conservatism for over 240 million years, suggesting persistence of lifestyle. The occurrence of Carcinoscorpius-type claspers on the first and second walking legs in male individuals of Y. luopingensis indicates that simple chelate claspers in males are plesiomorphic for horseshoe crabs, and the bulbous claspers in Tachypleus and Limulus are derived