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Harrisburg, PA, United States

Storm L.,Kutztown University of Pennsylvania | Needle M.D.,Kutztown University of Pennsylvania | Smith C.J.,Kutztown University of Pennsylvania | Fillmore D.L.,Kutztown University of Pennsylvania | And 3 more authors.
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2010

A burrow of probable amphibian origin was discovered in the upper member of the Mississippian Mauch Chunk Formation in eastern Pennsylvania. Facies analysis of the upper member indicates that deposition occurred in an ephemeral-braided stream setting. The burrow is housed in a mudstone and is filled by two graded beds of conglomerate to sandstone. It is characterized by a flared opening leading into a narrower slightly helical tunnel that ends in an inflated ovate chamber approximately 51 to 60. cm in diameter with a maximum height of 20. cm. The flared opening is stratigraphically higher than the elevation at the base of the chamber. The tunnel has a semicircular base.The geometries, abrupt angle changes, inflated termination, width-to-height ratios of the terminal chamber, and graded fill indicate that the structure was an open void prior to sedimentation. The geometry and size of this structure are incompatible with known invertebrate burrows and erosional features. Palaeosauropus primaevus, an amphibian footprint ichnotaxon, recovered from the Mauch Chunk Formation, was made by an amphibian of sufficient size to create such a large burrow. This type of burrowing was most likely a response to seasonal droughts as local water sources evaporated. © 2010 Elsevier B.V.

Grasslands are rare yet biologically rich habitats in the northeastern United States, including Pennsylvania. i examined the seasonal activity and aspects of reproduction of a grassland snake assemblage during 2002-2009 at Powdermill Nature Reserve in western Pennsylvania. Peak activity for the eight species captured under cover boards occurred in June. Most gravid females of this assemblage collectively were evident during May-July, spent females appeared as early as June, and no gravid females occurred after August. The activity patterns of this assemblage conformed to the stronger seasonal constraints typically associated with northerly populations. However, differences were evident among and within species when compared to other northerly populations. The temporally localized peak in activity of the ophidian segment of this grassland community must be considered when timing land management programs such as prescribed burning, disking, or mowing that are necessary to maintain the integrity of this vanishing habitat.

Smith C.J.,Kutztown University of Pennsylvania | Simpson E.L.,Kutztown University of Pennsylvania | Fillmore D.L.,Kutztown University of Pennsylvania | Lucas S.G.,New Mexico Museum of Natural History and Science | Szajna M.J.,State Museum of Pennsylvania
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2012

Continental communities represented by complex, rapidly evolving invertebrate ecosystems first appeared during the Early Palaeozoic Era and are recorded in surface and subsurface bioturbation. The Mississippian-age Mauch Chunk Formation contains several high-density bioturbated, fine-grained sandstones that are preserved as erosively based fluvial channel fills. Several of these channel sandstone bodies are almost completely homogenized by subsequent bioturbation throughout their entire thickness, up to a maximum depth of 1.6. m.The Mauch Chunk ichnofossil record demonstrates that high-density bioturbation occurred at least 30. my prior to the Permian and well before its widespread distribution in the Triassic. Hence, the Late Mississippian high-density bioturbated sandstones demonstrate a much earlier high-density exploitation of the continental subsurface ecospace than previously known. © 2012 Elsevier B.V.

Malenda H.F.,Kutztown University of Pennsylvania | Simpson E.L.,Kutztown University of Pennsylvania | Szajna M.J.,State Museum of Pennsylvania | Fillmore D.L.,Kutztown University of Pennsylvania | And 4 more authors.
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2012

Fish parts, bones and scale elements, preserved in sandstones and conglomerates characterize an uncommon type of lacustrine strandline setting identified in the Triassic Lockatong Formation of the Newark Supergroup. The Triassic fish-part sandstones and conglomerates are composed of disarticulated skeletal remains and formed during the lake expansion phase. Diverse mudstone-clast types derived from the underlying lowstand playa deposits integrated into the younger transgressive shoreline sequence that contains disarticulated fish parts. We propose that the Salton Sea, California, USA is a modern hypersaline lacustrine environmental analog for the deposition of fish remains. On the Salton Sea, high-wind events cause mass fish kills forming a modern shoreline dominated by barnacles and fish remains. Using modern day observations from fish kills in the Salton Sea, California, USA, we suggest that the following taphonomic scenario: mass kills of Triassic fish species took place during deposition of the lacustrine Lockatong Formation. High wind events caused overturning of the lake waters either depleting oxygen or toxically poisoning the fish. After death, bacterial decomposition bloated the fish by generated gas in tissues causing the fish carcasses to float. The decomposing fish carcasses were driven shoreward by wind and wave action and deposited on the shoreline and possibly scavenged by phytosaurs. Following soft tissue decay, the disarticulated remains were reworked into normally graded beds composed of intraclasts and fish-part elements. The intermixing of intraformational clasts and fish parts reflects the impact of storms on the lacustrine shoreline during the expansion phase of the Van Houten cycle, short period Milankovich frequency cycles that consist of three recorded phases of lake rise to fall recorded in various facies stackings. © 2011 Elsevier B.V.

Simpson E.L.,Kutztown University of Pennsylvania | Fillmore D.L.,Kutztown University of Pennsylvania | Szajna M.J.,State Museum of Pennsylvania | Bogner E.,Kutztown University of Pennsylvania | And 3 more authors.
Palaeobiodiversity and Palaeoenvironments | Year: 2015

Microbes within sediments often create films or thick mats that interact with mobile sediment, producing microbially induced sedimentary structures (MISS). Preserved microbes in these sedimentary features are difficult to find, especially in oxygen-rich environments. The study of recent discoveries in the Upper Triassic Norian Lockatong Formation, a dominantly lacustrine facies of the Newark Supergroup strata, has revealed rarely reported structures that are assignable as MISS, namely, sand-cored spheres encapsulated in thin mudstone which range in diameter from the sub-millimetre to millimetre scale. These spheres are embedded in a thin layer of very fine silt and mudstone developed in an interpreted marginal-lacustrine shoreline setting. The cores of the spheres consist of randomly oriented, graded, fine-grained sandstone to siltstone; this eliminates previously proposed physical and biological origins for spheres, leaving a microbial origin. The microbial bound sand balls are localised and generated from a graded bed bound by microbial mats both above and below. The bounded bed was eroded and shaped into spheres during transport. The mats added cohesion by providing extrapolymeric substances which prevented the breakdown of the spheres into individual grains. The mats were rolled into spheres during transportation, thus preserving the microbial bound core. These sand balls add to the catalog of microbial diversity that can be used to increase our understanding of biological systems in lacustrine settings. © 2015, Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg.

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