Trackways representing the earliest evidence for the origin of reptiles (amniotes) are reported from the basal Pennsylvanian Grande Anse Formation, New Brunswick, Canada. Amniote characters include pentadactyl manus and pes, slender digits whose relative lengths approximate a phalangeal formula of 23453 (manus) and 23454 (pes), narrow digit splay (40–63°), putative transverse scale impressions on digit pads, and straight tail drag. The trackways occur in the deposits of a seasonally active dryland river channel. Sedimentological context suggests, for the first time, that early amniotes existed in water-stressed environments, where the cleidoic egg would have presumably conferred reproductive advantage.
A large open-pit quarry in Plainville, Massachusetts, has yielded fourteen invertebrate ichnotaxa from the Pennsylvanian Rhode Island Formation of the Narragansett Basin. These traces include Cochlichnus anguineus, Diplichnites cuithensis, Diplichnites gouldi, Diplopodichnus biformis, Gordia carickensis, Helminthoidichites tenuis, Lockeia isp., Mitchellichnus cf. ferrydenensis, Planolites montanus, Siskemia elegans, Stiallia pilosa, Stiaria intermedia, Tonganoxichnus buildexensis and Narragansettichnus fortunatus new ichnogenus and ichnospecies. Specimens were collected from talus and the depositional environment has been inferred from sedimentary structures. The sediment-ology of the slabs on which the traces were preserved indicates that the rocks represent lake-margin and shallowlacustrine sedimentary facies. Distinct ichnofacies occur in the different sedimentary environments. The lake-margin traces belong to the Scoyenia ichnofacies and include traces of apterygote insects, arthropleurid myriapods, bivalved arthropods and vermiform animals in association with tracks of temnospondyl amphibians and diapsid reptiles. The lacustrine traces include arthropod trackways, fish trails and a newly named body imprint possibly produced by an aquatic mayfly larva. These shallow lacustrine traces are attributed to the Mermia ichnofacies.
This is the first detailed study of the coastal exposure of the Springhill Mines Formation within the Joggins Fossil Cliffs World Heritage Site. A 16.9-m-thick interval of dark laminated mudrocks and sharpbased sandstones at the base of our section is reassigned to the top of the Joggins Formation. This interval records a rapid, presumably widespread flooding event and the temporary establishment of a marginalmarine to brackish bay. The overlying 697 m of strata represent deposition in poorly drained and well-drained environments, and are assigned to the Springhill Mines Formation. Strata reflecting poorly drained environments contain green and grey mudrocks, thin coals, sheet sandstones, and channel bodies interpreted to have been deposited in coastal swamps and low-lying parts of a floodplain. Intervals reflecting well-drained conditions contain reddish brown mudrocks, sheet sandstones, and channel bodies interpreted to have been deposited on a vegetated floodplain that was periodically exposed to oxidizing conditions. Strata reflecting poorly drained conditions are thick and abundant in the lower half of the formation and well-drained intervals become thick and more abundant in the upper half. The shift in facies abundance is accompanied by an interpreted evolution in fluvial style from predominantly anastomosed channels (below 376 m) to sheet-like channel bodies (376-449 m) and ultimately to predominantly meandering-channel bodies (449-697 m). The formation-scale changes in drainage conditions and fluvial style records decreased halokinetic subsidence and aggradation of the alluvial surface as sediments shed from the Caledonia Highlands prograded into this part of the basin. rÉSUMÉ Il s'agit de la première étude détaillée sur l' exposition du littoral de la formation de Springhill Mines au sein du site du patrimoine mondial des falaises fossilifères de Joggins. Un intervalle de 16,9 m d' épaisseur de pélites feuilletées foncées et de grès à base nette situé au bas de la section a été rattaché au sommet de la formation de Joggins. Cet intervalle est le résultat d'une inondation rapide et probablement de grande envergure ainsi que de la formation temporaire d'un marginal marin dans une baie saumâtre. La couche sous jacente de 697 m de strate représente un dépôt dans des milieux mal drainés et bien drainés. Ces milieux se trouvent dans la formation de
The ichnogenus Kouphichnium and associated ichnofossils attributed to xiphosuran activity are here reexamined from samples collected from the Pennsylvanian-age Steven C. Minkin Fossil Site at the Union Chapel Mine, in Walker County, Alabama, USA. The large sample size offers an unique opportunity to evaluate some Kouphichnium ichnospecies. Thus, the morphological variability resulting from the taphonomic, ethological, taxonomic variability and underprint fallout are evaluated using this large sample set. Three morphotypes have been segregated from the material previously assigned to K. aspodon discovered at this and adjacent sites. Ichnospecies of Kouphichnium identified at the Union Chapel Mine site include: K. lithographicum, K. aspodon and two new ichnospecies (K. atkinsoni and K. minkinensis). Additionally, Kouphichnium-like traces that are associated with "jumper" traces have been previously misinterpreted as Kouphichnium and Selenichnites, respectively, and are excluded from this study, leaving them in open nomenclature as they will be the subject of a subsequent publication. We here redescribe the holotype of K. aspodon and designate lectoparatypes to better define the ichnospecies. New trace makers for some Kouphichnium ichnospecies are hypothesized, in contrast to the traditional xiphosuran attribution.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.