Ichnology of a Late Triassic lake margin: the Lockatong Formation, Newark Basin, Pennsylvania by D.L. Fillmore, M.J. Szajna, S.G. Lucas, B.W. Hartline and E.L. Simpson. New Mexico Museum of Natural History & Science Bulletin, 76: 1-107. 2017
This 107-page volume presents complete documentation (including numerous photographs) of one of the most extensive inverterbrate ichnoassemblages known from the Newark Supergroup. If you are interested in ordering Bulletin 76, it costs $20 and you can contact Holly Lowe, Store Manager for the NMMNH&S, at firstname.lastname@example.org to place orders.
Abstract—The Late Triassic Lockatong Formation exposed in the Newark Basin of eastern Pennsylyania yielded a spectacularly diverse and abundant nonmarine ichnofossil assemblage, formed in a lacustrine-margin setting. The specimens described in this report, numbering more than 200, now conserved by the State Museum of Pennsylvania Invertebrate and Vertebrate Paleontology Collections, were recovered from a single construction site located approximately 8 km northeast of Souderton, Pennsylvania, referred to herein as the Silverdale Development Discovery Site (SDDS). The ichnofossils are from the Tumble Falls Member near the top of the Lockatong Formation. Eighteen invertebrate ichnogenera are described and illustrated together with three vertebrate footprint ichnotaxa (the vertebrate ichnofossils are described more fully in separate reports), and five Undichna ichnospecies. The invertebrate trace fossils are dominated by arthropod trackways that include Acanthichnus, Bifurculpes, Cruziana, Diplichnites, Diplopodichnus, Kouphichnium, and Lithographus; arthropod resting traces, Rusophycus; invertebrate feeding traces, Selenichnites and Treptichnus; grazing trails, Cochlichnus; relatively larger burrows, Scoyenia; as well as six somewhat similar burrows-trails, Gordia, Haplotichnus, Helminthoidichnites, Helminthopsis, Planolites, and Sphaerapus. The vertebrate trace fossils described are assigned to Atreipus, Gwyneddichnium, Rhynchosauroides, and five Ichnospecies of Undichna. Additionally, a new ichnospecies, Diplichnites metzi, is identified and described. Enigmatic sedimentary structures, including unique sandy spheres of algal origin, and round, stellate-shaped structures, are present. Invertebrate trace fossils of this collection best fit the Mermia Ichnofacies, and, to a lesser degree, the Scoyenia ichnofacies. Vertebrate trackways of this collection fall Into the Grallator Ichnofacies. The large collection of well-preserved Invertebrate and vertebrate specimens, with a few sedimentary features, all Illustrate the Incredible biological diversity present along the Newark Basin lake shorelines of the Late Triassic.