Search

For many years, the fossil record of the latest Carboniferous to early Permian redbeds of Prince Edward Island (PEI) was considered to be sparse and inconsequential. Its most famous famous fossil Bathygnathus borealis, the first Dimetrodon discovery in 1845, was considered an anomaly. This perception changed with the publication describing the exceptional parareptile Erpytonyx arsenaultorum discovered in 1995. The footprint record of tetrapods was unknown prior to the 1980s, when trackways were reported from Point Prim and Malpeque. Since that time discoveries of tetrapod footprints have grown at an increasing rate and at increasing number of localities. The discovery in September 2022 of a yet undescribed articulated tetrapod skeleton near the Erpetonyx site caused an unexpected media stir that brought the fossil record of the Island into many people's homes. Subsequently in September 2022 the wrath of Hurricane Fiona was felt most profoundly on the north shore of PEI; large tetrapod trackway-bearing sandstone blocks in the National Park were completely removed in that event, while resulting erosion brought to light many new sites, across the north shore in particular. The footprint record represents a diverse record of vertebrates, favouring reptilian taxa from the diminutive Hyloidichnus sp. to Dimetropus sp., one of the largest early Permian reptilian taxa. The fossil record of tetrapods and their trackways now places PEI firmly in the league of the southwestern USA and Germany as important biodiverse paleoequatorial vertebrate sites of the early Permian. [ABSTRACT FROM AUTHOR]

A new specimen of Batrachichnus salamandroides was recovered from a recently discovered fossil-bearing site situated along the southern shore of Grand Lake, New Brunswick, among a diverse ichnofaunal assemblage from the Middle Pennsylvanian (upper Bolsovian; lower Moscovian), upper Minto Formation. The identity of the tracemaker of this ichnogenus is reinterpreted as a composite of various late Paleozoic tetrapod taxa, based on similarities of the postcranial skeletons, notably that of the manus and pes, of both temnospondyls and some “microsaurs”. These results indicate that the tracemaker of the monospecific ichnogenus Batrachnichus is not limited solely to a temnospondyl tracemaker, as previously interpreted, and that some “microsaurs” should also be considered among tracemaker candidates for this ichnotaxon. [ABSTRACT FROM AUTHOR]

The Early Mississippian (known as 'Romer's Gap') marks the beginning of a critical point in tetrapod history as they transitioned from dominantly aquatic to more terrestrial ecosystems. This paleoecological expansion set the stage for the radiation of all terrestrial tetrapod crown groups. The exact timing for the transition into freshwater continental environments is poorly understood. However, new discoveries in Scotland, England, and Nova Scotia, represent rare exceptions; offering a glimpse into coastal terrestrial ecologies during 'Romer's Gap'. These sites have evidence for a marine-water connection suggesting a coastal paleogeographic position. In contrast, Early Mississippian sedimentary deposits of the Moncton Subbasin in southern New Brunswick (NB) are interpreted as freshwater intra-continental conditions (lacustrine, wetland, fluvial, alluvial settings). A single stratigraphic horizon in the Albert Formation (Hiram Brook Member), exposed near Norton, NB, has yielded abundant tetrapod footprints. Preliminary assessments suggest at least four trackway ichnogenera: cf. Characichnos, cf.Matthewichnus, cf.Hylopus, and cf.Batrachichnus and a fifth trackway that may represent a new ichnogenus. Footprints range in size from 1 to 3 cm, suggesting that tetrapods were smaller than those documented from near time-equivalent sites in Nova Scotia, but are comparable in size to skeletal fossils described from younger strata in Scotland. These footprints are interpreted to be preserved in interfluvial crevasse splays associated with wetland forests dominated by Lepidodendropsis lycopods and Aneimites ferns preserved in their ecological context. The relatively large sample size of footprints suggests that a community of tetrapods were present and part of a diverse ecosystem, adapted to terrestrial and semi-aquatic continental environments in the earliest Mississippian. Additional trackways from slightly younger redbed playa lake deposits in the Sussex Group suggest tetrapods were also venturing into semi-arid continental environments. The ichnofossil assemblage from NB demonstrates considerable variation in ichnotaxa morphology and paleoenvironmental context from sites of approximately equivalent age. [ABSTRACT FROM AUTHOR]

The Carboniferous Joggins Fossil Cliffs UNESCO World Heritage Site, located in Nova Scotia, has long been known for its extensive paleobiodiversity. The ichnofossil record at Joggins is less known compared to body fossils. The late citizen scientist Donald Reid (known as "The Keeper of the Cliffs") contributed significantly to our understanding of the fossil record at Joggins. In his extensive ichnological collections is a morphologically unique "shrimp shaped" cubichnia (resting trace). The trace fossil is associated with faint invertebrate trackways that lead up to the resting trace and verifies the identification of this specimen as an invertebrate resting trace. The trace fossil was recovered from the upper Joggins Formation (876 m above the base) and was found in fine-grained rippled sandstones that are interpreted to be from an Open-Water to Poorly-Drained Lithofacies Assemblage transition. Horseshoe crab walking traces (Kouphichnium) are well known from this trace fossil horizon. The trace fossil specimen also has examples of invertebrate resting traces Selenichnites and Rusophycus preserved in convex hyporelief, that are commonly ascribed to horseshoe crabs and crustaceans, respectively, when found in freshwater paleoenvironments. This stratigraphic interval has previously yielded body fossils of Pygocephalus shrimp preserved in organic rich limestones and sideritic ironstone nodules. The Joggins Cliffs have yielded an abundance of trace fossils ascribed to horseshoe crabs, yet only two of their body fossils. Pygocephalus shrimp body fossils are common at Joggins, yet no trace fossils have yet been assigned to this invertebrate and perhaps have gone unrecognized. We interpret the trace fossil to have been produced by a Pygocephalus shrimp based on its morphological similarities to known body fossils from the Joggins Formation that are found in proximity to the trace fossil horizon. This new trace fossil morphology likely warrants a new ichnotaxon. [ABSTRACT FROM AUTHOR]

The 1125-m-thick type section of the Pennsylvanian Boss Point Formation is well exposed along the shore of the Bay of Fundy in Nova Scotia. We provide the first comprehensive account of the entirety of this formation, which comprises nearly one-third of the stratigraphic thickness of the Joggins Fossil Cliffs UNESCO World Heritage Site. The basal Chignecto Bay Member (0-91.5 m) is composed of redbeds, single-storey channel bodies with northerly paleoflow, and thin palustrine limestones. The middle Ward Point Member (91.5-951.7 m) contains up to 16 megacycles composed of alternations between thick packages of braided fluvial sandstone and fine-grained deposits. Although regional studies of the Boss Point Formation suggest that the fine-grained deposits are largely composed of lacustrine sediments, these intervals consist largely of poorly drained and well-drained floodplain deposits in the type section. The facies variations and southeast-directed paleoflow in the Ward Point Member record modest uplift associated with the growth of the salt-cored Minudie Anticline. The North Reef Member (951.7-1125 m) is composed of redbeds and two distinctive multistorey channel bodies. This uppermost member records a shift to more arid, oxidizing conditions, was the precursor to a major phase of salt withdrawal, and represents a transition to the overlying Little River Formation. The sedimentological framework, revised stratigraphy, and detailed measured section and map will provide a foundation for future study of this remarkable Pennsylvanian exposure. [ABSTRACT FROM AUTHOR]

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 sharp-based 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 marginal-marine 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. [ABSTRACT FROM AUTHOR]