Our Upcoming Speakers
Note: During the COVID-19 Pandemic our meetings are being held using the Zoom web app. Invitations will be sent to members and visitors on request by email
MONDAY, September 14, 2020 AT 7:00 PM Central Time USA
Matt Stimson: "Filling in “Romer’s Gap”. A stroll through time from 350 to 300 million years ago and the roll New Brunswick played in the evolution of vertebrate life on land
Olivia King: "Horseshoe crabs, synxiphosurans and sea scorpions OH MY. An ichnotaxonomic review of Kouphichnium aspodon and what it can tell us about other Carboniferous sites worldwide"
St. Mary's University, Halifax, Nova Scotia
Tetrapods (or 4 limbed vertebrates) made their first steps on land on the shores of North America during the Middle Devonian Period about 385 million years ago (ma). It would take these large crocodile-sized, salamander-like amphibians another 60 million years to establish themselves as fully terrestrial colonists as small lizard-like reptiles (amniotes) in the Pennsylvanian Period (325-315 ma). These early reptiles would set the stage for the radiation of all terrestrial vertebrate life to follow, but the exact timing and location during the Mississippian Period (360-325 ma) for this transition and diversification of early vertebrates into continental environments is not well known. This is due to a paucity of rocks exposed at the Earth’s surface that were deposited in ancient continental environments resulting in a lack of fossils available for study. We call this hiatus in the fossil record “Romer’s Gap”.
Atlantic Canada has long been known to contain one of the most complete fossil footprints records from the Carboniferous Period. Footprints can suggest the presence of animal life, even if the bones are not fossilized. New fossil discoveries (footprints, plants, invertebrates, bones of amphibians and fish) preserved in rocks that represent lake and forested wetland environments found near Norton NB are added to discoveries in Nova Scotia and Scotland to fill in this evolutionary gap. In this talk we will explore these fossils to better understand the biodiversity of life on land during one of the least understood intervals in the fossil record and track the evolution of early tetrapods through time examining what fossil footprints can tell us about North America’s oldest terrestrial vertebrate inhabitants. We will examine new fossil discoveries from various ancient environments during the seemingly barren Romer’s Gap, and interpret their footprints through time to the earliest reptiles, winged insects and the lush tropical wetland ecosystems of the younger Pennsylvanian Period (300 ma).
Currently the Assistant Curator of Geology and Paleontology at the New Brunswick Museum, Matt Stimson is pursuing his PhD in vertebrate and invertebrate ichnology of the Carboniferous. His PhD thesis encompasses the whole of Carboniferous of New Brunswick ichnology specializing in an important time interval called Romer’s Gap. These rocks and the fossils they contain are from a time when amphibians made the transition from water to land marking an important moment in the story of animal evolution. While his academic interest in ichnology started in his youth, he published in his undergraduate at Saint Mary’s University on the world’s smallest footprints from Joggins, which is the most read article in the international journal on trackways, Ichnos. Having discovered little literature on New Brunswick trace fossils, he took what he learned and started walking the beaches across New Brunswick. His discoveries and knowledge of NB Paleontology has made him an integral part of the international community of trace fossil scientists, with collogues and collaborators from the USA, Italy, Germany, and Mexico, just to name a few. He has been a part-time instructor at Saint Mary’s, has 15 publications, with over 30 conference abstracts, many of them award winning talks. Matt has achieved what most academics strive to have by the end of their career by the time he has started his PhD. Matt’s research in NB is in collaboration with Olivia King, Research Associate at the NBM, while also collaborating with other researchers internationally on many topics that include: fossil plants, skeletal remains of early amphibians, fossilized insect wings, and land snails (to name a few). – Written by Olivia King
Olivia King, is a Master’s student in Applied Science specializing in paleontology/ palynology at Saint Mary’s University in Halifax, Nova Scotia, Canada. Olivia’s research focus for her Master’s Thesis is on Mississippian-aged rocks in New Brunswick from 350 Million years ago known as Romer’s Gap in the Carboniferous Period. Her graduate work will refine the geological age of the Albert Formation in Norton NB by using fossil spores and pollen trapped in the rocks. These rocks and the fossils they contain are from a time when amphibians made the transition from water to land marking an important moment in the story of animal evolution. Olivia’s research in collaboration with Assistant Curator of Geology Matt Stimson, and other researchers internationally, also includes fossil footprints of amphibian, reptiles and invertebrates, feeding traces of giant sea scorpions, fossil plants, and early amphibian skeletons.
Olivia has been working at the New Brunswick Museum for 5 summers as the Geological Research Assistant and has been volunteering on various research related events during the school year that have led to a number of important fossil discoveries in NB and Nova Scotia. Her collaborative work in Devonian to Permian-aged rocks of Atlantic Canada and Alabama has covered a range of paleontology fields from from Ichnology, Paleobotany, ,palynology, to vertebrate paleontology. She has coauthored 3 papers, including the results presented here, numerous scientific presentations at the Atlantic Geoscience Society, media articles. Olivia was awarded the George Frederick Matthew Fellowship in 2017-2018 and her work has earned her the title of Research Associate at the New Brunswick Museum where she continues to conduct much of her research from.
Prior to her graduate studies, Olivia was an undergraduate student in the Department of Earth Sciences at Dalhousie University in Halifax. It was there that she completed a Directed Study paper re-evaluating the Ichnotaxonomy of Kouphichnium and Xiphosuran traces from the Union Chapel Mines in Alabama. This paper was co-authored with Matt Stimson and Dr. Spencer Lucas in the Peer reviewed journal Ichnos. She continues to work on invertebrate ichnological papers applying what she’s learned to similar aged strata at Joggins Nova Scotia and to Carboniferous rocks in New Brunswick.
Since its discovery, the Steven C. Minkin Fossil site at the Union Chapel Mine (UCM) in Walker County, Alabama, USA, has become one of the most productive continental ichnofossil sites from the Pennsylvanian Period. This exceptional trace-fossil Lagerstätte was preserved in a Pennsylvanian-aged, tidally influenced estuary known as the Pottsville Formation. This estuary was periodically inundated by normal marine conditions represented by limestones containing body fossils of punctate brachiopods and other saltwater organisms. Best known for its vertebrate trackways, the invertebrate trace fossil record at UCM is also extensive with the horseshoe crab ichnotaxa Kouphichnium aspodon being one of the more commonly identified ichnospecies. The ichnogenus Kouphichnium and many associated ichnotaxa have been attributed to xiphosuran (horseshoe crab) activity at this and many other sites worldwide and throughout the fossil record.
The ichnospecies K. aspodon was re-examined in a recently published paper, and has been better defined from the numerous samples collected from the UCM. New species (K. minkinensis and K. atkinsoni) have been identified and have been suggested to have been made by sea scorpions rather than the classic interpretation of Kouphichnium as made by horseshoe crabs. Additionally, many invertebrate tracks previously assigned to Kouphichnium have now reinterpreted and do not belong to the Kouphichnium and were made by insects.
The large sample size offers a unique opportunity to study the variation in some Kouphichnium ichnospecies from Pennsylvanian-age strata with broader implications for other localities where Kouphichnium are common, like Joggins, Nova Scotia. Although comparable in age, Joggins and UCM have very different fossil assemblages and depositional settings. What we have learned from UCM can be applied more broadly to use this trace fossil to help identify salt water influence at places like Joggins. These two sites will be compared to help us understand the broader ecologies and habitats of these living fossils.
MONDAY, September 14, 2020 AT 7:00 PM CDT USA
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