219 Paleontology, Diversity, Extinction, Origination (Posters)
Tuesday, 21 October 2025
8:00 AM - 5:30 PM
HBGCC, Hall 1
New Early Ordovician (Floian) trilobites from the Eleanor River Formation, Ellesmere and Devon Islands, Arctic Canada
Paper number: 219-3
Program: Technical Sessions
Time: 8:45 AM – 9:00 AM
Authors
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Joshua Laird Presenting AuthorUniversity of Iowa, 115 Trowbridge Hall, Iowa City, IA 52242, Iowa City, IA
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Jonathan AdrainUniversity of Iowa, 115 Trowbridge Hall, Iowa City, IA 52242, Iowa City, IA
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Stephen WestropUniversity of Oklahoma, Norman, OK, 73072, Norman, OK
Abstract
Early Ordovician (Floian) trilobite faunas from the Eleanor River Formation on the Bache Peninsula (localities at Sanddöla Creek and Bartlett Bay), Ellesmere Island, and Dundas Harbour, Devon Island, Arctic Canada, have been mentioned in stratigraphic work but never illustrated or studied. Fossils were recovered via surface collection of thin bedded dolomitic limestones, deposited in an inferred shallow subtidal environment. Most of the material is disarticulated, but some partially articulated specimens are present. Calcareous preservation is generally good, though there are varying degrees of surface abrasion and compaction. Thirteen species are present, of which only Ischyrotoma anataphra Fortey, 1979, has previously been described. The faunas include single species of Isoteloides (Asaphidae), Bathyurellus (Bathyuridae), Catochia (Bathyuridae), Petigurus (Bathyuridae), an indeterminate cheirurid, and a new genus of Dimeropygidae. Two species each of Bathyurina (Bathyuridae), Cullisonia (Bathyuridae), and the problematic Strotactinus (Pliomeridae) are present. The type species of Strotactinus was based on a unique holotype which has been lost, and the name should be restricted to this species. A new name will be proposed for the species group. The fauna is characteristic of the shallow water bathyurid biofacies typical of the Laurentian Early Ordovician. It has similar species diversity to other shallow-water Floian assemblages from the eastern to southern margin of (Ordovician) Laurentia and associated terranes, including those from the Catoche Formation of western Newfoundland, the Wandel Valley Formation in Northeast Greenland National Park, the Kirtonryggen Formation of the East Svalbard Terrane, and the Nunatami Formation of Avannaata, northwest Greenland.
Geological Society of America Abstracts with Programs. Vol. 57, No. 6
doi: 10.1130/abs/2025AM-414008
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