A new Early Jurassic (ca. 183 Ma) fossil Lagerstätte from Ya Ha Tinda, Alberta, Canada
Rowan C. Martindale1,2, Theodore R. Them II3,4, Benjamin C. Gill3, Selva M. Marroquín1,3 and Andrew H. Knoll2
- Author Affiliations
1Department of Geological Sciences, The University of Texas at Austin, 1 University Station C1100, Austin, Texas 78712, USA
2Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, Massachusetts 02138, USA
3Department of Geosciences, Virginia Polytechnic Institute and State University, 4044 Derring Hall (0420), Blacksburg, Virginia 24061, USA
4Department of Earth, Ocean and Atmospheric Science & National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
Figure 3. Exceptionally preserved fossils of Ya Ha Tinda Lagerstätte (Alberta, Canada; specimen numbers are provided in Data Repository [see footnote 1]). RDM—Red Deer Member; PCS—Poker Chip Shale Member.
A: Articulated ichthyosaur vertebrae and ribs (RDM, late Pliensbachian).
A: Articulated ichthyosaur vertebrae and ribs (RDM, late Pliensbachian).
B: Skull of small teleost fish (PCS, within Toarcian Oceanic Anoxic Event [T-OAE] carbon isotope excursion [CIE]); note preservation of gills (arrow). C: Seirocrinus subangularis (crinoid) calyx collected by Russell Hall (RDM, late Pliensbachian). D: Vampyropod gladius with mantle muscle (white arrow) and ink sac (black arrow) (RDM, early Toarcian). E: Loligosepiid vampyropod gladius with ink sac (arrow) (RDM, early Toarcian). F: Shrimp body fossil (PCS, within T-OAE CIE). G: Complete body fossil of Uncina pacifica lobster, proximodistally flattened (RDM, late Pliensbachian). H: Complete body fossil of eryonid lobster, dorsoventrally flattened, ventral view (RDM, late Pliensbachian).
Abstract
Lagerstätten—deposits of exceptionally preserved fossils—offer vital insights into evolutionary history. To date, only three Konservat-Lagerstätten are known from Early Jurassic marine rocks (Osteno, Posidonia Shale, and Strawberry Bank), all located in Europe. We report a new assemblage of exceptionally preserved fossils from Alberta, Canada, the first marine Konservat-Lagerstätte described from the Jurassic of North America. The Ya Ha Tinda assemblage includes articulated vertebrates (fish, ichthyosaurs), crinoids, crustaceans, brachiopods, abundant mollusks (coleoids with soft tissues, ammonites, gastropods, bivalves), wood, and microfossils. Paired bioand chemostratigraphies show that Lagerstätte deposition occurred during the late Pliensbachian through early Toarcian, capturing the carbon isotope excursion associated with the Toarcian Oceanic Anoxic Event. Therefore, the Panthalassan Ya Ha Tinda biota is coeval with Toarcian Lagerstätten from the Tethys Ocean (Posidonia Shale and Strawberry Bank). Comparisons among these deposits permit new insights into the diversity, ecology, and biogeography of Jurassic marine communities during a time of pronounced biological and environmental change (e.g., expanded subsurface anoxia, warming, and extinctions). They also highlight the possibility that Mesozoic Oceanic Anoxic Events are temporal foci of exceptional preservation.
Received 16 June 2016. Revision received 26 November 2016. Accepted 29 November 2016.
©The Authors
Gold Open Access: This paper is published under the terms of the CC-BY license.
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