Times are displayed in (UTC-06:00) Mountain Time (US & Canada) Change

292-6 Life in Cold Seeps during the Cretaceous: Seeps as Hotspots for Crustaceans and other Fauna in the Western Interior Seaway and Alaska

Session: New Advances in Mesozoic Paleontology, Stratigraphy, and Paleogeography of the Western Interior of North America (Part I)

Presenting Author:

Adiël Klompmaker

Authors:

Klompmaker, Adiël A.¹, Brezina, Jamie², Nyborg, Torrey ³, Landman, Neil H.⁴, Kiel, Steffen⁵, Robins, Cristina M. ⁶, Bowman, Andrew R.⁷, Wooller, Matthew J.⁸, Druckenmiller, Patrick S.⁹r> (1) The University of Alabama Museums Research & Collections, The University of Alabama, Tuscaloosa, Alabama, USA, (2) South Dakota School of Mines and Technology, Rapid City, South Dakota, USA, (3) Department of Earth and Biological Sciences, Loma Linda University, Loma Linda, California, USA, (4) American Museum of Natural History, New York, New York, , (5) Department of Palaeobiology, Swedish Museum of Natural History, Stockholm, Sweden, (6) Department of Geological Sciences, The University of Alabama, Tuscaloosa, Alabama, USA; The University of Alabama Museums Research & Collections, The University of Alabama, Tuscaloosa, Alabama, USA, (7) Geological Survey of Alabama, Tuscaloosa, Alabama, USA; The University of Alabama Museums Research & Collections, The University of Alabama, Tuscaloosa, Alabama, USA, (8) Alaska Stable Isotope Facility & College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, Alaska, USA, (9) University of Alaska Museum & Department of Geosciences, University of Alaska Fairbanks, Fairbanks, Alaska, USA,

Abstract:

Research over the last decades has demonstrated that methane (cold) seeps were much more common than previously recognized. Fossils within seep limestones indicate that seeps were inhabited by a variety of organisms, including facultative and obligatory inhabitants, often at higher abundance and diversity than in surrounding rocks. We focus on Cretaceous (Campanian) seeps from the Western Interior Seaway and Alaska, as shown by a combination of biogenic limestone structure reminiscent of seep limestones, low stable carbon isotopes values, and faunal components common at seeps. A survey of museum collections and field work have yielded rich assemblages. In the Pierre Shale of South Dakota and Wyoming, mollusks (bivalves, gastropods, cephalopods) tend to dominate seeps; other macrofossils include echinoderms, worms, sponges, corals, brachiopods, algae, bryozoans, vertebrates, and crustaceans. Trace fossils in bivalves demonstrate the presence of octopods. The decapod assemblage consists of Brachyura and Axiidea of at least seven species, all facultative inhabitants known from outside the seeps too. While preservation is usually mediocre, one remarkable crab shows mineralized soft tissues. Several lines of evidence showcase predation provisionally attributed to crustaceans. Unlike for South Dakota, seeps from Alaska are poorly known. A newly recognized seep from Alaska has yielded bivalves including chemosymbiotic lucinids, gastropods, worms, and decapods. Though mollusks dominate, the sole anomuran decapod species is abundant and is thought to be a stem-lineage taxon for a family living exclusively in seeps and hydrothermal vents today. Jointly, we suggest that seeps were an integral component of Campanian marine ecosystems in North America.

Life in Cold Seeps during the Cretaceous: Seeps as Hotspots for Crustaceans and other Fauna in the Western Interior Seaway and Alaska

Description

Session Format: Oral

Presentation Date: 10/14/2026

Presentation Start Time: 09:15 AM

Presentation Room: CCC, Bluebird Ballroom 3A

Back to Session