Journal article
A bite to the throat: A probable Xiphactinus attack on a Polycotylus from the Cretaceous Mooreville Chalk of Alabama, USA
Journal of vertebrate paleontology
03/12/2026
DOI: 10.1080/02724634.2026.2625732
Abstract
Fossil bite marks provide insights into trophic and agonistic behaviors, but they can be difficult to associate with a specific actor. Finding embedded teeth, while rare, removes this ambiguity. Here we describe a tooth embedded in a mid-cervical vertebra of a subadult plesiosaur, Polycotylus latipinnis, from the Santonian/Campanian Mooreville Chalk of Green County, Alabama, U.S.A. Exposed portions of the tooth are damaged, hindering identification, so internal visualization was accomplished via computed tomographic (CT) scanning. Sectioning revealed a conical, unornamented, slightly curved tooth with a large pulp cavity. These features are inconsistent with the marine reptiles and sharks present in the Mooreville Chalk. However, they are consistent with a large, osteichthyan fish, of which only the enormous, co-occurring ichthyodectid Xiphactinus had sufficiently large gape and dentition. Preservation of the Polycotylus suggests a short residence time near the surface, before sinking into anoxic waters, limiting the window during which extensive scavenging and decomposition could have occurred. The location and depth of the bite could certainly have been fatal, severing the carotid sheath and disrupting the trachea, causing a loss of lung pressure and associated buoyancy, highlighting the vulnerability of elongate necks to predatory attack. This find joins the surprising diversity of bite marks and gut contents known from the Mooreville and contemporaneous Smoky Hill Chalks. These lines of evidence reveal a complex, dynamic trophic structure in North America's Late Cretaceous coastal waters, with large marine reptiles and osteichthyan fish vying for position at the top of the food chain.
Details
- Title: Subtitle
- A bite to the throat: A probable Xiphactinus attack on a Polycotylus from the Cretaceous Mooreville Chalk of Alabama, USA
- Creators
- Stephanie K. Drumheller - University of Tennessee at KnoxvilleF. Robin O'Keefe - Marshall UniversityMiles L. Mayhall - University of Tennessee at KnoxvilleEmma Stalker - University of Tennessee at KnoxvilleChristopher A. Brochu - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Journal of vertebrate paleontology
- DOI
- 10.1080/02724634.2026.2625732
- ISSN
- 0272-4634
- eISSN
- 1937-2809
- Publisher
- Taylor & Francis
- Number of pages
- 7
- Grant note
- University of Tennessee Division of Student Success IUSE-GEOPATHS-IMPACT 1600376 / National Science Foundation; National Science Foundation (NSF)
- Language
- English
- Electronic publication date
- 03/12/2026
- Academic Unit
- School of Earth, Environment, and Sustainability; University College Courses
- Record Identifier
- 9985147181202771
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