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Article
Taphonomy and taxonomy of a vertebrate microsite in the mid-Cretaceous (Albian–Cenomanian) Blackleaf Formation, southwest Montana
Historical Biology (2011)
  • Paul V. Ullmann, Rowan University
  • David Varricchio, Montana State University
  • Michael J. Knell, Montana State University
Abstract
The vertebrate fauna of the Cretaceous Blackleaf Formation of southwest Montana remains largely undocumented. A microsite (BL1) discovered in the Flood Member in the Lima Peaks area, Montana, consists of a green siltstone and yields taxa previously unreported from the formation, including several dinosaurs: a hypsilophodont, dromaeosaurid, tyrannosauroid, hadrosaurid and an ankylosaurian. Non-dinosaurian taxa include goniopholidid and Bernissartia crocodilians; Glyptops, cf. chelydrid and other turtles and at least two neopterygiian fish. This diversity corresponds well with the fluvial–deltaic–estuarine environment interpreted for the uppermost unit of the Flood Member. Taphonomic data and sedimentologic relationships suggest that this assemblage represents a floodplain depression accumulation. Comparisons with contemporaneous faunas from around the Western Interior of the USA suggest a remarkably consistent faunal makeup, at least at the family level, existed across western North America in the mid-Cretaceous.
Keywords
  • Cretaceous,
  • Blackleaf Formation,
  • chelydrid,
  • taphonomy,
  • dinosaur,
  • microsite
Disciplines
Publication Date
July 21, 2011
DOI
10.1080/08912963.2011.602405
Citation Information
Paul V. Ullmann, David Varricchio and Michael J. Knell. "Taphonomy and taxonomy of a vertebrate microsite in the mid-Cretaceous (Albian–Cenomanian) Blackleaf Formation, southwest Montana" Historical Biology Vol. 24 Iss. 3 (2011) p. 311 - 328
Available at: http://works.bepress.com/paul-ullmann/7/