On the occurrence of fossil conifers with affinities to Geinitzia in the late Cretaceous (Campanian) Mesaverde Group, Williams Fork Formation of northeastern Utah, U.S.A.
- Published
- Accepted
- Subject Areas
- Paleontology, Plant Science
- Keywords
- Araucariaceae, Cupressaceae, Mesozoic, North America
- Copyright
- © 2016 Burger et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2016. On the occurrence of fossil conifers with affinities to Geinitzia in the late Cretaceous (Campanian) Mesaverde Group, Williams Fork Formation of northeastern Utah, U.S.A. PeerJ Preprints 4:e1862v1 https://doi.org/10.7287/peerj.preprints.1862v1
Abstract
In this paper we describe fossil conifer branches discovered in the Mesaverde Group, Williams Fork Formation in northeastern Utah, along Snake John Reef. Fossil conifers from the Campanian of northeastern Utah have not been previously studied, despite their common occurrence in the formation. The recovered fossils closely resemble Geinitzia known from the late Cretaceous of Europe, with several previous reported occurrences in North America, including New Jersey and Southern Utah. The fossils share morphological characteristics with Geinitzia, exhibiting short spirally arranged thin needles, with appressed scale-like leaves along the shoots. They differ from Araucarites in that the appressed needles are more scale like and smaller, and differ from the members of the modern Araucariaceae in lacking broad bases to the needles, although the fossils resemble the modern species Araucaria heterophylla (Norfolk Island Pine) native to the South Pacific. The observed branching pattern in the fossil reflects similarities found in the Cupressaceae Family, and Geinitzia may be regarded as an early member of this group, or having an affinity to fossil Araucariaceae conifers, which despite having a modern southern hemisphere geographic distribution today were widespread during the late Mesozoic, extending across North America and Europe.
Author Comment
Neither author is an expert in fossil conifers, yet we felt that the documentation of fossil conifers in the late Cretaceous of northeastern Utah was warranted, given how little has been published on the fossil plant record of late Cretaceous rocks in northeastern Utah. We gladly solicit comments on these fossil conifer specimens from Utah.
Supplemental Information
Slab containing fossils with affinity to Geinitzia from the late Cretaceous Williams Fork Formation of Utah
Slab containing fossils with affinity to Geinitzia from the late Cretaceous Williams Fork Formation of Utah. A. Over view of slab containing fossils. B. Close up view of the terminal branch. C. Close up view of terminal branch from isolated branch on same slab. D. Close up view of terminal branch on same slab, showing leaf scars. E. Close up view of terminal branch.
