Abstract Detail

Campanian-Maastrichtian floras on Laramidia: vegetation trends west of the seaway

Jud, Nathan A [1], D’Emic, M. D. [2], Williams, S. A. [3], Mathews, J. C. [4], Tremaine, K. M. [5], Bhattacharya, J. [6].

Fossil woods and the evolution of angiosperm body size.

Flowering plants occupy the full range of sizes evolved by land plants, from minute herbs to enormous trees. How quickly did they come to occupy this range of morphospace? The fossil record of angiosperm woods offers an opportunity to answer this question because stem diameter is related to tree height and standing biomass. We recently discovered an enormous permineralized angiosperm log in the Turonian Ferron Sandstone in Utah. The specimen has an estimated 1.8 m diameter and at is least 11 m long. We used allometric scaling equations to estimate that this tree was approximately 50 m tall. To understand the significance of this discovery, we reviewed the published record of Cretaceous woods worldwide and collected data on minimum stem diameter for angiosperm woods at each locality. Our review indicates that this is among the largest Cretaceous angiosperms to date, and the only documented case of an angiosperm trunk >1 m diameter older than the Campanian. We also confirm the presence of a latitudinal gradient in both the size and abundance of Late Cretaceous angiosperm woods for western North America. Our review of the literature plus this new discovery indicate that large angiosperm trees formed part of the forest canopy in southern Laramidia and Appalachia by the early Late Cretaceous, nearly 10 million years earlier than previously thought, but at least 35 million years after flowering plants first appear in the fossil record.

1 - Cornell University, School of Integrative Plant Sciences, Mann Library, Ithaca, NY, 14850, USA
2 - Adelphi Univeristy, Department of Biology, Garden City, NY, 11530, USA
3 - Burpee Museum of Natural History, Rockford, IL, 61103, USA
4 - Northern Illinois University, Department of Biology, DeKalb, IL, 60115, USA
5 - Montana State University and Museum of the Rockies, Earth Sciences, Bozeman, MT, 59715, USA
6 - McMaster University, School of Geography and Earth Sciences, Hamilton, Ontario, L8S 4L8, Canada

Keywords:
Cretaceous
Turonian
Angiosperm woods
fossil wood
anatomy
Laramidia.

Presentation Type: Colloquium Presentations
Session: CO3, Campanian-Maastrichtian floras on Laramidia: vegetation trends west of the seaway
Location: Sundance 3/Omni Hotel
Date: Wednesday, June 28th, 2017
Time: 8:30 AM
Number: CO3001
Abstract ID:254
Candidate for Awards:None