Abstract Detail

Paleobotany

Gallaher, Timothy [1], Senske, Ashly [2], Marvet, Claire [1], Desmond, Brian [2], Akbar, Sultan [2], Klahs, Phillip [3], Clark, Lynn [3], Stromberg, Caroline [4].

A 3D digital phytolith reference collection: A tool to improve the utility of GSSC phytoliths for the study of grasses and grassland evolution.

The use of phytoliths represents a promising advancement in the study of grass and grassland evolution. Grass silica short cell (GSSC) phytoliths have diagnostic shapes which when properly assigned to specific clades can provide important information about the presence and abundance of grass lineages in place and time. Fossil grass phytolith assemblages as old as Late Cretaceous have been collected and described providing new evidence for the age and diversification of the Poaceae, the timing, tempo and causes of grassland ecosystem expansion and the domestication history of our most important crops. However, the placement of ancient phytoliths into extant clades has been met with skepticism because a family-wide and statistically-robust analysis of 3D phytolith shape is not yet available. To address this problem we are using confocal microscopy to develop a 3D digital reference collection of GSSC phytoliths from extant taxa across the Poaceae. Currently 200 species representing all 80 subtribes are being digitized. The resulting 3D surface representations provide a high degree of shape detail and are suitable for geometric morphometrics, virtual animations and 3D printing. The data will ultimately facilitate robust statistical analyses and quantifiable placement of ancient phytolith taxa within the grass family. Our methodologies and initial results from the APP grade and the Oryzoideae will be presented.

1 - University of Washington, Biology, 24 Kincaid Hall, Box 351800, Seattle, WA, 98195, USA
2 - University of Washington, Biology, 24 Kincaid Hall, Box 351800, Seattle, WA, 98195, United States
3 - Iowa State University, Department Of Ecology, Evolution, And Organismal Biology, 251 Bessey Hall, Ames, IA, 50011-1020, USA
4 - University Of Washington, Department Of Paleobotany, 24 Kincaid Hall, Box 351800, Seattle, WA, 98195-1800, USA

Keywords:
Poaceae
Phytolith
Paleobotany
biogeography
Systematics
Geometric morphometrics
anatomy
Fossils.

Presentation Type: Oral Paper
Session: 1, Cookson/Moseley award presentations
Location: Sundance 4/Omni Hotel
Date: Monday, June 26th, 2017
Time: 8:30 AM
Number: 1003
Abstract ID:322
Candidate for Awards:Isabel Cookson Award