|2011 GSA Annual Meeting in Minneapolis (9–12 October 2011)|
|Paper No. 152-1|
|Presentation Time: 8:00 AM-8:15 AM|
A TEST FOR THE POSSIBILITY OF PHOTOSYMBIOSIS IN FUSULINIDS: SIZE AND SHAPE TRENDS RELATED TO DEPTH OF HABITAT
GROVES, John R., PIKE, Madison, and WESTLEY, Kasey, Department of Earth Science, University of Northern Iowa, Cedar Falls, IA 50614-0335, firstname.lastname@example.org|
Fusulinid foraminifera are extinct protists that are thought to have hosted photosymbionts, as in modern larger foraminifera, but the ancient host-symbiont relationship has never been demonstrated conclusively. Among modern larger foraminifera, deeper-dwelling species exhibit large surface-to-volume ratios (S/V) in order to maximize the amount of sunlight that can be captured for use by photosymbionts. Shallower-dwelling species exhibit small S/V in order to limit incoming sunlight, especially ultraviolet radiation. If modern symbiont-bearing foraminifera are useful analogues for fusulinids, then we predict that deeper-dwelling fusulinids ought to exhibit larger S/V than shallower-dwelling fusulinids. This prediction was tested by analyzing fusulinid shells from Virgilian (Upper Pennsylvanian) cyclothems in Kansas. Several hundred fusulinids from transgressive limestones and regressive limestones of the Oread, Lecompton and Deer Creek cycles were measured. Fusulinids from transgressive limestones exhibit larger S/V than those from regressive limestones, and specimens with the smallest S/V invariably occur in shoaling deposits at or near the tops of regressive limestones. Surprisingly, shell shape does not vary predictably with depth of habitat. Rather, changes in S/V were accomplished by changes in size, with larger shells always yielding small S/V values. The observed trends are significantly non-random with respect to depth of habitat (p = 0.037), a result that is consistent with the possibility of photosymbiosis in fusulinids.
2011 GSA Annual Meeting in Minneapolis (9–12 October 2011)
General Information for this Meeting
|Session No. 152|
Lessons from the Living: Paleontological Investigations Using Modern Analogs I
Minneapolis Convention Center: Room 205AB
8:00 AM-12:00 PM, Tuesday, 11 October 2011
Geological Society of America Abstracts with Programs, Vol. 43, No. 5, p. 379
© Copyright 2011 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.