| Abstract Detail
Paleobotanical Section Taylor, Wilson A. [1], Strother, Paul K [2], Vecoli, Marco [3], Beck, John H. [4]. One-Hundred-Year-Old Prediction Found at Fossil Mountain Utah. In presenting his initial antithetic (interpolational) theory for the origin of the plant sporophyte a century ago, F. O. Bower envisioned that the sporophyte evolved in two distinct stages: 1) an initial expansion of a multicellular mass of sporogenous tissue, 2) a secondary loss of spore-generating capacity in some cells to produce a vegetative body. We have recovered clusters and sheets of spore-like cells from the lower Middle Ordovician (Dapingian) Kanosh Shale, Fossil Mountain, Utah, which we interpret as packets of cryptospore dyads. The irregularly clustered forms are quite similar to the Upper Cambrian cryptospore, Agamachates casearius. The more highly organized thalli of attached cryptospore packets retain a history of sequential cell divisions that produced these sporogenous sheets. Combined with ultrastructural observations (which will be reviewed and elaborated), two kinds of growth patterns are demonstrated in these fossils – one parallels vegetative division in Coleochaete, the other matches the sarcinoid pattern found in the extant chlorophycean green alga, Prasiola. These fossils may not have been direct ancestors of the embryophytes, but they are an impressive testament to the predictive power of a good hypothesis. Broader Impacts:
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1 - University of Wisconsin-Eau Claire, Department of Biology, Eau Claire, WI, 54701
2 - Boston College, Geology & Geophysics, Weston Observatory, 381 Concord Road, Weston, Massachusetts, 02493, USA
3 - Université Lille 1, FRE 3298 Geosystems CNRS, SN5 Cité Scientifique, F-59655 Villeneuve d'Ascq, France
4 - Boston College, Weston Observatory - Department of Geology & Geophysics, 381 Concord Road, Weston, MA, 02498, USA
Keywords:
early land plants
cryptospores
algae.
Presentation Type: Oral Paper:Papers for Sections
Session: 8
Location: 555B/Convention Center
Date: Monday, August 2nd, 2010
Time: 11:00 AM
Number: 8004
Abstract ID:550 |
