A physiologically explicit morphospace for tracheid-based water transport in modern and extinct seed plants
- Creators
- Wilson, Jonathan P.
- Knoll, Andrew H.
Abstract
We present a morphometric analysis of water transport cells within a physiologically explicit three-dimensional space. Previous work has shown that cell length, diameter, and pit resistance govern the hydraulic resistance of individual conducting cells; thus, we use these three parameters as axes for our morphospace. We compare living and extinct plants within this space to investigate how patterns of plant conductivity have changed over evolutionary time. Extinct coniferophytes fall within the range of living conifers, despite differences in tracheid-level anatomy. Living cycads, Ginkgo biloba, the Miocene fossil Ginkgo beckii, and extinct cycadeoids overlap with both conifers and vesselless angiosperms. Three Paleozoic seed plants, however, occur in a portion of the morphospace that no living seed plant occupies. Lyginopteris, Callistophyton, and, especially, Medullosa evolved tracheids with high conductivities similar to those of some vessel-bearing angiosperms. Such fossils indicate that extinct seed plants evolved a structural and functional diversity of xylem architectures broader, in some ways, than the range observable in living seed plants.
Additional Information
© 2010 Paleontological Society. Accepted: 5 October 2009. We thank N. M. Holbrook, F. Rockwell, and S. Costanza for helpful discussion, and two anonymous reviewers for comments that improved this manuscript. J.P.W. is supported in part by the NASA Astrobiology Institute and a Deland Award for Botanical Research from the Arnold Arboretum of Harvard University.Additional details
- Eprint ID
- 18354
- DOI
- 10.1666/08071.1
- Resolver ID
- CaltechAUTHORS:20100519-114430714
- NASA Astrobiology Institute
- Deland Award for Botanical Research
- Created
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2010-06-28Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field