Early terrestrial ecosystems: the animal evidence
Work on fossil spores indicates that plants at a level of vegetative organization comparable to bryophytes and vascular plants existed on land in the Early Silurian. Vascular plants, limnetic fishes, and probable Ascomycetes have Late Silurian records. Charophytes are known in the Late Silurian but may have been marine. The presence of microarthropods in the Ludlovian has been hypothesized from fungal masses in the Burgsvik Sandstone that closely resemble microarthropod frass. A number of microarthropods such as collembolans and mites are microphagous; these animals are among the earliest known from the Early Devonian. These fungal masses as animal traces have been given added credibility by the recovery of animal body fossils from basal Llandovery age fluvial deposits of the Central Appalachians that yield abundant plant spores but that lack marine invertebrates, phytoplankton or chitinozoans. The remains are abundant and sufficiently varied to suggest that they may represent a variety of organisms. Some are eurypterid-like, others grossly arthropod-like, although they may represent an unknown phylum or phyla. Many small invertebrates are associated with extant bryophytes, which have been viewed as stepping stones or halfway houses for them as they emerged from water onto land. The occurrence of these Early Silurian invertebrate remains with abundant spore tetrads, which Gray has hypothesized represent land plants at a bryophyte or hepatic grade of organization, is of great interest in trying to understand the early development of nonmarine ecosystems.
- Research Organization:
- Univ. of Oregon, Eugene (USA)
- OSTI ID:
- 6598118
- Report Number(s):
- CONF-8510489-
- Journal Information:
- Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
- Country of Publication:
- United States
- Language:
- English
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