ReefHistory
Reefs in the Fossil Record
Formation
A. Range of Time Period of Origin
Reefs are found throughout the fossil record across millions of years of geological time. The earliest structures we might recognize as coral reefs appeared during the Cambrian period about 540 million years ago, although they may go back much further depending on how a reef is defined (Wood, 1999.) As early as 2.5 billion years ago, boulder-like structures were being produced by stromatolites, which are recognized as being the oldest form of reef-building organisms. More recently in geologic time, approximately the last 250 million years, calcium carbonate corals have begun to dominate the coral ecosystem.
Coral reefs have experienced a number of mass extinction events, many occuring during the Phanerozoic Era (Fagerstrom, 1988). During this time,
Location
A. Map with short description
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Interpretation
The fossil record has been used to gather data about the climate of prehistoric earth. Changes in the density, structure, and species composition of ancient reefs indicate shifts in global climate. Data gathered from fossil reefs have been used to model effects of various climate factors on modern coral reefs. Some scientists have used the fossil record to make predictions concerning the effects of climate change on modern reefs by examining analogous changes in the ancient climate. A link between changes in ancient climates causing great reductions in coral health and reef coverage has been suggested. Changes in the pH of the oceans and global temperature seen in the fossil record of reefs have been paralleled to changes in the modern climate.
Evolutionary changes over time can be tracked using fossil reefs. Ancient reef biomes have been examined by using the changes in species composition of the reefs over time. Changes in not only the primary reef building species and the species that live on the reef have demonstrated a great deal of convergent evolution. Niches such as the grazing species have remained constant in the fossil record though they have shown to have been filled by different species over time.
References
1. Lieberman, B. S., & Kaesler, R. (n.d.). Prehistoric Life : Evolution and the Fossil Record. Wiley-Blackwell. Retrieved from http://site.ebrary.com.libproxy.lib.unc.edu/lib/uncch/detail.action?docID=10387090
2. Bellwood, D. R., Goatley, C. H. ., Brandl, S. J., & Bellwood, O. (2014). Fifty million years of herbivory on coral reefs: fossils, fish and functional innovations. Proceedings of the Royal Society B, 281, 1–8.
3. Hopping Hotspots: Global Shifts in Marine Biodiversity. W. Renema, D. R. Bellwood, J. C. Braga, K. Bromfield, R. Hall, K. G. Johnson, P. Lunt, C. P. Meyer, L. B. McMonagle, R. J. Morley, A. O'Dea, J. A. Todd, F. P. Wesselingh, M. E. J. Wilson and J. M. Pandolfi.
Science. New Series, Vol. 321, No. 5889 (Aug. 1, 2008), pp. 654-657. http://www.jstor.org/stable/20054634.
4.Kiessling, W., & Simpson, C. (2011). On the potential for ocean acidification to be a general cause of ancient reef crises. Global change biology, 17(1), 56–67. doi:10.1111/j.1365-2486.2010.02204.x
5. Wood R (1999) Reef evolution. Oxford University Press, Oxford
6. G. D. Stanley Jr. and J. A. Fagerstrom
7. PALAIOS. Vol. 3, No. 2, Ancient Reef Ecosystems Theme Issue (Apr. - Jun., 1988), p. 110