Springer Online Journal Archives 1860-2000
Abstract Geological investigations of the crown-of-thorns starfish (COTS) have concluded that outbreaks are not only recent but also have occurred in the past. The evidence lies in the abundance of COTS skeletal elements found both on the sea floor and within the underlying sedimentary record. These studies are flawed in three respects. First, the processes of fossil preservation from the living population to the fossil assemblage have been ignored. Second, it has not been demonstrated that the fossil skeletal elements representing alleged outbreak populations of starfish are of the same age. Third, the existence of a relationship between the number of COTS skeletal elements sampled from the sedimentary record and the relative abundance of COTS in the once living population has not been substantiated. The limitations introduced when studying the fossil record need to be established through taphonomic analyses of the COTS. Techniques which will allow greater temporal resolution of skeletal element age include amino-acid geochronology, analysis of sedimentation mode and rate, and correlation among sub-surface cores. In order to establish a relationship between the number of fossil COTS elements and the original population size, methods must be developed which will relate the number of fossil skeletal elements to the relative abundance of starfish in both the fossil and death assemblages and then to relate the latter to the relative size of the original population. When these approaches are used together it may be possible to make some estimate of relative COTS abundances based on data contained in the fossil record.
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