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UNCW Undergraduate Research Fellowship Proposal Patti Mason, April 22, 2005. Predator/prey relationships in 40 million year old fossils from South Carolina: Latitudinal variation in drilling predation and selectivity of prey drill-hole site and prey species.
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UNCW Undergraduate Research Fellowship Proposal Patti Mason, April 22, 2005 Predator/prey relationships in 40 million year old fossils from South Carolina: Latitudinal variation in drilling predation and selectivity of prey drill-hole site and prey species Acknowledgments: Thanks to Dr. Richard A. Laws and Dr. Patricia H. Kelley for their assistance and support
Background • Escalation (Vermeij, 1987) : states that biohazards, such as predation and/or competition increase through geologic time • Vermeij looked at the fossil record of predatory snails for evidence of escalation. • Predatory naticids (snails) move within the sediment to find prey and then drill through the shell and ingest the prey tissue. Predatory Naticid (w/ drill hole) Bivalve Prey
Kelley and Hansen surveyed 143,000 fossil molluscs from 28 geologic formations. They found: • + correlations with: • Species diversity • % Naticids • % Preferred Prey Courtesy Kelley & Hansen, 2003 • The data showed a rising and falling of drilling frequency instead of a consistent rise, perhaps related to mass extinctions.
Justification • We have data from Virginia and North Carolina to the Gulf Coast states. • Data from South Carolina will help fill in the gaps! Drilling Frequencies: Turritellid snails vs all snail species
Fig. 1. Orangeburg Group (Nystrom et al, 1989) • Return bulk sample of fossils to lab for study. • Tabulate location and frequency of drill holes (Drill hole frequency = % individuals with complete naticid drill-holes). • Measure common prey species for size, shell thickness, and internal volume for cost-benefit calculations, and any drill holes documented. • Test my hypotheses. Methods
Research Hypotheses • Drilling frequencies between those for Virginia and the Gulf Coast • Drill site and prey selection will be more pronounced than older assemblages • Naticid predation in South Carolina predicted by cost-benefit analysis • Drilling frequencies similar to those of equivalent fossil assemblages • % of naticids present proportional to drilling frequency • % of preferred prey proportional to drilling frequency Thank You