Measuring and Interpreting Predation on Gastropod Shells

• Author / Creator

  Stafford, Emily S.

• This dissertation focuses on problems and progress in studying crushing predation on gastropods in the Modern and the fossil record. Although crushing predation tends to be destructive, it is possible to gather data on crushing predation from multiple angles. Chapter 2 applies an ichnotaxonomic name, Caedichnus, to the trace created by peeling crab predators. Chapter 3 the relationship between shell repair frequency and predation mortality in a modern gastropod community. In this case, repair frequency was likely a direct product of variation in predator abundance and strength. Chapter 4 focused on hermit crabs, an organism that inhabits gastropod shells and exposes those shells to predation even after the original gastropod inhabitant has died. The predatory crabs showed no preference for snail or hermit crab prey, which may mean that hermit crab habitation does not significantly alter the crab-on-snail predation patterns present in a shell assemblage. Chapter 5 expanded on previous work by the author, using a method by G.J. Vermeij to estimate crushing predation in a gastropod assemblage even when individual instances of predatory damage cannot be identified. Vermeij Crushing Analysis (VCA) uses drilled shells to establish a baseline of taphonomic damage in a shell assemblage; the chapter refines and examines this method more deeply, in addition to applying the method to compare predation on modern and fossil gastropod shell assemblages. Chapter 6 is the culmination of the previous chapters, combining predatory traces, VCA, and repair frequency, as well as predatory shell drilling, to examine predation at multiple trophic levels in a Miocene-age fossil shell assemblage from Maryland.

• Subjects / Keywords

  • Hermit crab
  • Durophagy
  • Crustacean

• Graduation date

  Spring 2015

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R37S7J01Q

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.