Evolutionary mode of the ostracod, Velatomorpha altilis, from the Joggins Fossil Cliffs UNESCO World Heritage Site
Article first published online: 16 AUG 2012
© 2012 The Authors, Lethaia © 2012 The Lethaia Foundation
Volume 45, Issue 4, pages 615–623, October 2012
How to Cite
GREY, M., FINKEL, Z. V., PUFAHL, P. K. and REID, L. M. (2012), Evolutionary mode of the ostracod, Velatomorpha altilis, from the Joggins Fossil Cliffs UNESCO World Heritage Site. Lethaia, 45: 615–623. doi: 10.1111/j.1502-3931.2012.00328.x
- Issue published online: 17 SEP 2012
- Article first published online: 16 AUG 2012
Grey, M., Finkel, Z.V., Pufahl, P.K. & Reid, L.M. 2012: Evolutionary mode of the ostracod, Velatomorpha altilis, at the Joggins Fossil Cliffs UNESCO World Heritage Site. Lethaia, Vol. 45, pp. 615–623.
The estuarine ostracod Velatomorpha altilis was analysed for size and shape changes over a 2–3 million-year interval within a portion of the Joggins Fossil Cliffs World Heritage Site. This represents one of a very few number of studies focused on evolutionary trends within marginal environments and contributes to a growing body of research that attempts to link evolutionary patterns with processes. We measured nearly 400 ostracod specimens and used a quantitative model-based test to assess mode of evolution. Samples of ostracods were also analysed for their stable oxygen and carbon isotopic compositions in an attempt to supplement paleoenvironmental interpretations. Stasis was the strongly supported model for mode of evolution in both size and shape metrics, lending support to previous hypotheses that organisms from fluctuating, and therefore stressed, environments, should exhibit stasis because they are genetically well adapted to environmental change over geological time-scales. Stable isotopic compositions indicate samples were diagenetically altered and thus do not preserve a primary signature of paleoenvironmental conditions. Future work should look to other marginal organisms to test whether stasis is indeed a trend in these types of environments. □Carboniferous, estuarine ostracod, environment, evolutionary mode.