Date of Award
6-26-2026
Date Published
August 2026
Degree Type
Thesis
Degree Name
Master of Science (MS)
Department
Earth & Environmental Sciences
Advisor(s)
Linda Ivany
Keywords
Biomineralization;Evolution;Paleobiology;Paleoecology;Paleozoic;Sclerochronology
Abstract
Brachiopods are one of the most abundant fossils in the Paleozoic, and they persist into the modern. While their diversity, morphology, and ecology have been extensively studied, we know surprisingly little about their life histories. Life history, specifically lifespan, can inform ecological context because of the connection to organism metabolism and environmental energetics, where slower growth and a longer lifespan generally imply a slower metabolism, and vice versa. Brachiopod life history data could therefore offer a means by which to test Bambach’s ‘Seafood Through Time’ hypothesis suggesting that the energetics of marine ecosystems have increased over the Phanerozoic. Despite being accretionary, resolving annual growth increments in brachiopod shells has proven difficult in both Modern and ancient specimens. Here, we use micro X-ray fluorescence (microXRF) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to explore the distribution of elements in Devonian brachiopod hinge areas in an effort to resolve seasonal variation in temperature and growth rate and produce growth curves. Work thus far demonstrates that element maps from the microXRF can spatially resolve growth banding, and that transects across bands with LA-ICP-MS pick up the variation seen in microXRF maps. Dark bands (low concentrations) in the µXRF Sr plot correspond to Sr lows and Mg peaks in LA-ICP-MS data, suggesting that growth slowdowns in this case correspond to warm temperatures. Discriminating what are (presumably) annual peaks from background noise involves ambiguity and patterns are not always clear, but our data suggest a lifespan of at least 10 years for Spinocyrtia.
Access
Open Access
Recommended Citation
Dempsey, Caitlyn Rose, "Resolving Life Histories of Paleozoic Brachiopods for a Test of ‘Seafood through Time’" (2026). Theses - ALL. 1062.
https://surface.syr.edu/thesis/1062
