Decoding the dynamics of dental distributions: insights from shark demography and dispersal

• Main Authors: Kim, Sora L., Yeakel, Justin D., Balk, Meghan A., Eberle, Jaelyn J., Zeichner, Sarah, Fieman, Dina, Kriwet, Jürgen
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Royal Society 2022
• Subjects: latitudinal gradient; Gulf of Mexico; Delaware Bay; metapopulation; Antarctic; Arctic; General Agricultural and Biological Sciences; General Environmental Science; General Immunology and Microbiology; General Biochemistry; Genetics and Molecular Biology; General Medicine; Currie; Antarc*; Climate change
• Online Access: https://doi.org/10.1098/rspb.2022.0808; https://www.ncbi.nlm.nih.gov/pmc/PMC9240680

Shark teeth are one of the most abundant vertebrate fossils, and because tooth size generally correlates with body size, their accumulations document the size structure of populations. Understanding how ecological and environmental processes influence size structure, and how this extends to influence these dental distributions, may offer a window into the ecological and environmental dynamics of past and present shark populations. Here, we examine the dental distributions of sand tigers, including extant Carcharias taurus and extinct Striatolamia macrota, to reconstruct the size structure for a contemporary locality and four Eocene localities. We compare empirical distributions against expectations from a population simulation to gain insight into potential governing ecological processes. Specifically, we investigate the influence of dispersal flexibility to and from protected nurseries. We show that changing the flexibility of initial dispersal of juveniles from the nursery and annual migration of adults to the nursery explains a large amount of dental distribution variability. Our framework predicts dispersal strategies of an extant sand tiger population, and supports nurseries as important components of sand tiger life history in both extant and Eocene populations. These results suggest nursery protection may be vital for shark conservation with increasing anthropogenic impacts and climate change. © 2022 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited. Manuscript received 26/04/2022. Manuscript accepted 06/06/2022. Published online 29/06/2022. Published in print 29/06/2022. This research would not be possible without the support of many individuals. We thank the curators and collection managers for their help and access to collect the empirical data: K. Shepherd and M. Currie at the Canadian Museum of Nature, P. Holroyd at ...