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Body-size trends of the extinct giant shark Carcharocles megalodon: a deep-time perspective on marine apex predators

The extinct shark Carcharocles megalodon is one of the largest marine apex predators ever to exist. Nonetheless, little is known about its body-size variations through time and space. Here, we studied the body-size trends of C. megalodon through its temporal and geographic range to better understand...

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Autores principales: Pimiento, Catalina, Balk, Meghan A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Cambridge University Press 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4541548/
https://www.ncbi.nlm.nih.gov/pubmed/26321775
http://dx.doi.org/10.1017/pab.2015.16
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author Pimiento, Catalina
Balk, Meghan A.
author_facet Pimiento, Catalina
Balk, Meghan A.
author_sort Pimiento, Catalina
collection PubMed
description The extinct shark Carcharocles megalodon is one of the largest marine apex predators ever to exist. Nonetheless, little is known about its body-size variations through time and space. Here, we studied the body-size trends of C. megalodon through its temporal and geographic range to better understand its ecology and evolution. Given that this species was the last of the megatooth lineage, a group of species that shows a purported size increase through time, we hypothesized that C. megalodon also displayed this trend, increasing in size over time and reaching its largest size prior to extinction. We found that C. megalodon body-size distribution was left-skewed (suggesting a long-term selective pressure favoring larger individuals), and presented significant geographic variation (possibly as a result of the heterogeneous ecological constraints of this cosmopolitan species) over geologic time. Finally, we found that stasis was the general mode of size evolution of C. megalodon (i.e., no net changes over time), contrasting with the trends of the megatooth lineage and our hypothesis. Given that C. megalodon is a relatively long-lived species with a widely distributed fossil record, we further used this study system to provide a deep-time perspective to the understanding of the body-size trends of marine apex predators. For instance, our results suggest that (1) a selective pressure in predatory sharks for consuming a broader range of prey may favor larger individuals and produce left-skewed distributions on a geologic time scale; (2) body-size variations in cosmopolitan apex marine predators may depend on their interactions with geographically discrete communities; and (3) the inherent characteristics of shark species can produce stable sizes over geologic time, regardless of the size trends of their lineages.
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spelling pubmed-45415482015-08-26 Body-size trends of the extinct giant shark Carcharocles megalodon: a deep-time perspective on marine apex predators Pimiento, Catalina Balk, Meghan A. Paleobiology Articles The extinct shark Carcharocles megalodon is one of the largest marine apex predators ever to exist. Nonetheless, little is known about its body-size variations through time and space. Here, we studied the body-size trends of C. megalodon through its temporal and geographic range to better understand its ecology and evolution. Given that this species was the last of the megatooth lineage, a group of species that shows a purported size increase through time, we hypothesized that C. megalodon also displayed this trend, increasing in size over time and reaching its largest size prior to extinction. We found that C. megalodon body-size distribution was left-skewed (suggesting a long-term selective pressure favoring larger individuals), and presented significant geographic variation (possibly as a result of the heterogeneous ecological constraints of this cosmopolitan species) over geologic time. Finally, we found that stasis was the general mode of size evolution of C. megalodon (i.e., no net changes over time), contrasting with the trends of the megatooth lineage and our hypothesis. Given that C. megalodon is a relatively long-lived species with a widely distributed fossil record, we further used this study system to provide a deep-time perspective to the understanding of the body-size trends of marine apex predators. For instance, our results suggest that (1) a selective pressure in predatory sharks for consuming a broader range of prey may favor larger individuals and produce left-skewed distributions on a geologic time scale; (2) body-size variations in cosmopolitan apex marine predators may depend on their interactions with geographically discrete communities; and (3) the inherent characteristics of shark species can produce stable sizes over geologic time, regardless of the size trends of their lineages. Cambridge University Press 2015-06 /pmc/articles/PMC4541548/ /pubmed/26321775 http://dx.doi.org/10.1017/pab.2015.16 Text en © The Paleontological Society. All rights reserved. 2015 This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Articles
Pimiento, Catalina
Balk, Meghan A.
Body-size trends of the extinct giant shark Carcharocles megalodon: a deep-time perspective on marine apex predators
title Body-size trends of the extinct giant shark Carcharocles megalodon: a deep-time perspective on marine apex predators
title_full Body-size trends of the extinct giant shark Carcharocles megalodon: a deep-time perspective on marine apex predators
title_fullStr Body-size trends of the extinct giant shark Carcharocles megalodon: a deep-time perspective on marine apex predators
title_full_unstemmed Body-size trends of the extinct giant shark Carcharocles megalodon: a deep-time perspective on marine apex predators
title_short Body-size trends of the extinct giant shark Carcharocles megalodon: a deep-time perspective on marine apex predators
title_sort body-size trends of the extinct giant shark carcharocles megalodon: a deep-time perspective on marine apex predators
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4541548/
https://www.ncbi.nlm.nih.gov/pubmed/26321775
http://dx.doi.org/10.1017/pab.2015.16
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