214 D40. Paleontology: Recent Developments in Paleoecology

Wednesday, 12 October 2022
8:00 AM - 12:00 PM
Mile High Ballroom 4A

EXPLORING THE METABOLIC RATE OF DIFFERENT ECTOCOCHLEATE CEPHALOPODS USING STABLE CARBON ISOTOPES OF SHELL MATERIAL

Paper number: 214-9
Program: Technical Sessions
Time: 10:00 AM – 10:15 AM

Authors

Abstract

Reconstructing the metabolic rate of fossil organisms is key to understanding their evolution. The metabolic rate of extant organisms is commonly determined by measuring the oxygen consumption in laboratory experiments. However, direct observations are difficult in extinct organisms. Therefore, paleontologists attempt to reconstruct the metabolic rate of extinct organisms using different approaches. For example, in cephalopods, a recent study suggested that ammonoids possessed a higher metabolic rate than nautiloids based on the pattern of chamber volume development. To test this hypothesis, another approach is needed to determine the metabolic rate of extinct organisms. The carbon isotopic value (δ 13C) of the shell is a function of both metabolic carbon in modern cephalopods and the dissolved inorganic carbon (DIC) in the water. Furthermore, another recent study reports that the metabolically derived carbon in modern cephalopods is correlated with metabolism-related factors. In this study, we use the fraction of metabolic carbon (Cmeta) as a proxy for the metabolic rate of cephalopods. We analyzed the δ 13C of the shell in the modern nautilid Nautilus macromphalus to estimate the fraction of metabolic carbon (Cmeta). Additionally, we explore the metabolic rate of extinct ectocochleate cephalopods (ammonoids and nautilids) using published values of δ 13Cshell and δ 13Cmeta to determine which group possessed a higher metabolic rate.

Geological Society of America Abstracts with Programs. Vol. 54, No. 6

doi: 10.1130/abs/2022AM-379625

© Copyright 2022 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.