Taphonomic bias and time-averaging in tropical molluscan death assemblages: Differential shell half-lives in Great Barrier Reef sediment

Matthew A. Kosnik, Quan Hua, Darrell S Kaufman, Raphael A. Wüst

Research output: Contribution to journalArticle

61 Citations (Scopus)

Abstract

Radiocarbon-calibrated amino acid racemization ages of 428 individually dated shells representing four molluscan taxa are used to quantify time-averaging and shell half-lives with increasing burial depth in the shallow-water carbonate lagoon of Rib Reef, central Great Barrier Reef, Australia. The top 20 cm of sediment contains a distinct, essentially modern assemblage. Shells recovered at depths from 25 to 125 cm are age-homogeneous and significantly older than the surface layer. Taxon age distributions within sedimentary layers indicate that the top 125 cm of lagoonal sediment is thoroughly mixed on a sub-century scale. The age distributions and shell half-lives of four taxa (Ethalia, Natica, Tellina, and Turbo) are found to be largely distinct. Shell half-lives do not coincide with any single morphological characteristic thought to infer greater durability, but they are strongly related to a combined durability score based on shell density, thickness, and shape. These results illustrate the importance of bioturbation in tropical sedimentary environments, indicate that age estimates in this depositional setting are sensitive to taxon choice, and quantify a taxon-dependent bias in shell longevity and death assemblage formation.

Original languageEnglish (US)
Pages (from-to)565-586
Number of pages22
JournalPaleobiology
Volume35
Issue number4
DOIs
StatePublished - Dec 2009

Fingerprint

Age Distribution
Great Barrier Reef
barrier reef
half life
shell
death
Burial
sediments
Carbonates
Ribs
sediment
durability
Amino Acids
Water
age structure
bioturbation
ribs
racemization
carbonates
reefs

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Palaeontology
  • Ecology, Evolution, Behavior and Systematics
  • Ecology

Cite this

Taphonomic bias and time-averaging in tropical molluscan death assemblages : Differential shell half-lives in Great Barrier Reef sediment. / Kosnik, Matthew A.; Hua, Quan; Kaufman, Darrell S; Wüst, Raphael A.

In: Paleobiology, Vol. 35, No. 4, 12.2009, p. 565-586.

Research output: Contribution to journalArticle

@article{ffc2e09cadbc4bc1a18e5e6fcbd9f343,
title = "Taphonomic bias and time-averaging in tropical molluscan death assemblages: Differential shell half-lives in Great Barrier Reef sediment",
abstract = "Radiocarbon-calibrated amino acid racemization ages of 428 individually dated shells representing four molluscan taxa are used to quantify time-averaging and shell half-lives with increasing burial depth in the shallow-water carbonate lagoon of Rib Reef, central Great Barrier Reef, Australia. The top 20 cm of sediment contains a distinct, essentially modern assemblage. Shells recovered at depths from 25 to 125 cm are age-homogeneous and significantly older than the surface layer. Taxon age distributions within sedimentary layers indicate that the top 125 cm of lagoonal sediment is thoroughly mixed on a sub-century scale. The age distributions and shell half-lives of four taxa (Ethalia, Natica, Tellina, and Turbo) are found to be largely distinct. Shell half-lives do not coincide with any single morphological characteristic thought to infer greater durability, but they are strongly related to a combined durability score based on shell density, thickness, and shape. These results illustrate the importance of bioturbation in tropical sedimentary environments, indicate that age estimates in this depositional setting are sensitive to taxon choice, and quantify a taxon-dependent bias in shell longevity and death assemblage formation.",
author = "Kosnik, {Matthew A.} and Quan Hua and Kaufman, {Darrell S} and W{\"u}st, {Raphael A.}",
year = "2009",
month = "12",
doi = "10.1666/0094-8373-35.4.565",
language = "English (US)",
volume = "35",
pages = "565--586",
journal = "Paleobiology",
issn = "0094-8373",
publisher = "Paleontological Society",
number = "4",

}

TY - JOUR

T1 - Taphonomic bias and time-averaging in tropical molluscan death assemblages

T2 - Differential shell half-lives in Great Barrier Reef sediment

AU - Kosnik, Matthew A.

AU - Hua, Quan

AU - Kaufman, Darrell S

AU - Wüst, Raphael A.

PY - 2009/12

Y1 - 2009/12

N2 - Radiocarbon-calibrated amino acid racemization ages of 428 individually dated shells representing four molluscan taxa are used to quantify time-averaging and shell half-lives with increasing burial depth in the shallow-water carbonate lagoon of Rib Reef, central Great Barrier Reef, Australia. The top 20 cm of sediment contains a distinct, essentially modern assemblage. Shells recovered at depths from 25 to 125 cm are age-homogeneous and significantly older than the surface layer. Taxon age distributions within sedimentary layers indicate that the top 125 cm of lagoonal sediment is thoroughly mixed on a sub-century scale. The age distributions and shell half-lives of four taxa (Ethalia, Natica, Tellina, and Turbo) are found to be largely distinct. Shell half-lives do not coincide with any single morphological characteristic thought to infer greater durability, but they are strongly related to a combined durability score based on shell density, thickness, and shape. These results illustrate the importance of bioturbation in tropical sedimentary environments, indicate that age estimates in this depositional setting are sensitive to taxon choice, and quantify a taxon-dependent bias in shell longevity and death assemblage formation.

AB - Radiocarbon-calibrated amino acid racemization ages of 428 individually dated shells representing four molluscan taxa are used to quantify time-averaging and shell half-lives with increasing burial depth in the shallow-water carbonate lagoon of Rib Reef, central Great Barrier Reef, Australia. The top 20 cm of sediment contains a distinct, essentially modern assemblage. Shells recovered at depths from 25 to 125 cm are age-homogeneous and significantly older than the surface layer. Taxon age distributions within sedimentary layers indicate that the top 125 cm of lagoonal sediment is thoroughly mixed on a sub-century scale. The age distributions and shell half-lives of four taxa (Ethalia, Natica, Tellina, and Turbo) are found to be largely distinct. Shell half-lives do not coincide with any single morphological characteristic thought to infer greater durability, but they are strongly related to a combined durability score based on shell density, thickness, and shape. These results illustrate the importance of bioturbation in tropical sedimentary environments, indicate that age estimates in this depositional setting are sensitive to taxon choice, and quantify a taxon-dependent bias in shell longevity and death assemblage formation.

UR - http://www.scopus.com/inward/record.url?scp=77749264615&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77749264615&partnerID=8YFLogxK

U2 - 10.1666/0094-8373-35.4.565

DO - 10.1666/0094-8373-35.4.565

M3 - Article

AN - SCOPUS:77749264615

VL - 35

SP - 565

EP - 586

JO - Paleobiology

JF - Paleobiology

SN - 0094-8373

IS - 4

ER -