When using this data, please cite the data package:
NCEAS 12081: Lockwood: RarityAndExtinction , NCEAS 3980: Alroy: Paleobiology Database (Hosted by NCEAS) , National Center for Ecological Analysis and Synthesis , and Lockwood R. 2008. Lockwood: Late Cretaceous Molluscan Abundance Data (Sohl and Koch) nceas.931.8
Lockwood: Late Cretaceous Molluscan Abundance Data (Sohl and Koch)
This data set contains abundance data for fossil mollusk genera from the Late Cretaceous of the U.S. Coastal Plain published by Sohl and Koch (1983, 1984, 1987). It also contains global stratigraphic ranges, global geographic ranges, and taxonomic information for genera, downloaded from the Paleobiology Database (PBDB) at http://paleodb.org in February 2008. This data set is used to examine the link between rarity and extinction across the end-Cretaceous mass extinction in Coastal Plain mollusks.
U.S. Coastal Plain, including Texas, Mississippi, Alabama, Georgia, South Carolina, Tennessee, Missouri, Arkansas, Maryland, New Jersey.
Sampling, Processing and Quality Control Methods
Step by Step Procedures
Sohl and Koch 1983, 1984, 1987 methods
Fossil abundance data for mollusks collected from bulk and non-bulk samples. See Sohl and Koch for more details:
Sohl and Koch 1983, 1984, 1987. USGS Open File Report 83-451; 84-687, 87-194.
Global stratigraphic and geographic range data downloaded from the PBDB February 2008 using "Analyze taxonomic range" tool.
Taxonomic data downloaded from the PBDB February 2008.
See metadata column descriptions for more detail.
R Script was used to transform the data table
R Software version 2.7.0 from the R Project for Statistical Computing at (http://www.r-project.org) was used to transform the data tables to make it easier to document the original table. The script is included in this data set as a dowloadable r file called lockwood_transform.r. There is also a lockwood_recreate.r script that will recreate Rowan Lockwood's original data table by joining the two tables that are stored in the data repository.
Sampling Area And Frequency:
Original fossil abundance data compiled by Sohl and Koch from the literature and their own field samples up until 1980's. Taxonomic, stratigraphic, and geographic range data compiled in PBDB.
Fossil abundance data collected in part via bulk sampling.