Estimating the Duration of the Cambrian Explosion

• Activity Number: 176 - Contributed Poster Presentations: Section on Statistics and the Environment
• Type: Contributed
• Date/Time: Monday, July 31, 2017 : 10:30 AM to 12:20 PM
• Sponsor: Section on Statistics and the Environment
• Author(s): Zijin Lin* and Steve Wang and Tuan Nguyen and Katrina Midgley and Heather Zhou and Daniel Wang and Linda Gai and Chengying Wang and Susannah Porter and John Moore and Adam Maloof
• Companies: Swarthmore College and Swarthmore College and Swarthmore College and Swarthmore College and Swarthmore College and Swarthmore College and Johns Hopkins University and Swarthmore College and UC Santa Barbara and UC Santa Barbara and Princeton University
• Keywords: paleontology ; extinction ; Signor-Lipps effect ; fossils

Abstract

The Cambrian explosion is a key event in the history of life, when almost all the modern groups of animals first appear in the fossil record. The general timeline of the Cambrian explosion is well established, but details about the duration and pattern of origination events remain unclear. Previous work suggested that the duration of the Cambrian explosion was approximately 16 million years, but this estimate did not account for the incompleteness of the fossil record. Here we attempt to provide a statistically rigorous estimate for the duration of the Cambrian explosion using novel methods that account for this incompleteness. We use an extensive dataset of fossils from Mongolia, Siberia, and China, dating from the earliest part of the Cambrian. To estimate the duration of the origination event, we construct a confidence interval for the time span between the earliest and latest originations, by inverting a hypothesis test for whether a given duration is consistent with the observed fossil record.