2019 AMI Online Salon

Sedimentary trace fossil record of predation by Cambrian trilobites

Project Details

  • Entrant Name: Stacy Cheavens
  • Membership Type: Professional Submission                     
  • Address: Columbia, MO
  • Client: University of Missouri Department of Geological Sciences
  • Medium/software used: Graphite, Photoshop
  • Final presentation format: Journal article
  • Primary Audience: Geologists

Project Description

The predator-prey relationship is understood to have a strong influence over both ecosystems and early evolution. However, visual evidence too often captures not the interaction, but the aftermath, particularly in soft-bodied taxa. Without these snapshots, we are left to rely on sedimentary trace fossil records. These burrows provide glimpses into the hunting behavior of the predator. This Cambrian era study looked at data from burrow intersections of trilobites and their vermiform prey to quantitatively determine what amount of trace fossils record an intentional interaction. It was determined that trilobite traces appear to intersect vermiform burrows far more than what would be expected by random chance alone. Once this was established, the next challenge was to determine a preferred angle of attack. It was found that indeed, low angle attacks seemed to be the preferred orientation.