Model Food Web (image) American Association for the Advancement of Science Share Print E-Mail Caption This is a detail of part of a model food web for the Karoo paleocommunity prior to onset of the mass extinction. The nodes (spheres) represent individual species, and the arrows between them are predator-prey links showing the direction of energy flow. Credit [Credit: Peter Roopnarine] Usage Restrictions Please cite the owner of the material when publishing. This material may be freely used by reporters as part of news coverage, with proper attribution. Non-reporters must contact Science for permission. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.