Cambrian. The first appearance of trilobites defines the start of Series 2 of the Cambrian, and they can be found in strata up to the upper Permian, after which trilobites (among a large number of marine organisms) went extinct in the great catastrophe that removed over 90% of all species on earth. The greatest numbers of trilobite species occurred during the Cambrian and Ordovician periods, after which trilobite extinction trends exceeded radiation events.
UT Department of Environmental Sciences
The University of Toledo
Digital Initiatives, University of Toledo Libraries
environmental sciences; virtual exhibitions
No Copyright - United States. URI: http://rightsstatements.org/vocab/NoC-US/1.0/
The organization that has made the Item available believes that the Item is in the Public Domain under the laws of the United States, but a determination was not made as to its copyright status under the copyright laws of other countries. The Item may not be in the Public Domain under the laws of other countries. Please refer to the organization that has made the Item available for more information.