Produced by the Population Genetics and Evolution class, Furman University

The Triassic: Ichthyosuars
Ichthyosaurs, or “fish lizards”, lived during the Triassic period about 20 million years before dinosaurs roamed the earth (Vitual Fossil Museum 2008). They were air-breathing, marine reptiles that reached up to 15 meters long. They resembled modern day dolphins in having a hydrodynamic shape (White and Kazlev 2010). In their fins, the bones were assembled in a “corn cob” pattern, to allow for mobility (Motani 2000). Ichthyosaurs were fast swimmers, but only for short distances. As they were reptiles, they did not have the metabolism to support the endurance needed for long distances (White and Kazlev 2010). Originally, Ichthyosaurs were land reptiles, but they evolved fins and moved into the ocean during the Early Triassic period. As they could no longer go on land to lay their eggs, Ichthyosaurs developed the ability to give birth to live young (Virtual Fossil Museum 2008). Ichthyosaurs are also credited with having one of the largest eyes ever discovered, with Temnodontosaurs platyodon having an eye thought to be 265 mm across (Motani 2000). Fossilized forms of the Ichthyosaur have been found in the Lower Triassic Strata of North America and Asia (Virtual Fossil Museum 2008).

Page by Julia Bobo
Ichthyosaur fossil, taken from: University of California Museum of Paloentology

Virtual Fossil Museum. 2008. “Triassic Ichthyosaur Fossil”.Accessed on March 23, 2010.

White T and Kazlev MA. 2010. “Eureptilia: Ichthyosauria”. Accessed on March 23, 2010.

Motani R. 2000. “Ichthyosaur”. University of California Museum of Paleontology. Accessed on March 23, 2010.