Reviews
ICHTHYOSAUR FOSSILS FOR SALE
What Are Ichthyosaurs?
Ichthyosaurs were swordfish-like marine reptiles of the order Ichthyosauria. They had torpedo-shaped bodies with long narrowly pointed jaws, large pectoral fins, and crescent-shaped tails. They were the high-speed predators of the Jurassic seas, indicating they ate a fish diet. This is confirmed by analysis of coprolites (fossil feces).
When Did Ichthyosaurs Live?
Ichthyosaurs evolved about 250 million years ago but did not hit their diversity apex until the Jurassic. 97 genera (plural of genus) are known. It is thought that they are descended from diapsids like dinosaurs and birds, but a recent theory suggest they may have descended from a distant relative of turtles.
Ichthyosaurs had disappeared from the fossil record by about 95 million years ago. It is not known why they died out.
What Did Ichthyosaurs Look Like?
Ichthyosaurs looked like today's swordfish or dolphins. Their bodies were larger near the head and tapered to a sleek crescent-shaped tail. Ichthyosaurs ranged in size from Shastasaurus sikanniensis at an estimated 69 feet (21 meters) to the diminutive Cartorhynchus lenticarpus, 1.3 feet (0.4 meters).
Ichthyosaurs had one of the largest eyes relative to body size of any organism. This likely allowed them to better scan the water column to find prey. The crescent tail allowed them to reach tremendous speed in the water. Some estimates put the top speed of the fastest species above 30 miles per hour. Like most fish living today, ichthyosaurs were likely dark colored on their back and sides and light on their bellies.
A fossil of the ichthyosaur Stenopterygius. Creative Commons License
Are Ichthyosaurs Fish?
Ichthyosaurs are not fish. Their resemblance to them is an example of two groups adapting to their environment with similar adaptations without having a common ancestor. This is called convergent evolution. Ichthyosaurs were reptiles with lungs that had to surface to breathe. Fish have gills that take dissolved oxygen from the water.
State Fossil Of Nevada
In 1928, a large bone-bed of giant ichthyosaur fossils was discovered in the Shoshone Mountains of central Nevada. Excavations decades later would reveal the remains of 37 different individuals, including one that was 49 feet long! Up until 2004 this was the largest ichthyosaur known. These ichthyosaurs were eventually described as Shonisaurus popularis after the mountains in which they were found and were designated as the state fossil of Nevada. The site of this find is now part of the Berlin-Ichthyosaur State Park, where visitors can see some of these massive fossils still in the ground.
View into the fossil shelter in Berlin–Ichthyosaur State Park in Nevada