Final for Stenopterygius quadriscissus. A member of the icthyosaur order, Stenopterygius was a marine reptile from the Early Jurassic period (183-179 million years ago). At around 10 to 13 feet in length, it was similar in size and body shape to it's better known relative Icthyosaurus, of which the first skeleton was discovered by fossil hunter, Mary Anning. Despite similarities, Stenopterygius had a smaller skull and more narrow flippers than it's more famous relative, but the fossil finds of this animal are perhaps even more amazing than that of any other icthyosaur.
Several complete and nearly complete, articulated animals have been found, including one famous example of a mother and child who died while giving birth. It is because of this fossil that we know that icthyosaurs, despite being reptiles, gave birth to live young and that those young were born tail first like modern day whales and dolphins to prevent the babies from drowning before fully clearing the birth canal. Like dolphins and whales, icthyosaurs were air breathers, so they and their young would have to swim to the surface of the water to take in oxygen right after giving birth.
Based on fossil stomach contents from a variety of specimens and the shaped of it's teeth we can safely say that Stenopterygius probably fed on a diet of mostly cephalopods and fish, and based on it's body shape and size we can estimate it's cruising speed to be similar to that of modern day tuna, roughly 40-50 miles per hour.
There has been some preserved skin from another icthyosaur that gave scientists enough melanosome data to get an approximation of the animal's color. This piece was reconstructed based on that data, which showed the presence of darker colors, like black, grey, or dark brown. I decided to present it with a bit of a marbled texture after looking at some darker colored reptiles and modern day cetaceans (whales and dolphins).
