Shastasaurus BW














†S. pacificus (type)

†S. liangae

†S. sikanniensis

Shastasurus was a genus of icthyosaurid from the Norian stage of the Triassic Period . To date it is the largest known marine reptile that has ever lived.


Shastasaurus was the largest reptile ever the swim the seas. S. sikanniesis (originaly assigned to Shonisaurus sikanniesis), the largest species, measured 21 meters (69 feet in length). Shastasaurus was a highly specialized animal that differed from other icthyosaurs. It had a relatively slender body; the largest specimen having a ribcage that was less than 2 meters (6.6 feet) deep. Traditionally, Shastasaurus, along with other members of the family Shastasauridae, have been depicted with a dorsal fin like that of a shark. This feature, although found in more advanced icthyosaurs, was likely not present in Shastasaurus. Additionally, the upper fluke of the tail was likewise less developed than the upper flukes of more advanced ichtyosaurs.

Shonisaurus scale mmartyniuk

Shastasaurus sikanniesis (red) compared to Shonisaurus popularis (green)

The SkullEdit

The skull of Shastasaurus was unusually short and completely lacked teeth. The snout indicates that the ichthyosaur may have been a suction feeder, preying on soft-bodied cephalopods. In S. liangae, several well preserved skulls indicate that the skull made up only about 8.3% of the total body length.

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