shastasaurs

Shastasaurs were an early group of ichthyosaurs. They dated back to about 215 million years ago. They had big heads with long snouts. They also had reduced dorsal fins, but were the largest of all ichthyosaurs. One species of western american shastasaurs grew to 23 meters long. shastasaurs ate small aqautic animals including Ammonites. They dissapeared about 90 million years ago. They were also supratemporal probably present primitevly but lost in many derived forms.