According to scientists, the new species was an ichthyosaur named Sclerocormus parviceps. It was a marine reptile dating to the Lower Triassic, and is completely different from other ichthyosaurs studied by the scientists so far.
Ichthyosaurs were marine reptiles that used to live at the same time as Earth's earliest dinosaurs. These creatures had dolphin-like forms - strong tail fin, long telltale snout and sleek body. But the new fossil showed that the animal had a stubby snout and a long tail - without the the big fin at the end.
Ichthyosaurs typically had ample teeth for catching food, but Sclerocormus parviceps is toothless. The researchers said that it is likely that its snout was built for sucking in food like a needle drawing blood.
The fossil dates to the time just after the Permian-Triassic event, which wiped out all marine species and the vast majority of terrestrial vertebrates. Scientists had always believed that it was slow going for marine reptiles rebounding from that period but the new fossil poses a strong challenge to this theory.
"Sclerocormus tells us that ichthyosauriforms evolved and diversified rapidly at the end of the Lower Triassic period," said study co-author Olivier Rieppel, of The Field Museum, in a statement.
"We don't have many marine reptile fossils from this period," Rieppel added, "so this specimen is important because it suggests that there's diversity that hasn't been uncovered yet."
Rieppel said the new reptile offered a clue into the real-world evolution in action. "Darwin's model of evolution consists of small, gradual changes over a long period of time, and that's not quite what we're seeing here," he said. "These ichthyosauriforms seem to have evolved very quickly, in short bursts of lots of change, in leaps and bounds."