Complex sentence: Thirty years later, they were excavated and it was found that the deposit contained the remains of 37 very large ichthyosaurs which were named "Shonisaurus", which means "Lizard from the Shoshone Mountains", after the formation where the fossils were found.
Split into simpler sentences: Thirty years later, they were excavated, uncovering the remains of 37 very large ichthyosaurs. These were named "Shonisaurus", which means "Lizard from the Shoshone Mountains", after the formation where the fossils were found.