These marine arthropods flourished from 505 million years ago to 487 million years ago.
Charles Doolittle Walcott found nine partially complete fossils of Opabinia regalis and a few of what he classified as Opabinia media, that he published in 1912.
The bizarre arthropod's name is derived from the Opabin pass between Mount Hungabee and Mount Biddle, southeast of Lake O'Hara, British Columbia, Canada.
In 1966–1967, Harry B. Whittington found a rather good specimen which he published in 1975. He provided a detailed description based on a very thorough dissection of some specimens and photographs of these specimens lit from a variety of angles. Harry was a very thorough fellow.
But he was still ridiculed. Opabinia looked so strange that the audience at the first presentation of Whittington's analysis laughed.
Earth's ancient seas teemed with new life 541 - 485 Million Years Ago. The Cambrian Explosion had arrived. Weird and wonderful life forms like Hallucigenia and Anomalocaris are found in the fossil record giving us a peek at ancient life half a billion years ago.