Simplify the following text for a Grade 10 native English-speaking person.
Original: Charles Doolittle Walcott found in the Burgess Shale nine almost complete fossils of Opabinia regalis and a few of what he classified as Opabinia media , and published a description of all of these in 1912 .
Simplified: Its sole species , Opabinia regalis , is known from the Middle Cambrian Burgess Shale of British Columbia . The discoverer of Opabinia , Charles Doolittle Walcott , named it after a local mountain , Opabin Peak in the Canadian Rockies .