| classis_authority = [[Johann Ernst Immanuel Walch|Walch]], 1771<ref name=Kihm&St.John07>{{chú thích |author1=Robert Kihm |author2=James St. John |chapter=Walch's trilobite research – A translation of his 1771 trilobite chapter |editor=Donald G. Mikulic, Ed Landing and Joanne Kluessendorf |title=Fabulous fossils – 300 years of worldwide research on trilobites |journal=New York State Museum Bulletin |volume=507 |pages=115–140 |publisher=University of the State of New York |year=2007 |url=http://www1.newark.ohio-state.edu/Professional/OSU/Faculty/jstjohn/Kihm-and-St.John-2007.pdf |format=[[PDF]] |postscript=. |access-date=2011-04-06 |archive-date=2011-07-20 |archive-url=https://web.archive.org/web/20110720020520/http://www1.newark.ohio-state.edu/Professional/OSU/Faculty/jstjohn/Kihm-and-St.John-2007.pdf }}</ref>
