Asymmetron Directory References Discover Timeline of the 1990s How Fast Is the World’s Fastest Human? Flags That Look Alike Does Ball Lightning Exist? 10 Best Hockey Players of All Time What’s the Difference Between a Turtle and a Tortoise? New Seven Wonders of the World Contents Asymmetron invertebrate genus Also known as: Epigonichthyes Learn about this topic in these articles:classification In amphioxus…Amphioxus) and Epigonichthyes (also called Asymmetron)—with about two dozen species. The chordate features—the notochord (or stiffening rod), gill slits, and dorsal nerve cord—appear in the larvae and persist into adulthood.Read More