Britannica
Sources used in this answer
When did the earliest known bivalves appear?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
The earliest known bivalves are generally believed to be Fordilla troyensis, which is found in lower Cambrian rocks in New York dating back approximately 510 million years, and Pojetaia runnegari from Cambrian rocks in Australia.1