The company that owns VxWorks, Wind River System, did involve in BSD circa 2000, and the most can be said is early VxWorks did share some lineage with BSD Unix,

The company that owns VxWorks, Wind River System, did involve in BSD circa 2000, and the most can be said is early VxWorks did share some lineage with BSD Unix, but ever since VxWorks has been switched to WIND kernel, I doubt we can really put these two OSes in the same group.