Humans, meet the ancient sea creature at the other end of your family tree

See the original posting on LA Times Science

A tiny wrinkled sack with a big mouth and no anus may well be the earliest-known of humans’ forebears. Meet Saccorhytus coronarius, a 540-million-year-old critter the size of a grain of sand, whose fossil remains were discovered in China.

Scientists say Saccorhytus is the most primitive of the…