Pinhead-sized sea creature was a bag with a mouth
Anus may have been absent in odd new fossils from 540 million years ago
![deuterostome fossil](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2017/02/020117_mr_deuterostome_free.jpg?fit=860%2C460&ssl=1)
MOUTHING OFF New fossils show tiny creatures with accordion mouths (one shown) that lived 540 million years ago. The animals are the earliest known deuterostomes, a category so big it includes everything from humans to starfish.
J. Han et al/ Nature 2017