‘Penis worms’ may have been the original hermits
Soft-bodied critters inhabited abandoned shells about 500 million years ago, researchers say
![illustration of a penis worm on the ocean floor](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2021/11/110521_sp_penis-worms_feat.jpg?fit=1030%2C580&ssl=1)
Sea creatures known as penis worms (one illustrated) hid out in empty shells, possibly for protection, about 500 million years ago, newly described fossils suggest.
Zhiqian Zhang/ Yunnan University