The sternaspids are short worms with a dark yellow or reddish chitinized shield and an inflated body. They are common in sandy and muddy substrates at all depths usually around 100-200 m depth. They are small and unworm-like with rounded shape and dull color. They are rarely found in large numbers and are burrowers of sand and mud. They are motile surface deposit feeders. They burrow head first into the substratum to feed on the organic matter. While inverted, the chitinized shield covers the burrow entrance.