- Kingdom: Animalia
- Phylum: Annelida
- Class: Polychaeta
- Subclass: Errantia
- Order: Phyllodocida
- Family: Polynoidae
- Scientific name: Lepidonotus squamatus
- Norwegian: vanlig skjellrygg
The scaleworm is easily confused with the not so common L. clava. They both have twelve pairs of shells on the back. They come in different shades of yellow or light brown, usually with dark spots. However, the two rows of shells overlap on the back of L squamatus, in contrast to L. clava. L. squamatus may grow to a body length of 5 cm.
It is usually found crawling under or in between rocks in the subtidal zone.
It is widespread over the entire northern hemisphere.