The rough-coated longhorned beetle (Ecyrus dasycerus) is a medium-sized beetle in the family Cerambycidae, notable for its elongated body and very long antennae that often equal or exceed the body length. Its coloration is generally dark brown to black, and the surface of the elytra and thorax is covered with coarse, rough hairs or granules, giving the beetle a dull, textured appearance that matches its common name. Like many longhorned beetles, the larvae are wood-borers, developing inside dead or dying wood, while adults are usually found resting on trunks or branches.