E. obscurus is a darkling beetle that ranges around 8.5mm to 10.0mm. These beetles are all black except for reddish appendages and antennae. They are moderately common in summer to fall on most beaches and are found in drier patches of kelp wrack. E. obscurus scavenged many arthropods and decaying matter on beaches. Not many predators are able to prey on these beetles due to their thick cuticle.