Ainiktozoon loganense ("Logan's enigmatic animal", from (aÃÂniktós, "riddling, enigmatical"), living thing), is a fossil arthropod from the Silurian of Scotland. It was found at the Birk Knowes site, part of the Patrick Burn Formation, near Lesmahagow. Originally described as an early chordate, recent studies suggest that it was in fact an arthropod, more precisely a thylacocephalan crustacean.