Skeemella and Acinocricus

Skeemella clavula is an "enigmatic" animal from the Wheeler Shales lagerstatten of Utah, which lived during the Middle Cambrian. Some people feel that it is an unusually long-tailed vetulicolian, while others reject this, alleging that its tail is far too long for a vetulicolian, and instead, is some sort of primitive "bivalved" arthropod.

Belong S. clavula is the lobopod Acinocricus stichus, which was originally identified as a seaweed.