Myopsolenites boutiouti Geyer 2004

This is characterized by some ancient traits such as a prominent fang-like macropleural spine on the last pleurae (10th segment). It also has a large shield-like pygidium which is unusual among Cambrian trilobites. Notice the spine on the segment on the back of the cephalon, called the occipetal spine. Also of note is the long palpebral lobes (the eye lobes) that go to the anterior (front) of the glabella. Both show good evidence of thoracic spines (the middle row of the body).  However, it is found in the same Lower Middle Cambrian layers as other more well known trilobites such as Acadoparadoxides briareus. The top two photos is of a larger individual (2.5 inches not counting the macropleural spine) and the bottom two is of a smaller individual (1 5/8 inches).  The top one has restored genal spines but a better preserved macropleural spines and pygidium.  The bottom one is more pristine example though clear coated.

 

Kenjiro Hakomori 2009.9.19 (Revised 2014.11.11)