Myopsolenus staminops Jell and Adrain 2001 (syn.Collyrolenus staminops Hupe 1953)

Family: Protolenidae Richter and Richter 1948 ; Sub-family: Myopsoleninae Hupe 1953; Location: Tasmamte

Geyer's revision of the Myopsolenus genus is that the palpebral lobe is shorter than in Hamatolenus and does not reach the posterior border which is the case with this particular specimen.  This also fits Hupe's description of Collyrolenus staminops (Treatise on Invertebrate Paleontology, Part O, Trilobita page O211).  The glabella in the staminops is somewhat pointed in front (posterior) which makes the overall shape narrower than in H. Myopsolenus magnus which has a rounded glabella anteriorly.  The para-frontal band is not visible and is interrupted on the very narrow pre-glabellar field which also fits with the description in the Treatise.  Revised name is Myopsolenus staminops Jell and Adrain 2001; however, the original name is Collyrolenus in the Treatise.

Note the pre-glabellar field and the somewhat pointed glabella that characterizes this genus.  Also, notice that the parafrontal band is interrupted. The palpebral lobe is shorter and does not reach the posterior furrow noticeable on the left side especially where the lobe stops where the natural breakage of the free cheek occurs.  The right side lobe is also visible though the prep job there was not very good since I did not have air abrasive tools. Otherwise, the preservation of the specimen is very good.

Kenjiro 2009.5.10 (updated 2020.5.4.)