Bumastoides ?

[Tidgy's Dad]

Hello, Roommates! 

I received this little trilobite as part of my Secret Santa package, and, though i know the eyes are missing, and parts of the pygidium etc., am rather fond of the little fellow. 

The label with it said Illaenus americanus and it was said to be from the Galena Limestone, Upper Ordovician nr, Postville, North East Iowa, a quarry or a roadcutting. 

Now the first thing I discovered, and please correct me if I'm wrong, is that the name is no longer valid and this is now Thaleops laurentiana. And on looking closer, it doesn't seem to be it at all. The lack of axial furrows and general effacement led to me to think Bumastoides sp. so i then read up on the paper   https://www.researchgate.net/publication/257656692_A_systematic_revision_of_the_Upper_Ordovician_trilobite_genus_Bumastoides_Illaenidae_with_new_species_from_Oklahoma_Virginia_and_Missouri?enrichId=rgreq-42948ac4406fefc77dead768950eae0b-XXX&enrichSource=Y292ZXJQYWdlOzI1NzY1NjY5MjtBUzo5NzE0MzExMzEyNTg5NUAxNDAwMTcyMTMxNjE4&el=1_x_2&_esc=publicationCoverPdf

and so on. I also discovered this (second item down, left hand margin : http://www.robertcharleswolf.net/newsletter942186.htm

So it could actually be Maquoketa Formation, Elgin Member. 

The specimen seems to have 10 segments in the thorax so I'm thinking B. porrectus or B. beckeri.

Any help greatly appreciated, here are a few photos:

[indominus rex]

Nice trilobite.

[Northern Sharks]

Based only on what I find in my local Ordovician, it looks a lot like a Bumastoides to me, certainly not Illaenus or Thaleops.