Maclurites crassus & Maclurites Trivia

This is an internal cast (It is almost unheard of to find one with the shell still intact.) of a Maclurites crassus, front and back.

Maclurite crassus front view.

Maclurite crassus back view.

Dummy me, I just found out this week that there are many species of Maclurites! The Maclurites crassus is not as common as the regular Maclurites we find here (which I am trying to get a confirmation of the correct species name…). The fronts are virtually identical; it is the backs that define them.

Maclurtites for a front view comparison. Crassus in middle but broke the tip off in prepping – must glue it back on.

Back view of same four Maclurites.

Out of a five gallon bucket full of Maclurites, I only found two Maclurites crassus! Neither in great condition without cracks which makes it hard to prep them. FYI, I prepped this one with just a $7 electric engraver from Harbor Freight to get the matrix off. Now I have to figure out how to glue the tip back on. 🙂

So, when labeling your Maclurites and you can’t determine the species, just put “Maclurites sp.”. Correct labeling should include formation: Stewartville member of the Galena Formation (Most common for Maclurites here.) Either county or area, both would be correct, so:

Maclurites sp.

Galena Formation

Southeastern Minnesota

OR

Maclurites crassus – if that is what it is.

Stewartville member of the Galena Formation

Fillmore County, Minnesota, U.S.A.

Maclurites Trivia 😀

One TFF discussion of cephalopods vs. gastropods.

Google Images search for Maclurites species.

In search of the largest Maclurite. 25 cm for a full fossil, 31 to 39 cm extrapolating from a piece of Maclurites. So, almost double the size of the biggest one I’ve ever found!