Three Ordovician Uncertainties

[Kane]

I have a hunch about these, but I felt it best to get some more seasoned input. 

 

The first two are trilobite partials. I'm tempted to call the one on the right just another small Isotelus, but the segmentation doesn't appear quite right. Found in the Lindsay Fm.

 

The second image is a matter of dispute (or so I was told) with one expert stating it is an ammonoid, and another stating it is a gastropod. Found in the Whitby shale. About 5 cm in diameter.

[Peat Burns]

My thought is cf. Maclurites (Gastropod) in the 2nd photo.

[Northern Sharks]

The larger trilobite piece is likely from an Isotelus, although from the pic, I can't tell what part or how much of the piece is missing. The smaller bug on the right looks to be a small Isotelus "mafrizae" -the morph with genal spines. Your last pic is a rarity-I believe that is is classified as a cephalopod, not a gastropod, but the name escapes me at the moment. I'm at work so I can't look it up, but it is mentioned at the very back of Hessin's book without a description (reported from Ontario but not described in the book). If nobody else comes up with it, I'll find the name tomorrow if I remember. I have a meeting tonite and will likely forget by the time I get home.

[Kane]

17 minutes ago, Northern Sharks said:

The larger trilobite piece is likely from an Isotelus, although from the pic, I can't tell what part or how much of the piece is missing. The smaller bug on the right looks to be a small Isotelus "mafrizae" -the morph with genal spines. Your last pic is a rarity-I believe that is is classified as a cephalopod, not a gastropod, but the name escapes me at the moment. I'm at work so I can't look it up, but it is mentioned at the very back of Hessin's book without a description (reported from Ontario but not described in the book). If nobody else comes up with it, I'll find the name tomorrow if I remember. I have a meeting tonite and will likely forget by the time I get home.

My thanks! I've added a better lit solo image of the one on the left just to be certain (at least of where this fragment fits - I'm used to seeing a more triangular pygidium on I. mafritzae, so maybe I. latus?). 

 

And I'll look at my Hessin for this ceph. 

[Northern Sharks]

Found it on the interwebs. Trocholites ammonius