Orthoconic cephalopods are also found in the Utica shale (Ordovician, Darriwillian stage) and can get somewhat large. The downside is that they are not preserved very well it can be difficult to definitively ID any specimen. These are some that I found this past fall on Nowadaga Creek. This first one is pyritized but not a great many details are retained.
Others are just impressions in the shale.
This specimen, however, does show evidence of sutures and chambers.
Various publications have ascribed the cephalopds found in the Utica shale variously to Endoceras, and Geisonoceras. I posted pictures of a specimen I purchased back in 2011 here.