I think this is a wonderful mass of ammonoids (Popanoceras, Metalegoceras and others) and orthocones. The two largest Popanoceras individuals are each about 25 mm across. This is from the Lower Permian of Aktubinskya.
I've not seen much written on this cephalopod limestone, but it's incredibly rich and diverse. Here's a pile of Kazakh cephalopods thrown together on my desk.
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