problematic fossil造句

"Diskagma buttonii " is a problematic fossil that has been named before its biological affinities have been understood.
""'Angarella " "'is an early palaeozoic genus of problematic fossils, long held to belong to the molluscs based on supposed similarities in its musculature to that of hyoliths and mobergellids, but now considered to represent a brachiopod based on its calcitic mineralogy and paired symmetrical valves.
It's difficult to find problematic fossil in a sentence. 用problematic fossil造句挺难的