Mystery Petalodont

[Archie]

I found this little tooth a few months ago in the Coal Measures (Westphalian A) of Scotland in a fresh/brackish water deposit and thought it might be a Janassa sp. of some sort but now I'm not so sure, the only other Petalodont genus's I'm aware of in the British Coal Measures are Ageleodus and Ctenoptychius but they both have multicuspid crowns, the tooth is in labial view and is 11mm across. Any thoughts would be greatly appreciated!