This is an incredibly rare London Clay fish with one confirmed specimen in the collection of the Natural History Museum, London and a more complete specimen which is also believed to represent P.sheppeyensis. The Holotype for this specimen is only a neurocranium so provides some limitations when comparing it to more complete specimens which is why it is somewhat difficult to say conclusively that the second, more complete specimen, represents the same species. The second specimen is certainly Promegalops genus however.