Identified as being from the Purbeck Beds, this specimen actualy looks identical to Mene rhombea, a Tertiary-aged fish from Monte Bolca in Italy. Even the matrix, the rock in which the fossil is preserved, looks wrong for the Purbeck Beds. To make things more complicated, if you were to do an internet search for ‘Microdon wagneri’ , you would find this species described as ‘a small-toothed harvest mouse’! So this name has probably been revised to something new.
Find out more on the fish page.