 The teeth or "fimbriations" are obliquely directed towards the front and the top.They are grooved at their sides, the striations continuing over the sides of the raker.Detailed study of exquisitely preserved French specimens revealed to Liston that these teeth were, again via soft tissue, each attached to delicate 2-millimetre-long (0.08-inch-long) bony plates, structures that had never before been observed among living or extinct fishes.