Is very technical, I would not expect anyone but a person with qualifications in the area to understand exactly because the sentence itself lacks information to tell the meaning to an unequalled person. But the weird mean something like this ; There was some aspect of the object that d recognisable to a trained eye - the angle of the centre of some part of the object was exactly as expected in an object of this type. Assuming it is a jawbone, I would guess that he d able to confirm the type of animal or age of the animal from this 'medial (central) angling (the angle of the centre)'

The characteristic medial angle is the usual medial angle, or the angle of the jaw we would expect to fine. To find the medial angle of your jaw, place a finger under the edge of your jaw and move it back. When you get to the point under the ear, the direction of the bone goes up into the skull. This angle of the curve is the medial angle of the jaw.