The jaw of
Ambondro mahabo, seen in lingual view (from the side of the tongue). The scale bar is 1 mm (0.039 in) long. This
mammal species is known only from this fragmentary
lower jaw with three teeth, interpreted as the last
premolar and the first two
molars. It is the oldest known mammal with putatively
tribosphenic teeth.
Photo: André R. Wyss