Trituberculy

[Sarah]

A theory of the development of mammalian molar teeth. Theprimitive stage is that of simple cones, as in reptiles. The simplecone then developed a smaller cone in front and another behind. Next,a cingulum was developed, and the three cones became arranged in atriangle, the two smaller cusps having moved to the outer side inupper and to the inner in lower molars. This primitive triangle iscalled the trigon or trigonid and this stage the tritubercular ortrigonodont. The trigon being a cutting apparatus, an extension ofthe posterior part of the crown was developed in lower molars forcrushing, and a smaller corresponding part appeared in upper molars.Another large cone then arose, usually from the cingulum. In morecomplex forms, smaller intermediate cusps appeared.