Another M2 of S. bolligeri has this crest on the labial side.

It is visible on the labial (outer) side of the mandible (lower jaw) as a raising in the bone.

Second, there was a small protuberance on the labial side of the crown, which is also present in many other species of the family.

Also unlike in Lundomys, there is an additional small root present at the labial (outer) side of the first upper molar.

A weak cingulum is present on the labial side of the tooth between the protoconid and hypoconid.

A well-developed small cusp, a mesostyle, is present on the labial side.

On the labial side, the four ridges at the back are more widely separated than the four in front of them.

The back and front margins of the tooth are parallel and there is no small cusp on the labial side.

Two ridges descend from the tip of each cusp to the lingual and labial sides.

The labial side of the tooth is taller and less worn than the lingual side.