Paronychodon lacustris

Fig. 4

Material: Teeth: UCM 38288 (UCMP-V57 ll) H 4 mm, W 1.3 mm; UCMP 38459 (UCMP-V5711) H 1.7 mm, W 2.3 mm; UCMP 124990 (UCMP-V73087) H 3.4 mm, W 1.7 mm; UCMP 124991 (UCMP-V73087) H 4.8 mm, W 1 1.9. 9 mm; and UCMP 124992 (UCMP-V73087) H 4.3 mm, W 1.6 mm.

Discussion: Despite their small size, these teeth are clearly referable to Paronychodon lacustris. The anterior and posterior edges are vertical and parallel near the base (Fig. 4), but then curve sharply posteriorly with the two edges meeting in a pointed tip. The teeth are laterally compressed, with one side being flat and covered by long ridges parallel to the edges of the crown. These ridges cover the one side of the crown between the tip and where the tooth curves posteriorly. Serrations may or may not be present on the posterior edge; none occurs on the anterior edge.