Saurorhynchus, Reis, 1892

Maxwell, Erin E. & Stumpf, Sebastian, 2017, Revision of Saurorhynchus (Actinopterygii: Saurichthyidae) from the Early Jurassic of England and Germany, European Journal of Taxonomy 321 (321), pp. 1-29 : 20-21

Saurorhynchus sp.

Material studied

GERMANY: Numismalismergel jaw ( SMNS 96082).

Remark

SMNS 96082 is the only Pliensbachian record of Saurorhynchus of which we are aware. Although clearly referable to Saurorhynchus , SMNS 96082 is distinct from S. anningae sp. nov. in the shape of the posterior mandible and position of the mandibular sensory canal, and also from S. brevirostris , in that the posterior edge of the mandible is more strongly sinusoidal. However, there are few features to differentiate SMNS 96082 from the Toarcian-aged S. acutus and S. hauffi sp. nov. One notable difference is the development of plicidentine, which is easily visible around all tooth bases in this specimen. In Toarcian saurichthyids, plicidentine, while present at least some of the time, does not appear to be as well-developed or consistently present. However, body size/absolute tooth size may be playing a role: with a mandibular depth of 23 mm, the Numismalismergel jaw ranks among the largest Saurorhynchus skulls from southwestern Germany (Suppl. Table 1; Hauff 1938). As in the Toarcian material, the collar region of the teeth does not appear to be corrugated.

Comparing the jaw depth to other Toarcian Saurorhynchus skulls, a skull length of between 114 mm (based on PMU 30009) and 143 mm ( Hauff 1938) is predicted, which would result in an estimated fork length of 40–50 cm.