? Varanus sp. Figure 2. Material. Two isolated teeth (NMB Hüe.1 and NMB Hüe.2). Description. Both teeth are incomplete, with NMB Hüe.1 missing the tip and tooth base, and NMB Hüe.2 being slightly abraded and also lacking the tooth base (Fig. 2). They are rather small, unicuspid, labiolingually compressed, and posteriorly curved; the curvature is more pronounced in NMB Hüe.1. Asharp carina runs throughout both the mesial and distal margins of both teeth, being especially prominent in NMB Hüe.1. In that specimen, both mesial and distal carinae are distinctly serrated, comprising prominent denticles; these denticles are fairly regular in size (about 0.09 mm /denticle) and gently rounded in profile, separated by interdenticle grooves. The serration of the distal carina of NMB Hüe.1 is prominent throughout its preserved length, while that of the mesial carina is more prominent at mid-height on the tooth and diminishes apically and especially basally. In NMB Hüe.2, the portions where the two carinae are preserved are eroded. Plicidentine (the infolding of dentine in the pulp cavity; Kearney & Rieppel, 2006) is not documented in either tooth, although it could have been present on the non-preserved tooth bases. The pulp cavity of both teeth is distinctive in being labiolingually compressed. Surrounding this slot-like pulp cavity, the basal surface of the tooth is covered by scallop-shaped erosional features reminiscent of Howship’s lacunae, which mark the action of osteoclasts that have destroyed dental tissue in preparation for tooth shedding (LeBlanc et al., 2023). In NMB Hüe.1, where the pulp cavity is more well exposed and visible, measurements on these scallop-shaped erosional features reveal typical diameters of around 30–40 μm (mean range around 20–50 μm), values that are consistent with our interpretation of them as Howship’s lacunae.

Published as part of Georgalis, Georgios L., Mennecart, Bastien & Smith, Krister T., 2023, First fossil record of Varanus (Reptilia, Squamata) from Switzerland and the earliest occurrences of the genus in Europe, pp. 1-10 in Swiss Journal of Geosciences 116 (9) on page 3, DOI: 10.1186/s00015-023-00440-5, http://zenodo.org/record/8136616