Theriosuchus undetermined

CF. THERIOSUCHUS SP.

Localities: Molí del Baró-1, Serrat del Pelleu, Serrat del Rostiar-1, Camí del Soldat, L’Espinau.

Material: MCD-5565–66, MCD-7008, IPS-105919, IPS-96630, IPS-96637, IPS-96644, IPS-96647, IPS-96648, IPS-96654, IPS-96655, IPS-96663, IPS-96665, IPS-96671, IPS-85797, IPS-96680, IPS-96683, IPS-85799, IPS-96699–702 ( Fig. 3A–I View Figure 3 ).

Description: Wide and lanceolate teeth bearing a well-marked basal constriction. They are 1.6‒2.7 mm high basiapically and 0.9‒2.1 mm wide mesiodistally. The teeth are labiolingually flattened, with the lingual surface flat or slightly convex and the labial one more convex ( Fig. 3C–E View Figure 3 ). The apex is curved lingually. The enamel is ornamented with longitudinal ridges, well-marked on the lingual side but faint on the labial face. Ridges are not parallel: median ridges converge towards the apex whereas lateral ones diverge towards the carinae ( Fig. 3P–Y View Figure 3 ). Carinae lack denticles or false ziphodont serrations.

Remarks: This morphotype differs from morphotype X in bearing ornamented carinae and labial surface with ridges. These features have been commonly described in fossil remains referred to Theriosuchus , in which heterodonty have been well assessed ( Tennant et al., 2016). Specifically, the shape of the morphotype V matches well with Theriosuchus teeth of anterior dental positions, preserved in situ. However, the tooth MCD-7008 is especially larger (3.7 mm high and 2.3 wide) and acute, despite being included in the same morphotype. It also shows a more developed central region in lingual view with a strong ornamentation and well-marked carinae ( Fig. 3R–U View Figure 3 ). MCD-7008 might represent a caniniform, according to the variation observed in dental series of ‘atoposaurids’ ( Martin et al., 2014; Tennant et al., 2016).

However, after the revision of this clade carried out by Tennant and collaborators, most of the taxa included in Theriosuchus split into Theriosuchus (sensu Tennant et al., 2016) and Sabresuchus . According to these authors, Theriosuchus is restricted to the Jurassic and Early Cretaceous, whereas the Late Cretaceous species (e.g. Martin et al., 2014) were relocated into the genus Sabresuchus . Although the studied material from the Tremp Formation falls within the chronological range of Sabresuchus , it differs from the dental morphology of this taxon in the enamel ornamentation and in the lack of false-ziphodont carinae (see: Martin et al., 2014), resembling instead teeth of Theriosuchus ( Tennant et al., 2016) and the? Theriosuchus sp. teeth from Cruzy ( Martin et al., 2014). This morphotype corresponds to morphotype 8 described by Marmi et al. (2016) from the Molí del Baró-1 site.