Allodaposuchus undefined-2

CF. ALLODAPOSUCHUS SP. 2

Localities: Fontllonga-6.

Material: MCD-6868 ( Fig. 9 View Figure 9 ).

Description: The specimen MCD-6868 preserves the anterior branch of the right mandible that includes the first nine dental alveoli. The lateral surface of the jaw is heavily ornamented with pits and grooves. The fourth, sixth, seventh and ninth teeth have been preserved. The dorsal margin of the tooth row is festooned, with its maximum convexity at the height of the fourth tooth, which is the largest. Posteriorly to the fourth tooth, the size of the alveoli decreases and the dorsal margin of the tooth row becomes concave. The point of maximum concavity is placed between the seventh and eighth teeth, where there is a large interalveolar diastema, probably for the reception of the fourth or fifth maxillary tooth. From the eighth tooth onwards, the dorsal margin of the tooth row begins to rise again acquiring a convex contour in lateral view accompanied by a new increase in dental size. The region of the mandibular symphysis is not completely preserved, but seems to reach the third dentary tooth posteriorly. The splenial is lost, allowing observation of a channel that corresponds with the Meckelian groove. Therefore, the presence of foramina, the anterior extension of the splenial and its relation to the mandibular symphysis cannot be determined.

The preserved teeth ( Fig. 9D–F View Figure 9 ) are conical, with a slight constriction at the base and slightly lingually curved. The labial surface of the enamel is convex and smooth. The lingual surface is flatter, with well-marked longitudinal ridges extending from the base to the apex. There are two well-developed and smooth carinae on the mesial and distal margins. On the lingual surface two grooves adjacent to the carinae are present. These morphological features match with those from morphotype X.

Remarks: MCD-6868 preserves few diagnostic characters, but shows several similarities and differences with other dentaries referred to allodaposuchids ( Blanco et al., 2014; Narváez et al., 2015, 2016). Tooth morphology differentiates it from Acynodon and from any ‘atoposaurid’ or ziphosuchian taxon known in the Upper Cretaceous of Europe, but it resembles those of Allodaposuchus precedens and the allodaposuchid from Velaux-La Bastide Neuve ( Delfino et al., 2008a; Martin et al., 2016). MCD-6868 shows the diastema between the seventh and the eighth teeth, as do allodaposuchid specimens preserving the lower jaw. The occlusal outline is festooned as in Agaresuchus , but unlike Allodaposuchus palustris and Lohuecosuchus . MCD-6868 does not bear packed teeth, unlike IPS-105939 and Lohuecosuchus , and the dentary symphysis is shorter than in Allodaposuchus palustris , Lohuecosuchus , Agaresuchus and the VBN allodaposuchid. Remarkably, the medial projection of the dentary symphysis is reduced in MCD-6868, the symphysis remaining close to the dentary ramus in the parasagittal plane. The dentary MCD-6868 is also markedly narrow lateromedially – the dorsoventral axis being much larger than the lateromedial one – compared to any other lower jaw described in allodaposuchids.

EUSUCHIA INDET.