Anura gen. et sp. indet.

REFERRED MATERIAL. — Nine fragments of maxillae (MNHN.F.IBC1989a, IBC1989b, IBC1991a-IBC1991f, IBC2063).

DESCRIPTION

Maxillae

Three maxilla morphotypes distinct from the unnamed neobatrachian can be identified within In Becetèn: maxillary morphotypes A, B and C.

The two fragments attributed to the maxillary morphotype A (MNHN.F.IBC1989a, IBC1989b) bear ornamentation made of pits and ridges on their labial surface (Fig. 3A, B). This ornamentation covers the whole pars facialis, and most of the pars dentalis, leaving only a thin strip of smooth bone along the margin of the crista dentalis (Fig. 3B). The crista dentalis is shallow. One fragment (MNHN.F.IBC1989a) bears a distinct, rounded lamina horizontalis lingually (Fig. 3C). On the second fragment (MNHN.F.IBC1989b), there is no lamina horizontalis (Fig. 3D). Morphotype A can be differentiated from the above unnamed neobatrachian in being ornamented by pits and ridges (instead of small tubercles).

Four fragments are assigned to the maxillary morphotype B (MNHN.F.IBC1991a, IBC1991b, IBC1991c, IBC1991d). Three of them lack ornamentation on their labial surface (Fig. 3E, F). The only exception is the largest fragment (MNHN.F.IBC1991a), where a faint patch of rugose ornamentation is present near the base of the frontal process (Fig. 3E). All fragments bear a crista dentalis, with poorly-preserved teeth (Fig. 3C, D, G, I). In lingual view, the rounded, prominent lamina horizontalis is distinct on all fragments (Fig. 3G). The recessus vaginiformis is shallow, but well delimited ventrally and anterodorsally by two crests (Fig. 3G). The anterodorsal crest (processus palatinus) extends dorsally onto the lingual surface of the frontal process. This morphotype can be differentiated from the maxillary morphotype A and the unnamed neobatrachian in: 1) lacking ornamentation on its labial surface; and 2) by a thin lamina horizontalis that protrudes lingually.

Two fragments are assigned to the maxillary morphotype C (MNHN.F.IBC1991e, IBC2063). Their labial surface is covered in small pits and ornamentation imparting rugosity (Fig. 3H). This ornamentation seems to extend onto the whole labial surface. The maxilla is toothed (Fig. 3I). The zygomaticomaxillaris process projects posterodorsally (Fig. 3H, I). The orbital margin strongly decreases in height posterior to the latter process (Fig. 3H). Lingually, the lamina horizontalis is indistinct from the lingual surface of the maxilla (Fig. 3I), and no pterygoid process is present. The presence of a zygomaticomaxillaris process indicates that squamosal and maxilla were articulated in the maxillary morphotype C. This morphotype differs therefore from maxillary morphotypes A and B and the unnamed neobatrachian in being ornamented over the whole labial surface of the maxilla. It is also differentiated from the unnamed neobatrachian in: 1) lacking a pterygoid process; and 2) lacking a distinct lamina horizontalis.

DISCUSSION AND ATTRIBUTION

All three maxillary morphotypes are distinct from the unnamed neobatrachian and appear to represent three other distinct taxa. It should be noted that the presence of teeth does not exclude an attribution to the four pipimorph taxa known (Lemierre et al. 2023, 2025). Although most pipids lack teeth (Trueb et al. 2000), xenopodines and extinct pipimorphs are known to have teeth (Henrici & Báez 2001; Báez & Púgener 2003). However, the ornamentation present in morphotypes A and C differs from that of Pachycentrata Báez & Rage, 2004 and the unnamed pipimorph 2 (Báez & Rage 1998; Lemierre et al. 2025), while Inbecetenanura Lemierre, Bailon, Folie & Laurin, 2023 and the unnamed pipimorph 1 lack ornamentation. Hence, maxillary morphotypes A, B and C can be assigned neither to Pachycentrata nor to unnamed pipimorph 2. Furthermore, the presence of small patches of ornamentation in the maxillary morphotype B around the frontal process renders an attribution to Inbecetenanura unlikely, as such ornamentation would likely be present on the frontoparietal. Hence, the maxillary morphotype B could be attributed to the unnamed pipimorph 1 or to another non-pipid taxon in In Becetèn. Maxillary morphotypes A and C are assigned to indeterminate non-pipid anurans.

Thus, based on maxilla elements, between three and four non-pipid anuran taxa are present in In Becetèn.