Chainodus sp.

Van Den Hoek Ostende, Lars W., Casanovas-Vilar, Isaac & Furió, Marc, 2020, Stuck in the middle. A geographical appraisal of the oldest insectivores - and a marsupial - from the Vallès-Penedès Basin (early Miocene, Catalonia, Spain), Comptes Rendus Palevol 19 (1), pp. 1-25 : 12

Chainodus sp.

( Fig. 4G)

MATERIAL AND MEASUREMENTS (in cm). — Spain. Material from Turó de les Forques , 1 m 1 dext., IPS85453 , 2.16 × 1.74 . Material from Costablanca 2, 2 mandibles bearing m1 and m2: sin. IPS116323 , m1 2.04 × 1.75, m2 1.68 × 1.20; dext. IPS 116324 m 1 2.07 × 1.72, m2 1.79 × 1.21 .

DESCRIPTION

M1

The molar is strongly amblyodont. The trigonid is only slightly higher than the talonid. The protoconid, paraconid and metaconid are regularly spaced, bordering a shallow but open trigonid basin. The hypoconid is massive. The oblique cristid ends against the base of the protoconid, the hypolophid connects to the entoconid. The posterior cingulid slopes up to just below the point where hypoconid and entoconid meet. A thick entocristid borders the shallow talonid basin on the lingual side. The labial cingulid is very strong at the base of the protoconid, but tapers out in both directions against the base of the hypoconid and the base of the paraconid, respectively. There is a stretch of bulbous lingual cingulid at the base of the trigonid.

m2

The trigonid is clearly longer and somewhat wider than the talonid. Because of the long, regularly curved paralophid, the trigonid basin is very open. The metaconid lies somewhat anterolingually of the protoconid. The talonid cusps are very reduced and incorporated in a low ridges surrounding the shallow talonid basin.

REMARKS

The genus Chainodus is a rare occurrence in the Iberian faunas. Its presence was first noted by Gibert (1975) as Cordylodon (= Chainodus ) intercedens from Rubielos de Mora 2. The observation by Furió et al. (2011a) that Chainodus was present in lower Miocene strata of the Vallès-Penedès was based on the material that is described here. Recently, Van den Hoek Ostende et al. (2017) confirmed the presence of Chainodus in other assemblages from the Rubielos de Mora Basin. However, the species was not C. intercedens , a taxon which is very common in central Europe in the later part of the early Miocene (e.g. Müller 1967; Ziegler 1990a; Klietmann et al. 2014b). Instead, the authors identified the dimylid from Alto de Ballester as C. sulcatus , based on the loose symphysis of the lower jaw. As this character cannot be observed in our material, we leave the identification at the genus level.