Gobiconodon, Trofimov, 1978
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publication ID |
https://doi.org/ 10.5252/geodiversitas2022v44a25 |
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publication LSID |
urn:lsid:zoobank.org:pub:EA12DCB7-A5BE-4763-B805-25087EBD726D |
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DOI |
https://doi.org/10.5281/zenodo.6928938 |
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persistent identifier |
https://treatment.plazi.org/id/03C887B9-FF99-FFC4-745C-A30FFCEDF93C |
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treatment provided by |
Felipe |
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scientific name |
Gobiconodon |
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Gobiconodon ? sp.
( Fig. 32A, B View FIG )
DESCRIPTION
Within the eutriconodontan material from Angeac-Charente, the specimen ANG M-21 ( Fig. 32A, B View FIG ) consists of an isolated tooth crown, the main central cusp a being surrounded by two unequal cusps b and c (see figures 4.7 and 7.2 by Crompton & Jenkins [1968] and Kielan-Jaworowska et al. [2004] respectively for an explanation of the cusp-numbering system). The root is missing but the tooth was probably uniradiculate. The crown is labiolingually compressed and the lingual face appears almost planar in occlusal view, while the labial face is convex at its base ( Fig. 32A View FIG ). There is no trace of either a labial or lingual cingulid. Cusp a dominates the crown and is triangular in lateral profile ( Fig. 32B View FIG ). Its mesial surface is rounded, but its distal edge shows a well-defined crest ( Fig. 32A View FIG ). An oval wear facet can be observed on the labiodistal surface of cusp a ( Fig. 32A View FIG ). Cups b is smaller than cusp c; it is also placed higher relatively to cusp a and less separated from it than cusp c. The apex of cusp c appears to be slightly flexed labially. Both cusps b and c bear small labially oriented wear facets. The presence of a probably single root indicates a tooth from the anterior dentition, but the well-developed accessory cusps show that it is a distal premolar and not a more mesial tooth. Among Laurasian Early Cretaceous mammals, single-rooted distal premolars are only seen within the Gobiconodontidae family ( Sweetman 2006). Moreover, the specimen ANG M-21 closely resembles the gobiconodontid distal premolar (possibly right p4) described by Sweetman (2006) in the Early Cretaceous Wessex Formation of the Isle of Wight, southern England, and tentatively referred to Gobiconodon . Considering this, and the general morphology of ANG M-21 (tricuspid tooth with mesiodistally aligned cusps; dominant cusp a and small but well-developed accessory cusps; labial inflation of the crown; lack of cingulid), the specimen is identified as a left distal premolar, probably a p3 (as the accessory cusps are less developed than in the possible p4 described by Sweetman [2006]), of a gobiconodontid mammal, and is tentatively referred to Gobiconodon .
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.