The functional role of Carabelli trait in early and late hominins

Luca Fiorenza, John Kaidonis, Ottmar Kullmer, Jacopo Moggi-Cecchi, Grant Clement Townsend

Research output: Contribution to conferenceAbstract

Abstract

Carabelli trait is an accessory dental feature that forms along the lingual margin of the protocone of deciduous and permanent maxillary molars [1, 2]. It is variably expressed, ranging from a small pit or furrow to a large cusp, and its development, at least in Homo sapiens, is associated with crown size and intercuspal distance. This, nevertheless, seems to differ systematically between hominin taxa, and the variation in frequency and degree of expression of Carabelli trait has been used extensively for phylogenetic analysis. However, its functional implications remain unclear [3, 4]. In this preliminary study, we analyze the dental wear pattern of maxillary molars of early (Australopithecus afarensis, Australopithecus africanus, Paranthropus robustus and Paranthropus boisei) and late hominins (Neanderthal, Middle Paleolithic Homo sapiens and recent modern humans) using the Occlusal Fingerprint Analysis method, an approach based on digital models of teeth [5]. We only selected one molar for each species with a clearly visible Carabelli cusp that showed signs of wear. We manually outlined each wear facet onto the polygonal surface, measuring their dip directions (the angle between the projected and the reference vectors). The resulting occlusal movements were described using the occlusal compass, a circular space that ranges from 0° to 360°. In tooth crowns with a small Carabelli cusp, a large facet 5 was generally noticeable which extended cervically, while in teeth characterized by a large Carabelli cusp, two new facets, a mesial 5.1 and a distal 6.1, could be identified. These facets are created by lateroretrusive and/or lateroprotrusive movements, occluding with the lingual groove of the lower molars, between the metaconid and entoconid cusps. It has been suggested that Carabelli cusp provides an additional surface area that extends the molar’s functional life in highly abrasive environments [1, 3]. The facets observed in this study increase occlusal shearing area and this may be useful for a diet rich in tough and fibrous foods.
Original languageEnglish
Pages89
Number of pages89
Publication statusPublished - 2015
EventAnnual Meeting of the European Society for the study of Human Evolution (ESHE 2015) - London, United Kingdom
Duration: 10 Sep 201512 Sep 2015
Conference number: 5th
http://www.eshe.eu/meeting_2015.html

Conference

ConferenceAnnual Meeting of the European Society for the study of Human Evolution (ESHE 2015)
Abbreviated titleEHSE 2015
CountryUnited Kingdom
CityLondon
Period10/09/1512/09/15
Internet address

Keywords

  • Carabelli
  • Tooth wear
  • Occlusion

Cite this

Fiorenza, L., Kaidonis, J., Kullmer, O., Moggi-Cecchi, J., & Townsend, G. C. (2015). The functional role of Carabelli trait in early and late hominins. 89. Abstract from Annual Meeting of the European Society for the study of Human Evolution (ESHE 2015), London, United Kingdom.