Meeting Abstract

77.3  Sunday, Jan. 6  Bite performance of the extant coelacanth Latimeria chalumnae DUTEL, H*; HERREL, A; CLÉMENT, G; HERBIN, M; Muséum national d’Histoire naturelle; Muséum national d’Histoire naturelle; Muséum national d’Histoire naturelle; Muséum national d’Histoire naturelle dutel@mnhn.fr

The coelacanth Latimeria is the only extant genus of a group of lobe-finned vertebrates (sarcopterygian) originating in the Devonian times. Since its discovery in 1938, this genus has been of considerable interest due to its striking similarity with fossil coelacanths and the presence of anatomical features that are only known in fossil sarcopterygian fishes. Notably, it is the only extend genus showing a skull divided into an anterior (i.e. ethmosphenoid) and a posterior (i.e. otoccipital) part, which articulate by means of an intracranial joint. This complex articulation is thought to allow an elevation of the snout by 10° to 20°, which would enhance mouth opening distance and velocity allowing a powerful suction. Although the cranial anatomy of Latimeria is well known, the function of its kinetic joint during feeding remains poorly understood. Indeed, the lack of information on some key anatomical structures as well as on the actual movements of the cranial elements during feeding has led to the proposition of a number of hypotheses on the role of the intracranial joint and other structural elements of the head during jaw movement. Based on morphological data acquired from the recent dissection of a coelacanth specimen from the MNHN collections, we re-describe the jaw closer muscles, and estimate bite forces using a static equilibrium model. Implications in the skull kinesis and feeding behaviour of Latimeria will be discussed, and future directions of this study will be presented.