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The feeding apparatus of the fringed turtle Chelus fimbriatus (Schneider, 1783) was studied to elucidate the feeding mechanics of an aquatic feeding specialist that has never been investigated in detail before, regarding gross morphology. The skull and hyoid apparatus as well as associated musculature were examined by computer tomography and dissection; the tongue was examined by scanning electron microscopy. The flat skull, the possibility to enormously depress the mandible combined with a cheek-like development, the large, ossified hyoid apparatus, and a well-distensible esophagus enable the turtle to produce an enormous suction force the prey is inhaled with. The jaw adductors are poorly developed in relation to other turtles and thus help keep the skull shape flat; nevertheless, they are able to generate high velocities and exhibit some new performance lines. The hyoid musculature is as well-developed as the hyoid apparatus itself, promoting the high depression velocity that is necessary for good feeding performance. The tongue is nearly reduced and lacks dorsal morphological differentiations. Taking all the morphological features into account, C. fimbriatus is an extremely well-adapted turtle making this species a very interesting object of investigation.

The kinematics of intraoral food transport of Testudo hermanni were investigated by radiographic video analysis. Small lead markers and contrastmedia marked food pellets were used to describe the movements of the hyolingual apparatus, the jaws, and the food passage during feeding events. The feeding cycle is divided into food uptake, several intraoral transport cycles, and finally swallowing of the food. The results show features of a terrestrial feeder highly adapted to herbivorous diet: usage of tongue during ingestion, tongue-based intraoral transport combined with food manipulation prior to swallowing. The tongue of T. hermanni is equipped with long papillae and numerous lingual glands. Roughness of the tongue surface and sticky saliva produce interlocking forces acting on the food which facilitate food uptake, transport, and manipulation. Cineradiographic analysis enables complete documentation of the food passage during feeding events and, combined with conventional video recordings, allows more valid statements about the kinematics of feeding mechanisms.