Oral food processing in two herbivorous lizards, Iguana iguana (Iguanidae) and Uromastix aegyptius (Agarnidae)
- 1 March 1976
- journal article
- research article
- Published by Wiley in Journal of Morphology
- Vol. 148 (3), 363-390
- https://doi.org/10.1002/jmor.1051480307
Abstract
The anatomy and function of the feeding apparatus in Iguana iguana and Uromastix aegyptius were studied by dissection, cinematic and cineradiographic techniques. The feeding behavior of these species differs from that of insectivorous lizards in the cropping action which separates a piece from the whole plant. The food is manipulated by a fleshy tongue and by movements of the whole head. There is no mastication of food. The cropping action involves movement of both the upper jaw around the atlantooccipital joint and the lower jaw around the mandibular joint; and in Uromastix only, streptostylic movement of the quadrate. Often movements of the whole head playa supplementary role in the cropping action. In both species the feeding apparatus has been modified to facilitate cropping. In Iguana the pleurodont dentition is multicusped and laterally compressed. Each tooth forms a shearing blade whose function does not require contact with other teeth. In Uromastix the dentition is acrodont and the cheek teeth are massive and lack cusps. Occlusion is necessary for shearing plant material. The skull system of Uromastix also has a number of modified structures which allow protraction and retraction of the lower jaw to facilitate cropping while maintaining a gape equivalent to that in Iguana. It is suggested that the differences in the feeding apparatus between Iguana and Uromastix are attributable to differences in the mode of tooth replacement and implantation.Keywords
This publication has 15 references indexed in Scilit:
- A problematic reptile from the British Upper TriasJournal of the Geological Society, 1973
- Lizard Energetics and DietEcology, 1973
- The dentition and dental tissues of the agamid lizard, UromastyxJournal of Zoology, 1973
- The dentition of agamid lizards with special reference to tooth replacementJournal of Zoology, 1970
- Comments on Inertial FeedingIchthyology & Herpetology, 1969
- The functional basis of the retroarticular process in some fossil reptilesJournal of Zoology, 1966
- Further Comments on Herbivorous LizardsEvolution, 1963
- THE FEEDING MECHANISM OF SNAKES AND ITS POSSIBLE EVOLUTIONAmerican Zoologist, 1961
- The head Skeleton of the LizardActa Zoologica, 1960
- A Survey of Adaptive Relationships of Dentition to Diet in the North American IguanidaeThe American Midland Naturalist, 1955