Subdigital and subcaudal microornamentation in chamaeleonidae—A comparative study

Authors

  • Marlene Spinner,

    Corresponding author
    1. Institute of Zoology, University of Bonn, Poppelsdorfer Schloss, 53115 Bonn, Germany
    2. Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten, Kiel 24098, Germany
    • Institut für Zoologie, Poppelsdorfer Schloss, Meckenheimer Allee 169, 53115 Bonn, Germany

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  • Guido Westhoff,

    1. Institute of Zoology, University of Bonn, Poppelsdorfer Schloss, 53115 Bonn, Germany
    2. Tierpark Hagenbeck gGmbH, Lokstedter Grenzstr, Hamburg 22527, Germany
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  • Stanislav N. Gorb

    1. Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten, Kiel 24098, Germany
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Abstract

Locomotion on horizontal and vertical substrates requires effective attachment systems. In three clades of arboreal and rupicolous Iguanidae, Gekkota and Scincidae adhesive systems consisting of microscopic hair-like structures (setae) have been evolved independently. Also the substrate contacting sites on toes and tails of chameleons (Chamaeleonidae) are covered with setae. In the present comparative scanning electron microscopy study, we show that representatives from the chamaeleonid genera Calumma, Chamaeleo, Furcifer, and Trioceros feature highly developed setae that are species-specific and similar on their feet and tail. These 10 μm long, unbranched setae rather resemble those in anoline and scincid lizards than the larger and branched setae of certain gecko species. In contrast to the thin triangular tips of other lizards, all examined species of the genera Furcifer and Calumma and one of the five examined species of the genus Trioceros have spatulate tips. All other examined species of genera Trioceros and Chamaeleo bear setae with narrowed, fibrous tips. Unlike the setae of other lizards, chamaeleonid setal tips do not show any orientation along the axis of the toes, but they are flexible to bend in any direction. With these differences, the chameleon's unique microstructures on the zygodactylous feet and prehensile tail rather increase friction for arboreal locomotion than being a shear-induced adhesive system as setal pads of other lizards. J. Morphol., 2013. © 2013 Wiley Periodicals, Inc.

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