Lateral osteoderms of the Nile crocodile Crocodylus niloticus
Abstract
A.B. Kiladze and O.F. Chernova
The article shows morphometry of large and small lateral osteoderms on the Nile crocodile body, which forms into arc-like lines. Length of large lateral osteoderms is 2.52 times greater than small lateral osteoderms, width of large lateral osteoderms is 2.20 times greater than small lateral osteoderms, and area of large lateral osteoderms is 5.59 times greater than small lateral osteoderms. Configuration index (length to width ratio) is similar in large (2.03 ± 0.06) and small (1.92 ± 0.17) lateral osteoderms, but scale range of this factor is less significant in large lateral osteoderms (1.67–2.50), than in small lateral osteoderms (1.00–3.00).
Keywords: Nile crocodile Crocodylus niloticus; Osteoderms; Lateral areas; Topography; Sizes, Configuration; Bioinformatic model
References
Chernova, O.F., & Kiladze, A.B. (2019). Heterochrony as the Basis for Inter- and Intraspecific Diversity of Skin in Vertebrates. Biology Bulletin Reviews, 9(2), 174–189.
Clarac, F., Souter, T., Cornette, R., Cubo, J., Buffrenil, V.de. (2015). A Quantitative Assessment of Bone Area Increase Due to Ornamentation in the Crocodylia. Journal of Morphology, 276(10), 1183−1192.
Clarac, F., Goussard, F., Teresi, L., Buffrénil, V., De Sansalone, V. (2017). Do the ornamented osteoderms influence the heat conduction through the skin? A finite element analysis in Crocodylomorpha. Journal of Thermal Biology, 69, 39−53.
Clarac, F., Buffrénil, V.de., Cubo, J., Quilhac, A. (2018). Vascularization in Ornamented Osteoderms: Physiological Implications in Ectothermy and Amphibious Lifestyle in the Crocodylomorphs? The Anatomical Record, 301(1), 175−183.
Cott, H.B. (1961). Scientific results of an inquiry into the ecology and economic status of the Nile crocodile (Crocodilus niloticus) in Uganda and Northern Rhodesia. The Transactions of the Zoological Society of London, 29(4), 211−356.
Downs, C.T., Greaver, C., Taylor, R. (2008). Body temperature and basking behavior of Nile crocodiles (Crocodylus niloticus) during winter. Journal of Thermal Biology, 33, 185−192.
Grigg, G., Gans, C. (1993). Morphology and physiology of the Crocodylia. In: Fauna of Australia, 2A: Amphibia and Reptilia. Canberra: Australian Government Publishing Service, 326−336.
Jackson, D.C., Andrade, D.V., Abe, A.S. (2003). Lactate sequestration by osteoderms of the broad-nose caiman, Caiman latirostris, following capture and forced submergence. Journal of Experimental Biology, 206, 3601–3606.
Janis, C.M., Devlin, K., Warren, D.E., Witzmann, F. (2012). Dermal bone in early tetrapods: a palaeophysiological hypothesis of adaptation for terrestrial acidosis. Proc. R. Soc. B, 279, 3035–3040.
Kiladze, A.B. (2018a). Angle of mouth gaping of the Nile crocodile Crocodylus niloticus at basking. International Research Journal, 9(75), 103−105.
Kiladze, A.B. (2018b). Some features of the location of the Nile crocodile osteoderms. Postulat, 11(37), 62.
Kofron, C.P. (1993). Behavior of Nile crocodiles in a seasonal river in Zimbabwe. Copeia, 1993(2), 463–469.
Kuckir, I. (2019). Voronoi diagram in JavaScript. Available at: http://blog.ivank.net/voronoi-diagram-in-javascript.html.
Modha, M.L. (1968). Basking behavior of the Nile crocodile on CentralIsland, Lake Rudolph. East Afr. Wildl J, 6, 81–88.
Seebacher, F., Grigg, G.C. (1997). Patterns of body temperature in wild freshwater crocodiles, Crocodylus johnstoni: Thermoregulation versus thermoconformity, seasonal acclimatization, and the effect of social interactions. Copeia, 1997(3), 549–557.
Seebacher, F., Grigg, G.C., Beard, L.A. (1999). Crocodiles as dinosaurs: behavioural thermoregulation in very large ectotherms leads to high and stable body temperatures. Journal of Experimental Biology, 202(1), 77–86.
Seebacher, F., Franklin, C.E., Read, M. (2005). Diving behaviour of a reptile (Crocodylus johnstoni) in the wild: interactions with heart rate and body temperature. Physiol. Biochem. Zool, 78(1), 1–8.
Spotilia, J.R., Terpin, K.M., Dodson, P. (1977). Mouth gaping as an effective thermoregulatory device in alligators. Nature, 265, 235–236.
Vickaryous, M.K., Sire, J.Y. (2009). The integumentary skeleton of tetrapods: origin, evolution, and development. J Anat, 214(4), 441−464.