Komodo Reptile Scales

Product Information

Many lepidosaurs have a photosensory organ on the top of their heads called the parietal eye, which are also called third eye, pineal eye or pineal gland. This "eye" does not work the same way as a normal eye does as it has only a rudimentary retina and lens and thus, cannot form images. It is, however, sensitive to changes in light and dark and can detect movement. [112] a b c Lee, M.S.Y. (2013). "Turtle origins: Insights from phylogenetic retrofitting and molecular scaffolds". Journal of Evolutionary Biology. 26 (12): 2729–2738. doi: 10.1111/jeb.12268. PMID 24256520. Sometimes snakes have enlarged scales, either single or paired, under the tail; these are called subcaudals or urosteges. [22] These subcaudals may be smooth or keeled as in Bitis arietans somalica. The end of the tail may simply taper into a tip (as in the case of most snakes), it may form a spine (as in Acanthophis), end in a bony spur (as in Lachesis), a rattle (as in Crotalus), or a rudder as seen in many sea snakes. The terms reptile and amphibian were largely interchangeable, reptile (from Latin repere, 'to creep') being preferred by the French. [8] J.N. Laurenti was the first to formally use the term Reptilia for an expanded selection of reptiles and amphibians basically similar to that of Linnaeus. [9] Today, the two groups are still commonly treated under the single heading herpetology.

AZ Animals is a growing team of animals experts, researchers, farmers, conservationists, writers, editors, and -- of course -- pet owners who have come together to help you better understand the animal kingdom and how we interact. Reptiles: Different Types, Definition, Photos, and More FAQs (Frequently Asked Questions) Reptile activity is strongly dependent on the temperature of the surrounding environment. Reptiles are ectothermic—that is, they require an external heat source to elevate their body temperature. They are also considered cold-blooded animals, although this label can be misleading, as the blood of many desert reptiles is often relatively warm. The body temperatures of many species approximate the surrounding air or the temperature of the substrate, hence a reptile can feel cold to the human touch. Many species, particularly lizards, have preferred body temperatures above 28 °C (82 °F) and only pursue their daily activities when they have elevated their body temperatures to those levels. These species maintain elevated body temperatures at a relatively constant level by shuttling in and out of sunlight. DABVP, Ryan S. De Voe DVM MSpVM DACZM. "Reptilian cardiovascular anatomy and physiology: evaluation and monitoring (Proceedings)". dvm360.com. Archived from the original on 2018-11-06 . Retrieved 2017-04-22.

Lyson, Tyler R.; Schachner, Emma R.; Botha-Brink, Jennifer; Scheyer, Torsten M.; Lambertz, Markus; Bever, G.S.; Rubidge, Bruce S.; de Queiroz, Kevin (2014). "Origin of the unique ventilatory apparatus of turtles" (PDF). Nature Communications. 5 (5211): 5211. Bibcode: 2014NatCo...5.5211L. doi: 10.1038/ncomms6211. PMID 25376734. It is generally assumed that reptiles are unable to produce the sustained high energy output necessary for long distance chases or flying. [79] Higher energetic capacity might have been responsible for the evolution of warm-bloodedness in birds and mammals. [80] However, investigation of correlations between active capacity and thermophysiology show a weak relationship. [81] Most extant reptiles are carnivores with a sit-and-wait feeding strategy; whether reptiles are cold blooded due to their ecology is not clear. Energetic studies on some reptiles have shown active capacities equal to or greater than similar sized warm-blooded animals. [82] Respiratory system [ edit ] X-ray fluoroscopy videos of a female American alligator showing contraction of the lungs while breathing Despite the early proposals for replacing the paraphyletic Reptilia with a monophyletic Sauropsida, which includes birds, that term was never adopted widely or, when it was, was not applied consistently. [2] Bearded dragon ( pogona) skeleton on display at the Museum of Osteology The earliest known proto-reptiles originated around 312 million years ago during the Carboniferous period, having evolved from advanced reptiliomorph tetrapods which became increasingly adapted to life on dry land. The earliest known eureptile ("true reptile") was Hylonomus, a small and superficially lizard-like animal. Genetic and fossil data argues that the two largest lineages of reptiles, Archosauromorpha (crocodilians, birds, and kin) and Lepidosauromorpha (lizards, and kin), diverged near the end of the Permian period. [4] In addition to the living reptiles, there are many diverse groups that are now extinct, in some cases due to mass extinction events. In particular, the Cretaceous–Paleogene extinction event wiped out the pterosaurs, plesiosaurs, and all non-avian dinosaurs alongside many species of crocodyliforms, and squamates (e.g., mosasaurs). Modern non-bird reptiles inhabit all the continents except Antarctica. a b Sahney, S.; Benton, M.J.; Falcon-Lang, H.J. (2010). "Rainforest collapse triggered Pennsylvanian tetrapod diversification in Euramerica". Geology. 38 (12): 1079–1082. Bibcode: 2010Geo....38.1079S. doi: 10.1130/G31182.1.

Antediluvian monster", a Mosasaurus discovered in a Maastricht limestone quarry, 1770 (contemporary engraving) a b c d e f g Greene, Harry W. (2004) Snakes – The Evolution of Mystery in Nature. University of California Press, pp. 22–23 ISBN 0520224876. a b Piñeiro, Graciela; Ferigolo, Jorge; Ramos, Alejandro; Laurin, Michel (2012). "Cranial morphology of the Early Permian mesosaurid Mesosaurus tenuidens and the evolution of the lower temporal fenestration reassessed". Comptes Rendus Palevol. 11 (5): 379–391. Bibcode: 2012CRPal..11..379P. doi: 10.1016/j.crpv.2012.02.001. Breathing during locomotion has been studied in three species, and they show different patterns. Adult female green sea turtles do not breathe as they crutch along their nesting beaches. They hold their breath during terrestrial locomotion and breathe in bouts as they rest. North American box turtles breathe continuously during locomotion, and the ventilation cycle is not coordinated with the limb movements. [90] This is because they use their abdominal muscles to breathe during locomotion. The last species to have been studied is the red-eared slider, which also breathes during locomotion, but takes smaller breaths during locomotion than during small pauses between locomotor bouts, indicating that there may be mechanical interference between the limb movements and the breathing apparatus. Box turtles have also been observed to breathe while completely sealed up inside their shells. [90] Sound production [ edit ]

Karasov, W.H. (1986). "Nutrient requirement and the design and function of guts a b c d Romer, A.S; Parsons, T.S. (1985) [1977]. The Vertebrate Body (5thed.). Philadelphia, PA: Saunders.

Werneburg, Ingmar; Sánchez-Villagra, Marcelo R. (23 April 2009). "Timing of organogenesis support[s] basal position of turtles in the amniote tree of life". BMC Evolutionary Biology. 9: 82. doi: 10.1186/1471-2148-9-82. ISSN 2730-7182. PMC 2679012. PMID 19389226. article82. When Sauropsida was used, it often had the same content or even the same definition as Reptilia. In 1988, Jacques Gauthier proposed a cladistic definition of Reptilia as a monophyletic node-based crown group containing turtles, lizards and snakes, crocodilians, and birds, their common ancestor and all its descendants. While Gauthier's definition was close to the modern consensus, nonetheless, it became considered inadequate because the actual relationship of turtles to other reptiles was not yet well understood at this time. [2] Major revisions since have included the reassignment of synapsids as non-reptiles, and classification of turtles as diapsids. [2] Other authors have used Sauropsida to include [3] [ clarification needed] Deaths from snakebites are uncommon in many parts of the world, but are still counted in tens of thousands per year in India. [159] Snakebite can be treated with antivenom made from the venom of the snake. To produce antivenom, a mixture of the venoms of different species of snake is injected into the body of a horse in ever-increasing dosages until the horse is immunized. Blood is then extracted; the serum is separated, purified and freeze-dried. [160] The cytotoxic effect of snake venom is being researched as a potential treatment for cancers. [161] Divers, Stephen J.; Mader, Douglas R. (2005). Reptile Medicine and Surgery. Amsterdam: Elsevier Health Sciences. pp.481, 597. ISBN 9781416064770.Laurenti, J.N. (1768). Specimen medicum, exhibens synopsin reptilium emendatam cum experimentis circa venena[ Medical Specimen: Presenting an improved synopsis of reptiles with experiments on poisons] (in Latin). Archived from the original (facsimile) on 2015-09-04. — shows the mixed composition of Reptilia. The parareptiles, whose massive skull roofs had no postorbital holes, continued and flourished throughout the Permian. The pareiasaurian parareptiles reached giant proportions in the late Permian, eventually disappearing at the close of the period (the turtles being possible survivors). [51] The scales around the eye are called circumorbital scales and are named as ocular scales but with appropriate prefixes. The ocular scale proper is a transparent scale covering the eye which is called the spectacle, brille or eyecap. [9] [23] The circumorbital scales towards the snout or the front are called preocular scales, those towards the rear are called postocular scales, and those towards the upper or dorsal side are called supraocular scales. Circumorbital scales towards the ventral or lower side, if any, are called subocular scales. Between the preocular and the postnasal scales are one or two scales called loreal scales. [22] Loreal scales are absent in elapids. Euryapsida– one high fenestra (above the postorbital and squamosal)– protorosaurs (small, early lizard-like reptiles) and the marine sauropterygians and ichthyosaurs, the latter called Parapsida in Osborn's work.

Main article: Evolution of reptiles Origin of the reptiles [ edit ] An early reptile Hylonomus Mesozoic scene showing typical reptilian megafauna: dinosaurs including Europasaurus holgeri, iguanodonts, and Archaeopteryx lithographica perched on the foreground tree stump a b Thorpe, Roger S.; Thorpe, R. S.;Wüster, Wolfgang & Malhotra, Anita (1997). Venomous snakes: ecology, evolution, and snakebite. Vol. 70 of Symposia of the Zoological Society of London. Oxford University Press, London. ISBN 0-19-854986-5. Excluding the head, snakes have imbricate scales, overlapping like the tiles on a roof. [20] Snakes have rows of scales along the whole or part of their length and also many other specialised scales, either singly or in pairs, occurring on the head and other regions of the body. Pincheira-Donoso, Daniel; Bauer, Aaron M.; Meiri, Shai; Uetz, Peter (2013-03-27). "Global Taxonomic Diversity of Living Reptiles". PLOS ONE. 8 (3): e59741. Bibcode: 2013PLoSO...859741P. doi: 10.1371/journal.pone.0059741. ISSN 1932-6203. PMC 3609858. PMID 23544091. The scales of a snake primarily serve to reduce friction as it moves, since friction is the major source of energy loss in snake locomotion. Rainbow boas get their name from the coloration of their scales caused by iridescence.

The benefit of a low resting metabolism is that it requires far less fuel to sustain bodily functions. By using temperature variations in their surroundings, or by remaining cold when they do not need to move, reptiles can save considerable amounts of energy compared to endothermic animals of the same size. [77] A crocodile needs from a tenth to a fifth of the food necessary for a lion of the same weight and can live half a year without eating. [78] Lower food requirements and adaptive metabolisms allow reptiles to dominate the animal life in regions where net calorie availability is too low to sustain large-bodied mammals and birds. Directorate General Armed Forces Medical Services, India. Memorandum No 102: Snakebite. Undated.pdf available [ online]. Accessed on 21 Feb 2010.