2008. Has not changed in 225 million years Living fossil! Reptiles are divided into four orders: Crocodilia, Squamata, Testudines, and Tuatara. , Snake venom has been shown to have evolved via a process by which a gene encoding for a normal body protein, typically one involved in key regulatory processes or bioactivity, is duplicated, and the copy is selectively expressed in the venom gland. Order-1: Testudines They have strong limbs to lift their heave bodies. Largest order of reptiles, comprising lizards, snakes and amphisbaenians , which are collectively known as squamates or scaled reptiles. Large animals are potentially dangerous. 2. The family has only one species left and is critically endangered. Marine reptiles include. •They are lizard like. Some species even have forked hemipenes (each hemipenis has two tips). Order-2: Rhynochophalia This order includes the tuataras which are restricted only in New Zealand. Crocodilia is similar to these species: Crocodile, Reptile, Dinosaur and more.  Scientists believe crown group squamates probably originated in the Early Jurassic based on the fossil record. This is particularly visible in snakes, which are able to open their mouths very wide to accommodate comparatively large prey. A large, predatory marine reptile is the crocodile, which belongs to the order Crocodilia. Other, now extinct, reptilian orders included Earth’s largest terrestrial animals, and some enormous marine creatures. … , Parthenogenesis is a natural form of reproduction in which the growth and development of embryos occur without fertilization.  The WW females are likely produced by terminal automixis. 11. 2. The Komodo dragon has been known to kill people due to its size, and recent studies show it may have a passive envenomation system. This article is about the Squamata order of reptiles. The order Testudines includes both extant (living) … Most crocodilians live in the tropics. The three groups are distinguished from one another by the shape of their heads. The Testudinea have the horny jaws naked and cutting, or denticulated. marine species that grows to 916 kg and 1.9 m long; 18 Reptilians. Some species, such as the Komodo dragon, can reproduce asexually through parthenogenesis. Though they survived the Cretaceous–Paleogene extinction event, many squamate species are now endangered due to habitat loss, hunting and poaching, illegal wildlife trading, alien species being introduced to their habitats (which puts native creatures at risk through competition, disease, and predation), and other anthropogenic causes. Class Reptilia is made up of four orders: Squamata, Testudines, Crocodilia and Rhynchocephalia. Reptiles are tetrapod animals in the class Reptilia / r ɛ p ˈ t ɪ l i ə /, a paraphyletic grouping comprising all amniotes except mammals and birds.Properly, reptiles and birds are grouped together in the monophyletic group known as sauropsids.The class Reptilia comprises turtles, crocodilians, snakes, amphisbaenians, lizards, tuatara, and their extinct relatives. Active selection of sperm by females appears to occur in a manner that enhances female fitness. Slide 6 The Four Reptilian Orders Crocodilia Testudines SquamataSphenodontia Slide 7 2 species of Tuatara living in New Zealand; all others went extinct 60 mya. Historically, the order Squamata has been divided into three suborders: Of these, the lizards form a paraphyletic group, since "lizards" excludes the subclades of snakes and amphisbaenians. Crocodilians • Carnivores that ambush fish, turtles, rodents, birds, both small and large mammals, other reptiles and insects, or young or immature crocs or alligators • Swim under water or along surface until within striking range, grab prey in jaws • Drag prey underwater to drown. Reptiles are divided into four orders: Crocodilia, Squamata, Testudines, and Tuatara.While there is great diversity across this taxa, all species display a similar general immune response that sets reptiles apart from other jawed vertebrates. One example of a modern classification of the squamates is, All recent molecular studies suggest that several groups form a venom clade, which encompasses a majority (nearly 60%) of squamate species. Sea snakes B. Saltwater crocodiles C. seven species of marine turtle. They also possess movable quadrate bones, making it possible to move the upper jaw relative to the neurocranium. Most tortoises have domed carapaces, and many have forelimbs that are modified for digging. Class Reptilia is made up of four orders: Squamata, Testudines, Crocodilia and Rhynchocephalia. Reptiles have a moderate humoral immune system; and typically have a broad, robust innate component which can include antimicrobial peptides and the complement … The Nile Crocodile takes care of its young, a unique trait among reptiles. Crocodiles have powerful jaws with many conical teeth and short legs with clawed webbed toes. Galapagos Giant Tortoise – Chelonoidis nigra. Near the equator, only in the Southern Hemisphere, Organisms in class Mammalia have characteristics that include, Hair, nourishing their young with milk provided by mammary glans, being homeothermic, that almost all give birth to live young, Marine mammal adaptations to the challenges of living in the sea include, All the above; the mammalian diving reflex, myoglobin for storing oxygen, breathing air to meet oxygen demands. Other, now extinct, reptilian orders included Earth's largest terrestrial animals, and some enormous marine … True. ... Two orders of fish that are particularly important to the worldwide fisheries are orders _____ and _____ species in these two orders include _____ respectively ... Organisms in class reptilia share characteristics of. Class Reptilia is made up of four orders classified as Chelonia, Rhynchocephalia, Squamata, and Crocodilia (Frye, 1991).In class Amphibia, animals more commonly encountered in research setting are in the order Anura, containing frogs and toads (such as Xenopus, Bufo, Rana, Hyla, and Dendrobates spp. Modern turtles are variously herbivores, omnivores, and carnivores -none have teeth, have a horny beak instead All have internal fertilization, … Squamates are a monophyletic sister group to the rhynchocephalians, members of the order Rhynchocephalia. … In order to create a playlist on Sporcle, you need to verify the email address you used during registration. Some … Order Testudinata (Chelonia) - turtles Order Crocodilia - crocodiles and allies Order Rhynchocephalia - tuatara Order Squamata - snakes and lizards Subdivided into three subclasses Subclass Anapsida based on lack of a temoral opening on the side of the skull only living order Testudinata - turtles Subclass Diapsida reptiles with two temporal openings have radiated into large groups Archosaurians: … Snakes and lizards are in class Reptilia, order Squamata; chelonians (turtles, tortoises, terrapins) are in order Chelonia; and alligators, caimans, and crocodiles are in order Crocodilia.  On the basis of this selective process, the sperm of males that are more distantly related to the female are preferentially used for fertilization, rather than the sperm of close relatives. The hemipenis has a variety of shapes, depending on the species. The order is divided into three …  Previous literature hypothesized that venoms were modifications of salivary or pancreatic proteins, but different toxins have been found to have been recruited from numerous different protein bodies and are as diverse as their functions. There are only a few members, and all modern crocodilians have adapted to a semi-aquatic life, although as recently as 3000 years ago there may have been a terrestrial crocodilian species on New Caledonia. Snakes (Serpentes): There are about 2,900 species of snakes alive today. There are more than 8,200 living species of reptiles, with the majority being snakes or lizards. Species similar to or like Crocodilia. Chelonia breathe … In what parts of the world can penguins be found? Tongue is broad, … 3.19).They have the highest bicarbonate (HCO 3) level of all vertebrates, which helps them buffer lactic acid accumulation during anaero-biasis.. Upper respiratory tract. Whales, porpoises, and dolphins belong to order _____. Figure 7.14 . Birds (class Aves) share a common ancestor with crocodiles in subclass Archosauria and are technically one lineage of reptiles, but they are treated … Estonian reptiles (five species) belong to the order of Squamata. Class Reptilia is made up of four orders: Squamata, Testudines, Crocodilia and Rhynchocephalia. True or False: Orders Crocodilia, Chelonia, and Squamata all have marine species. Most of them are dry land animals and are divided into four orders: Chelonia, Rhyncocephalia, Crocodilia and Squamata. Compare and contrast crocodilians with other orders of reptiles. Squamates (Squamata) are the most diverse of all the reptile groups, with approximately 7400 living species. Recent studies also show that the close relatives of the Komodo, the monitor lizards, all have a similar envenomation system, but the toxicity of the bites is relatively low to humans. Largest freshwater species Alligator snapping turtle (80 cm, 143.3 kg) 20 Reptilian Origins. Squamates include lizards, snakes, and worm lizards. The shape of the limb is variable. Order of mostly large, predatory, semiaquatic reptiles, known as crocodilians. With over 10,900 species, it is also the second-largest order of extant (living) vertebrates, after the perciform fish. Alligators are found mainly in North and South America Alligators only show their upper teeth when their mouth is closed, snouts are round Crocodiles can live in fresh or saltwater. Other, now extinct, reptilian orders included Earth's largest terrestrial animals, and some enormous marine creatures. Members of this group include iguanas, chameleons, geckos, night lizards, blind lizards, skinks, anguids, beaded lizards and many others. Semiaquatic … The different Reptilia orders are – Chelonia, Rhyncocephalia, Squamata, Crocodilia. Reproduction in squamate reptiles is ordinarily sexual, with males having a ZZ pair of sex determining chromosomes, and females a ZW pair. Squamates are the most diverse living clade of reptiles, including about 1,440 genera and 4,450 species of lizards plus 440 genera and 2,750 species of snakes. Share. Fossils of rhynchocephalians first appear in the Early Triassic, meaning that the lineage leading to squamates must have also existed at the time. Due to being everted and inverted, hemipenes do not have a completely enclosed channel for the conduction of sperm, but rather a seminal groove that seals as the erectile tissue expands. Also the second-largest order of extant vertebrates, after the perciform fish, and roughly equal in number to the Saurischia (one of the two major groups of dinosaurs). "Turtle" may either refer to the Testudines as a whole, or to particular Testudines which make up a form taxon that is not monophyleticsee also sea turtle, terrapin, tortoise. 10. For the Roman scale armour, see, "Tikiguania and the antiquity of squamate reptiles (lizards and snakes)", "Resolving the phylogeny of lizards and snakes (Squamata) with extensive sampling of genes and species", http://www.reptile-database.org/db-info/SpeciesStat.html, "Integration of molecules and new fossils supports a Triassic origin for Lepidosauria (lizards, snakes, and tuatara)", "The oldest known snakes from the Middle Jurassic-Lower Cretaceous provide insights on snake evolution", "Mass extinction of lizards and snakes at the Cretaceous-Paleogene boundary", "A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes", "This 240-Million-Year-Old Reptile Is the 'Mother of All Lizards, "Komodo Dragons, World's Largest Lizards, Have Virgin Births", "Facultative parthenogenesis discovered in wild vertebrates", "Consecutive virgin births in the new world boid snake, the Colombian rainbow Boa, Epicrates maurus", "From genome to "Venome": Molecular origin and evolution of the snake venom proteome inferred from phylogenetic analysis of toxin sequences and related body proteins", "Coevolution of diet and prey-specific venom activity supports the role of selection in snake venom evolution", "Snake-bites: appraisal of the global situation", http://ufwildlife.ifas.ufl.edu/venomous_snake_faqs.shtml, "Komodo dragon kills boy, 8, in Indonesia", "Integrated Analyses Resolve Conflicts over Squamate Reptile Phylogeny and Reveal Unexpected Placements for Fossil Taxa", National Center for Biotechnology Information, https://en.wikipedia.org/w/index.php?title=Squamata&oldid=999616940, Articles with disputed statements from December 2015, Creative Commons Attribution-ShareAlike License, Earless, spiny, tree, side-blotched and horned lizards, Glass lizards, alligator lizards and slowworms, Cobras, coral snakes, mambas, kraits, sea snakes, sea kraits, Australian elapids, Shield-tailed snakes, short-tailed snakes, Evans SE. The first order of living Reptiles is that of the Chelonia, comprising the Tortoises and Turtles, and distinguished by the following characters: - There is an osseous exoskeleton which is combined with the endoskeleton to form a kind of bony case or box in which the body of the animal is enclosed, and which is covered by a leathery skin, or, more usually, by horny epidermic plates. This data was then compared with a phylogenetic dataset combining the morphological and molecular data of 129 extant and extinct reptilian taxa. (See Figure 13-1.) 11. Studies of squamate relationships using molecular biology have found several distinct lineages, though the specific details of their interrelationships vary from one study to the next.  The rapid evolution and diversification is thought to be the result of a predator–prey evolutionary arms race, where both are adapting to counter the other. Go to your Sporcle Settings to finish the process. Each order is further divided into sub‐orders, families, genera and species. Both captive-born and wild-born A. contortrix and A. piscivorus appear to be capable of this form of parthenogenesis.. Evolution and systematics . [dubious – discuss] Ritual combat between males for the females they want to mate with includes topping, a behavior exhibited by most viperids, in which one male will twist around the vertically elevated fore body of its opponent and forcing it downward. They therefore do not appear on the list above. Examples – turtles, tortoise. All species of crocodilians have similar body structures; elongated snout, powerful jaws, muscular tail, large protective scales, streamlined body, and … Among other reptiles, squamates are most closely related to the tuatara, which superficially resembles lizards. The comparison revealed Megachirella had certain features that are unique to squamates. Lizard bites, unlike venomous snake bites, are not fatal. 10.  Only one is used at a time, and some evidence indicates that males alternate use between copulations. Review. A dults provide extensive parental care to young; Oviparous; Habitat requirements of the organisms in … Order Crocodilia Predatory, aquatic reptiles. Order-1: Testudines •They are oviparous and lay egg in the nest chamber. Eastern Rat Snake (P. alleghaniensis) Gopher Tortoise (Gopherus polyphemus) Burmese Python (Python bivittatus) Reticulated Python (Python … … , Natural selection has driven the origination and diversification of the toxins to counter the defenses of their prey. The only surviving member of Rhynchocephalia is the tuatara. Reptiles The class Reptilia includes over 6,000 species grouped into four orders: the turtles (Chelonia), the snakes and lizards (Squamata), the crocodiles and alligators (Crocodilia), and the tuataras (Sphenodonta). The varied results indicate that turtles and tortoises have found a variety of solutions to this problem. They have acrodont teeth, amphicoelous vertebrae and a parietal eye. Anura (frogs and toads). pp1–344. Class Reptilia is made up of four orders classified as Chelonia, Rhynchocephalia, Squamata, and Crocodilia (Frye, 1991).In class Amphibia, animals more commonly encountered in research setting are in the order Anura, containing frogs and toads (such as Xenopus, Bufo, Rana, Hyla, and Dendrobates spp. Most people are familiar with the general body structure of anurans and salamanders, but may have never seen a caecilian.  The type of parthenogenesis that likely occurs is automixis with terminal fusion (see figure), a process in which two terminal products from the same meiosis fuse to form a diploid zygote. There are more than 8,200 living species of reptiles, and they are placed in four orders: Crocodilia, which includes crocodiles and alligators; Sphenodontia, or tuataras; Squamata, which includes lizards and snakes; and Testudines, such as turtles and tortoises. However, breeding programs and wildlife parks are trying to save many endangered reptiles from extinction. The reptiles include more than 6,000 species grouped into four orders: the turtles (Chelonia), the snakes and lizards (Squamata), the crocodiles and alligators (Crocodilia), and the tuataras (Sphenodonta), large lizardlike animals found only on islands off the coast of New Zealand. Order Squamata – Amphisbaenids, lizards, and snakes: Suborder Lacertilia – Lizards The phylogenetic analysis was conducted by performing high-resolution microfocus X-ray computed tomography (micro-CT) scans on the fossil specimen of Megachirella to gather detailed data about its anatomy. Each order is further divided into sub-orders, families, genera and species. However, the Colombian Rainbow boa, Epicrates maurus, can also reproduce by facultative parthenogenesis resulting in production of WW female progeny.  The fossil record shows the divergence between anguimorphs, iguanians, and advanced snakes dates back roughly 200 Mya to the Late Triassic/Early Jurassic. 19 Reptilians. Like all insects, the body of grasshoppers… Amphibia, Amphibia is one of the five major classes of vertebrates. Chelonia can make difficult anesthetic patients because they can easily switch to the dive reflex and employ anaerobic respiration (Fig. Staff writer | Reptiles, South America, Vulnerable. Number of families About 42. Members of the order are distinguished by their skins, which bear horny scales or shields. The fishlike ichthyosaurs were large marine reptiles, as were the long-necked plesiosaurs. Genetic data also suggests that the various limbless groups; snakes, amphisbaenians and dibamids, are unrelated, and instead arose independently from lizards. Reptiles The class Reptilia includes over 6,000 species grouped into four orders: the turtles (Chelonia), the snakes and lizards (Squamata), the crocodiles and alligators (Crocodilia), and the tuataras (Sphenodonta). Recent research suggests that the evolutionary origin of venom may exist deep in the squamate phylogeny, with 60% of squamates placed in this hypothetical group called Toxicofera. Katie Stromsland, Laura M. Zimmerman, in Reference Module in Life Sciences, 2017.  This preference may enhance the fitness of progeny by reducing inbreeding depression. A. 3. "Turtle" may either refer to the Testudines as a whole, or to particular Testudines which make up a form taxon that is not monophyleticsee also sea turtle, terrapin, tortoise. In contrast to most sea turtles, leatherback turtles are often found in the cooler waters of temperate regions. The study also found that geckos are the earliest crown group squamates not iguanians. • Crocodiles often “roll” large prey to rip off chunks of flesh before swallowing. Ithaca, New York, Society for the study of Amphibians and Reptiles. They eat fish, birds, turtles, and mammals. Other, now extinct, reptilian orders included Earth’s largest terrestrial animals, and some enormous marine creatures. Crocodile. Reptile, Most reptiles can be classified into three large groups: the turtles (order Chelonia), the snakes and lizards (order Squamata), and the alligators an… Grasshopper, Grasshoppers are plant-eating insects characterized by long hind legs designed for locomotion by jumping. The class Reptilia includes over 6,000 species grouped into four orders: the turtles (Chelonia), the snakes and lizards (Squamata), the crocodiles and alligators (Crocodilia), and the tuataras (Sphenodonta). Crocs have a pointed snout and show both rows of teeth when their mouths are closed Would you stand this close? In order to create a playlist on Sporcle, you need to verify the email address you used during registration. Venom has been known in the clades Caenophidia, Anguimorpha, and Iguania, and has been shown to have evolved a single time along these lineages before the three groups diverged, because all lineages share nine common toxins. Elongated body is provided with two pairs of limbs except limbless lizards.  In the US alone, more than 8,000 venomous snake bites are reported each year, but only 1 in 50 million people (5-6 fatalities per year in the USA) will die from venomous snake bites.. Often it bears spines or hooks, to anchor the male within the female. Members of the crocodile group have legs and feet designed for walking on land and a strong flattened tail used for swimming. Wikipedia. Start studying Marine Science Chapter 7 Review. Caudata (salamanders and newts). Orders Crocodilia, Chelonia, and Squamata all have marine species. , An estimated 125,000 people a year die from venomous snake bites. Iguanians were long thought to be the earliest crown group squamates based on morphological data, however, genetic data suggests that geckoes are the earliest crown group squamates. Wikipedia Animals frequently walk overland between water bodies and may be encountered in any habitat. amphisbaenians), gliders (e.g. Crocodiles often hunt by remaining just below the water’s surface, with only their eyes and nostrils above the water, waiting to catch a meal by surprise. Organisms in class Reptilian share the characteristics of, All of the above; breathing with lungs at all stages of their life, having scales, laying internally fertilized eggs. , There have been studies on how sexual selection manifests itself in snakes and lizards. Class Reptilia Subclass Pararep tilia (Anapsida) Order Testudinata (Chelonia) The Parareptilia have a distinctive ear region wherein the eardrum is supported by the squamosal bone rather than the quadrate bone and by the retroarticular process of the lower jaw. Turtles are reptiles of the order Testudines (the crown group of the superorder Chelonia), characterised by a special bony or cartilaginous shell developed from their ribs that acts as a shield. Includes distribution and habitat information (plus maps), photographic images and head drawings, plus biology, ecology and conservation information in an easy to navigate format. All of the above; breathing with lungs at all stages of their life, having scales, laying internally fertilized eggs Orders Crocodilia, Chelonia, and Squamata all have marine species. RESPIRATORY SYSTEM. Order … There are three … That is, they are capable of switching from a sexual mode of reproduction to an asexual mode. Number of genera, species About 1,880 genera; 7,200 species. Basiliscus), climbers (e.g. Rhyncocephalia. • Have a secondary bony palate – enables breathing when … Each order is further divided into sub‐orders, families, genera and species. 1. Resembles lizards but dietary … Squamates are characterized by their scaled skin, which is shed periodically (ecdysis), and a moveable quadrate bone that allows the maxilla to open wide relative to the rest of the skull. 3,848,900,975 quizzes played  Iguanians are now united with snakes and anguimorphs in a clade called Toxicofera. Each order is further divided into sub-orders, families, genera and species. Squamata (/skwæˈmeɪtə/, Latin squamatus (“scaly, having scales”)) is the largest order of reptiles, comprising lizards, snakes and amphisbaenians (worm lizards), which are collectively known as squamates or scaled reptiles. The over 10,900 extant squamates are divided into 58 families. Source for information on Reptiles: The Gale Encyclopedia of Science … They are able to leap from […] Read more . The skull of lizards and tuatara. 3. Some crocodiles may venture into larger bodies of fresh or salt water, but all must lay their eggs on dry land. While there is great diversity across this taxa, all species display a similar general immune response that sets reptiles apart from other jawed vertebrates. The reptiles include more than 6,000 species grouped into four orders: the turtles (Chelonia), the snakes and lizards (Squamata), the crocodiles and alligators (Crocodilia), and the tuataras (Sphenodonta), large lizardlike animals found only on islands off the coast of New Zealand. Weblink to purchase, This page was last edited on 11 January 2021, at 02:38. There are two characteristics that unite the squamates. Play this game to review Science. , The male members of the group Squamata have hemipenes, which are usually held inverted within their bodies, and are everted for reproduction via erectile tissue like that in the human penis. Abstract. Order Characteristics Example; Crocodilia: crocodiles, alligators, caimans, gharials: They have four sprawling legs that can be used to gallop; they replace their teeth throughout life; they have strong …  But the only good fossil evidence is from the Jurassic. Whereas alligators are freshwater species, there are a dozen fresh-water and saltwater species of crocodiles, found in Africa, Asia, Aus-tralia, and the … The Chelonia are divisible into the Testudinea, the Emydea, the Trionychoidea, and the Euereta. All other species are only known as fossils. Pinnipedia, lack ear flaps, have ear flaps. This process leads to genome wide homozygosity, expression of deleterious recessive alleles and often to developmental abnormalities. Crocodilia (or Crocodylia) is an order of large reptiles that appeared about 84 million years ago in the late Cretaceous Period (Campanian stage). Order Rhynchocephalia (=Sphenodontia), 2 species of tuatara (Sphenodon) in New Zealand. Go to your Sporcle Settings to finish the process. Agkistrodon contortrix (copperhead snake) and Agkistrodon piscivorus (cotton mouth snake) can reproduce by facultative parthenogenesis. Furthermore the foot is unique in the way the digits articulate with the ankle bone. ), and Anguimorpha (monitor lizards, Gila monster, glass lizards, etc.).. Draco), bipedal runners (e.g. (True/False) Orders Crocodilia, Chelonia and Squamata all have marine species. Zoos, private hobbyists and breeders help educate people about the importance of snakes and lizards. Largest non-marine turtle is the Galapagos Tortoise -grows to 310 kg, lives over 200 yrs . Approximately 6,000 species of vertebrates belong to the class of reptiles (Reptilia). When female sand lizards mate with two or more males, sperm competition within the female's reproductive tract may occur. The only exceptions are the American alligator ( … Order-1: Testudines •They are oviparous and lay egg in the nest chamber. … Order Chelonia (Testudines) Turtles ~330 species Ancient group that survived, remained mostly unchanged from early ancestors 8. Squamata is the most variably sized order of reptiles, ranging from the 16 mm (0.63 in) dwarf gecko (Sphaerodactylus ariasae) to the 5.21 m (17.1 ft) green anaconda (Eunectes murinus) and the now-extinct mosasaurs, which reached lengths of over 14 m (46 ft). Alligators … Snakes use a variety of tactics in acquiring mates. Leatherback turtle-- Dermochelys coriacea (Vandelli, 1761) [CR] Chelydridae. Usually movable an upper and a lower eyelids are present but in Geckonidae the eyelids are fused. Crocodiles (subfamily Crocodylinae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. … 7-22) 1. The class Reptilia includes over 6,000 species grouped into four orders: the turtles (Chelonia), the snakes and lizards (Squamata), the crocodiles and alligators (Crocodilia), and the tuataras (Sphenodonta). In Clinical Anatomy and Physiology of Exotic Species, 2005. The largest terrestrial species, the Asian softshell turtle (Pelochelys cantorii), produced a few individuals up to 200 cm (6.6 ft).This dwarfs the better-known alligator snapping turtle, the largest … Squamata (/ s k w æ ˈ m eɪ t ə /, Latin squamatus (“scaly, having scales”)) is the largest order of reptiles, comprising lizards, snakes and amphisbaenians (worm lizards), which are collectively known as squamates or scaled reptiles.