There are four main groups of reptiles, known as Crocodilians, Squamates, Tuataras, and Turtles. Crocodilians consists of large reptiles which includes alligators, crocodiles, gharials, and caimans. Squamates are lizards, snakes, and worm-lizards. A worm-lizard is a subterranean burrowing reptile that resembles an earthworm, a legless lizard. Tuataras are a group of reptiles that are lizard-like in appearance but are different from squamates because their skull isn’t jointed. Turtles are the most ancient reptiles alive today. They have changed very little since they first showed up 220 million years ago. The first turtle appeared 220 million years ago.(Laura Klappenbach)
Though it is not a reptile, Gephyrostegus bohemicus is where the evolution of reptiles begins (Jaeckel 1902). It was an Upper Carboniferous lizard-like tetrapod (four footed animal), or reptilomorph (clade (group consisting of an ancestor) containing the amniotes and those tetrapods that share a common ancestor with amniotes than with amphibians), from Nyran in the Czech Republic. Since some reptile fossils, like Westlothiana, are older than Gephyrostegus, it's obvious that we haven't found the oldest gephyrostegid yet…. thought that reptiles originated as tiny tetrapods (Carroll 1970). He then came to find out that he was correct. Cephalerpeton, the most primitive reptile, was small-scaled compared to this specimen of Gephyrostegus. Shortly after a very early sister to Cephalerpeton, members of the Reptilia split into two groups represented at their bases by Westlothiana and Cephalerpeton. The new Lepidosauromorpha, are those sharing a more recent common ancestor with living lizards, the Lepidosauria, than with Archosauria (Gauthier 1986). The most recent Arch...
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...tats. Many reptiles have specially adapted to life in some of the areas that are being lost at a frightening rate - for example the rain forests in the tropics and much of the shrubland of Europe. Although governments are now more aware of the situation and have agreed to help some severely threatened species, too little may have been done too late.(Colin McCarthy)
After researching so many things that I never even knew about reptiles, I believe I would much rather be a reptile instead of an amphibian. Reptiles were able to adapt to land while amphibians can barely even stay away from water for long periods of time. After all these years reptiles have evolved to modern day qualities and are still evolving to fit in. This paper is important to people who want to learn a little history about reptiles. It also tells what changes occurred in reptiles as they evolved.
1) Carroll, R. L. 1988. Vertebrate Paleontology and Evolution. W. H. Freeman and Company, New York.
Oxygen breathing lungs are a universal trait of class reptilia. As such, it would have been necessary for the Plesiosauroid - a marine reptile, to return to the ocean surface to inhale air. Oxygen expenditure in reptiles is proportional to strenuosity of locomotion (Frappell, Schultz & Christian, 2002). Therefore the Plesiosauroid must have held physiological traits that enabled the species to avoid oxygen deficit while hunting deep-sea dwelling prey. This essay will outline the hypothesised respiratory, circulatory, pulmonary and sensory attributes of the Plesiosauroid as they relate to diving. These hypotheses will be supported by investigating the physiological adaptations of the Plesiosaur’s biological analogues, and the prospect of similar adaptations in the former will be speculated upon.
The invasive reptiles are eating almost everything in sight like raccoons, opossums, bobcats, alligators and many federally protected animals like the Key Largo wood rat and Wood stork. There have been cases of children and pets being eaten or even squeezed to death by the large snakes in their own yards.
In the early 1800’s, a new discovery that left paleontologists in awe was the fossil finding of the immeasurable amount of species of reptiles, Ichthyosaurs. Greek for “fish lizards”, these fossils were found all over the world. Because these large aquatic reptiles migrated just as whales do today, paleontologists have had the amazing advantage of collecting fascinating bone fragments throughout the past 177 years. Ichthyosaurs swam the ocean life from about 245 million until about 90 million years ago- approximately the same time dinosaurs ruled the land. The earliest Ichthyosaur fossil findings were in parts of Canada, China, Japan, and possibly Thailand. Countless fossils came from coatings of limestone produced out of the ocean-floor ooze that was predominantly superior at preserving very well facts of the creatures it digested (Perkins 2).
Pianka, E. and Parker, W. 1975. Ecology of horned lizards: A review with special reference to Phrynosoma platyrhinos. Copeia 1975: 141-162.
Nicholson KE, Harmon LJ, Losos JB. Evolution of Anolis Lizard Dewlap Diversity. PLOS ONE. 2007
...ll. This group still remained successful during the Jurassic period and had a wide geopraphic distribution. Other reptiles evolved to not only live on land, but to fly. The earliest known birds appeared during this period; Archaeoteryx being the first to be considered the intermediate between the birds and predatory dinosaurs. It is debated on whether this ancient bird could actually fly or merely glid from tree to tree. Carnosaurus, meaning “meat-eating” is another group of dinosaurs that ruled during the Jurassic. With such large herbivorous prey animals, the correlation of these large predators make sense of why they were so common. An Allosaurus was one of the most common Carnosaurs in North America. Upon finding numerous intact skeletons in fossil beds, it has been reported that the Allosaurus was superficially similar to the later evolving Tyrannosaurus rex.
The debate of whether dinosaurs were cold blooded or warm blooded has been ongoing since the beginning of the century. At the turn of the century scientists believed that dinosaurs had long limbs and were fairly slim, supporting the idea of a cold blooded reptile. Recently, however, the bone structure, number or predators to prey, and limb position have suggested a warm blooded species. In addition, the recent discovery of a fossilized dinosaur heart has supported the idea that dinosaurs were a warm blooded species. In this essay, I am going to give supporting evidence of dinosaurs being both warm and cold blooded. I will provide background information on the dinosaur that was discovered and what information it provides scientists.
The Genus Varanus komodoensis, or more commonly known as the Komodo dragon is the largest living lizard on Earth. The Komodo dragon belongs to the class reptilian and the phylum Chordata. They are a species of Monitor Lizard that have been isolated for millions of years on the islands in Indonesian Archipelago and were not discovered until the First World War (Diamond, 1994).
There are two kinds of species of alligators. There is the American alligator and the Chinese alligator. Many people have a hard time telling the difference between alligators and crocodiles. Alligators are related in the same family as the crocodile, but these two animals are very different. An alligator’s upper jaw overlaps the lower jaw. Alligators have a broad snout while crocodile have a very narrow snout. Alligators have much less aggressive and energetic than the crocodiles. Alligators live in tropical climates and crocodiles live in somewhat colder climates. Their kingdom is Animalia. Their Phylum is Chordata. They come from the class Reptilia. Their order is Crocodylia. Their family is Alligatoridae. Their genus is Alligator and their species is alligator messissipiensis and they are known as American alligators.
Shreeve, jamie “Species Revival: Should We Bring Back Extinct Animals?” ngm.nationalgeographic.com 5 March 2013, 22 March 2014
With its abundance of genera, the Burgess Shale is one of the world’s most important fossil fields. It’s discovery in 1909 led to over 100 years of paleontological study in the Canadian Rockies, a majority of which has been carried out in two quarries known as the Walcott and Raymond quarries (Hagadorn, 2002). Though he was originally in search of trilobites in the Burgess Shale Formation, paleontologist Charles Walcott also discovered a diverse group of soft- and hard-bodied fossils, from algae and sponges to chordates and cirripeds (Hagadorn, 2002). Soft-bodied fossils are incredibly rare due to their delicate structure and susceptibility to decay, so it is hard-bodied fossils that more regularly occur in fossil findings. However over 75,000 soft-bodied specimens have been found in the Burgess Shale formation (Hagadorn, 2002). These specimens are preserved in layers of shale formed from deposits of fine mud. One of the most significant species discovered is the Pikaia gracilens. Believed to be an early chordate, the Pikaia gracilens existed very close to the beginning of the evolutionary path that ultimately lead to humans (McGraw-Hill Encyclopedia, 2006).
The world we live in today is full of an exceptional variety of animals. The time it took to conclude to the various sorts of species seen today has been throughout a period of millions of years. The vast majority of these animals are accredited to evolutionary advancements. When the environment changes, organisms have become accustomed to changing to fit their environment, to ensure their species does not die off. These physical changes have resulted in different phyla, ranging from basic structures, like sponges to advance systems, like that of an octopus.
In Wilcove’s article, it is examined within the 50 states the four types of animals being discussed such as mammals, birds, reptiles, and amphibians with the possibility of becoming extinct or critically imperiled determined by The Nature Conservancy (TNC). David Wilcove states that, “A total of 2,490 imperiled species, subspecies, and populations fit these criteria” (Wilcove, Rothstein, Dubow, Phillips, & Losos, 1998, p. 607). In response, within these 2,490 animals at risk the science of these problems is that their home is destroyed, and when introduced to a new environment they cannot adapt to the normal life in the same manner. Native animals cannot compete with the new species discovered and...
Without evolution, and the constant ever changing environment, the complexity of living organisms would not be as it is. Evolution is defined as a process that results in heritable changes in a population spread over many generations (8).Scientists believe in the theory of evolution. This belief is based on scientific evidence that corroborates the theory of evolution. In Figure 1 the pictures of the skulls depict the sequence of the evolution of Homo-sapiens. As the figure shows, man has evolved from our common ancestor that is shared by homo-sapiens. The change of diet of homo-sapiens over time has thought to contribute to the change in jaw structure and overall skull shape.