For the past 300 million years, terrestrial ecosystems on Earth have been dominated by tetrapods: four-limbed terrestrial vertebrates (Zimmer, n.d.). Modern examples of tetrapods include amphibians, mammals, reptiles, and birds (Hall, 2015). They first evolved from sarcopterygian fishes approximately 400 million years ago, in the Devonian period (Speer, 1995). In the following period, the Carboniferous, tetrapods diversified, including the distant ancestors of modern groups. The first tetrapods had moist skin and laid their eggs in water, like modern amphibians. (Wilcox, 2012) However, it is important to keep in mind that modern amphibians (also called lissamphibians) are a distinct monophyletic group that excludes these primitive tetrapods (Cannatella, 2012). This article will be an analysis of the rise of tetrapods from the Carboniferous period and how they branched into many new forms. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay The first tetrapods that survived the Devonian extinction soon branched into many new forms. Some of them, such as Perderpes and other members of Whatcheeriid, were more terrestrial than previous tetrapods (Daeschler, 2011). Others, such as Crassigyrinus, became more aquatic, reducing their limbs and becoming more eel-like (Naish, 2007). In the mid-Carboniferous the first members of the Temnospondyl appear in the fossil record. Temnospondyls share several characteristics, including their uniquely divided vertebrae; unlike modern amphibians, temnospondyls possessed a lateral line, which is a pressure-sensitive organ that ran along their sides (often found in fish today) (Schoch, 2007). Scales, claws and bony skin plates have also been found in some members (Savage, 2012). Some Temnospondyls lived entirely in water, such as Brachiosaurus, which had external gills; others were more terrestrial, such as dyssorophoids. Temnospondyls often became much larger than modern amphibians (Huttenlocker, 2007). Many Carboniferous temnospondyls were large crocodile-like predators such as the meter-long Cochleosaurus; one of the largest was Dendreropeton acadianum, which reached three meters in length (Godfrey & Holmes, 1995). Most evidence seems to suggest that Temnospondyls are the ancestors of modern amphibians. While other tetrapods diversified, some tetrapods were on their way to fully adapting to terrestrial life. Today, most terrestrial vertebrates are amniotes: animals whose embryos develop inside amniotic sacs inside eggs (or in the mother's body), and this frees them from the need to lay eggs in water (Duscheck , n.d.). Reptiliomorpha is defined as all tetrapods that are more closely related to amniotes (mammals, reptiles, and birds) than to modern amphibians; however, because classifications of these early tetrapods are not very well agreed upon, it is difficult to know whether or not some groups fall into the reptiliomorpha category (“Palaeos Vertebrates Reptiliomorpha: Overview,” n;.d.). Regardless, many groups of reptiliomorphs display amniote-like features, including a deeper skull with eyes on the sides of the head rather than on top; their limbs were more well developed, except for those that were later reduced or lost again. Please note: this is just an example. Get a custom paper from our expert writers now. Get a Custom Essay As you can see, tetrapods of the Carboniferous period were creatures that dominated terrestrial ecosystems of that time. Even though they were on the verge of extinction during the period