Synapsid

Despite this phenomenon, synapsids were still abundant (and in some cases dominant) throughout the Triassic Period. Therapsid predators remained dominant until the Middle Triassic, when diapsid archosaurs eventually overcame. Therapsid herbivores persisted until the Late Triassic, when both therapsid herbivores and carnivores declined again and nearly disappeared. The rise in diapsid abundance and dominance was coincident with the Triassic synapsid decline. The rise of the diapsids was slow, and is likely attributed to the improved respiration in diapsids provided by their erect gait. What were the first dinosaurs like and where did they live? [4] The first dinosaurs were the agile, bipedal carnivores, Herrerasaurus and Eoraptor. Herrerasaurus and Eoraptor differed in size (Eoraptor was about one meter in length, Herrerasaurus was between three and six meters in length), but this pair invariably possessed carnivore-like characteristics (grasping, clawed forelimbs and sharp teeth). In their early ecosystems, Herrerasaurus and Eoraptor lived among synapsid and diapsid fauna and comprised around thirty-three percent of local carnivores. Compare and contrast the two dinosaur clades Ornithischia and the Sauropoda-Theropoda clade.…

Throughout the history of life, organisms have been in a constant evolutionary flight to adaptations that better suit their surroundings, while becoming more complex in nature and achieving evolutionary hallmarks in the process. One such evolutionary leap is the transition from aquatic environment to terrestrial. One of the early terrestrial animals, the primitive amniotic synapsids are an important group of animals that pawed the way for endothermy, a significant adaptation that helped animals…

waste as salts of uric acid. Mammals use the loop of Henle in the kidney, this lets them produce urine that has a high concentration of urea and salt. Sauropsids and synapsids both started to evolve endothermic behaviors. High metabolic rates are essential for animals that need to walk long distances for a long period of time, and also it is essential for animals that need to thermoregulate. This is how endothermy evolved into the sauropsids and the synapsids. Sauropsids and synapsids both…

Dimetrodon Response Paper The article “Dimetrodon Is Not a Dinosaur: Using Tree Thinking to Understand the Ancient Relatives of Mammals and their Evolution” by Kenneth D. Angielczyk attempts to demystify the evolutionary history of mammals using evolutionary trees and succeeds in doing so. The author begins with the Dimetrodon as an example to demonstrate the power in using evolutionary trees. It is revealed that the Dimetrodon, a synapsid that closely resembles a dinosaur, is more…

over other males. Figure 2. Skeleton of Dimetrodon displayed in Evolving Planet. (Image Source: http://www.fieldmuseum.org/fossil-non-mammalian-synapsid-collection-field-museum) The form of Dimetrodon, specifically the spines, is very much similar to that of its close relative Edaphosaurus. One main difference is the size of the skull, with the Dimetrodon having a bigger one. This adaptation might be explained with the fact that Dimetrodon is a carnivore, which is another difference…

Therapsida – *Therapsida is a group of synapsids, and includes mammals and their ancestors. *They were advanced mammal like reptiles that appeared during early Jurassic and became dominant land animal during middle Permian period. *They evolved from a group of pelycosaurs called sphenacodonts. *The legs are positioned more vertically…

providing offspring with fluids. Nowadays, female jerboas use mammary glands to feed offspring and supply them with proper nutrition. Another structural key the jerboa’s integument is hair. Hair developed from an interaction between the dermal papilla and the epidermis. The skulls of the flying fish and the jerboa are formed of the same subunits. However, they different slightly in design and jaw articulation. The flying fish has an amphstyly skull made up of sections of chondrocranium,…

Blue light is filtered by the overlaying yellow pigment and thus appears green. Many frogs can adjust their colour to match their background and thus to camouflage themselves. (Integrated Principles of Zoology, 15th edition, Hickman Roberts Keen, McGraw-Hill, 2011, P558) 4.2) The structure of the skull roof permits us to identify three majour groups of amniotes that diverged in the Carboniferous period of the Palezoic era. Synapsids, anapsids and diapsids. The synapsids group which includes,…

1. The movie Life on Earth focused on how fossils are glimpses of a distant past because they explain how life evolved on earth. They also used a Cladogram to explain the cladistic relationship between a number of species. The first organism with a nucleus lived one and a half million years ago. An animal with a braincase and a beginning of a backbone appeared 500 million years ago. Amniotes were split into two main lineages. One is identified by a hole that evolved in the skull behind the eye…

fossil shows that Sinodelphys szalayi had foot structures affiliated with climbing. This fossil suggests that prior to the division of Gondwana, the marsupial ancestors (Metherians) originated from Asia from Eutherians, then dispersed to Gondwana, before becoming isolated in Australia. The fossil provides evidence that the diversification of the earliest metherians occurred in modern Asia, what was then Laurasia during the cretaceous period (Lou et al, 2003). The oldest placental mammal…