Therapsids

A cheap adventure of Professor Sanderson 's magic in paleontology. Part 1: Therapsids I hope you are interested as much as I wrote this article. ^ _ ^ *** Surprisingly crappy adventure of Professor Sanderson's paleontology course. Survey 1: Where are mammals? Or: Therapsids. ** Professor Sanderson 's class is very popular. Part of the reason is that he is a good soul tutor; the image he produces is neat, tidy, often funny. But, primarily because he is a young male teacher at a female college, he is lucky to be compared with Jai in the eyes of a straight boy. These two factors lead to unnaturally high enrollment rates

Traditionally, synapusides are divided into original groups and advanced groups, called pelycosaurs and therapsids. "Pelycosaurs" constitutes the six most primitive synapss families. They are all like big walkers and perhaps horny lizards. Celapsides, in at least some forms, contain more advanced synapsps with more upright posture and possible hair. In traditional taxonomy, Synapsida is composed of two different grades close to mammals. Low pely cosaurs produce more upright cerapide, which in turn produces mammals. In the classification of traditional vertebrates, both Pelycosauria and Therapsida are considered to be orders of Synapsida subclass.

Lystrosaurus is a herbivorous herbivorous ricinodontal cerapsid, accounting for 90% of the initial Triassic terrestrial vertebrate. Smaller carnivorous cynomolgus monkeysides, including mammalian ancestry, also survived. Terra cephalian, tetracyclodone, moschorhinus, icctoskoide, survived in the Karo region of southern Africa, but not so much in the Triassic. Archosaurs (including dinosaurs and crocodile ancestors) were initially rarer than therapsid, but they began to replace therapsid in the middle of the Triassic. From the middle to the late Triassic, the dinosaurs evolved from a group of dragons that continued to dominate terrestrial ecosystems from Jurassic to Cretaceous.

During the first 40 million years of their evolution, the dinosaurs were still minorities of the world ruled by other reptile groups - those with names like such cerapsid, etosaurus and rauisuchians. Our research focuses on the understanding of this "long-term integration" in the evolution of dinosaurs. By combining phylogenetic trees with data such as body size, we can quantitatively and explicitly verify assumptions about time, velocity and process of dinosaur radiation. At the end of the Triassic of 200 million years ago, many other reptile populations disappeared during the Triassic - Jurassic extinction, again related to large volcanic activity and climate change . The dinosaur survived, rapidly increased diversity, experienced a dramatic scale expansion, and showed the beginning of the dinosaur era.