Comparing Three Different Classes of Vertebrates

A dinosaur has an antorbital fenestra with an open hole hip socket. The definition differs from the term used informally because it helped understand how the dinosaur moved and how they were categorized as species. There are four general characteristics that dinosaurs have as a result of their synapomorphies which are permeated acetabulum, ball-shaped head on proximal femur, the Cnemial crest on the proximial tibia, and an ascending process on astragalus. These four dinosaur synapomorphies are related to vertical limb support.

Crocodiles and Alligators are often confused with because of the physical similarities. When an average person encounters a crocodile or alligator, it is most probable that they guess which animal it is and get it wrong. However, the only thing in common is the body structure. Not all of the similarities have to do with the similar physical shape of the crocodiles and alligator’s. In fact, the similarities go beyond. On the other hand, the differences deal with the most detailed dissimilarities between the crocodiles and alligators body.

Scientists say reptiles evolved from amphibians 340 million years ago. The first reptile was an insect eater. Reptiles were more adaptable and able to

In marine mammal biology a large portion of the study is dedicated towards the study of adaptations to the marine environment. By comparing the anatomy between marine mammals and terrestrial mammals scientists can better understand evolutionary history of how these two categories of mammals diverged from one another. The purpose of this lab was to study the anatomy of different marine and terrestrial mammals and compare their similarities and differences in homologous traits and how adaptations were made specifically for marine mammals to survive the aquatic environment. To accomplish this bones of different species of animals were studied since these structures serve as the basis for comparison across species as well as an indicator of each animal’s individual morphology and physiology. A standard measurement protocol for bones of particular regions of the skeleton was established with emphasis on length versus width ratio as well as it’s overall size relative to its more complex features, i.e. humerus length versus hand length.

From both the title of the chapter and the introduction by Dr. Shubin, this chapter begins with a focus on teeth. Because the function of teeth is to break down food before it enters the esophagus, the different shapes of teeth can represent many different things about the organism it belongs to including what type of eater it was (carnivore, herbivore, or omnivore). Teeth are the hardest tissue (not bone) in the human body and therefore fossilize well. As Dr. Shubin stated in chapter one, there must be many points that permit a fossil to make any kind of scientific conclusion. Obviously, the state of their presence is important, so the fact that teeth preserve well allows for them to be great specimens for analysis. Dr. Shubin and his team analyzed fossilized teeth in areas as different as Nova Scotia and the Arizona desert. Studying different fossils in these diverse regions allowed the team to see that mammalian and reptilian teeth are very different. For example, mammalian teeth differ from organism to organism to fit with the organisms need (Cheetahs that eat only meat will have different teeth than deer who are herbivores) and are replaced only once in the lifetime of the organism while reptilian teeth are usually sharp and are constantly replaced if damaged. These differences allowed scientists to characterize fossils as either a reptile or a mammal. Similar to Tiktaalik discussed in chapter one, the discovery of fossils that were part reptile and part mammal allowed the researchers to see that mammals evolved from reptiles, and further supported the theory of evolution. Further studies yielded even more

90. Mammals are members of a class of reptiles characterized by pressure of hair and

It lacks a backbone, but has a nerve cord that runs down its back and a rod that runs the length of its body parallel to the nerve cord that supports the body (notochord). Humans have a notochord as an embryo, but it breaks up and becomes part of the disks that lie between our vertebrae. Also shared with Amphioxus are gill arches, the bar of cartilage associated with each arch and the cartilage that form jaws, ear bones and our voice box.

.*They are omnivorous, plantigrade and highly social animals *Body is covered with hairs (except palms, soles and face) *Limbs have five digits.

Part 2) Explain and evaluate the significance of the evidence given to justify this phylogeny. Using the relationship between jaw bone, size, brain and body weight, etc.

The nervous system is one of the most important organ systems in the body. It is in charge of all of the things that happen within the body. Being responsible for receiving sensory input from internal and external stimuli, integrating and processing information, and generating output, it would be hard to survive without a nervous system; however, there are different types of nervous systems in various organisms. Humans, cnidarians, flatworms, and annelids all have very diverse nervous systems. There are similarities and differences in each of these beings.

The fur on these animals differ from red to brown, sometimes grey. They have long wings. Their black ears point forward, and have wrinkled lips and their tails go beyond the third tail membrane; that is where they got their name. A lot of people say that their tails look like a mouse's. Their Kingdom is the Animalia, their Phylum is Chordate. This animal is a Chordate because they have nerve fibers,

The fossil of Tiktaalik confirmed a major prediction of paleontology in that it showed characteristics of both aquatic animals, such as fish, and land animals, such as reptiles and amphibians. While it had fins and scales, it also had a flexible neck, a flat head, and complex bone structure in its fins that correspond with the structure of the legs of terrestrial animals. Thus, it demonstrates the evolutionary transition between aquatic and terrestrial life.

Furthermore, the diet of both animals are very different. To begin with, Salamanders are carnivores.

Females for the nourishment of the young could define a mammal as a warm-blooded vertebrate animal of a class that is distinguished by the possession of hair or fur, the secretion of milk. The roots of the mammalian line reach back almost 300 million years. Some of the very early mammal relatives dominated the landscape millions of years before dinosaurs appeared, and most of these species became extinct. During the age of dinosaurs, most mammals were not much bigger than small rodents. It was after the extinction of the large dinosaurs that the great diversity of mammals arose. The timeline in this hall displays the development of such key mammalian physical features as the synapsid opening in the skull, a large hole behind the eye socket

Frogs, toads, caecilians, and salamanders are the members of the class Amphibian (amphi- meaning “on both sides” and bios- meaning “life”). These members always require water for reproduction. Most Amphibians undergo metamorphosis, which is a usually degenerative pathological change in the structure of a particular body tissue. And, in the case of Amphibians, it is the changing of a tadpole into