Comparing Mammal Species Across Different Habitats

The origin of modern day whales, a mystery that has puzzled paleontologists for years, may have just been solved with the discovery of an ankle bone. This discovery might sound simple and unimportant, but the bones of these ancient animals hold many unanswered questions and provide solid proof of origin and behavior. The relationship between whales and other animals has proven to be difficult because whales are warm-blooded, like humans, yet they live in the sea. The fact that they are warm-blooded suggests that they are related to some type of land animal. However, the questions of exactly which animal, and how whales evolved from land to water, have remained unanswered until now.

In this exercise, we will examine a fresh raw chicken bone to study bone structure.

Figure 4. Skeleton of Basilosaurus; the tiny hind limb is shown enlarged. Adapted from National Geographic's The evolution of whales by Douglas H. Chadwick, Shawn Gould and Robert Clark Re-illustrated for public access distribution by Sharon Mooney ©2006. Open source licence CC ASA 2.5 as viewed at http://palaeo.gly.bris.ac.uk/palaeofiles/whales/archaeoceti.htm

Louis Herman- University of Hawaii- Kewalo Basin Marine Mammal Laboratory- Phoenix and Akeakamai- since 1979

One hundred and fifty million years ago, large aquatic species of reptile such as the Plesiosaur dominated the ocean, and were pre-eminent predators of the sea. The branch of now extinct Plesiosaurs, or ‘near lizards', evolved into variant closely related species specialised to take different niches in the food chain. Such species of Plesiosaur include the phenotypically similar Plesiosauroid and Pliosauroid. The physiological adaptations of the long necked variant, the Plesiosauroid, as it relates to deep sea diving, will be addressed in depth.

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.

Some evolutionists claim whale ancestors were originally land mammals. Though many people refute this claim, there is much evidence. First is the Indohysus. The Indohysus was discovered to share a thickened bone that helps with hearing underwater with modern whales. The Indohysus also had denser bones, which meant it was partially aquatic. Next is the Pakicetus; the Pakicetus also had very dense bones, indicating it was semi-aquatic. The Pakicetus was similar in structure to a wolf, but the skull had eye sockets that were adapted for looking upwards, most likely at objects or animals floating above it. The Ambulocetus was found to have reduced limbs and an elongated skull and reduced limbs; it most likely spent most of its time in the water.

terrestrial mammals, bends and the mechanisms used by diving marine mammals to avoid them and how these animals work to deal with the issues of depth and deep

Skeletal System Case Study Molly Hennard Wright State University Skeletal System Case Study In this case study, an 18-year old boy was brought to the emergency room after a football game injury. He had an open fracture on his wrist and after an x-ray was taken, it showed that his wrist was broken into three parts and a small part of that was showing through the skin. The patient was admitted to the hospital so that he could undergo surgery to repair the fracture. Case Study Question 1

and Megyesi, M. S., (2004) studied gender and ethnic differences in bone architecture. One of the limitations of these models is that ethnic differences are not counted in femur geometry although these differences are less. Clark, J. M., et.al (1987) showed that there are big differences in the neck shaft angle, horizontal offset from person to person. Significant differences will femoral geometry (Crabtree, N., et al., 2000) (Greendale, G. A., et al., 2003). Khemachit, S. and Surasith, P. (2008) studied contour of the skull using two-dimesional image data where as Buranarugsa, and Mr. Houghton. P. (1981) studied contour of the skull with rectangular coordinates. Schenkar, R., et al. (1999) explained the application of advanced technologies to achieve physical models of the

Beaked whales, which often have dolphinlike snouts rather than blunt muzzles, typically dive hundreds of meters or more to chase squid, fish, and other prey. But at least one ancestral species in this group of toothed whales, also known as ziphiids, was cruising near-surface waters for its meals, new evidence from newly described fossils suggest. Those remains—the first of any toothed whale to also include fossils of its presumed prey, researchers say—were unearthed along the southwestern coast of Peru last year. The rocks that entombed the partial remains of the whale (Messapicetus gregarius, depicted in an artist’s reconstruction, above) accumulated as sea-floor sediments between 8.9 million and 9.9 million years ago, other fossils in the

Magee, Justin, Brian McClelland, and John Winder. "Current Issues With Standards In The Measurement And Documentation Of Human Skeletal Anatomy." Journal Of Anatomy 221.3 (2012): 240-251. Academic Search Premier. Web. 16 Dec. 2013.

Narwhals are considered to be the rarest mammals of the sea, the only species to belong in the genus Monodon. With their unique appearance, and dwindling existence, they are the least researched sea mammal; resulting in many unknowns of how Narwhals descended from the Beluga whale. From the family of Monodontidae, the narwhal evolved from the common ancestor Denebola. Their distinct feature, a tusk(which is in actuality a canine, the only tooth they possess), differentiates these creatures from other sea mammals, giving the species a selective advantage. The change in climate, scarcity in food, and fierce competition in sexual selection led to the significant evolution of Narwhals.

The relationship between the mass of the ossicles and tympanic plate area in the remingtonocetid and protocetid is comparable to the ear anatomy found in modern whales. The odontocete transmits sound by means of a large mandibular fat pad and received by the tympanic plate. Sound passes through the odontocete middle ear by means of two lever-arm systems, and the freely suspended involucrum forms the axis of one of these. In contrast, the pakicetids retain the land mammal morphology of the mandible, remingtonocetids and protocetids have a large mandibular foramen that indicates that the mandibular fat pad was present, and that the tympanic plate was functional during underwater hearing. The contact between periotic and tympanic bones in remingtonocetids

On average, gray wolves will eat 20 to 30 pounds of meat in one meal, but have also been known to go up to 14 days between meals with no ill effects.