Elasmobranchs are a Subclass Chondrichthyes that are Classified as Carilaginous Fish

The evolutionary path of a whale is a fascinating process of a terrestrial mammal that evolves into a marine mammal. This evolutionary path started with one of the earliest ancestors called “Pakicetus”. A Pakicetus was discovered to be a land animal with four legs that had teeth as carnivores. It skull structure was long, but this organism didn’t look like any marine animal. The scientist then discovered that on the skull’s ear region it was surrounded by a bony wall. This feature on an organism only was distinct from one type of species, scientist discovered that this animal “Pakicetus” was an ancestor of a whale. By comparing the early whales Pakicetus to the next generation of ancestors Ambulocetus, the Ambulocetus whale looks more like

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.

Sharks do not have skeletons, but just cartilage. Also their jaws can move independently without any of their other body parts. It allows them to have a stronger hold on their prey. Sharks have oil in their liver that allow them to eat less often. So when they eat us up, they must be really hungry. Their fins help them feel vibrations of other creatures so that they can get into position to pounce on their prey.

Sharks have been in our oceans for almost 450 million years. Those millions of years of evolution have allowed many different shark species to develop abilities, and to become perfect predators.

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.

Tiktaalik roseae, the creatures scientific name, was found in Arctic Canada and it lived around 375 million years ago. The Tiktaalik’s remains were found in Nunavut Territory in Canada and therefore scientists asked locals to propose a name for the species. According to, A Fish Out of Water, “The Elders Council of Nunavut suggested “Tiktaalik”. This word means “a large, shallow water fish”.” Fishapod is a nickname for the Tiktaalik because some scientists believe that it is a missing link between fish and tetrapods, the first animals to walk on land that were four-legged. “Fishapod fossils indicate that the creature was a mixture of animal types,” explains Greg Pardo, the author of A Fish Out of Water. The fishapod had similar parts to four-legged land animals, such as a skull, a neck and a large ribcage. This large

Beginning with the simplest one-celled organism, an extraordinary animal rose in the murky waters entitled to a non-comparable killing-eating machine. This organism has become nature’s most genuine and most successful creature that it has remained unchanged for over 250 million years. Nature finally invented the perfect king of the sea. This animal has given the sea it’s “living” adjective; in turn, it was entitled—the “great white shark.”

Throughout the early Paleozoic and Mesozoic ages, the major sharks belonged to a set called Hybodontoidea. They had fins and bony structure

This article talks about what sharks does in order to survive and what are they capable of doing. According to the article, sharks do not sleep; but rather, they have rest periods throughout their day. Sharks are capable of hearing anything below 1000 Hertz and can also swim up to 20 mph. Sharks skeleton is made up of cartilage rather than bone. According to the article, cartilages are lighter than bones. What keep them from floating are their large livers. Sharks can gather and keep the air into their stomach to keep them from floating.

In “What do you know about sharks?” by Sharon Guynup and “Great White Sharks” by Peter Benchley the clique thought of the “anthropophagous”, savage, and villainous shark is turned on its head. The two articles take widely accepted myths and debunk them with facts. Evidence that supports that the fish aren’t the vicious marine people-eaters that the media has depicted them as has been found. In this text the findings on the animal will be explored. This is the shark’s Real Bite.

They have 5 to 7 pairs of gills (leading to gill slits in rays and sharks and covered by operculum in chimaeras). Some have spiracles behind each eye (Skin surface openings leading to respiratory system).

Sharks have a long history, they can be dated back to over 400 million years ago, one of very few species that live for such a long period without distinction. Within over 400 different species, the smallest shark is only 17 cm in length which is the dwarf shark; while the largest

The smalltooth sawfish Pristis pectinata (Latham 1794) species are a large batoid elasmobranch that prefers very specific habitats (Simpfendorfer et al., 2010). They are also a K-selected species, which means that the smalltooth have a late maturity, a small pup size and a slow growth rate (Seitz & Poulakis, 2006). The smalltooth sawfish species can be identified from the undefined or undeveloped lower caudal fin (Gómez-Rodríguez et al., 2014). Another identifier is the first dorsal fin is in line with the beginning of the pelvic fin (Gómez-Rodríguez et al., 2014). Unlike the other sawfish, the P. pectinata have about 20 to 34 rostral teeth on the saw, which is more than most species (Gómez-Rodríguez et al., 2014).

The Goblin Shark, also known as a “living fossil” is not the most well known animal, mostly because it is counted as a rare species. It has a sluggish and inactive lifestyle. We have not seen much of these species, the ones we have seen are very slow and do not do much moving. These sharks pose no threat to humans because of how deep they live in the ocean and we have only ever caught one goblin shark, but it only survived a few days in the aquarium. Getting to know the goblin shark has been a challenge because of how little information is known, but it is an interesting and fun species to learn about.

Sharks don't have a swim bladder. This is what helps regulate depth control. Sharks do not have this organ. Yet, they do have a oil organ that also acts as a gas bladder. This oil is less dense than water and acts as a gas bladder.