Sharks: The Evolution For roughly 420 million years, the greatest predator of the ocean has been swimming freely around in the water (450 Million Years of Sharks). Fish scurry away escape the rows of teeth in the jaws of a shark. With over 400 species of shark, how did they all get here? (A Timeline of Shark Evolution). Most importantly, how did they get such unique features that help them become the rulers of the ocean? In the article titled “Sharks,” it states, “[Sharks] range in size from the length of a human hand to more than 39 feet (12 meters) long” (Frost). All of these different sized sharks evolved from the same species, that roamed millions of years ago. Sharks have roamed the waters 200 million years longer than dinosaurs have …show more content…
This shark lived around 360 million years ago and swam in North American and European waters (Britannica). How does the Cladoselache differ from modern day sharks? For starters, Cladoselache sharks did not have ‘claspers’, which is what modern day male sharks use during reproduction. Scientists are still unsure on how Cladoselache sharks mated, being that they didn’t have the claspers to transfer sperm (Pepper). The structure of the mouth was also something scientists noticed was different. The mouth of a Cladoselache was aligned properly, not like modern day sharks that have their top jaw hang over their bottom jaw. Darren Pepper, author of the article titled “Cladoselache” wrote, “The jaw joint appears to have been quite weak, but was supported by powerful muscles, something that would have enabled Cladoselache to tackle larger prey” (Pepper). The last difference Pepper talks about is the number of gills these sharks had. A Cladoselache shark could have had up to seven gill slits, meanwhile modern day sharks only have up to …show more content…
Prehistoric sharks weren’t very large, as mentioned earlier. Being so small, they were often meals for bigger animals swimming in the ocean. Now, sharks such as the hammerhead shark and the great white shark are apex predators, meaning they are at the top of the food chain. Sharks have grown into a variety of sizes, ranging from the smallest shark, the dwarf lantern reaching a maximum of 8.5 inches long, to the largest shark, the extinct megalodon shark, reaching a maximum of 59 feet long (Megalodon & 20 Smallest Sharks). All of these different sharks descended from the prehistoric sharks, and have evolved from 16 inches to being up to 59 feet, moving sharks way up the food chain. Their fins have evolved into the perfect size for their body, to help them swim more swiftly through the water. Sharks pectoral fins are now as long or longer than the shark’s dorsal fin to provide fast movements. The tails of a shark now have more muscle, to let them swim further than they used to be able to. The male sharks, now have developed the claspers they need in order to reproduce properly and more effectively, like said before. Involving the head of the shark, they have changed in two major ways. Firstly, the teeth of sharks used to be flat. Now, shark teeth are very sharp, in order to be able to cut through the flesh of their prey with ease. Secondly, the jaws of sharks have become more
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How much do you really know about the hammerhead shark? Most people assume a shark is a shark, but there are many different types of sharks all with their own distinct qualities. However, the nine species of hammerhead sharks are easily identified by the unique shape of their head which resembles a hammer and is the origin of their name. Hammerheads are cold-blooded mammals that can grow up to 25 feet in length and weight as much as 1000 lbs.
Hammerhead Sharks protect themselves by swimming away from predators and attacking their predators. The Carnivores can outswim a sea creature and they will lose where the Hammerhead went. Even if another species can go as fast as a hammerhead shark, they will still escape. The hammerhead tries to stay away from where their predator was chasing them for some time and then returns if they need to. While swimming, they have very strong senses that can tell when something is getting near them.
But how did we get sharks? And then how did we get hammerheads? Well, sharks have been in the ocean for about 450 million years. This was during the early devonian period and it is recommended by scientists, and accepted that sharks evolved from fish. The first modern sharks were known as Sixgill, Sevengill, and Frilled.
The Great White Shark The Great White Sharks, known mostly because of their white underbellies, are one of the most powerful aquatic animals in the world. They can swim at about 25 Miles Per Hour (40 Kilometers per hour) because of their strong muscles and forceful tails. In addition to that, male Great Whites can grow around 11.5 to 13.1 feet long, while females can grow from 14.8 to 16.4 feet long. This paper will demonstrate how Great White Sharks are an important part of their ecosystem, how their diets work and will adequately describe their habitats. As predators in their ecosystem, Great White sharks help maintain the coral reefs and seagrass habitats.
Anatomy Their prolonged upper and lower jaws shape what is known as a platform, or nose, which gives the creature its basic name. The genuine, practical nose is the blowhole on top of its head; the nasal septum is unmistakable when the blowhole is open. Bottlenose dolphins have 18 to 28 cone shaped teeth on each side of each jaw. The flukes (flaps of the tail) and dorsal blade are framed of thick connective tissue and don't contain bone or muscle. The creature moves itself by moving the flukes all over.
I am going to tell you all about whale sharks’ adaptations. First, whale sharks diet is that they do not attack They do eat shrimp. Second, there habitat is in the warmer areas. Some have been spotted in the cooler warters. Last there habits they are solitary creatures.
Vertebrates are known to be animals with backbones. Tooth reduction is one of the major evolutionary trends that developed among major vertebrate groups that allowed for the transition from aquatic to terrestrial life. Evolution of limbs and being able to breath air are other evolutionary trends that took placeThese trends include improved respiration and protective and insulating body coverings. More over the transition from water to land also included changing to more efficient reproductive methods like having a placenta for some animals or egg layers for other animals. Lastly, the morphology of organisms evolved such that for land they would have paired, muscular appendages used for crawling and
and it is not safe for anybody to swim with sharks. So people are now saying that we need to kill the sharks before they have the chance to attack us. Sharks started hunting people after they saw them pondering around in the ocean. By researching people that hunt sharks are saying that it is easier to
Sharks have been swimming the world’s oceans for more than 400 million years - 100 years before the first dinosaurs appeared (Griffin et al., 2008). Sharks fall under the kingdom Animalia, the phylum Chordate and the class chondrichthyes. There are more than 400 known shark species found in the ocean (Musick and Musick, 2011). In the ocean, sharks help maintain the health of ocean ecosystems and help regulate and maintain the balance of the marine environment (Griffin et al., 2008). These sharks have slow growth rates and reach sexual maturity at a relatively late age compared to other marine fish, which leaves their population vulnerable to any outside sources (Musick and Musick, 2011).
But it does however, give us the 3 main suspects. For the tiger shark, they are known “to have a low metabolic rate and doesn't have to feed very often.” (25:15). But is knowing that, gonna keep you from keeping your guards up when in the water? Probably not.
Dolphins are mammals, breath air, give birth and nurse their young ones. The ancestors of dolphins were animals that once lived on land but turned to the sea about 50 million years ago and never returned to land hence the dolphin’s ancestor had to slowly adapt to its new environment. Its front legs became flippers and its tail became flukes that it uses for swimming and steering respectively. The same bone structure is shared by bats, flying mammals in the order Chiroptera. While the trait for them was inherited from a common ancestor, the bones that form flippers in dolphins form a bat’s wings (homologous trait, example of divergent evolution) Its back legs diminished completely into the body.
They have pectoral fins, dorsal fins, and a vertical tail. The skin of sharks is very rough and made up of millions of sharp scales. Sharks have gills for breathing. What 's can be up to 3,000 pounds. They have a long and wide body, dorsal fins, and a horizontal tail.