What killed the Mosasaurus?

What is a mosasaur and why is it important?

Gnathomortis is derived from the Greek and Latin words for “Jaws of Death.” After other marine reptiles like ichthyosaurs and pliosaurs went extinct, mosasaurs terrorized the oceans. “In general, mosasaurs actually filled a lot of roles in the oceans over the last 15 million years of the age of dinosaurs,” Lively said.

Are mosasaurs snakes?

Mososaurs belong to a group of reptiles called Toxicofera, which includes snakes as well as monitor lizards and Komodo dragons. The ancestor of the mosasaurs probably looked a lot like a modern Komodo dragon.

What happened to the mosasaurs?

The mosasaurs disappeared from the fossil record alongside non-avian dinosaurs 65.5 million years ago, after a giant asteroid crashed into Earth at the end of the Cretaceous period.

Are mosasaurs more closely related to crocodiles or snakes?

There is currently much debate about whether mosasaurs are more closely related to snakes or varanids, but in either case they are all members of the group toxicofera. This means that they are more closely related to monitor lizards than they are to crocodiles, dinosaurs, turtles, and non-toxicoferan lizards at the very least.

Is thermoregulation possible in late Cretaceous mosasaurs (Reptilia)?

Possible thermoregulation of Late Cretaceous mosasaurs (Reptilia, Squamata) indicated by stable oxygen isotopes in fossil bioapatite in comparison with coeval marine fish and pelagic seabirds”. Palaeontology. 59 (3): 351–363. doi: 10.1111/pala.12240. ^ a b Vanessa C. Bowman; Jane E. Francis; James B. Riding (2013).

What is the difference between large reptiles and other reptiles?

These large reptiles are an interesting group of animals. Although they’re very anatomically similar, there are large differences between the sizes of the members of the group. They’re much more active than other reptiles, so they have a higher metabolic capacity.

What type of animal is a Mesosaurus?

Mesosaurus, (genus Mesosaurus), early aquatic relative of reptiles, found as fossils from the Early Permian Period (299 million to 271 million years ago) in South Africa and South America. Mesosaurus lived in freshwater lakes and ponds.

Did Mesosaurus ever swim in the Atlantic Ocean?

The fossils of this prehistoric reptile have been discovered in eastern South America and southern Africa, and since Mesosaurus lived in freshwater lakes and rivers, it clearly couldn’t have swum across the expanse of the southern Atlantic Ocean.

What is the difference between Mesosaurus and Stereosternum?

Mesosaurus had a long skull that was larger than that of Stereosternum and had longer teeth. The teeth are angled outwards, especially those at the tips of the jaws. The bones of the postcranial skeleton are thick, having undergone pachyostosis. Mesosaurus is unusual among reptiles in that it possesses a cleithrum.

What is unique about the cleithrum of a Mesosaurus?

Mesosaurus is unusual among reptiles in that it possesses a cleithrum. A cleithrum is a type of dermal bone that overlies the scapula, and is usually found in more primitive bony fish and tetrapods.

How did Mesosaurus get its food?

It would roam the shoreline of rivers and lakes looking for small marine organisms and would occasionally get in the water to eat its favorite food: plankton. It would catch the plankton by filtering fresh water through its oddly shaped teeth. One of the most fascinating facts about Mesosaurus, however,…

How did Mesosaurus stay in the water?

The pachyostosis seen in the bones of Mesosaurus may have enabled it to reach neutral buoyancy in the upper few meters of the water column. The additional weight may have stabilized the animal at the water’s surface. Alternatively, it could have given Mesosaurus greater momentum when gliding underwater.

How does Mesosaurus support the theory of continental drift?

For this reason, the existence of Mesosaurus helps support the theory of continental drift; that is, the now-well-attested fact that South America and Africa were joined together into the giant continent Gondwana 300 million years ago before the continental plates supporting them broke apart and drifted into their current positions.

How did Mesosaurus catch plankton in its mouth?

It would catch the plankton by filtering fresh water through its oddly shaped teeth. One of the most fascinating facts about Mesosaurus, however, is the fact that it was instrumental in proving continental drift theory. It lived in both eastern South America and southern Africa.

How was Mesosaurus significant in providing evidence for the theory of continental drift?

Mesosaurus was significant in providing evidence for the theory of continental drift, because its remains were found in southern Africa, Whitehill Formation ,and eastern South America ( Melo Formation, Uruguay and Irati Formation, Brazil), two widely separated regions. As Mesosaurus was a coastal animal,…

What is Stereosternum?

Shikama & Ozaki, 1966 Stereosternum? Cope, 1885 Mesosaurus (meaning “middle lizard”) is an extinct genus of reptile from the Early Permian of southern Africa and South America. Along with it, the genera Brazilosaurus and Stereosternum, it is a member of the family Mesosauridae and the order Mesosauria.

Are mesosaurids amphibians?

Mesosaurids are a group of small aquatic reptiles and are the first known family of reptiles that are aquatic. It is estimated that they would have come from ancestors that were land reptiles. The fact that mesosaurids are aquatic animals cannot be fully guaranteed and some of them might have been amphibians.

What are the adaptations of a mesosaur?

Mesosaurs have been considered strictly aquatic animals. Their adaptations to the aquatic environment are well known and include putative viviparity, along with the presence of several skeletal characters such as a long, laterally compressed tail, long limbs, the foot larger than the manus, and presence of pachyosteosclerotic bones.

What is the theory of continental drift?

Theory of Continental Drift. The continental drift hypothesis was developed in the early part of the 20th century, mostly by Alfred Wegener. Wegener said that continents move around on Earth’s surface and that they were once joined together as a single supercontinent. While Wegener was alive, scientists did not believe that

How did Mesosaurus get from South America to Africa?

About Mesosaurus. However, since it only swam in fresh water, it is highly unlikely it could have swum the Atlantic Ocean to get from South America to Africa. This most likely means that these two areas were connected at one point in time and over time, spread apart. A theory that is known as continental drift.

What did Mesosaurus use its teeth for?

This animal’s teeth were very thin and were used to filter plankton and not to bite into fish or small animals. Not to mention the fact that it was quite a bit smaller than most of the prehistoric crocodiles that would come later. Mesosaurus was approximately 3 feet long and weighed around 20 pounds.

What is the distribution of Mesosaurus’s remains?

Distribution. Mesosaurus was significant in providing evidence for the theory of continental drift, because its remains were found in southern Africa, Whitehill Formation ,and eastern South America ( Melo Formation, Uruguay and Irati Formation, Brazil), two widely separated regions. As Mesosaurus was a coastal animal,…

What evidence supports the theory of continental drift?

Over the course of this essay I will review some of the evidence that support continental drift, such as fossil records and mountain ranges. One of the strongest pieces of evidence is Continental break up/fit, this is the idea that the continents were once joined together.

How does a Mesosaurus move in water?

Mesosaurus was one of the first reptiles to return to the water after early tetrapods came to land in the later Devonian. It was around 1 metre (3.3 ft) in length, with webbed feet, a streamlined body, and a long tail that may have supported a fin. It probably propelled itself through the water with its long hind legs and flexible tail.

What is the sister taxon of Reptilia?

These taxa together formed a clade (informally designated “parareptiles”) that Gauthier et al. (1988a) identified as the sister taxon of Reptilia.

Do mesosaurs belong to the clade Reptilia?

These studies show that mesosaurs do not form a clade with turtles that excludes diapsids, but fossil evidence still suggests that mesosaurs form a group with parareptiles. In most recent studies, Reptilia is not used as a crown group and still contains mesosaurs and Parareptilia.

Were the first amniotes fully terrestrial?

Mesosaurs were the first known aquatic reptiles, having apparently returned to an aquatic lifestyle from more terrestrial ancestors. It is uncertain which and how many terrestrial traits these ancestors displayed; recent research cannot establish with confidence if the first amniotes were fully terrestrial, or only amphibious.