Why is an ichthyosaur not a dinosaur?

Is there a link between the Ichthyosaurus and crocodile?

“Notice of the discovery of a new animal, forming a link between the Ichthyosaurus and crocodile, together with general remarks on the osteology of Ichthyosaurus”. Transactions of the Geological Society of London. 1. 5: 559–594. doi: 10.1144/transgsla.5.559.

Was Plesiosaurus a crocodile or ichthyosaur?

What the naturalists did not realize was that Plesiosaurus was not an intermediate form between crocodiles and ichthyosaurs, after all, but a unique and starkly different sort of marine reptile. Missing bones were what caused them to miscast their mosnter.

What is the difference between Ichthyopterygia and Ichthyosauria?

Within Motani’s phylogeny, the Ichthyopterygia were the larger parent clade of a smaller stem clade Ichthyosauria that was defined as the group consisting of Ichthyosaurus communis and all species more closely related to Ichthyosaurus than to Grippia longirostris.

How did the order Ichthyosauria get its name?

In 1835, the order Ichthyosauria was named by Henri Marie Ducrotay de Blainville. In 1840, Richard Owen named an order Ichthyopterygia as an alternative concept. The discovery of a hitherto unsuspected extinct group of large marine reptiles generated much publicity, capturing the imagination of both scientists and the public at large.

What is a ichthyosaur?

Ichthyosaurs belong to the order known as Ichthyosauria or Ichthyopterygia (‘fish flippers’ – a designation introduced by Sir Richard Owen in 1842, although the term is now used more for the parent clade of the Ichthyosauria).

What is the distribution of ichthyosaur fossils?

Ichthyosaurs had a very wide geographic distribution, and their fossil remains span almost the entire Mesozoic Era (251 million to 65.5 million years ago); but they were most abundant and diverse during the Triassic and Jurassic periods (251 million to 145.5 million years ago).

What did ichthyosaur eat?

Ichthyosaur. (Pliosaurs were large carnivorous marine reptiles thought to prey on ichthyosaurs.) The nostrils were positioned far back on the top of the skull (another specialized adaptation to an aquatic existence). They probably fed largely upon fish as well as other marine animals. It is unlikely that they ventured onto land,…

Are there any ichthyosaurs similar to the dinosaurs?

Rhaetian (latest Triassic) ichthyosaurs are known from England, and these are very similar to those of the Early Jurassic. Like the dinosaurs, the ichthyosaurs and their contemporaries the plesiosaurs survived the end-Triassic extinction event, and immediately diversified to fill the vacant ecological niches of the earliest Jurassic.

When did the ichthyosaur go extinct?

Ichthyosaurs thrived during much of the Mesozoic era; based on fossil evidence, they first appeared approximately 245 million years ago ( mya) and disappeared about 90 million years ago, about 25 million years before the dinosaurs became extinct.

Were ichthyosaurs warm blooded reptiles?

Fossil blubber shows ichthyosaurs were warm blooded reptiles. The discovery of blubber in an ichthyosaur fossil suggests these ancient marine reptiles were probably warm blooded, as has long been suspected.

What did ichthyosaurs eat?

McGowan speculated that forms with protruding upper jaws, in the Eurhinosauria, would have used their pointy snouts to slash prey, as has been assumed for swordfish. The most commonly preserved gut contents in ichthyosaurs are the remains of cephalopods. Less commonly, they fed on fish and other vertebrates, including smaller ichthyosaurs.

Did ichthyosaur bite off more than it could chew?

For its last meal, an ancient marine reptile called an ichthyosaur may have bitten off more than it could chew. The dolphinlike creature was nearly 5 meters long, about the length of a canoe.

How did this giant ichthyosaur die?

The exact cause of death is unknown, according to a team from the University of California, Davis, but analysis reveals the predator died shortly after its enormous meal. This prehistoric ichthyosaur had jaws powerful enough to rip the smaller marine lizard to pieces before eating it and researchers say ‘it started in the middle’.

When did ichthyosaur live?

They first appeared around 250million years ago and at least one species last until about 90million years ago. Meanwhile dinosaurs lived between 230 and 65 million years ago, in a time known as the Mesozoic Era. Ichthyosaur remains have been found in America, Europe and Australia. The sea beasts’ diversity…

Is a ichthyosaur a mammal or reptile?

Ichthyosaur. Ichthyosaur, any member of an extinct group of aquatic reptiles, most of which were very similar to porpoises in appearance and habits. These distant relatives of lizards and snakes (lepidosaurs) were the most highly specialized aquatic reptiles, but ichthyosaurs were not dinosaurs.

Why did all ichthyosaurs go extinct?

All ichthyosaurs went extinct tens of millions of years before the dinosaurs were wiped out during the famous Cretaceous-Paleogene extinction event. But we still don’t know why.

What did the ichthyosaur skull reveal about evolution?

The giant skull of the ichthyosaur fossil — an extinct marine reptile — that has been discovered in the Augusta Mountains of Nevada. (CNN) The discovery of a giant marine reptile skull in the United States has revealed new theories about the speed of evolution and how quickly the process can produce diversity.

Did ichthyosaur evolve from sea lizards?

But it took whales 45 million years of living in the ocean to evolve their most giant body sizes. This new species of giant ichthyosaur appeared only three million years after the first ichthyosaurs took to the seas, suggesting the sea lizards evolved big bodies at a breakneck speed.

Did a ichthyosaur kill its predator?

A bulge in the belly of a fossilized ichthyosaur (pictured) contains the remains of a reptile called a thalattosaur. That prey was nearly as long as the ichthyosaur itself. Such a big meal may have killed the predator, scientists say.

How big is the ichthyosaur fossil?

The giant ichthyosaur fossil — with a skull measuring almost two meters (6.6 feet) in length, an estimated body length of more than 17 meters (55.7 feet) and a weight of 45 tonnes-was found in Nevada.

What caused the ichthyosaurs to disappear?

The last ichthyosaurs disappeared in the Cretaceous — several million years before the last dinosaurs died out. Whatever caused the extinction of the dinosaurs did not cause the ichthyosaurs to die out.