What makes ichthyosaur a reptile?

Is the ichthyosaur an example of convergent evolution?

Evolutionary biologist Stephen Jay Gould said that the ichthyosaur was his favourite example of convergent evolution, where similarities of structure are analogous, not homologous, thus not caused by a common descent, but by a similar adaptation to an identical environment:

Is an ichthyosaur a dinosaur?

Written By: 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 are ichthyosaurs important to the world?

Ichthyosaurswere the first important reptile group to successfully adapt to marine life. They have been found in many parts of the world and thrived throughout most of the Age of Dinosaurs, though they declined in the Cretaceous Period and likely became extinct before its end.

How can you tell the difference between different types of ichthyosaurs?

Anatomically speaking, it’s relatively easy to distinguish the early ichthyosaurs of the Mesozoic Era from more advanced genera. The ichthyosaurs of the middle to late Triassic period, such as Grippia, Utatsusaurus, and Cymbospondylus, tended to lack dorsal (back) fins and the streamlined, hydrodynamic body shapes of later members of the breed.

How are ichthyosaurs similar to whales and dolphins?

Later species, such as Ophthalmosaurus, had relatively larger eyes, again an indication that diving capacity was better in late Jurassic and Cretaceous forms. Similar to modern cetaceans, such as whales and dolphins, ichthyosaurs were air-breathing. Whales and dolphins are mammals and warm-blooded.

Why do ichthyosaur give birth headfirst?

That position is telling: Most viviparous marine reptiles are born tail first so that they can continue to draw oxygen from their mother during labor. The headfirst birth position indicates the ichthyosaur inherited live birth from an even more ancient land ancestor.

Were ichthyosaurs cold-breathing?

Similar to modern cetaceans, such as whales and dolphins, ichthyosaurs were air-breathing. Whales and dolphins are mammals and warm-blooded.

What is an example of convergent evolution?

Convergent evolution is a unique concept in biology which refers to the animals having similar revolutionary niches. An Ichthyosaur is the best example to explain more about this concept. They also have certain similar evolutionary natures which match with the dolphins and Blue Fins present today.

Did ichthyosaurs really look like fish?

Although ichthyosaurs looked like fish, they were not. Evolutionary biologist Stephen Jay Gould said that the ichthyosaur was his favourite example of convergent evolution, where similarities of structure are analogous, not homologous, thus not caused by a common descent, but by a similar adaptation to an identical environment:

What is the difference between an ichthyosaur and a bottlenose dolphin?

You can’t ask for two animals more separated in geologic time than Ophthalmosaurus and the bottlenose dolphin. The former was an ocean-dwelling ichthyosaur (“fish lizard”) of the late Jurassic period, 150 million years ago, while the latter is an extant marine mammal.

What is the best example of convergent evolution?

Biologist Stephen Jay Gould said the ichthyosaur was his favorite example of convergent evolution, where similarities of structure are analogous not homologous, for this group: “converged so strongly on fishes that it actually evolved a dorsal fin and tail in just the right place and with just the right hydrological design.

What are some interesting facts about ichthyosaurs?

The Ichthyosaurs are famous for having a variety of dolphin-shaped species. The group also includes the largest marine reptiles (reptiles living in the sea) that ever lived. The Ichthyosaurus was a small, slim-snouted Ichthyosaur. It had dozens of sharp, needle-like teeth and used them to catch squid or other kinds of molluscs.

What kind of ichthyosaur is Reptilia?

A revision of the longipinnate ichthyosaurs of the Lower Jurassic of England, with descriptions of two new species (Reptilia, Ichthyosauria). Life Sciences Contributions, Royal Ontario Museum.

Were ichthyosaurs cold-blooded or warm-blooded?

Of ichthyosaurs it was traditionally assumed that they were cold-blooded, being reptiles. However, since the 1970s many dominant reptile groups of the Mesozoic, such as theropod dinosaurs, pterosaurs and plesiosaurs, have been considered warm-blooded, as this offers an elegant explanation of their dominance.

Were ichthyosaurs negatively buoyant?

Modern researchers generally concur that ichthyosaurs were negatively buoyant. Despite their considerable size, the flippers of the Amazon river dolphin are mainly used as rudders. In 1994, Judy Massare concluded that ichthyosaurs had been the fastest marine reptiles.

What do ichthyosaur tail fins tell us?

Derived ichthyosaur tail fins are more like those of tuna fish and indicate a comparable capacity to sustain a high cruising speed. A comparative study by Motani in 2002 concluded that, in extant animals, small tail fin lobes positively correlate with a high beat frequency.

What was the ichthyosaur’s last meal?

A bulge in the belly of this fossilized creature (pictured) contains the remains of a reptile called a thalattosaur, which was nearly as long as the ichthyosaur itself. For its last meal, an ancient marine reptile called an ichthyosaur may have bitten off more than it could chew.

How big was the ichthyosaur that killed its prey?

Called an ichthyosaur (IK-thee-oh-sore), the dolphinlike predator was nearly 5 meters (16 feet) long. That’s about the length of a canoe. In its belly were the remains of a lizardlike reptile called a thalattosaur. At 4 meters (13 feet), this prey was almost as long as the predator.

Did an ancient reptile bite off more than it could chew?

For its last meal, an ancient marine reptile may have bitten off more than it could chew. And that may have proved a lethal mistake. Called an ichthyosaur (IK-thee-oh-sore), the dolphinlike predator was nearly 5 meters (16 feet) long. That’s about the length of a canoe.

What is the difference between Ichthyosaurus and Ophthalmosaurus?

Ichthyosaurs were still common in the Middle Jurassic, but had now decreased in diversity. All belonged to the single clade Ophthalmosauria. Represented by the 4 meter long Ophthalmosaurus and related genera, they were very similar to Ichthyosaurus, and had attained a perfect “tear-drop” streamlined form.

What are the similarities between ichthyosaurs and fish?

Apart from the obvious similarities to fish, ichthyosaurs also shared parallel developmental features with dolphins, lamnid sharks, and tuna. This gave them a broadly similar appearance, possibly implied similar activity levels (including thermoregulation), and presumably placed them broadly in a similar ecological niche.

Why do ichthyosaurs look like dolphins?

Despite their distance from the oceanic mammals in both time and evolutionary history, though, ichthyosaurs look enough like dolphins for the two to be practically inseparable in textbooks. They’re a striking example of convergent evolution – two lineages independently evolving extremely similar anatomy from different starting points.