"Liopleurodon"'s nose allowed it to smell underwater. It could smell prey from some distance away. Despite needing to breath air, Liopleurodon spent its entire life at sea and was unable to leave the water. Consequently, it would have given birth to its young alive and may have visited shallower water to breed.
Libonectes
Libonectes was a plesiosaur related to "Elasmosaurus". It lived 80 to 65 million years ago. It grew up to 12 metres long. It was a predator of small fish; the fish ate plankton in the upper pelagic layers of the sea.
Dimetrodon
Dimetrodon was a pelycosaur (early Synapsida) from the first part of the Permian period (about 295–272 million years ago).
"Dimetrodon" walked on four legs and had a tall, curved skull with large teeth of different sizes set along the jaws. Most fossils have been found in the southwestern United States, from red beds in Texas and Oklahoma. The largest known species of "Dimetrodon" is "D. angelensis" at and the smallest is "D. teutonis" at .
"Dimetrodon" was a carnivore, probably the top predator in its environment. Its main feature is the large sail on its back formed by elongated spines extending upwards from the vertebrae. The spines would be joined by skin. The general opinion of palaeontologists is that it was a temperature-regulating device. The idea is that the animal could warm up in the early morning by placing itself broadside to the Sun, and later could cool off in the shade, or arrange for its body to get less sunlight. At this stage in evolution, no land animals were homoiotherms. Very likely the sail was also used for sexual or territorial signalling. In which case, the skin would be coloured. This, of course, is supposition, but it does make sense of the animal's most extraordinary feature.
In evolutionary terms, "Dimetrodon" was a synapsid, a line of land animals which eventually gave rise to the mammals. It was not on the direct line of descent, but a good example of the evolutionary grade typical of Permian synapsids.
Spinosaurus
Spinosaurus (which means 'spiny lizard') was a huge semi-aquatic dinosaur from the Cretaceous, 112 to 93.5 million years ago. It had paddle-like feet and nostrils on top of its crocodile-like head. This would let it submerge as a crocodile does.
The same research suggests it was perhaps larger than "Tyrannosaurus rex", but more clumsy on land, moving as a quadruped. All these ideas had been suggested before. The discovery of a more complete skeleton made palaeontologists think they were correct. The fossil was found in Morocco by a private collector who let scientists examine it.
"Spinosaurus" bones were first discovered in Egypt in 1912 by German paleontologist Ernst Stromer in 1915. Two species, "S. aegyptiacus" and "S. marocannus", are recognized by many paleontologists, but there may only be one. "Spinosaurus" looked like "Baryonyx" except it was larger and more heavily built. Six specimens of "Spinosaurus" have been uncovered. Apparently, good material was destroyed in Munich in a 1944 bombing raid.
100 million years ago, the Sahara Desert was wet. Animals included the pterosaur "Alanqa", types of giant crocodiles, and theropod predators the size of "T. rex". The largest predator was "Spinosaurus". In the past, it was thought that Spinosaurus aegyptiacus was bipedal. In 2014, scientists believed that "Spinosaurus aegyptiacus" was quadrupedal because it is front-heavy. If "Spinosaurus aegyptiacus" were to walk on two legs, it would topple. "Spinosaurus" probably walked on its knuckles. Spinosaurus's legs were short. "Spinosaurus"'s jaws were designed to catch slippery prey like fish. Scientists say that "Spinosaurus" spent most of its time in the water and it was a semi-aquatic dinosaur.
"Spinosaurus" was larger than "Tyrannosaurus". Estimates published in 2005, 2007, and 2008 suggested that it was between 15 metres (50 ft) in length and 7 to 20.9 tonnes (7.7 to 23.0 short tons) in weight. A new estimate published in 2014 and based on a more complete specimen, supported the earlier research, finding that "Spinosaurus" could reach lengths of over 15 m (49 ft). It had a two meter high sail on its back like "Dimetrodon". Several uses have been suggested for this sail, such as to help control its body temperature, as a way to attract a mate, and to intimidate or frighten enemies. It lived in what is now the Sahara Desert, but which then was mangrove forests alongside shoreline conditions, tidal flats and channels.
The skull of "Spinosaurus" was long and narrow like that of a modern gharial. "Spinosaurus" is known to have eaten fish. Evidence suggests that it lived both on land and in water like a modern crocodilian.
It was featured as the main dinosaur in the 2001 film Jurassic Park III where it fights and kills a T-Rex. It has also appeared on postage stamps in several countries, and many toy companies have made models of "Spinosaurus".
Anhanguera
Anhanguera, which means 'Old Devil', was a pterodactyl from the Upper Cretaceous. It was found in the Santana Formation of Brazil, and specimens from England are also placed in this genus.
It ate fish and grew to 14 feet (4.5 meters) across. The species "Anhanguera piscator" is now placed in the genus "Coloborhynchus".
Rhamphorhynchus
Rhamphorhynchus is a genus of long-tailed pterosaurs in the Upper Jurassic. It is the best-known of the long-tailed pterosaurs, the sub-order Rhamphorynchoidea.
"Rhamphorhynchus" had a long tail, stiffened with ligaments, which ended in a small diamond-shaped rudder on the end of its tail which helped keep it stable when it was flying.
The jaws of "Rhamphorhynchus" housed needle-like teeth, which were angled forward, with a curved, sharp, beak-like tip lacking teeth. Their diet was mainly fish and insects.
Like other pterosaurs, its body was covered with hairs, which suggests it had termperature regulation ('hot-blooded') and a high rate of metabolism. This is also found in birds and bats, and seems necessary for active flight.
The genus was quite successful: it is the most common pterosaur found in the Solnhofen limestone beds in Bavaria, Germany. These are the same strata where "Archaeopteryx" was found.
This early group flourished from the Upper Triassic to the end of the Jurassic. When we first see them in the fossil record they have developed three families, so biologists know their early evolution is not yet revealed. These three families are represented by the three genera "Rhamphorhynchus", "Dimorphodon" and "Eudimorphodon". This sub-order was the earliest kind or pterosaur, which were succeeded by the more 'derived' short-tailed pterosaurs, the Pterodactyloids, such as "Pterodactylus". In the Upper Jurassic both the two sub-orders were extant (living).
The group always has a long tail, stiffened by rod-like bony tendons to keep it straight. This indicates their flight was extremely stable, which means it kept on course, and did not dart about much. This feature is also found in "Archaeopteryx" and in early bats, and in insects like dragonflies.
It can be interpreted like this. To dart about quickly requires special advanced brains and reflexes to keep control. Later birds and pterosaurs had extra 'control wiring' in their brains, but early ones did not. The evidence for this is the extra size of pterodactyl and bird brains compared with the reptile brains the groups started out with. That much of this increase is connected to seeing and flying is clear from how bird brains work.
The analogy would be planes. Early planes were highly stable, and so are airliners. Fighter planes are fundamentally much less stable, and have to be in order to jink about. This needs such fast reactions that the details are worked out by computer, with the pilot indicating where to go.