Pelagosaurus

Cast of Pelagosaurus typus in the Muséum national d' histoire naturelle, Paris

• Western Europe (England, France, Germany )

• Pelagosaurus typus Bronn, 1841

Pelagosaurus ( "lizard of the high seas " ) is an extinct genus of Thalattosuchia that lived during the stage of Toarciums in the Lower Jurassic in the shallow shelf seas that covered at that time, large parts of today's Western Europe. The type species Pelagosaurus typus was described in 1841 by the German paleontologist Heinrich Georg Bronn. The taxonomy of Pelagosaurus is hotly debated for years. Pelagosaurus similar in terms of adaptation and feeding habits strongly the modern gharial.

Discovery history

Pelagosaurus was originally described based on a specimen from Normandy, the holotype of P. typus was found north of the English town of Ilminster in Somerset. Most Pelagosaurus - remains were discovered in the region of Ilminster, but also in other areas of Western Europe, in France and Germany, they found numerous fossils, mostly skulls and skeletons fully intact. The specimens from the region of Somerset come mainly from the Strawberry Bank quarry north of Ilminster; although the reference contained more fossils, it was overbuilt in the meantime. One of the recovered individuals was not fully grown, so that insights were possible in the growth pattern of Pelagosaurus.

Classification

The evolutionary relationships of Pelagosaurus are so far unclear, as the exact position within the Thalattosuchia is controversial:

Recent phylogenetic analyzes have all found that Pelagosaurus is a basal Teleosauride and no basal Metriorhynchide or Thalattosuchier.

Mosellaesaurus ( Monard 1846) is a synonym of Pelagosaurus.

Ecology

Pelagosaurus was well adapted to an aquatic lifestyle; The animal had a long streamlined nose, with a tail fin-like properties and paddle-like limbs to swim around in the warm and shallow waters at that time. Pelagosaurus had 30 teeth, with which the animal while swimming fish, crustaceans and insects hunt and could grab. In the stomach of a fossil specimen of Pelagosaurus they found the remains of a Leptolepis, an early representative of the genuine bony fish found. The forward-facing eyes and the streamlined body indicate that it was at Pelagosaurus a Hetzjäger and not a scavenger and-wait predator. Pelagosaurus was very similar to the modern crocodiles and moved probably in a similar way with meandering movements of the tail continued, although the vertebral structure was slightly more agile than in modern crocodiles. This allowed a higher mobility in the water. Pelagosaurus spent the most time in the water and went well only to lay eggs or to rest on land.

Evidence

• Extinct crocodile
• Crocodiles
• Crocodilia