They can be divided into two main types: ones with short heads on long necks and ones with long heads on short necks. The long-necked ones ate a variety of seafood, including fish, squid and clams.

Among them was the fearsome plesiosaur, a marine reptile with a long neck and four large flippers that ruled the ancient seas. However, their unique body structure has puzzled researchers for decades.

Plesiosaurs might have had the most bizarre of body types, with necks that could grow as long as an entire giraffe (up to about 20 feet). That seems as if it would get in the way.

Some plesiosaurs had long necks and reached lengths of over 50 feet from head to tail, while others had shorter necks and grew to only about six feet. Unlike many reptiles, plesiosaurs gave birth ...

A research group may have unraveled the mystery behind the locomotion of the ancient marine reptile, the plesiosaur, by recreating a bio-inspired control system that accounts for motion adjustment.

Plesiosaurs gained their famous long necks rapidly, researchers have shown. Their lengthy necks, used for chasing fast-moving fishes, developed quickly over a five million period around 250 ...

The discovery of a giant 100 million-year-old marine reptile’s skeleton in Australia has been hailed by researchers as a breakthrough that may provide vital clues about prehistoric life.

Stock image of a styxosaurus, a plesiosaur of the Cretaceous era. ISTOCK / GETTY IMAGES PLUS Tanystropheus, on the other hand, had extremely long and thin neck vertebrae that were internally ...

Plesiosaurs had some of the most extreme necks to have ever evolved, with some species, such as Albertonectes vanderveldei, boasting 7-metre-long appendages made up of 76 vertebrae.

The short-necked ones were the “killer whales” of their time, eating other marine vertebrates, including other plesiosaurs of both varieties.