The fossilized remains of a huge sea monster known as a mosasaur were recently discovered in Texas. The land of what is now Texas was submerged underwater around 80 million years ago. The predator ...

was not only "unique among squamata" — the order to which mosasaurs belong — but also among tetrapods, or four-limbed vertebrates. Related: 80 million-year-old sea monster jaws filled with ...

Some paleontologists think that fossils recovered from Antarctica are evidence of birds similar to modern geese and ducks ...

These sea monsters grew upwards of 40 feet (12 meters ... such as the sharp-toothed shark Cretoxyrhina and the giant mosasaur Tylosaurus. Like all plesiosaurs, Styxosaurus's limbs were two ...

The short-necked plesiosaur likely had few enemies, but those that attacked were some of the fiercest monsters of the seas, including sharks with razor-sharp teeth and the giant mosasaur Tylosaurus.

setting it apart from other mosasaurs or huge extinct sea reptiles of the time. It also had "extra-long rear flippers" that helped it push its body forward in coordination with its elongated tail.

similar to a sea turtle or humpback whale. The shape of the spine also indicates that the species may have had a dolphin-like dorsal fin, a first for mosasaurs. Since 2010, the Wakayama ...