Marine crocodiles

Among the variety of dinosaurs, one other prehistoric archosaur group often escapes comment: the marine crocodiles.

Here is Dakosaurus maximus in yellow at 5 meters, compared to a modern sea otter in brown at 1.2 meters and two better-known marine reptiles: Mosasaurus in black at 12 meters, and Liopleurodon in green at 9 meters.



Here is a picture of Dakosaurus alone.

Velociraptor, continued: and why Jurassic Park is wrong

Finishing out this week's theropod:

The most famous Velociraptor fossil is the "Fighting Dinosaurs", which shows the creature entangled in a death-grip with a Protoceratops. The latter is a much heavier animal, so Velociraptor must have been quite aggressive.

Velociraptor, in reality, was just over 6 feet long and weighed only about 33 pounds (according to Gregory Paul's Predatory Dinosaurs of the World, anyway). This is no heavier than a good-sized male coyote. The Jurassic Park movies' giants big enough to look a man in the eye are not Velociraptors! They're more like the very biggest Deinonychus. Also, the movie 'raptors have too high of skulls. This post's picture (of the original type specimen of Velociraptor!) shows the correct flat skull.

None of this is the movie-makers' fault, however. In the books, the 'raptors are described as weighing ninety kilos and being "as fast as cheetahs and as smart as chimps". (Velociraptor was intelligent for a dinosaur, but its brain isn't anywhere near large enough to be as smart as that.) The size is understandable, because in 1988, two years before Jurassic Park was published, Gregory Paul lumped the genus Deinonychus into Velociraptor.

Sources:

Paul, Gregory S. Predatory Dinosaurs of the World. 1988.

Crichton, Michael. Jurassic Park. 1990.

Crichton, Michael. The Lost World. 1993.