Brachiosaurus is one of the largest animals that has even walked on Earth. It's probably best known from the "snotty vegisaurus"-scene in Jurassic Park I. Like Elephants the giant Sauropods like Brachiosaurus, Diplodocus and Camarasaurus relied on sheer size for protection.

Fossils has been found in western North America (Colorado, Wyoming and Utah), Portugal, Algeria and Tanzania.

Brachiosaurus was 85 feet (25 m) long and stood 40-50 feet (12-16 m) tall. It weighed an impressive 50 tons or maybe even more! It walked on four legs, but unlike most other dinosaurs it's front legs were longer than the hind legs. 

The long flexible neck enabled Brachiosaurus to forage both from tall trees and smaller plants near the ground. The food was swallowed whole and digested using gastroliths. Brachiosaurus probably lived in small herds that moved slowly through the forests while eating their favorite plants. If it was warm-blooded it must have eaten more than 500 pounds (200 kg) each day. On the other hand if it was poikilothermic it could have taken as much as 100 years to grow up.

The Lego model is very close to the real animal. But it's way too small to be used with minifigs.

This Prosauropod is one of the first large herbivores with long necks. The Prosauropods evolved into the giant Sauropods. More than 50 fossils has been found around Central Europe (France, Germany and Switzerland). But an almost complete skeleton has also been discovered in East Greenland.

Plateosaurus was 20-30 feet (6-10 m) long and weighed 1-2 tons. The front legs was considerably shorter than the rear legs. But it normally walked on four legs with the tail clear off the ground. When threatened by predators the best defense would seem to run on the rear legs. It had small claws on all limbs and might have reared up to use the large thumb claws against a predator.

The finding of a bone bed at Trossingen in Germany indicates that Plateosaurus lived in herds that migrated to find food. Such a herd in close ranks might have be able to fight off a predator.

I don't think that Lego did a very good job in modeling this dinosaur. Furthermore it's too big to be used with minifigs.

Diplodocus got it's name from the shape of the tail vertebrates. It is thought that this peculiar shape protected the blood vessels when the tail was on the ground. This suggests that the tail and rear legs could form a tripod that enabled it to rear up and eat from trees as well as smaller plants. Alternatively the long neck could have enabled it to eat soft-leaved plants in wet areas where other heavier Sauropods like Brachiosaurus and Camarasaurus couldn't go. There has only been found fossils in western North America (Colorado, Wyoming and Utah).

Diplodocus was 90 feet (27 m) long and 25 feet (8 m) tall. That's longer than a tennis court and makes it the longest land animal even. But it only weighed 10-15 tons. This relatively low weight was achieved by using various weight saving methods. The body was like a suspension bridge supported by the four legs.

Fossilized footprints suggest that Diplodocus lived in herds that migrated when local food supply was depleted. It used the blunt teeth to strip the foliage. The food was swallowed whole and digested using gastroliths. 

The Lego model is very close to the real animal. Unfortunately it's way too small to be used with minifigs. But if you make the neck shorter and call it Saltasaurus it is perfect in scale.

Plesiosaurus is the first and smallest of the Plesiosaurs. The Plesiosaurs was not Dinosaurs but marine reptiles that lived in the open oceans and competed with the the dolphin-like Ichthyosaurs. They breathed air but might have laid eggs on the shore. Other Plesiosaurs include Cryptocleidus 13 feet (4 m), Muraenosaurus 20 feet (6 m), Wolungosaurus 26-33 feet (8-10 m) and the giant Elasmosaurus "Thin-plated Lizard" 46 feet (14 m). 

Fossils of Plesiosaurus has been found in England and Germany, while remains of the other Plesiosaurs are found in all parts of the World.

Plesiosaurus was 8-15 feet (2.5-5.0 m) long. It had four flippers that was used much like modern turtles. The front flippers was slightly larger than the hind flippers and the tail was short and pointy. The long neck, strong jaws and sharp conical teeth enabled it to eat fish and other marine animals. 

This Lego model is very good looking. It's just too big to be used with minifigs. But if you just call it Elasmosaurus it's almost perfect. And the 4077 Plesiosaurus is just right in size.