Prehistoric Animals : Theropod Dinosaurs

Theropod dinosaurs were the top predators in the Jurassic and Cretaceous periods. For over 100 million years theropods were the only large carnivores on land and included all the infamous carnivorous dinosaurs - Tyrannosaurus, Velociraptor and Spinosaurus. However, not all theropods were predators. Some evolved away from their carnivorous origins to consume an omnivorous or herbivorous diet. Birds are the only living descendants of the theropods.

Scientific name: Theropoda
Rank: Suborder

beast-footed

Prehistoric Animals ; Brachiosaurus

Brachiosaurus

Prehistoric Animals : Stegosaurus

                                                                      Stegosaurus

   Stegosaurus

Stegosaurus

Although nowhere near the largest of the Jurassic dinosaurs, Stegosaurus were still about the size of a bus. Distinctive and heavily built, they were herbivores with short forelimbs and would have walked with their small head close to the ground and the four-spiked tail held high. The double row of plates running along the back helped control body temperature and were probably used in display or possibly in defence against carnivorous Allosaurs. Most fossils for the three known species, including some complete skeletons, have come from the USA, although a recent discovery in Portugal suggests a wider distribution.

Scientific name: Stegosaurus
Rank: Genus

Common Name : Roof-lizard

Prehistoric Animals : Armoured Dinosaurs

Armoured Dinosaurs

While early armoured dinosaurs had bony scutes like crocodiles, later forms took armour to the extremes, evolving large plates, spikes, clubs and carapaces. Covering yourself in heavy armour proved to be a very successful anti-predation strategy, as armoured dinosaurs evolved during the early Jurassic and lasted right up until the mass extinction at the end of the Cretaceous period. Though there were many variations and modifications within each type, they came in two basic forms: the stegosaurs with their rows of spikes or plates along the spine, and the more heavily amoured ankylosaurs.

Scientific name: Thyreophora
Rank: Suborder

Common Name : Shield Bearers

Prehistoric Animals : Ankylosaurs

Ankylosaurs

Looking like reptilian armadillos, or prehistoric tanks, Ankylosaurs were heavily armoured dinosaurs with protective plates over their head and shoulders. Some species took their protection to extremes and even had armoured eyelids. Spikes and protrusions were common in a bid to deter predators from taking a bite. Some ankylosaurs had a large, heavy club at the end of the tail for wielding as a weapon or, as has also been suggested, for sexual selection. To carry the weight of all this heavy armour, these plant-eating dinosaurs had very short, stout legs.

Scientific name: Ankylosauria
Rank: Infraorder

Common Name : Fused Lizards

Prehistoric Animals : Apatosaurus

Apatosaurus

Apatosaurus used to be known as brontosaurus, following a labelling error on a very similar specimen. Subsequently renamed, Apatosaurus was one of the larger sauropod dinosaurs, and therefore one of the largest animals ever to have walked the Earth. Peg-like teeth effectively stripped leaves from trees, but were no use for chewing, so Apatosaurus probably swallowed stones to grind up its meals in the gizzard. Enormous size, herding behaviour and a whip-like tail would all have provided valuable defence against the meat-eaters of the time.

Scientific name: Apatosaurus
Rank: Genus

Prehistoric Animals : Diplodocus

 

 

Diplodocus

Diplodocus was one of the longest animals to have lived on Earth and may have reached over 30 metres and weighed around 15 tonnes. The quantity of plant material eaten by roaming herds of this massive herbivore is unimaginable. Once the most famous dinosaur in the world, Diplodocus had four large sturdy legs supporting a long neck and a long tail that could be flailed around like a whip. Several different species have been described since the first Diplodocus discovery was made in North America in 1877. They lived there about 150 million years ago during the late Jurassic period.

Scientific name: Diplodocus
Rank: Genus

Common Name : Double Beam