dinosaurs

the big ballers.

The bony plates along its back were embedded in the skin of the animal, not attached to its skeleton, which is why in most fossil finds the plates are separated from the body.
When O C Marsh described the first fossil of aStegosaurus, he concluded that the plates would have lain flat on its back. After finding a specimen that had been covered with mud, which had held the plates in place, Marsh realised that they stood vertically, alternately on either side of the spine.
Scientists are not exactly sure what the plates were used for. They may have warned off predators, or allowed members of the same species to recognise each other. Another suggestion is that the plates were used to regulate body temperature.
There are tiny grooves in the plate surfaces, possibly where blood vessels would have been. The amount of blood passing through these vessels would determine the amount of heat transfer.

Bite marks found on Triceratops and Edmontosaurus fossil bones show that Tyrannosaurus could crunch through bone. Analysis of fossilised Tyrannosaurus dung show that it contained the bones of its prey.

Hunter or scavenger?

The Tyrannosaurus skull was over 1.5 metres (5 feet) long and the cavity that housed the part of the brain responsible for smell was relatively large.Tyrannosaurus would have used its good sense of smell to hunt live prey and locate dead bodies to scavenge. It would have been able to scare off any other scavengers, so it didn't have to share.

Tyrannosaurus lives up to its reputation as one of the most fearsome animals of all time. Its powerful jaw had 60 teeth, each one up to 20 cm (8 inches) long and its bite was around 3 times as powerful than that of a lion.

Lone or pack hunter?

We know that close relatives of Tyrannosaurus sometimes lived together because there are fossils of groups who were buried together, but we don't know for sure if they hunted alone, or in packs like lions and wolves do today. So far, no groups of Tyrannosaurus skeletons have been found.

Many Tyrannosaurus fossils show bite marks from other tyrannosaurs, so it's clear that they fought each other, whether over food or mates.

Diplodocus had a long neck that it would have used to reach high and low vegetation, and to drink water. There has been some debate over how such a long neck would have been held.

Scientists now think that ligaments running from the hip to the back of the neck would have allowed Diplodocus to hold its neck in a horizontal position without using muscles. The vertebrae (back bones) are split down the middle and this space could have held ligaments like these.

A Museum icon

In 1905 a cast of a Diplodocus skeleton was donated to the Museum by the wealthy businessman Andrew Carnegie, based on the original specimen in the Carnegie Museum in the USA.

King Edward VII had requested a copy of the newly discovered dinosaur after seeing a picture of it in Carnegie's Scottish castle. Today the cast is still on display in the Museum's Central Hall and is known affectionately as Dippy.

In 1993, Dippy's tail was lifted from the ground after research revealed that Diplodocus tails would have been raised high to balance the neck.

Every 2 years or so, Museum experts use specialist equipment to clean the 292 bones that make up Dippy. It takes 2 staff 2 days to clean the cast and make sure it is maintained for future generations to enjoy.

Early carnivores

In the Late Triassic Period dinosaurs were not at the top of the food chain. Instead, early large reptiles called phytosaurs and rauisuchids domintated.

Early meat-eating dinosaurs like Coelophysis relied on their speed and agility to catch a variety of animals like insects and small reptiles. The sharp teeth and grasping claws of Coelophysis would have helped them to hold and kill their food.

Cannibalism?

A fossil find of an adult skeleton with what appeared to be young Coelophysis bones inside its rib cage led scientists to speculate that Coelophysis ate each other when the opportunity arose.

Recent analysis has disproved this, however, by showing that the bones inside the ribcage are not a babyCoelophysis after all, but belong to a small crocodile.

Hollow bones

Coelophysis means 'hollow form' and this comes from the hollow limb bones. This feature was shared by many other dinosaurs, and would have given Coelophysis a lightly-built body, helping it to be a swift, agile hunter.

With its 3 horns, a parrot-like beak and a large frill that could reach nearly 1 metre (3 feet) across, the Triceratops skull is one of the largest and most striking of any land animal.

The horns could have been used to fend off attacks fromTyrannosaurus. A partial Triceratops fossil collected in 1997 has a horn that was bitten off, with bite marks that match Tyrannosaurus. The fossil shows that the horn healed after being bitten, so at least some Triceratopssurvived these encounters.

Puncture marks on fossil frills show that male Triceratopsalso used their horns to fight each other, probably to impress females.

Herd instinct

Many other horned dinosaurs are known to have lived in herds because of a fossil find of many different individuals at the same location.

By moving in herds, prey animals can warn each other of danger and lessen their chances of being singled out by a predator.

However, Triceratops was unusual in this respect, as their remains are usually found individually, suggesting they may have spent much of their lives alone.

Why the frill?

The Triceratops frill might have helped to protect its neck, but some specimens show Tyrannosaurus bite marks puncturing the frill, so it wasn't always enough.

The frills could also have been used to attract mates, as a way for members of the same species to recognise each other, or to regulate body temperature.