Dinosaurs: The Fact Files

Abelisaurus

Named after Roberto Abel of the Argentinian Museum of Natural Sciences, this late Cretaceous dinosaur is something of a mystery – but we do know it’s a pretty fearsome predator.

Detective work

The problem with Abelisaurus is that it’s an elusive character. What’s more, palaeontologists have very few remains to work with; the only evidence found so far is one skull – and that’s incomplete! However, even from such an unpromising start scientists can make an amazing number of assumptions about its size and what it looks like.

Hanging around

Of course, much of a palaeontologist’s work is open to debate and contradiction. Many scientists are not convinced that Abelisaurus is a separate sort of dinosaur at all, but suspect it is actually Carcharodontosaurus (car-CHA-row-DON-toe-SORE-us), the big Moroccan predator. If so, it would mean Carcharodontosaurus was in existence not only later, but also in a different area.

Fact File

How to say it: a-BEEL-ee-SORE-us

Meaning of name: Abel’s lizard

Family: Abelisauridae

Period: Late Cretaceous

Where found: Argentina

Height: 2 metres (6.6 feet)

Length: 9 metres (29.7 feet)

Weight: 1,300 kilograms (1.4 tons)

Food: Meat

Special features: Not enough specimens spotted to be certain

Acrocanthosaurus

This Cretaceous dinosaur is a classic predator: it has a big head filled with sharp teeth, powerful legs and a big, bulky body. There is also an interesting decorative feature not normally seen on dinosaurs of this type – a frill.

Spiny

The most striking feature of this powerful dinosaur is a series of spikes running down its spine. The spikes measure around 0.4 metre (1.3 feet) in length, which is big, but probably not long enough to be useful as a form of defence. Instead, they support a frill which runs down the length of the body. But what is the purpose of this crest? If you can answer that, you’re going to be a great palaeontologist because nobody is sure at the moment.

Track attack

Acrocanthosaurus is nearly as big as Tyrannosaurus rex and it would seem just as fearsome a predator. There are some dinosaur tracks in Texas called the Paluxy River tracks. Some palaeontologists believe that a set of these belong to Acrocanthosaurus and, if that’s true, the tracks show it chasing Pelorosaurus (pe-LOH-ro-SORE-us), a type of sauropod twice the size of this predator.

Fact File

How to say it: a-kroh-kan-tho-SORE-us

Meaning of name: High-spine lizard

Family: Carcharodontisauridae

Period: Early Cretaceous

Where found: North America

Height: 4 metres (13.2 feet)

Length: 12 metres (40 feet)

Weight: 2,300 kilograms (2.5 tons)

Food: Meat

Special features: Crest along spine

Alamosaurus

With its long neck and whippy tail, Alamosaurus looks much like any other sauropod. However, it is rare because it is the only type of sauropod to be found in North America at this time.

A long way from home?

Sauropods are the giants of the dinosaur age. The biggest animals to have walked on land, the sauropods peaked during the Jurassic period. By the late Cretaceous period, they had disappeared from North America, apart from Alamosaurus, who can be found in Texas, Utah and New Mexico. Some palaeontologists believe that these dinosaurs wandered up from South America, where more sauropods may still be