Baryonyx

  • Pronounced: Bah-ray-on-niks
  • Origin: Spain and UK
  • Discovered in 1983
  • Lived: Early Cretaceous – 125 million years ago
  • Size: height - 1.76m, length - 7.02m
  • Name means: Heavy claw

The nostrils are set back on the snout of the Baryonyx. This indicates that Baryonyx probably had a fish-based diet, and potentially swam to catch prey, since they could keep
their nostrils out of the water while swimming. It is thought they also stalked prey from the water’s edge with their huge claw, which was up to 31cm long!

It was thought that Baryonyx had twice as many teeth as a Tyrannosaurus!

Compsognathus

  • Pronounced: Komp-sog-nath-us
  • Origin: Germany and France
  • Discovered in 1859
  • Lived: Late Jurassic – 145-140 million years ago
  • Size: height - 46cm, length - 87cm
  • Name means: Pretty jaw

Compsognathus were small speedy dinosaurs. They were one of the smallest dinosaurs, about the size of a chicken! Their hollow bones enabled them to be light on their feet so that they could run fast and chase prey.

Their long tail acted as a counterbalance and stability for fast turns while running. Its name means ‘pretty jaw’ as its mouth was filled with many small sharp teeth.

When first discovered in 1859, scientists believed Compsognathus was a swimmer, using its arms to propel itself through water like oars. Since then, it has been reinterpreted as a land-based bipedal dinosaur. One of the Compsognathus fossils found had lizard bones in its stomach.

Deinonychus

  • Pronounced: Die-non-ih-kus
  • Origin: North America
  • Discovered in 1964
  • Lived: Early Cretaceous – 115-108 million years ago
  • Size: height - 1.22m, length - 3.71m
  • Name means: Terrible claw

The discovery of Deinonychus in 1964 changed the way we looked at dinosaurs. It was previously thought that dinosaurs were slow, lethargic reptiles. Deinonychus showed that dinosaurs could have been more active and agile. Their discovery also reinforced the theory that birds evolved from dinosaurs! They may not look so similar on the outside, but there are similarities in their hands and hips.

Although it has not been proven that Deinonychus had feathers, many closely related raptors* did have feathers. *Raptor is the common name used for a group of dinosaurs called dromaeosauridae. These were small to medium sized dinosaurs with a large toe claw.

The name Deinonychus means ‘terrible claw,’ which refers to the large claw on each foot. This claw was likely used to attack prey. The Deinonychus kept this claw sharp by holding it up off the ground as it walked or ran.

Deltadromeus

  • Pronounced: Del-tah-dro-me-us
  • Origin: Algeria, Egypt and Morocco
  • Discovered in 1995
  • Lived: Mid-Late Cretaceous – 99-94 million years ago
  • Size: height - 2.44m, length - 7.78m
  • Name means: Delta runner

Thought to be one of the fastest dinosaurs to ever exist, Deltadromeus had a delicate skeletal structure with long thin limbs which enabled it to run fast.

What we know about Deltadromeus is known from just a single partial skeleton. So there is still plenty to discover about this dinosaur. Did you know a Deltadromeus skull has not yet been found!

Deltadromeus was a theropod. Theropods were dinosaurs that walked on 2 legs and had three forward-facing toes.

Dilophosaurus

  • Pronounced: Dee-lof-oh-sor-us
  • Origin: USA
  • Discovered in 1940
  • Lived: Early Jurassic – 184 million years ago
  • Size: height - 1.86m, length - 6.61m
  • Name means: Double-crested lizard

The name Dilophosaurus means ‘double crested lizard’ after the twin crests on top of its head. These crests were made of keratin, which is the same material as a rhino’s horn and your finger nails! Nobody knows for sure what the crests were for; but scientists think they could have evolved to attract mates.

Dilophosaurus is often depicted in movies spitting venom, but there is no evidence that this is what they did. 

Scientists believe Dilophosaurus were active predators rather than scavengers. This was for two reasons. The first was that they had a very strong jaw. The second was that their bones were found to be reinforced with air pockets in a honeycomb structure which made their skeleton strong but light - a combo perfect for chasing prey.

Dimetrodon

  • Pronounced: Dai-meh-truh-don
  • Origin: Germany and USA
  • Discovered in 1845
  • Lived: Permian – 280-265 million years ago
  • Size: height - 1.86m, length - 2.88m
  • Name means: Two-measure tooth

Not actually a dinosaur, Dimetrodon lived long before dinosaurs existed! In fact they lived during the Permian period, more than 20 million years before dinosaurs evolved. There are more than 12 species of Dimetrodon.

Dimetrodon were more closely related to mammals than reptiles and are thought to be the first big land predator with strong jaw muscles and large canine teeth. The large sail on its back was held up by long bones. There is still debate as to what the purpose of the sail was; some thoughts are:

  • To help control temperature
  • For mating rituals
  • To make them appear bigger to predators

Giganotosaurus

  • Pronounced: Gee-gah-no-toe-sor-us
  • Origin: Argentina
  • Discovered in 1987
  • Lived: Mid Cretaceous – 112-90 million years ago
  • Size: height - 3.86m, length - 12.04m
  • Name means: Giant southern lizard

It is hard to say how big Giganotosaurus actually were as very few fossils have been found. But some say they rivalled Tyrannosaurus on height and length, but possibly weighed less. Another key difference was that the Giganotosaurus had three fingers per hand while the Tyrannosaurus had two. Giganotosaurus had serrated teeth to help tear flesh from their prey.

Some scientists argue the Giganotosaurus was faster than a Tyrannosaurus. However, determining the running speed of extinct animals is tricky, especially when you only have incomplete skeletons to work with.

Megalosaurus

  • Pronounced: Meg-uh-lo-sor-us
  • Origin: England, France and Portugal
  • Discovered in 1676
  • Lived: Middle Jurassic – 168-165 million years ago
  • Size: height - 2.19m, length - 6.18m
  • Name means: Big lizard

Megalosaurus was one of the first dinosaurs ever discovered with the first bone found in 1676! At the time, people had no idea what this bone was from (or even if it was a bone at all). Ideas ranged from, a bone from an elephant as not many people had seen an actual elephant before, to the bone of a giant man.

Megalosaurus was not officially named until 1824! That was still before the term ‘dinosaur’ appeared in 1842. It wasn’t until two more dinosaurs, including the Iguanodon, were discovered that scientists agreed that they were all part of a group of extinct animals – now known as dinosaurs.

Quetzalcoatlus

  • Pronounced: Ket-sahl-kow-at-lus
  • Origin: USA
  • Discovered in 1971
  • Lived: Late Cretaceous – 72-66 million years ago
  • Size: height - 4.76m, length - 4.98m
  • Name means: Feathered-serpent

While Quetzalcoatlus lived at the same time as dinosaurs, it was not a dinosaur. Instead, it was classified as a type of flying reptile known as a pterosaur.

With a beak longer than a human (up to 2.5m) and a wingspan of up to 11m, it was certainly impressive. With such a big wingspan, take-off would have been difficult. Scientists believe they may have had to jump up to 2.5m in the air before flapping their wings for take-off.

Their large breast bones indicate that they had powerful flight muscles and were strong fliers, potentially able to reach speeds of 90km/h.

Tyrannosaurus

  • Pronounced: Tie-ran-oh-sor-us
  • Origin: Canada and USA
  • Discovered in 1902
  • Lived: Late Cretaceous – 90-66 million years ago
  • Size: height - 3.86m, length - 12.04m
  • Name means: Tyrant lizard

Despite being one of the most well-known dinosaurs, we continue to learn more about Tyrannosaurus. When first discovered in 1902, not a lot was known about how dinosaurs looked or moved. Tyrannosaurus was originally thought to stand like a kangaroo, dragging their tail behind.

To date, over 50 skeletons, including some almost complete individuals, have been discovered. This has helped to prove that Tyrannosaurus walked with their tail off the ground, using it as a counterbalance. Although all these specimens have been found, scientists still do not know why Tyrannosaurus had such short arms.

Utahraptor

  • Pronounced: Yoo-tah-rap-tohr
  • Origin: USA
  • Discovered in 1975
  • Lived: Early Cretaceous – 139-135 million years ago
  • Size: height - 2.34m, length - 6.41m
  • Name means: Predator of Utah

Scientists believe that carnivorous dinosaurs, including the Utahraptor used a “grip and rip” feeding style. Imagine the initial bite is like using a fork to hold prey. Then as they pulled backwards, the serrated teeth worked like steak knives to cut through the prey. Utahraptor also had a curved claw on each foot that was up to 24cm long!

Utahraptor was the largest and oldest known dromaeosaurid (also known as ‘raptors’). Due to their size, it’s believed Utahraptor was not very fast and instead used an ambush* style of hunting. *Ambush hunting is either sitting and waiting or stalking prey before launching a surprise attack. Many animals that use this technique are well camouflaged.