Absolutely Everything You Want to Know About Dinosaurs
But seriously, what actually killed the dinosaurs? When did they exist in the first place? And how do scientists really know what they look like?
Dinosaurs: be it the fearsome Tyrannosaurus rex, gigantic Brachiosaurus or the curiously pot-bellied Nothronychus, you definitely have a favourite.
However, while everyone can point to their number one dino, most non-palaeontologists probably have several reasonable questions about these prehistoric animals. From when dinosaurs actually existed in the first place, to what made them extinct and how we know what they look like, here’s everything worth knowing.
What killed the dinosaurs?
It’s believed dinosaurs were killed off by an asteroid. Although some scientists theorised a flurry of volcanic activity wiped out the reptiles, research now points to a major impact off the coast of modern-day Mexico about 66 million years ago.
After blasting into the Earth, scientists say the asteroid would have released particles and gases, which blocked out the Sun and caused a lengthy winter. While this caused the extinction of many dinosaurs, many species that later evolved into birds survived.
When did dinosaurs live?
Most dinosaurs lived in what’s called the Mesozoic Era, a time roughly 245 to 66 million years ago. Scientists generally divide this period into three separate ages:
- Triassic Period (252 to 201 million years ago) The era when reptiles first evolved into creatures we know as dinosaurs. However, the Earth they lived on was different from today’s. Almost all animals lived on Earth’s one extremely hot and dry landmass, Pangaea.
- Jurassic Period (201 to 145 million years ago) In this period, temperatures on Earth fell, leading to more water, plants and dinosaurs. It’s in time period species such as the Brachiosaurus first emerged.
- Cretaceous Period (145 to 66 million years ago) With more continents forming around the globe, more dinosaurs started evolving independently, which led to more dino diversity. Despite what a certain Jeff Goldblum movie might suggest, the Tyrannosaurus rex and Velociraptor first actually appeared in this Cretaceous Period, not the Jurassic.
Why were dinosaurs so big?
With a length between 30 to 40 metres, the Argentinosaurus was the world’s largest dinosaur. A modern blue whale measures an average of 25m
It’s all about climate. Dinosaurs were so big due to the sheer amounts of food available to eat at the time.
With Earth holding up to four times more CO₂ than today, the planet was packed with plant life, which could fuel the biggest herbivores (such as the Diplodocus).
This growth also encouraged bigger carnivores, with only the largest predators – like the T. rex and Spinosaurus – able to catch their prey.
What came before dinosaurs?
No, not aliens. The answer to what dinosaurs evolved from is simple: more reptiles – just ones a lot smaller than a T. rex. Known as dinosauromorphs, they were the size of house cats and flourished around 242 to 244 million years ago.
They were animals by no means at the top of the food chain, but they were speedy enough to outpace most attackers.
When were dinosaurs discovered?
The short answer: in 1842, when British scientist Richard Owen coined the term Dinosauria, literally meaning “terrible lizard” in Greek. Owen is often credited as the first person to place dinosaur in their own category of creature after examining a particularly large dino bone.
However, Owen is by no means the first to find dinosaur remains. For instance, many were unearthed in ancient China, but were treated as dragon bones.
Many historians have also noted how many dinosaur bones in Europe were believed to be the remains of biblical creatures. Even as late as 1763, British physician Richard Brookes believed a broken dinosaur femur was actually a fossilised giant’s testicle.
How do we know what dinosaurs looked like?
Scientists can estimate the appearance of dinosaurs with some very clever detective work. Not only can experts piece together the size of these creatures from their remains, but tiny details on each bone can offer big clues.
For instance, many fossilised bones have tiny scars that indicate how dinosaur muscles connected to their bones, also illuminating how they moved. In recent years, palaeontologists have also used 3D computer modelling to test exactly how dinosaurs could have moved, and thus looked.