There are almost as many reasons why popular myths about dinosaurs appear as there are myths. Just about all knowledge that can be gained from dinosaurs comes from fossil records and this to some extent leads to speculation about how dinosaurs lived and interacted. However, there are some established facts and these should not be obscured with popular myths about dinosaurs.
1/ All Fossil Finds Are Dinosaurs
The fossil record has brought to light many species from all periods of the planets history. It is the skeletal characteristics that separate the dinosaur fossils from other species such as plesiosaurs and pterosaurs. For instance the skeletons in many dinosaurs were designed to allow them to stand erect whilst their front legs were adapted for either supporting their weight or for slashing or grasping prey.
The skulls of dinosaurs were designed for maximum strength and minimum weight, and in carnivores for holding and tearing prey.
2/ Humans Coexisted With Dinosaurs
Although small mammals, including a shrew sized primate existed alongside dinosaurs, humans did not evolve until 65 million years after dinosaurs were extinct. The first genus of primitive apes appeared 23 million years ago and Homo erectus around 1.6 million years ago. Modern humans or Homo sapiens did not exist until 130,000 years ago.
Apart from some questionable evidence such as the Icas stones which appear to depict images of large dinosaurs and humans coexisting, there is no reason to believe humans have encountered dinosaurs.
3/ All Dinosaurs Existed At The Same Time
Dinosaurs existed during the Mesozoic Era which lasted for 186 million years and ended 65 million years ago, and is further divided into the Triassic, Jurassic and Cretaceous Eras. At the beginning of the Mesozoic Era Earth consisted of one large land mass called Pangea, and many dinosaur species ranged across it.
As Pangea broke up to form continents dinosaurs became scattered and separated, and each geographical area evolved its own dinosaur species over millions of years. Different species lived in different eras and in different geographical locations.
4/ Tyrannosaurus Rex Was the Largest Carnivorous Dinosaur
Tyrannosaurus rex was 12.8 metres long and weighed around 7.2 tons. Its teeth were 16 centimetres long which is twice the size of a lion’s canines. Tyrannosaurus was not however the largest carnivorous dinosaur.
In 1993 an even larger carnivore was discovered in Argentina
and was named Gigantosaurus. It was about 13.2 metres long and weighed around 8 tons. Although it was bigger it was probably not as powerful as Tyrannosaurus. Its head was larger but it had a smaller brain and a less powerful jaw.
The largest known carnivore species was Spinosaurus discovered in North Africa. It reached up to eighteen metres in length and weighed about nine tons. It had a spiny sail on its back and was more slender than Tyrannosaurus with a crocodile like head.
5/ Dinosaurs Were Cold Blooded
Although some Palaeontologists believe dinosaurs might have had a high metabolic rate and were therefore warm blooded, this point is not entirely settled.
It is thought dinosaurs could have had a similar respiratory system to birds allowing them to circulate air twice through their lungs. A consequence of this system is that it creates a high metabolic rate.
If dinosaurs were warm blooded they would have needed more prey biomass (needed to eat more meat) than a cold blooded animal. The fossil records show there was a ratio of 50 tons of prey biomass per ton of predator biomass, which is the expected ratio if dinosaurs were warm blooded.
6/ Dinosaurs Were Slow Moving
The estimated speeds of dinosaurs vary depending on the methods used to calculate them, but possibly the most reliable studies were carried out at Manchester University in the UK using computer simulations. The simulations were based on the skeletal and muscle structure of five carnivore species, and to ensure accuracy of the data it was run tens of millions of times.
The results showed that a Tyrannosaurus had a running speed of 29 kph, a Velociraptor 38kph and a Compsognathus, a smaller dinosaur could reach 60 kph. By comparison a human sprinter can reach speeds of up to 40 kph whilst the fastest living bipedal species, an ostrich can run about 50 kph.
7/ Dinosaurs Are Extinct
During the end of the Cretaceous Era a mass extinction event killed off up to 70% of all life on the planet. The cause of this mass extinction is still widely debated but the two most accepted theories are that an asteroid hit the Earth changing the climate and making life impossible for the dinosaurs. The other leading theory suggests an increase in volcanic activity forced large amounts of ash into the atmosphere cutting out sunlight and causing acid rain. This would have disrupted the food chain, and as one species died out another would have followed.
Some species did manage to survive this extinction event however, and as there is growing evidence that birds are related to dinosaurs it can be said that dinosaurs did not become extinct and are still with us in the form of avian dinosaurs.
8/ Dinosaurs Were A Dull Grey Colour
Although fossils give no indication of skin colour it is thought dinosaurs may have made use of colouration in a number of ways. For instance a pale underside would have reduced shadowing, and an irregular colour patterning would have been useful camouflage. The larger armoured plated dinosaurs might not have needed camouflage but could have used colour as a warning to other dinosaurs, or as species recognition. Colour could also have been used for in mating rituals.
Amongst fossil finds skin impressions have been found showing different sized scales indicating striping or other skin markings. This could be a sign that dinosaurs did make use of colour in just the same way modern reptiles.
9/ Dinosaurs Laid Huge Eggs
The largest known dinosaur egg was about the size of a football. The size of a dinosaur egg was naturally restricted because if it was too large the shell would have to be thick, preventing the young dinosaur from breaking out. A thick shell would also have suffocated the inhabitant as it would not have allowed air to filter in.
In 2005 an Oviraptor fossil was found with two unlaid eggs which suggested to palaeontologists that eggs were laid two at a time with at least one day in between further eggs. This is similar to birds with one day intervals between egg laying.
10/ Palaeontologists Give Dinosaurs Long Names To Confuse People
Dinosaur names are usually made up from two parts, the genus and the species name. The names often contain Greek or Latin words, or a mixture of both. A dinosaur is usually named after a distinctive body part, the person who discovered it, or the place it was found. For instance, dinosaur means “terrible lizard” and Tyrannosaurus rex means “king of the lizards”.