When someone mentions the word ‘dinosaur’, for most people the first thing to come to mind is a load of enormous grey lizards roaming the plains of a ‘Jurassic Park’ style island (that movie has a lot to answer for!) – but not all dinosaurs were large, and in fact recent research has shown that they might have been quite brightly coloured! Here are 20 interesting dinosaurs facts
1 – Dinosaurs (‘terrible lizards’) lived on the earth during the periods called Triassic, Jurassic and Cretaceous, which together made up the Mesozoic era. This era ran from around 250 to 65 million years ago and therefore lasted for about 185 million years. During this time the world changed a great deal, with all the continents in one big block called Pangaea at the start, and gradually separating into something resembling our modern earth (except that Antarctica and Australia had yet to part) by the end. This period, incidentally, also saw the first flowering plants and insects.
2 – The dinosaurs’ proper name is ‘Dinosauria‘, and within dinosauria there are two main groups – Saurischia (‘lizard-hipped’) and Ornithischia (‘bird-hipped’). Saurischia included the mostly carnivorous bipedal Theropods (eg T Rex) and the long-necked, long-tailed herbivorous Sauropods (e.g Argentinosaurus and Diplodocus), while the Ornithischia were all herbivores, both bipedal and quadrupedal (e.g Iguanodon and Ankylosaurus).
3 – The earliest dinosaurs developed in the Triassic era around 228 million years ago, and one of the first was an ancestor of the lizard-hipped saurischias, eoraptor, a near-complete skeleton of which was found in 1991 in Argentina. It was a bipedal carnivore and looked a lot like its descendants, the raptors that chased our heroes through the abandoned facility in the aforementioned movie – but it was a lot smaller, weighing just 22 lb (10 kg) and being about a metre long.
4 – The first dinosaur that scientists named was the lizard-hipped sauropod Megalosaurus (‘great lizard’). However, when the first bone, the end of a femur, was originally discovered in 1676, it was thought to belong to some kind of giant human and, because of a superficial visual resemblance, it was labelled ‘Scrotum humanum‘! Fortunately, by the time more bones had been discovered and a serious effort made to identify them accurately, it was realised the ‘giant’ animal was more like a lizard and in 1824 the less fanciful name ‘Megalosaurus bucklandi‘ was assigned. It was named after William Buckland, an Oxford geology professor who did a lot of the research on the bones and published descriptions in the Geological Society’s journal, ‘Transactions’, that year.
5 – The most famous dinosaur of all, Tyrannosaurus Rex (‘Tyrant Lizard King’) was one of the fiercest predators that ever existed – and it was also one of the last dinosaurs, being one of the many that were wiped out by the catastrophe that destroyed that entire section of the family tree of life around 65 million years ago. Although it’s not known for certain what happened, the mostly likely reason is that the massive asteroid that crashed here at that time caused changes to the Earth’s weather systems that were too extreme for these animals to be able to adapt.
6 – Having said that, fossil records indicate that birds evolved from dinosaurs so there is a basis for the claim that dinosaurs still live among us now. One of the fossils that demonstrate this was the Archaeopteryx, which has characteristics of both sides – it was basically a dinosaur with feathers, but it was only when fossils were found with the feathers extremely clearly delineated that scientists believed it existed!
7 – One of the first dinosaurs to be extensively studied was the bird-hipped Iguanadon (‘iguana tooth’) – in fact, it was one of the first three fossils to be used to define ‘dinosauria’ in the first place, and only the second to be named (after Megalosaurus). This 3-tonne, 33 ft (10 m) herbivore usually walked on its much larger back legs, but its forelegs were large and strong enough that it could use them to walk on all fours if it wished – its proportions were a bit like a modern kangaroo (although it never hopped, just walked!). It was slightly quirky in that it had conical spikes for thumbs that stuck out at 90º from the rest of the digits and its high, narrow skull ended in a beak-like mouth containing the aforementioned iguana-like teeth.
8 – The smallest dinosaur we know about is a theropod called ‘Anchiornis huxleyi’ which was about the size of a modern pigeon – its total length was about 1.1 ft (35 cm) and about 100 g in weight.
9 – At the other end of the scale, the largest dinosaurs are probably the largest land animals that ever existed and although we don’t have complete details, scientists believe that the largest so far is the massive herbivorous sauropod Argentinosaurus, discovered in Argentina and named for that country in 1993. From the few bones found to date they have extrapolated that could have been up to 115 ft (35 m) long and weighed up to 100 tonnes! There are, however, tantalizing fragments of bones that lead scientists to believe they haven’t yet discovered the biggest ever dinosaur (only a tiny percentage of remains ever became fossils and of those, by the far the greatest majority are still underground) but until more is discovered about them, they have to remain shrouded in mystery.
10 – The longest known dinosaur for which reasonably complete remains are available was Diplodocus, another herbivorous sauropod, and at one time scientists estimated it could be as much as 177 ft (54 m) long and 113 tonnes! However, the discovery that some vertebrae had been placed wrong (and one or two weren’t actually from that animal at all) caused them to revise that estimate down by about a third. As with the ‘largest’ dinosaurs, it is thought there were probably longer ones but with only fragments found so far to hint at their existence no real estimates can be made. Yet.
11 – The tallest known dinosaur is also a sauropod herbivore, the Sauroposeidon (‘earthquake god lizard’!), and at 59 ft (18 m) tall he could have looked into a sixth floor window with ease. The entire animal is thought to have been up to 112 ft (34 m) long and up to 60 tonnes in weight. In fact, the bones were so large and so old that originally it wasn’t realised they were bones at all, and they were misclassified as petrified wood!
12 – The largest (and longest) carnivore (that we know about so far!) is the sauropod Spinosaurus (‘spine lizard’), named in 1915 for the large fan or sail of (probably webbed) spines along its back, which could have weighed anything from 9 to 21 tonnes (depending on whose calculations you use) and been up to 59 feet (18 m) in length. The function of the spines is not really known, but best guesses include thermoregulation and display in mating rituals.
Dinosaurs (‘terrible lizards’) as we previously mentioned lived on the earth during the periods called Triassic, Jurassic and Cretaceous, which together made up the Mesozoic era. This era ran from around 250 to 65 million years ago and therefore lasted for about 185 million years but that’s not the only thing you need to know about these interesting but extinct animals
13 – The many types of dinosaur often included their own versions of creatures that have cropped up again in modern animals, mostly mammals. For instance, the hadrosaurs were the dinosaur equivalent of the modern ‘duck-billed platypus’, at least for the duck-billed part. At 31 ft (9.5 m) and around 2.5 tonnes they were just a tad bigger than the dog-sized modern animal, however. It is thought that the duck-bill was ideally shaped to enable them to clip twigs and leaves to eat.
14 – The dinosaur equivalents of the modern-day armadillos were the bird-hipped Thyreophora – armoured herbivores. Again, at up to 9 m (30 ft) long, 6 ft (1.8 m) tall and 6 tonnes in weight, the Ankylosaurus was also considerably bigger! The Ankylosaur’s armour, like an armadillo’s, is made of plates and knobs of bone called scutes or osteoderms that were embedded in the animal’s skin (and probably covered by a layer of horny keratin). A heavy cap of the same protected the head with four large spikes at the back of the skull. It also had triangular, flat spikes in rows down each side of its tail and a heavy club at the end formed of the last few vertebrae with osteoderms fused to each, which it swung at predators with deadly effect.
More Facts about Dinosaurs
15 – All dinosaurs laid eggs, usually in a nest which may have been anything from a scrape in the earth to an elaborate dome – some dinosaurs used communal nests, and it’s the males who did most of the incubating. Female dinosaurs grew an extra bone, the medullary, which was rich in calcium and was used to make eggshell. Perhaps surprisingly, they were good mothers and looked after their offspring for some time after birth – one dinosaur was even named Maiasaura, meaning ‘good mother lizard’, because it is known only through a nesting ground discovered in Montana.
16 – Despite what you see in the various movies, it is currently thought that dinosaurs could not actually produce any vocal sounds at all – all those roaring dinosaurs on-screen are total fabrications! There are two ways vocalisations are produced – using vocals chords in a larynx, which dinosaurs did not have, or with a syrinx, an organ found solely in birds that relies on a clavicular air sac to produce sounds. This air sac leaves some distinctive signs on the adjacent bones, and scientists have not found these signs in dinosaurs either. It is thought that dinosaur communication was mostly visual or using non-vocal sounds and indicators instead.
17 – Like their descendants, our modern birds, dinosaurs are thought to be quite social, living in large groups or flocks – one of many deductions of their behaviour that scientists have made based on fossilized skeleton poses, comparisons with modern-day animals in similar ecological situations, examining their habitat and reproducing their biomechanics using computer simulations. Evidence has also been found for predatory dinosaurs attacking more peaceful ones and other live prey, and even for cannibalism in the theropod Majungasaurus.
18 – Since dinosaurs are by definition reptiles and all modern reptiles are cold-blooded, it was assumed for a long time that dinosaurs must be cold-blooded too. However, the fact that their descendants, modern birds, are warm-blooded, led to more research and scientists have changed their minds – they now think all dinosaurs must have been warm-blooded. The discovery of dinosaur bones in cooler climates and even in the southern polar regions, where they would not have survived for one day if they had been cold-blooded (in the more temperate weather they enjoyed then), and the structure of their blood vessel systems, which is typical of warm-blooded organisms, combined to clinch the matter. Now they’re just arguing over the specific ways the dinosaurs might have used to regulate their temperatures…
Dinosaurs and Us
19 – Dinosaurs are such fantastical creatures, with their weird appearance and gigantic size, that it is perhaps not surprising that they should have captured the imaginations and become an established part of our culture. Even the word has been co-opted to mean anything old-fashioned, too large for practicality or, of course, on the way to becoming extinct. However, this is not new – the Victorians were just as fascinated as we are, and there was even a series of life-size statues created for the Crystal Palace Park in 1853. They are now known to have been quite inaccurate, of course, but then it was over one and a half centuries ago, when the studies were in the very early stages.
20 – Their enduring popularity has ensured that dinosaurs have made plenty of appearances in literature and film, too – their first fictional mention was in Charles Dickens’ Bleak House in 1852 (merely in passing), but they have since featured in a great number of books, including those by Jules Verne and Sir Arthur Conan Doyle. They have also caused many headaches for the special effects folks making films, from 1933’s King Kong to 1993’s Jurassic Park (and of course the original novel of the same name by Michael Crichton, published three years earlier).
For a creature that hasn’t been seen alive for many millions of years (long before humans even started to develop) they are amazingly popular today!