This is a continuation of our article on facts about dinosaurs, we previously published one some days back, take a look at the article here. 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!