This is a follow up to our Facts About Dinosaurs article that we published a few days ago, check out the article here. Dinosaurs (“terrible lizards”), as we mentioned earlier, lived on Earth during the Triassic, Jurassic, and Cretaceous periods that together make up the Mesozoic. This era lasted about 250 to 65 million years ago, making it about 185 million years, but that’s not the only thing you need to know about these interesting but extinct animals
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13 – The many types of dinosaurs often contain their own versions of creatures that have reappeared in modern animals, mainly mammals. For example, the hadrosaurs were the dinosaur equivalent of the modern duck-billed platypus, at least for the duck-billed part. However, at 9.5 m and around 2.5 t, they were only slightly larger than the modern dog-sized animal. It is believed that the duck bill was ideally shaped so they could cut twigs and leaves for eating.
14 – The dinosaur equivalents of today’s armadillos were the birdhopper Thyreophora– armored herbivores. Again, the Ankylosaurus was considerably larger, measuring 9 m in length, 1.8 m in height and weighing 6 t! The armor of the ankylosaur, like that of an armadillo, consists 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 thick cap of the same protected the head with four large spikes on the back of the head. It also had triangular, flat spines in rows on each side of its tail and a heavy club at the end, composed of the last few vertebrae with osteoderms fused together, which it wielded to deadly effect against predators.
More facts about dinosaurs
15 – All dinosaurs laid eggs, usually in one nestIt could have been anything from a scratch on the ground to an elaborate dome – some dinosaurs used communal nests, and it’s the males that did most of the incubation. Female dinosaurs grew an extra bone called the marrow cavity, which was rich in calcium and used to make egg shells. Perhaps surprisingly, they were good mothers and continued to care for their offspring for some time after birth – one dinosaur was even named Maiasaura, meaning “good mother lizard,” since it’s only known from a nesting site discovered in Montana.
16 – Despite what you see in the various films, it is currently believed that dinosaurs could not produce any vowel sounds at all – all those roaring dinosaurs on screen are sheer fabrications! There are two ways vocalizations are produced: with vowel chords in a larynx, which dinosaurs didn’t have, or with a syrinx, an organ found only in birds that rely on an air sac to produce sound. This air sac leaves some distinctive marks on adjacent bones, and scientists have not found these marks in dinosaurs either. It is believed that communication with dinosaurs was primarily visual, or used non-vocal sounds and indicators instead.
18 – Since dinosaurs are reptilian by definition, and all modern reptiles are cold-blooded, it has long been assumed that dinosaurs must also be cold-blooded. The fact that their descendants, the modern birds, are warm-blooded has led to more research and scientists have changed their minds – they now think that 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 a day if they had been cold-blooded (given the milder weather they then enjoyed), and the structure of their blood vessel systems that typical of warm-blooded organisms combine to decide the matter. Now they just argue
dinosaurs and us
19 – Dinosaurs are such fantastic creatures, with their odd appearance and gargantuan size it is perhaps not surprising that they have captured the imagination and have become an integral part of our culture. Even the word has been co-opted to mean something old-fashioned, too big for practicality or, of course, on the way to extinction. This isn’t new though – the Victorians were just as fascinated as we are, and there was even a number of life-size statues created for Crystal Palace Park in 1853. but then it was over a century and a half ago when the studies were still in a very early stage.
20 – Their enduring popularity has ensured that dinosaurs have also made frequent appearances in literature and film – their first fictional mention was in Charles Dickens’ Bleak House in 1852 (just in passing), but they’ve since appeared in a variety of books, including those of Jules Verne and Sir Arthur Conan Doyle. They also puzzled filmmakers with special effects from 1933’s King Kong to 1993’s Jurassic Park (and of course Michael Crichton’s novel of the same name, published three years earlier).
For a creature that hasn’t been alive for many millions of years (long before humans even evolved), they’re amazingly popular today!