Dinosaurs: Biology’s Extinct Superstars
If someone told you a story, or sang you a song;
that told marvellous tales of monsters long gone;
would you believe that those monsters left footprints astray?
right under our feet, so we’d find them today?
You’ve probably heard of dinosaurs. They are pretty famous. But as we grow up, it’s easy to lose a bit of the excitement, because we learn about dinosaurs so early in our lives. But just pause for a second and look at them as if you were discovering them for the first time. Dinosaurs were actually real. For millions of years, there were genuinely massive lizards with legs the size of cars and necks the size of cranes, that dominated all other life on Earth. However, despite fact that everyone has heard of dinosaurs, we don’t really know that much about them. New research is constantly being dug up (pun intended) which makes us re-assess what we know about the reptiles that ruled our planet for such a long time. In short, a lot has changed, since the days of walking with dinosaurs. Let’s dive in, to dinosaurs.
Dinosaurs and Birds
Dinosaurs lived from 240 million years ago to about 60 million years ago. It’s easy to glance over that – but that’s an incredibly long period of time. Mammals have only really been around for 60 million years – dinosaurs were around for more than three times as long. In fact, the earliest dinosaurs lived closer to the time when animals starting coming onto land, than they did to the later dinosaurs. Dinosaurs were the dominant form of land animal for almost all of that time – the aristocracy of the terrestrial world. They lived on every continent and in every imaginable environment and there was incredible variety – from massive 100-tonne diplodocuses to tiny little 100-gram insect eaters.
There are a few things we need to note about dinosaurs.
Firstly birds are dinosaurs. The modern birds that we see around us today, evolved directly from dinosaurs. This is actually not that surprising when you see a bird without feathers – they are a really similar shape. But also, the relationship between birds and dinosaurs is now clearly established by the fossil record. There are lots of examples of in-between animals, dinosaurs that got smaller and adopted many of the characteristics of birds (the most famous being archeopteryx). So really, the proper term for what people refer to as “dinosaurs” is “non-avian dinosaurs” – the dinosaurs that died out, that don’t include birds.
Secondly, dinosaurs had a lot of the characteristics of birds. When we first discovered dinosaurs, we saw them as giant reptiles (that’s actually what the word dinosaur means, “terrible lizard”). And many of the older more reptilian dinosaurs were less bird-like (your triceratopses, your stegosaurus etc). However now we know that a lot of the later dinosaurs had feathers; many even had beaks. Most of the two-legged dinosaurs, that ran around hunting other animals, were more feathered and birdlike than they were lizard-like. This also means there’s a good chance that some of them were brightly colored, did weird bird-like mating displays, made loud birdlike calls and moved together socially in flocks – as birds do.
Dinosaurs: Some more weird things
Dinosaurs were also not cold-blooded. Lizards and most reptiles are cold-blooded, meaning they rely the outside world to heat them up. This is why a lot of lizards are so slow in the morning and spend so much time sunbathing – they need to warm up before they can do anything. This means they can get away with eating a lot less, but also makes them a fair bit slower, less agile and dynamic creatures. It’s very likely dinosaurs were much more active than modern reptiles. Not only do we know that they sit on their eggs like birds did to keep them warm, there were also dinosaurs that lived in the arctic. That’s not something a typical reptile would be able to do.
Fourthly, a lot of the famous prehistoric creatures, that lived around the same time as dinosaurs, are not dinosaurs. This includes pterodactyls, which were a completely different type of flying reptile (that did not have feathers), and similarly, a lot of the big ocean predators (ichthyosaurs, mosasaurs and plesiosaurs) were also not dinosaurs.
Fifthly, there was an enormous variety of dinosaurs – they were not all massive. There were some tiny dinosaurs that were only a hundred few grams and flew around mainly eating insects. Some had two legs and ran around like raptors, highly predatory. Others were four-legged and slow, with clubs on their tails. They were probably more diverse in terms of shape and size than any other type of animal (which makes sense they were around for more than 150 million years). And while they ate plants, a lot of the common plants we know today had not evolved yet (see our post on plant evolution).
We’ve also recently started to get a lot better evidence about dinosaurs. In the old days, the best we got were some fossilized partial skeletons. However, as we’ve gotten better at finding fossils, better at getting them out of the ground and just generally better at studying them, we’ve got some truly remarkable finds.
Dinosaurs: A few real weirdos
To give you a sense of just how weird some dinosaurs were, here is a list (images below):
– Heterodontosaurs – a group of quilled dinosaurs, some were only about 60cm long (think a porcupine crossed with a parrot, photo and sculpting by Tyler Keillor);
– Carnotaurus – people like to make jokes about a Trex not having long enough arms to do anything – this guy had it really rough in that department, basically being a large Trex-shaped dinosaur that completely lost its front arms (Fred Wierum, Wikimedia Commons);
– Ganzhousaurus – wings, a beak, hands, and feet all at the same thing (Image: Michael B. H, Wikimedia);
– Therisanasurus – a very large raptor dinosaur, shaped like a T-rex that seems to have at some point decided to start eating plants (Wikimedia, PaleoNeolitic);
– Kosmoceratops – like triceratops, but with about 20 horns instead of three (Image: N Tamura, Wikimedia); and
– Alverazaurds – little mole-like dinosaurs that probably burrowed, or broke into termite mounds like anteaters (Image: Karkemish, Wikimedia).
Dinosaurs: What can we learn?
Dinosaurs are famous. Much more famous than almost any other prehistoric creatures. This is great – it’s wonderful that they get people so excited about biology, science and the history of life on our planet. However, it also means people have a really clear picture of what they think dinosaurs looked like. And popular culture is always a few decades behind the research. We know a lot more now about what dinosaurs were like, and we know we were wrong about a lot of things.
For example, what do you picture in your mind when you think of a T-rex? Probably something massive, scaley and predatory – like in Jurassic Park. This is reasonable, it’s what a lot of scientists thought about twenty years ago. However, on further study, some researchers have proposed that T-rex was mainly a scavenger, using its massive head and enormous bite force to eat the bone and carcasses left behind by other mammals. This happens surprisingly often with lions in Africa even in the present day.
T-rex might also have had feathers. T-rex is one of the later dinosaurs that definitely evolved into birds. And there are other dinosaurs closely related to T-rex that definitely had feathers.
Now imagine what Trex sounded like? If they were birds, they definitely did not roar. In fact, T-rexes may even have chirped, particularly when they were younger.
Some people get surprisingly angry when confronted with this new research. It makes them uncomfortable. They want their T-rexes like they remember them in Jurassic Park. And don’t want scientists to come along and spoil their fun.
This is ludicrous. Dinosaurs were the dominant lifeform on our planet for more than 150 million years. Our species has been around, at max for 500,000. Dinosaurs were their own unique, varied, and wonderful creatures. They have no obligation to fit themselves to human expectations and be good movie villains. No animal and frankly none of nature is under that obligation. Dinosaurs were weird. And if T-rexes were brightly colored feathered birds, that did mating dances and chirped, then that’s what T-rex were like. We here at the Universal Story, think it would make them all the more glorious.
