Dino Quest

A skeleton is what’s left after something died. A footprint is a moment from a living animal: it pressed its foot into the mud, lifted it out and carried on, and then the mud set. One dinosaur might take a few thousand steps a day for twenty years, so there are vastly more footprints than dinosaurs, and they turn up where no bones survive, because a bone needs burying fast while a footprint needs to dry slowly and be covered gently. They also answer a question a skeleton can’t. Not how fast dinosaurs could go, which was episode one, but how fast they were actually going on an ordinary Tuesday. For most of them it was two or three miles an hour, about the speed you walk to the shops.
This week’s word is trackway. Scientists say track rather than footprint, because a foot pressed into sloppy mud collapses into something that doesn’t look like a foot at all. One track is one step. A trackway is a run of them, and a trackway is a journey: which way the animal was heading, how fast, where it stopped, whether it turned round and whether anything was walking alongside it.
Lauren and Cassius Morrison hear from Professor Peter Falkingham, who studies dinosaur tracks at Liverpool John Moores University and was on his hands and knees brushing mud out of the Oxfordshire footprints. He explains how speed comes out of a trackway: measure the stride, from one left foot to the next left foot, and the length of the foot, then plug them into equations worked out in the 1970s. You can’t get the sprint from the stroll, though, because a walking lion and a walking cheetah look practically identical. Peter looks for tiny scratches on the walls of a track, left by the scales on the foot, which turn a hole in the ground into a little film of a foot moving. The longest trackway in the world runs to about 200 metres and nothing interesting happens along any of it, but some sauropod trackways show a herd on the move with the youngsters in the middle and the adults on the outside, something no skeleton could ever tell you. And if every dinosaur lined up for a race, his money is on something the size of Velociraptor or Deinonychus, because across living animals top speed peaks at about the weight of a cheetah.
Fresh from the Dig goes to Dewars Farm Quarry in Oxfordshire: around 200 footprints and five trackways, one more than 150 metres long, made about 166 million years ago by long-necked sauropods, probably Cetiosaurus, and a meat eater, probably Megalosaurus, the first dinosaur ever named to science and an Oxfordshire local. It’s a working quarry, so every time rock comes off more turns up, and the same layer carries on for kilometres under roads, houses and farmland. Then swimming tracks from places including Spain and Utah, just a few toe-tip scratches where a big meat eater’s feet brushed the bottom, which feed straight into the argument over how well Spinosaurus could swim. In the Dino-Mite Question, Rosa, eight, from Aberdeen, asks whether she can work out how fast she goes from her own footprints. She can, this weekend: walk normally across wet sand or mud with a grown-up, measure your foot from heel to toe, then measure from one left footprint to the next left footprint, and send in your numbers.
Then it’s Build a Dino Lab. Week eleven is the feet, and it’s the quickest decision yet: three forward-facing toes with claws, a theropod foot, rather than the round, elephant-like column of a sauropod, which is superb if you weigh 40 tonnes and stand on four legs. That leaves the question dodged since episode one: how big is it? Cheetah sized, around 50 or 60 kilograms, would be fastest, but it couldn’t carry the plates, throat armour, shoulder spikes and thagomizer. Six or seven tonnes like T. rex would need a far bigger head than last week allowed, and would break the week one promise that our dinosaur runs. So Lauren goes middling: about the weight of a large pony, around 350 kilograms and four metres long, most of it neck and tail. Not the fastest thing around, but big enough that the small fast things leave it alone, and fast for its size. A heavily armoured pony. Next week, where it lives, and the answer is underground.
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T. rex’s arms are the joke everyone makes, but each one was about a metre long, thick and muscular, and by some estimates could lift around 200 kilograms. They only shrank compared with the head, which grew long, wide and strong enough to do the catching and the killing on its own. Other dinosaurs went the opposite way. Megaraptorans had huge arms with claws so big that the first one found was thought to belong on a foot.
This week’s word is palaeobiology. Professor Emily Rayfield, who has clearly been asked at a lot of parties, calls it “the biology of long dead extinct animals”. It’s the difference between what an animal was and what it was like: what it ate, how fast it could run, whether it got enough food.
Lauren and Cassius Morrison hear from Emily, Professor of Palaeobiology at the University of Bristol. She took finite element analysis, the engineering maths used to test bridges, planes and hip replacements, and used it to work out how hard extinct animals could bite. The first dinosaur she tested was Allosaurus. Its skull is about 80 centimetres long but only about 25 wide, with no room for big jaw muscles, and its lower jaw turned out to be quite weak. T. rex’s skull is well over a metre long and massively wide at the back, with teeth like bananas to match. Even so, Allosaurus could still bite three or four times harder than you can. Emily also explains why the answer is always a range rather than a single number, and how her student Sydney tested whether the little alvarezsauroids could use their arms to dig into termite mounds.
Fresh from the Dig links that study back to last week’s owl dinosaur, Shuvuuia, which turns out to be an alvarezsauroid too. Then Deinocheirus, the “terrible hand”: a pair of arms two and a half metres long, found in Mongolia in 1965, that had people imagining a giant killer for nearly fifty years. When the rest turned up in 2014, it was a duck-faced, humpbacked dinosaur with no proper teeth that ate plants and fish. In the Dino-Mite Question, Callum, seven, from Newcastle, asks why T. rex had such tiny arms. There are three good answers and no winner yet: the head took over, the arms were short, strong hooks for holding on, or they shrank so other T. rexes couldn’t bite them off at a shared meal.
Then it’s Build a Dino Lab. Week ten is the arms, and Emily says heads and arms sit at opposite ends of a scale: a T. rex-style crushing head with stumpy arms, or a tiny head with long digging arms. The first is ruled out by episode three, when our dinosaur got thin, slicing steak-knife teeth. Those are the Allosaurus kind, and they come with a narrow skull and a modest bite. So for the first time Lauren picks neither: short, thick, seriously strong arms with a big shoulder blade and three curved claws, to pin prey down while the teeth do the slicing, and a bite about three or four times a human’s. Cassius points out that arms like that are also good for moving a lot of soil. Next week, footprints, and a 166-million-year-old motorway in Oxfordshire.
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Dinosaurs had bones in their eyes. You don’t, and nor does any other mammal, from dogs to whales to elephants. We’re the odd ones out. Birds, lizards, turtles and fish all have a ring of thin bony plates sitting in the white of the eye, holding a big eyeball steady so it can focus. Because it’s bone, it sometimes fossilises, and that matters, because the age of the dinosaurs lasted around 160 million years and roughly half of it happened in the dark.
This week’s word is sclerotic ring. Sclerotic comes from a Greek word meaning hard, and the ring is usually made of 10 to 15 overlapping plates, arranged like the stones in an archway. Measure the hole in the middle, like the hole in a Polo mint, and compare it with living animals. A big hole lets in lots of light, which suits an animal that was up at night. A small hole means a daytime animal. It works just like a camera.
Lauren and Cassius Morrison hear from Dr Stephan Lautenschlager, a palaeontologist at the University of Birmingham who uses computer models to work out how dinosaurs looked, lived and behaved. Bigger eyes mean bigger lenses and room for more light-sensing cells, so bigger eyes see better. The middle of a Jurassic night was probably busy, with some dinosaurs out in the day, some at night and some at dawn and dusk, which may have been ideal hunting conditions for meat-eaters. He explains why owls hear so well (one ear sits higher than the other), what the optic lobes in a dinosaur’s brain tell us, and admits that nobody knows how dinosaurs slept or what colour their eyes were.
Fresh from the Dig names the owl dinosaur: Shuvuuia, a chicken-sized dinosaur from the Mongolian desert with huge eyes and an inner ear to match a barn owl’s. Then a study that compared the eye rings of dozens of fossil animals with living ones: small meat-eaters were mostly out at night, big plant-eaters snacked around the clock, and big predators came out at dawn and dusk. And birds can see ultraviolet light that humans can’t, so dinosaurs may have been far more patterned than any picture shows. In the Dino-Mite Question, Noor, nine, from Birmingham, asks whether dinosaurs slept standing up or lying down. The best clue is Mei long, the “sleeping dragon”, a duck-sized fossil from China found curled up with its head tucked in, just like a bird.
Then it’s Build a Dino Lab. Week nine is the eyes: small, cheap daytime eyes, or big eyes, a wide sclerotic ring and big optic lobes for working in the dark. Big eyes win, with a twist. Our dinosaur’s reflective skin, chosen back in episode five, would shine like a headlight under the moon and stand out at midday, so it hunts at dawn and dusk, when the night animals are going to bed, the day animals are only just getting up, and everyone is half asleep. Lions and foxes do the same. Next week, arms.
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The most important part of your nose is inside your brain. Your nose catches the smell, but it’s a lump at the front of your brain that works out what it is: sweet, horrible, or dangerous, like gas in the kitchen. Humans tend to put smell near the bottom of their list of senses. For most animals it’s essential, for marking territory, finding each other and sniffing out food.
This week’s word is olfactory bulb. That’s the lump. The bigger it is for your size, the better your nose, and because it takes up room in the skull, it leaves a space scientists can measure. But room in a head is a trade-off. A bigger bulb means a bigger head and a bigger brain, and a bigger brain needs more energy and more food.
Lauren and Cassius Morrison hear from Dr Jared Voris, a palaeontologist at the University of Calgary in Canada who studies T. rex and its relatives. When you rebuild a tyrannosaur’s brain, the smell bulbs run almost half its length, so T. rex could probably sniff out prey, a dead animal or anything else nearby, the way a wolf or a bear does today. Nobody has a real dinosaur brain, so long ago the American Museum of Natural History sawed a T. rex braincase in half to look inside. Now scientists put skulls through a CT scanner, a 3D X-ray, and rebuild the shape of the brain on a computer without breaking anything. Plant-eaters had good noses too, perhaps for finding water and telling which plants were safe to eat.
Fresh from the Dig starts with Jared’s own tyrannosaur, Thanatotheristes, the “reaper of death”, which had unusual ridges along its long face. It was found in Alberta by a family who spotted the bones, photographed them and told the museum instead of digging them up themselves. Then ankylosaurs, whose nasal passages loop round and round inside the skull and may have worked like air conditioning under all that armour. And the kiwi, which has its nostrils at the very tip of its beak and sniffs out worms on the forest floor at night. In the Dino-Mite Question, Ada, six, from Bristol, asks whether she could hide from a T. rex. Behind a tree it can’t see you, but it can smell you, and follow the trail you left ten minutes ago. Your best bet is to stand downwind.
Then it’s Build a Dino Lab. Week eight is the nose: huge T. rex-style smell bulbs that need a bigger skull and more food, or small bulbs and a hawk’s sharp eyes. Lauren picks the big bulbs. A hawk’s eyes work because it can fly and look down from above, and this dinosaur lives on the ground among the trees, where you can’t see very far and smell matters most. Next week, the lights go off.
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Loads of dinosaurs had wings, but not many of them could fly. There’s a dinosaur in your garden right now, probably the one that keeps stealing your chips, because a seagull is a dinosaur, and so is every robin, pigeon and chicken. Feathers turn up again and again across the dinosaur family tree, and most of them had nothing to do with flying. Oviraptors spread their feathered arms over their nests to keep their eggs warm, and some parents have been found still sitting on them. Others used feathers for showing off and for keeping warm in the cool forests of north-east China.
This week’s word is primaries. Hold your arm out: shoulder, elbow, wrist, hand. The primaries are the big, long, stiff feathers that grow from the hand, and they do the hard work of flying. Every bird that flies, from a hummingbird to an albatross, has between nine and eleven of them. So if you find a fossil wing, you can count.
Lauren and Cassius Morrison hear from Dr Jingmai O’Connor, Associate Curator of Fossil Reptiles at the Field Museum in Chicago. She explains why Microraptor, with feathers on its arms and its legs, probably glided down from the trees like a flying squirrel, and why Anchiornis, with a skeleton almost exactly like Archaeopteryx, has 30 primaries and probably couldn’t fly at all. She also owns up to getting something wrong. She once wrote that Microraptor couldn’t cough up pellets, then looked again at a Microraptor with a whole lizard in its stomach. A skeleton that size can’t go all the way through, so it had to come back up, and she is now writing a paper to say so. As she puts it, saying “I don’t know” is the most powerful thing a scientist can say.
Fresh from the Dig starts with Jingmai’s own brand new dinosaur, Jian changmaensis, a barn-owl-sized, four-winged cousin of Microraptor from about 120 million years ago in the Changma Basin in north-west China. It might finally explain the little bundles of smashed-up early bird bones found there for years. Then Yi qi, whose name means strange wing, a tiny dinosaur with bat-like skin wings that looked a lot like a mini dragon. And how scientists worked out the real colours of a dinosaur: Anchiornis was grey and black with white stripes on its wings and a rusty red crest, a bit like a woodpecker. In the Dino-Mite Question, Jonah, eight, from Glasgow, asks whether a chicken nugget is a dinosaur nugget. It is. And the wishbone in your roast chicken is the same bone you’d find in T. rex.
Then it’s Build a Dino Lab. Week seven is the arms: four wings like Microraptor, or feathered arms only with bare scaly legs underneath. Lauren picks feathered arms with seven primaries and no leg wings. Seven is two short of what you need to fly, and that’s fine, because this dinosaur was built to run, big feathers on its legs would trip it up, and it’s already carrying a heavy tail, plates and a thagomizer. Jingmai would have chosen the same. Next week, our dinosaur gets a nose.
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