The Story Behind In A Million Years: Last Dinosaurs' Tribute to Evolution, Creativity, and Fun
"This is the first time dinosaur footprints have been found in strata known as the 'Folkestone Formation' and it's quite an extraordinary discovery because these dinosaurs would have been the last to roam in this country before becoming extinct," said David Martill, Professor of Palaeobiology, at the University of Portsmouth.
Last Dinosaurs - In A Million Ye
They are thought to be from ankylosaurs, rugged-looking armoured dinosaurs which were like living tanks; theropods, three-toed flesh-eating dinosaurs like the Tyrannosaurus rex; and ornithopods, plant-eating 'bird-hipped' dinosaurs so-called because of their pelvic structure being a little bit similar to birds.
A team of scientists has discovered the youngest dinosaur preserved in the fossil record before the catastrophic meteor impact 65 million years ago. The finding indicates that dinosaurs did not go extinct prior to the impact and provides further evidence as to whether the impact was in fact the cause of their extinction.
An artist's impression of what an asteroid colliding with Earth might look like. Sixty-six million years ago an event like this, although on a much smaller scale, caused 75% of all animals to die out. Image: Don Davis Via NASA Image and Video Library
In 1980, Nobel Prize-winning physicist Luis Walter Alvarez and his geologist son Walter published a theory that a historic layer of iridium-rich clay was caused by a large asteroid colliding with Earth. The instantaneous devastation in the immediate vicinity and the widespread secondary effects of an asteroid impact were considered to be why the dinosaurs died out so suddenly.
Luis Walter Alvarez (left) and his son Walter (right) are known for their theory that an asteroid collided with our planet 66 million years ago and caused all non-bird dinosaurs and many other animals to die out. Image: Lawrence Berkeley Laboratory/ Wikimedia Commons
Paul says, 'An asteroid impact is supported by really good evidence because we've identified the crater. It's now largely buried on the seafloor off the coast of Mexico. It is exactly the same age as the extinction of the non-bird dinosaurs, which can be tracked in the rock record all around the world.'
Paul explains, 'The asteroid hit at high velocity and effectively vaporised. It made a huge crater, so in the immediate area there was total devastation. A huge blast wave and heatwave went out and it threw vast amounts of material up into the atmosphere.
'There is a lot of discussion over the actual kill mechanism and how long that period lasted. There are still a lot of unknowns. But it was a massive event affecting all life on Earth, from microorganisms all the way through to dinosaurs,' says Paul.
During the Cretaceous extinction event, plants were less affected than animals because their seeds and pollen can survive harsh periods for longer. After the dinosaurs' extinction, flowering plants dominated Earth, continuing a process that had started in the Cretaceous, and continue to do so today. But all land animals weighing over 25 kilogrammes died out.
'It was only around 15 million years after the non-bird dinosaurs disappear, during what's termed the Oligocene Epoch, that we started to get really big mammals. This is when rhino-sized animals start to reappear. But up until that point it's a world filled with small animals, especially in comparison with the dinosaurs that came before them. It took a while for body size to catch up.'
'I suspect some of them would still be around. We don't know a lot about the last 10 million years of their reign and what we do know is based on only one area in the world, western North America. There is a really good record of those classic last non-bird dinosaurs like Tyrannosaurus and Triceratops.
'From that part of the world it looks like dinosaurs are thriving in terms of numbers, but the number of different types of dinosaurs is reduced. We don't know if that pattern held elsewhere - it's still a big mystery.'
Explore the age of the dinosaurs. Discover what the prehistoric world was like and how it changed between when dinosaurs first appeared and the mass extinction at the end of the Cretaceous Period.
Non-bird dinosaurs lived between about 245 and 66 million years ago, in a time known as the Mesozoic Era. This was many millions of years before the first modern humans, Homo sapiens, appeared.
Scientists divide the Mesozoic Era into three periods: the Triassic, Jurassic and Cretaceous. During this era, the land gradually split from one huge continent into smaller ones. The associated changes in the climate and vegetation affected how dinosaurs evolved.
It was in this environment that the reptiles known as dinosaurs first evolved. Reptiles tend to flourish in hot climates because their skin is less porous than, for example, mammal skin, so it loses less water in the heat. Reptile kidneys are also better at conserving water.
At the end of the Triassic Period there was a mass extinction, the causes of which are still hotly debated. Many large land animals were wiped out but the dinosaurs survived, giving them the opportunity to evolve into a wide variety of forms and increase in number.
During the Cretaceous the land separated further into some of the continents we recognise today, although in different positions. This meant that dinosaurs evolved independently in different parts of the world, becoming more diverse.
Other groups of organisms also diversified. The first snakes evolved during this time, as well as the first flowering plants. Various insect groups appeared, including bees, which helped increase the spread of flowering plants. And mammals now included tree climbers, ground dwellers and even predators of small dinosaurs.
Do you have a burning question about science or nature that you want the answer to? Fill out the form below to let us know. \\nWe'll work with Museum scientists to turn some of your questions into stories featured in our online magazine Discover or videos on our YouTube channel.\\n \\nThis new feature is in beta. Find out more. \\n\",\"name\":\"textdraw1645607798401\",\"sling:resourceType\":\"fd/af/components/guidetextdraw\",\"textIsRich\":\"true\",\"documentFragmentVariables\":[]},\"guidetextbox\":\"templateId\":\"guideContainer-rootPanel-guidetextbox__\",\"id\":\"\",\"jcr:path\":\"/content/forms/af/nhmwww/ask-a-question/jcr:content/guideContainer/rootPanel/items/guidetextbox\",\"guideNodeClass\":\"guideTextBox\",\"jcr:title\":\"Your question\",\"mandatory\":\"true\",\"name\":\"textbox1645607810912\",\"maxChars\":\"280\",\"sling:resourceType\":\"fd/af/components/guidetextbox\",\"autofillFieldKeyword\":\"name\",\"textIsRich\":[\"true\",\"true\",\"true\"],\"placeholderText\":\"e.g. Why do zebras have stripes?\",\"nonLocalizedTitle\":\"Your question\"},\"toolbar\":\"templateId\":\"guideContainer-rootPanel-toolbar__\",\"id\":\"\",\"jcr:path\":\"/content/forms/af/nhmwww/ask-a-question/jcr:content/guideContainer/rootPanel/toolbar\",\"guideNodeClass\":\"guideToolbar\",\"jcr:title\":\"Toolbar\",\"css\":\"\",\"name\":\"toolbar\",\"sling:resourceType\":\"fd/af/components/toolbar\",\"nonLocalizedTitle\":\"Toolbar\",\"items\":\"submit\":\"templateId\":\"guideContainer-rootPanel-toolbar-submit__\",\"id\":\"\",\"jcr:path\":\"/content/forms/af/nhmwww/ask-a-question/jcr:content/guideContainer/rootPanel/toolbar/items/submit\",\"guideNodeClass\":\"guideButton\",\"jcr:title\":\"Submit your question\",\"name\":\"toolbarsubmit\",\"type\":\"submit\",\"dorExclusion\":\"true\",\"sling:resourceType\":\"fd/af/components/actions/submit\",\"textIsRich\":[\"true\",\"true\"],\"clickExp\":\"\\ntry \\n guideBridge.submit();\\n \\n \\n catch (e) \\n window.guideBridge._guide.logger().error(\\\"AF\\\",\\\"Failed to execute rule: \\\" + e);\\n\\n\",\"nonLocalizedTitle\":\"Submit your question\",\"layout\":\"templateId\":\"guideContainer-rootPanel-toolbar-layout__\",\"id\":\"\",\"jcr:path\":\"/content/forms/af/nhmwww/ask-a-question/jcr:content/guideContainer/rootPanel/toolbar/layout\",\"sling:resourceType\":\"fd/af/layouts/toolbar/defaultToolbarLayout\"},\"autoSaveInfo\":\"templateId\":\"guideContainer-autoSaveInfo__\",\"id\":\"\",\"jcr:path\":\"/content/forms/af/nhmwww/ask-a-question/jcr:content/guideContainer/autoSaveInfo\",\"metadataselector\":\"global\",\"signerInfo\":\"templateId\":\"guideContainer-signerInfo__\",\"id\":\"\",\"jcr:path\":\"/content/forms/af/nhmwww/ask-a-question/jcr:content/guideContainer/signerInfo\",\"firstSignerFormFiller\":\"false\",\"workflowType\":\"SEQUENTIAL\",\"signer0\":\"templateId\":\"guideContainer-signerInfo-signer0__\",\"id\":\"\",\"jcr:path\":\"/content/forms/af/nhmwww/ask-a-question/jcr:content/guideContainer/signerInfo/signer0\",\"countryCode\":\"undefined\",\"phoneSource\":\"form\",\"securityOption\":\"NONE\",\"signerTitle\":\"Signer One\",\"email\":\"undefined\",\"phone\":\"undefined\",\"countryCodeSource\":\"form\",\"emailSource\":\"form\",\"repeatBindRef\":[],\"guideGlobalLazyField\":[],\"allLazyChildren\":[],\"assetRefs\":[]}","guidecontext":"\"disablePreview\":true,\"scriptingBehaviourVersion\":\"None\",\"makeFileNameUnique\":false,\"schemaType\":\"none\",\"guidePath\":\"/content/forms/af/nhmwww/ask-a-question/jcr:content/guideContainer\",\"guideName\":\"guide1\"","guidemergedjson":"","xfajson":"","xfarendercontext":""});window.guideBridge._readRuntimeLocale("en");};window.guidelib.runtime.target.loadExperience();$("#loadingPage").removeClass("guideLoading"); 0Evolution
Feature
Prehistoric
Dinosaurs
Discover dinosaursFind out what Museum scientists are revealing about how dinosaurs looked, lived and behaved.
The shovel-beaked hadrosaurs and horned ceratopsids showed different trends. Horned dinosaurs suffered a significant drop in disparity between the Campanian and the Maastrichtian, at least partially attributable to the disappearance of an entire ceratopsid subgroup. During the Campanian, both centrosaurines (like Centrosaurus) and chasmosaurines (like Chasmosaurus) roamed North America, but by the Maastrichtian, only the chasmosaurines were left. And while hadrosaur disparity dipped slightly from a global perspective, the pattern differed between continents. In Asia, hadrosaurs appear to show very slight increases in disparity, but North American hadrosaurs suffered a sharp decline across the 12-million-year study range. What was true for North American dinosaurs was not necessarily true for the rest of the world.