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On the nuances of ankylosaurs (and their osteoderms)
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How we found the world's oldest modern bird skull
Introducing Asteriornis maastrichtensis
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Fossil bird from Limburg
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Hadrosaurus
Dinosaur Discovery in New Jersey (1)
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Courtenay hadrosauroid
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Were dinosaurs social creatures or lone rangers?
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Wyoming fossil retailer pleads guilty to smuggling dinosaur and other fossils into the US
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The real Czech "Loch Ness monster" (elasmosaurid from Hudcov, described in 1906 as "Cimoliasaurus teplicensis") (in Czech)
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Ichthyosaur: digits and phalanges
Mandible of Libonectes
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Plesiosaur found at the bottom of a well (in French)
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Cenomanian-Turonian impact
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Dinosaur extinction for students
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Darkness, not cold, likely responsible for dinosaur-killing extinction
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Article link:
Prolonged periods of low light and cold temperatures at Earth's surface are hypothesized effects of the endâCretaceous asteroid impact. However, debate remains about the causes and consequences of this âimpact winter.â We perform simulations of the Chicxulub impact with an Earth system model that can simulate the evolution of extreme aerosol loading to quantify the climatic responses to emissions (soot, sulfur, and dust) associated with the impact winter. We show that all impact winter emissions can drastically reduce surface temperature and precipitation. However, only soot emission from impactâdriven firestorms is capable of reducing light to below the photosynthetic threshold for many months. Therefore, our results suggest that widespread fires may have been necessary to produce the observed pattern of marine extinction across the CretaceousâPaleogene boundary. We identify polar coasts and the surrounding open oceans as regions likely to have experienced the least climatic, and biotic, disruption from the impact winter.
Plain Language Summary
Over 75% of all species went extinct across the CretaceousâPaleogene boundary (66 million years ago). This extinction coincided with a massive asteroid impact in the Yucatan Peninsula, which emitted material high into the atmosphere and potentially caused widespread fires. These emissions from the impactor, impact site, and fires would have blocked sunlight from reaching the surface, resulting in an âimpact winterâ that likely contributed to the mass extinction. However, details of the impact winter have been difficult to quantify. Here we use a stateâofâtheâart Earth system model to simulate the climate responses to emission of dust and sulfur from the asteroid impact and soot from fires. We find that all simulated emission scenarios reduce sunlight at the surface, cause global cooling, and disrupt the hydrologic cycle. However, only soot emission from fires is able to reduce sunlight, and therefore prevent the growth of primary producers, for long enough to potentially starve large marine organisms. Our results suggest that widespread fires and the resulting soot emission may have been an important component of the extinction. Further, in all emission scenarios we find that the impact winter was least disruptive to the climate in the highâlatitude regions, potentially providing refugia for life.
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Videos:
Christa Sadler: What the Fossils of Utahâs Grand Staircase-Escalante National Monument Can Tell Us about our Future.
Research Quest Live with Carrie Levitt-Bussian (starts about 53:45 minutes in) with dinosaur stuff
Natural History Museum of Utah
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Mass Extinction Events: Pushing Life to the Limit - with Alex Dunhill
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Non-dino:
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Geographic Dispersal across the Tetrapod Water-Land Transition
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Fossil snake with infrared vision: Early evolution of snakes in the Messel Pit examined
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Sudden Ancient Global Warming Event (Paleocene-Eocene Thermal Maximum) Traced to Magma Flood
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