{"id":6448,"date":"2019-04-02T09:12:35","date_gmt":"2019-04-02T13:12:35","guid":{"rendered":"http:\/\/spaceandplanetarynewswire.com\/?p=6448"},"modified":"2019-04-02T09:12:35","modified_gmt":"2019-04-02T13:12:35","slug":"stunning-discovery-offers-glimpse-of-minutes-following-dinosaur-killer-chicxulub-impact","status":"publish","type":"post","link":"https:\/\/spaceandplanetarynewswire.com\/?p=6448","title":{"rendered":"Stunning Discovery Offers Glimpse of Minutes Following &#8216;Dinosaur-Killer&#8217; Chicxulub Impact"},"content":{"rendered":"<div class=\"flex-video widescreen youtube\"><iframe title=\"Stunning discovery offers glimpse of minutes following \u2018dinosaur-killer\u2019 Chicxulub impact\" width=\"500\" height=\"281\" data-src=\"https:\/\/www.youtube.com\/embed\/EpNMHwnxpC8?feature=oembed&#038;showinfo=0&#038;rel=0&#038;modestbranding=1&#038;iv_load_policy=3&#038;playsinline=1&#038;enablejsapi=1\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" class=\"lazyload\" data-load-mode=\"0\"><\/iframe><\/div>\n<p>A <a href=\"https:\/\/www.pnas.org\/content\/early\/2019\/03\/27\/1817407116\" target=\"_blank\" rel=\"noopener noreferrer\">study<\/a> published in the <em>Proceedings of the National Academy of Sciences<\/em>&nbsp;offers a scientific first: a detailed snapshot of the terrible moments right after the Chicxulub impact &#8212; the most cataclysmic event known to have befallen life on Earth.<\/p>\n<p>At a site called Tanis in North Dakota&#8217;s Hell Creek Formation, a team of paleontologists whose headquarters are at the University of Kansas unearthed a motherlode of exquisitely-preserved animal and fish fossils &#8212; creatures that lived in and around a deeply chiseled river connected to the ancient Western Interior Seaway &#8212; that were killed suddenly in events triggered by the Chicxulub impact.<\/p>\n<p>The fossils were crammed into a &#8220;rapidly emplaced high-energy onshore surge deposit&#8221; along the KT boundary that contained associated ejecta and iridium impactite associated with the impact about 66 million years ago &#8212; an impact that eradicated about 75 percent of Earth&#8217;s animal and plant species.<\/p>\n<p>&#8220;A tangled mass of freshwater fish, terrestrial vertebrates, trees, branches, logs, marine ammonites and other marine creatures was all packed into this layer by the inland-directed surge,&#8221; said lead author Robert DePalma, a KU doctoral student in geology who works in the KU Biodiversity Institute and Natural History Museum. &#8220;Timing of the incoming ejecta spherules matched the calculated arrival times of seismic waves from the impact, suggesting that the impact could very well have triggered the surge.&#8221;<\/p>\n<p>DePalma, who discovered the fossil motherlode, said the find outlines how the impact could have devastated areas very far from the crater quite rapidly.<\/p>\n<p>&#8220;A tsunami would have taken at least 17 or more hours to reach the site from the crater, but seismic waves &#8212; and a subsequent surge &#8212; would have reached it in tens of minutes,&#8221; he said.<\/p>\n<p>DePalma and his colleagues describe the rushing wave that shattered the Tanis site as a &#8220;seiche.&#8221;<\/p>\n<p>&#8220;As the 2011 Tohoku earthquake in Japan showed us, seismic shaking can cause surges far from the epicenter,&#8221; he said. &#8220;In the Tohoku example, surges were triggered nearly 5,000 miles away in Norway just 30 minutes after impact. So, the KT impact could have caused similar surges in the right-sized bodies of water worldwide, giving the first rapid &#8216;bloody nose&#8217; to those areas before any other form of aftermath could have reached them.&#8221;<\/p>\n<p>According to KU researchers, even before the surge arrived, Acipenseriform fish (sturgeon) found at the site already had inhaled tiny spherules ejected from the Chicxulub impact.<\/p>\n<p>&#8220;The fish were buried quickly, but not so quickly they didn&#8217;t have time to breathe the ejecta that was raining down to the river,&#8221; said co-author David Burnham, preparator of vertebrate paleontology at the KU Biodiversity Institute. &#8220;These fish weren&#8217;t bottom feeders, they breathed these in while swimming in the water column. We&#8217;re finding little pieces of ejecta in the gill rakers of these fish, the bony supports for the gills. We don&#8217;t know if some were killed by breathing this ejecta, too.&#8221;<\/p>\n<p>The number and quality of preservation of the fossils at Tanis are such that Burnham dubs it the &#8220;lagerst\u00e4tte&#8221; of the KT event &#8212; paleontologist-speak for a landmark sedimentary deposit with exceptionally intact specimens. He said this is especially true as the fish are cartilaginous, not bony, and are less prone to fossilization.<\/p>\n<p>&#8220;The sedimentation happened so quickly everything is preserved in three dimensions &#8212; they&#8217;re not crushed,&#8221; Burnham said. &#8220;It&#8217;s like an avalanche that collapses almost like a liquid, then sets like concrete. They were killed pretty suddenly because of the violence of that water. We have one fish that hit a tree and was broken in half.&#8221;<\/p>\n<p>Indeed, the Tanis site contains many hundreds of articulated ancient fossil fish killed by the Chicxulub impact&#8217;s aftereffects and is remarkable for the biodiversity it reveals alone.<\/p>\n<p>&#8220;At least several appear to be new species, and the others are the best examples known of their kind,&#8221; DePalma said. &#8220;Before now, fewer than four were known from the Hell Creek, so the site was already magnificently significant. But we quickly recognized that the surrounding sediment was deposited by a sudden, massive rush of water, and that the surge was directed inland, away from an ancient nearby seaway. When we noticed asteroid impact debris within the sediment and a compact layer of KT boundary clay resting on top of it from the long-term fallout, we realized that this unusual site was right at the KT boundary.&#8221;<\/p>\n<p>According to Burnham, the fossil trove fills a void in scientific knowledge with vivid new detail.<\/p>\n<p>&#8220;We&#8217;ve understood that bad things happened right after the impact, but nobody&#8217;s found this kind of smoking-gun evidence,&#8221; he said. &#8220;People have said, &#8216;We get that this blast killed the dinosaurs, but why don&#8217;t we have dead bodies everywhere?&#8217; Well, now we have bodies. They&#8217;re not dinosaurs, but I think those will eventually be found, too.&#8221;<\/p>\n<p>DePalma said his find provides spectacular new detail to what is perhaps the most important event to ever affect life on Earth.<\/p>\n<p>&#8220;It&#8217;s difficult not to get choked up and passionate about this topic,&#8221; he said. &#8220;We look at moment-by-moment records of one of the most notable impact events in Earth&#8217;s history. No other site has a record quite like that. And this particular event is tied directly to all of us &#8212; to every mammal on Earth, in fact. Because this is essentially where we inherited the planet. Nothing was the same after that impact. It became a planet of mammals rather than a planet of dinosaurs.<\/p>\n<p>&#8220;As human beings, we descended from a lineage that literally survived in the ashes of what was once the glorious kingdom of the dinosaurs. And we&#8217;re the only species on the planet that has ever been capable of learning from such an event to the benefit of ourselves and every other organism in our world.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A study published in the Proceedings of the National Academy of Sciences&nbsp;offers a scientific first: a detailed snapshot of the terrible moments right after the Chicxulub impact &#8212; the most cataclysmic event known to have befallen life on Earth. At a site called Tanis in North Dakota&#8217;s Hell Creek Formation, a team of paleontologists whose&hellip;<\/p>\n","protected":false},"author":71,"featured_media":7472,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"fifu_image_url":"https:\/\/news.ku.edu\/sites\/news.ku.edu\/files\/images\/general\/social-news\/HellCreed-bl-FB.jpg","fifu_image_alt":"Stunning Discovery Offers Glimpse of Minutes Following &#8216;Dinosaur-Killer&#8217; Chicxulub Impact","footnotes":""},"categories":[216],"tags":[],"class_list":["post-6448","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-discovery"],"_links":{"self":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts\/6448","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/users\/71"}],"replies":[{"embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6448"}],"version-history":[{"count":1,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts\/6448\/revisions"}],"predecessor-version":[{"id":6450,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts\/6448\/revisions\/6450"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/media\/7472"}],"wp:attachment":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6448"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6448"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6448"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}