{"id":10517,"date":"2014-08-05T15:47:16","date_gmt":"2014-08-05T06:47:16","guid":{"rendered":"https:\/\/www.waseda.jp\/top\/en\/?p=10517"},"modified":"2014-10-24T18:43:06","modified_gmt":"2014-10-24T09:43:06","slug":"waseda-researchers-discover-the-worlds-oldest-true-dolphin-species-rewrite-the-known-fossil-record","status":"publish","type":"post","link":"https:\/\/www.waseda.jp\/top\/en\/news\/10517","title":{"rendered":"Waseda researchers discover the world&#8217;s oldest true dolphin species &#8211; rewrite the known fossil record"},"content":{"rendered":"<section>Waseda researchers have described the earliest example of a true dolphin in the known fossil record.<\/p>\n<p>In an article published in the &#8220;Journal of Vertebrate Paleontology&#8221;, Waseda Department of Earth Sciences researchers\u00a0<small>(lead author Mizuki Murakami)\u00a0<\/small>conclude that the specimen, which was originally categorized in 1977 as Stenella kabatensis, actually belongs to the Eodelphis kabatensis species. This means that true dolphins existed 2 to 7 million years earlier than had been previously suggested by fossil records, and aligns with the results of molecular studies.<\/p>\n<p>This work also includes the most comprehensive analysis yet of the relationships within the group of marine mammals that encompasses toothed whales such as orcas and sperm whales.<\/p>\n<div><img decoding=\"async\" alt=\"Eodelphis kabatensis skull (original by Mizuki Murakami) \u00a9Society of Vertebrate Paleontolog\" src=\"http:\/\/www.waseda.jp\/jp\/news14\/data\/140702_kabato1.jpg\" \/><br \/>\nEodelphis kabatensis skull (original by Mizuki Murakami) \u00a9Society of Vertebrate Paleontolog<\/p>\n<\/div>\n<div><img decoding=\"async\" alt=\"\u00a0Eodelphis kabatensis (simulation by Robert W. Boessenecker) \u00a9Society of Vertebrate Paleontology\" src=\"http:\/\/www.waseda.jp\/jp\/news14\/data\/140702_kabato2.jpg\" \/><br \/>\nEodelphis kabatensis (simulation by Robert W. Boessenecker) \u00a9Society of Vertebrate Paleontology<\/p>\n<\/div>\n<p>&nbsp;<\/p>\n<p>In another study, Murakami and a team of researchers also described the oldest known dolphin fossil with an asymmetrical skull, and created a new simulation of their evolution.<\/p>\n<div><img decoding=\"async\" alt=\"\u00a0Diagram of the ancient dolphin's asymmetrical skull (by Mizuki Murakami)\" src=\"http:\/\/www.waseda.jp\/jp\/news14\/data\/140702_nbhf1.jpg\" \/><br \/>\nDiagram of the ancient dolphin&#8217;s asymmetrical skull (by Mizuki Murakami)<\/p>\n<\/div>\n<p>It has been accepted theory that dolphin ancestors earlier than 10 million years ago all had symmetrical skulls, and that asymmetry was the result of subsequent evolution. This study suggests a different evolutionary path for the marine mammals.<\/p>\n<h4>Links<\/h4>\n<p><a href=\"http:\/\/www.tandfonline.com\/doi\/full\/10.1080\/02724634.2013.816720#.U9C72ZR_tU0\" target=\"_blank\">Journal of Vertebrate Paleontology\u00a0<\/a><\/p>\n<p><a href=\"http:\/\/www.eurekalert.org\/pub_releases\/2014-05\/sovp-rot043014.php\" target=\"_blank\">Society of Vertebrate Paleontology press release\u00a0<\/a><\/p>\n<p><a href=\"http:\/\/www.palaeo-soc-japan.jp\/English\/index-e.html\" target=\"_blank\">Palaeontological Society of Japan\u00a0<\/a><\/p>\n<p><a href=\"http:\/\/www.bioone.org\/doi\/abs\/10.2517\/2014PR013\" target=\"_blank\">Abstract<\/a><\/p>\n<p>&nbsp;<\/p>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>Waseda researchers have described the earliest example of a true dolphin in the known fossil record. In an art [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":10056,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[81],"tags":[178],"class_list":["post-10517","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news","tag-research-en"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.waseda.jp\/top\/en\/wp-json\/wp\/v2\/posts\/10517","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.waseda.jp\/top\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.waseda.jp\/top\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.waseda.jp\/top\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.waseda.jp\/top\/en\/wp-json\/wp\/v2\/comments?post=10517"}],"version-history":[{"count":0,"href":"https:\/\/www.waseda.jp\/top\/en\/wp-json\/wp\/v2\/posts\/10517\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.waseda.jp\/top\/en\/wp-json\/wp\/v2\/media\/10056"}],"wp:attachment":[{"href":"https:\/\/www.waseda.jp\/top\/en\/wp-json\/wp\/v2\/media?parent=10517"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.waseda.jp\/top\/en\/wp-json\/wp\/v2\/categories?post=10517"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.waseda.jp\/top\/en\/wp-json\/wp\/v2\/tags?post=10517"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}