{"id":141895,"date":"2024-09-25T17:48:07","date_gmt":"2024-09-25T17:48:07","guid":{"rendered":"https:\/\/news.talkwithrattan.com\/index.php\/2024\/09\/25\/some-of-earths-extinct-giants-may-have-been-smaller-than-thought\/"},"modified":"2024-09-25T17:48:07","modified_gmt":"2024-09-25T17:48:07","slug":"some-of-earths-extinct-giants-may-have-been-smaller-than-thought","status":"publish","type":"post","link":"https:\/\/news.talkwithrattan.com\/index.php\/2024\/09\/25\/some-of-earths-extinct-giants-may-have-been-smaller-than-thought\/","title":{"rendered":"Some of Earth\u2019s extinct giants may have been smaller than thought"},"content":{"rendered":"<div style=\"text-align:center\"><img decoding=\"async\" src=\"https:\/\/i0.wp.com\/www.sciencenews.org\/wp-content\/uploads\/2024\/09\/091724_cg_extinct-size_inline_mobile.png?fit=680%2C450&amp;ssl=1\" class=\"attachment-post-thumbnail size-post-thumbnail wp-post-image\" alt=\"Some of Earth\u2019s extinct giants may have been smaller than thought\" title=\"Some of Earth\u2019s extinct giants may have been smaller than thought\" \/><\/div> \r\n<br><div style=\"clear:both\">\n<style><![CDATA[\n.subscribe-cta {\n  color: black;\n  margin-top: 0px;\n  background-color: #EDD695;\n  background-size: cover;\n  padding: 20px;\n  border: 1px solid black;\n  border-top: 5px solid black;\n  clear: both;\n}\n\n.centered {\n  text-align:center;\n  margin:auto;\n}\n\n]]><\/style>\n<!-- \/wp:html -->\n\n<!-- wp:group {\"className\":\"subscribe-cta\"} -->\n<div id=\"subscribeConversion\" class=\"wp-block-group subscribe-cta\"><!-- wp:heading {\"textAlign\":\"center\",\"style\":{\"typography\":{\"fontSize\":\"2em\"}}} -->\n<h2 class=\"wp-block-heading has-text-align-center\" style=\"font-size:2em\">Extreme Climate Survey<\/h2>\n<!-- \/wp:heading -->\n\n<!-- wp:paragraph {\"align\":\"center\",\"style\":{\"typography\":{\"fontSize\":\"1.1em\"}}} -->\n<p class=\"has-text-align-center\" style=\"font-size:1.1em\"><strong><em>Science News <\/em>is collecting reader questions about how to navigate our planet&#8217;s changing climate.<\/strong><\/p>\n<p class=\"has-text-align-center\" style=\"font-size:1.1em\">What do you want to know about extreme heat and how it can lead to extreme weather events?<\/p>\n<!-- \/wp:paragraph -->\n\n<!-- wp:spacer {\"height\":\"20px\"} -->\n\n<!-- \/wp:spacer -->\n\n<!-- wp:buttons {\"className\":\"centered\",\"layout\":{\"type\":\"flex\",\"justifyContent\":\"center\"}} -->\n\n<!-- \/wp:buttons --><\/div>\n<!-- \/wp:group -->\n\n\n<p>That\u2019s just one example. Size estimates of many of the planet\u2019s extinct giants <a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/ece3.70218\" target=\"_blank\" rel=\"noopener\">have been called into question<\/a> in the last decade as new data and analytical techniques have emerged, researchers report in the September <em>Ecology and Evolution<\/em>.<\/p>\n\n\n\n<p>To some extent, that\u2019s just how science works, say evolutionary biologist Joel Gayford and colleagues. But the scale of the size dispute in some cases calls for much more caution in making those initial estimates, the researchers say.<\/p>\n\n\n\n<p>\u201cThere\u2019s an ongoing trend of \u2026 high profile papers publishing <em>world\u2019s largest<\/em>, <em>world\u2019s heaviest<\/em> something,\u201d says Gayford, now at James Cook University in Brisbane, Australia. \u201cBefore long, there\u2019s another paper in a lower profile journal saying, \u2018Hold on, it wasn\u2019t actually that long.\u2019\u201d<\/p>\n\n\n\n<p>When it comes to estimating body size, there isn\u2019t always a lot to go on. The extinct <em>Otodus megalodon<\/em>, the largest shark to ever live, left only teeth behind; the ancient whale\u00a0<em>Perucetus<\/em>, <a href=\"https:\/\/www.sciencenews.org\/article\/colossal-ancient-whale-heaviest-animal\">initially estimated to be heavier than the modern blue whale<\/a>, left just a few vertebrae, ribs and a single individual\u2019s pelvis (<em>SN: 8\/2\/23<\/em>)<em>.<\/em>\u00a0To extrapolate from these pieces to a whole animal, researchers may compare the fossils with living or extinct relatives \u2014 if any are known \u2014 or plug the data into computer analyses of evolutionary trees.<\/p>\n\n\n<figure class=\"wp-block-image \"><picture class=\"sn-responsive-image\"><source srcset=\"https:\/\/i0.wp.com\/www.sciencenews.org\/wp-content\/uploads\/2024\/09\/091724_cg_extinct-size_inline_desktop.png?w=680&amp;ssl=1 680w, https:\/\/i0.wp.com\/www.sciencenews.org\/wp-content\/uploads\/2024\/09\/091724_cg_extinct-size_inline_desktop.png?resize=579%2C383&amp;ssl=1 579w, https:\/\/i0.wp.com\/www.sciencenews.org\/wp-content\/uploads\/2024\/09\/091724_cg_extinct-size_inline_desktop.png?resize=281%2C186&amp;ssl=1 281w\" width=\"680\" height=\"450\" media=\"(min-width: 600px)\" sizes=\"(max-width: 1023px) 100vw, 680px\"><source srcset=\"https:\/\/i0.wp.com\/www.sciencenews.org\/wp-content\/uploads\/2024\/09\/091724_cg_extinct-size_inline_mobile.png?w=680&amp;ssl=1 680w, https:\/\/i0.wp.com\/www.sciencenews.org\/wp-content\/uploads\/2024\/09\/091724_cg_extinct-size_inline_mobile.png?resize=579%2C383&amp;ssl=1 579w, https:\/\/i0.wp.com\/www.sciencenews.org\/wp-content\/uploads\/2024\/09\/091724_cg_extinct-size_inline_mobile.png?resize=281%2C186&amp;ssl=1 281w\" width=\"680\" height=\"450\"><\/source><\/source><\/picture><figcaption><span class=\"caption mobile-caption wp-caption-3143793\">Four famous ocean dwellers, known from just a few scant fossils, may each have been a bit smaller than first thought. At top are the skull of the ancient armored fish <em>Dunkleosteus terrelli<\/em> (a), the tooth whorl of the fish <em>Helicoprion<\/em> (b), a tooth from the giant shark <em>Otodus megalodon<\/em> (c), and vertebra from the whale <em>Perucetus colossus<\/em> (d). Past reconstructions of these creatures are in grey, with black silhouettes representing newer, revised reconstructions \u2014 though these, too, are still uncertain. (Fossils are not to scale.)<\/span><span class=\"credit mobile-credit wp-credit-3143793\">J.H. Gayford et al\/Ecology and Evolution 2024<\/span><span class=\"caption desktop-caption wp-caption-3143792\">Four famous ocean dwellers, known from just a few scant fossils, may each have been a bit smaller than first thought. At top are the skull of the ancient armored fish <em>Dunkleosteus terrelli<\/em> (a), the tooth whorl of the fish <em>Helicoprion<\/em> (b), a tooth from the giant shark <em>Otodus megalodon<\/em> (c), and vertebra from the whale <em>Perucetus colossus<\/em> (d). Past reconstructions of these creatures are in grey, with black silhouettes representing newer, revised reconstructions \u2014 though these, too, are still uncertain. (Fossils are not to scale.)<\/span><span class=\"credit desktop-credit wp-credit-3143792\">J.H. Gayford et al\/Ecology and Evolution 2024<\/span><\/figcaption><\/figure>\n\n\n<p>But those extrapolations come with assumptions that can lead researchers astray.<\/p>\n\n\n\n<p><em>Megalodon<\/em> is one of several examples that Gayford and colleagues zero in on. Scientists had thought it was closely related to great white sharks, and so assumed its body was proportionally broad to match its perhaps 11 meters in length. But a recent study upended that assumption, suggesting instead that <em>Megalodon<\/em> may have been a few meters longer but also more slender, <a href=\"https:\/\/www.sciencenews.org\/article\/megalodon-largest-shark-fossil-long-body\">built more like a bus than a van<\/a> (<em>SN: 1\/21\/24<\/em>).<\/p>\n\n\n\n<p>Similarly, the methodology behind the initial size estimates of the whale <em>Perucetus<\/em> <a href=\"https:\/\/peerj.com\/articles\/16978\/\" target=\"_blank\" rel=\"noopener\">were called into question earlier this year<\/a>. Using different methods of calculation, researchers downgraded its estimated weight from up to 340 metric tons to about 100 \u2014 still a big whale, they argued, just not quite in the blue whale\u2019s weight class, which can weigh as much as 245 metric tons.<\/p>\n\n\n\n<p>Paleontologists have previously called out \u201cspurious size estimates\u201d as creating lasting bias when it comes to perceptions of how big it\u2019s possible to get, Gayford says. These estimates of size matter, the team notes, because larger-than-most species can have an outsize impact on ecology, such as food resources and predator-prey relationships. And changes to the environment \u2014 loss of those food sources, for example \u2014 can, in turn, have an outsize impact on the giants.<\/p>\n\n\n\n<p>Paleontologists have hailed the study for highlighting a core challenge in the field. It is \u201ccorrect in pointing out that we need to be cautious and acknowledge wide margins of error when reconstructing any extinct taxon,\u201d says vertebrate paleontologist Jack Cooper of Swansea University. But not every case study discussed in the paper was analyzed equally rigorously, he says. For example, there is still a great deal of reasonable debate about how best to estimate <em>Megalodon<\/em>\u2019s size.<\/p>\n\n\n\n\n\n<p>Cooper adds that the report inaccurately claimed his own work on the giant shark, based on a rare vertebral fossil, was \u201cunreplicable.\u201d That, he says, makes him \u201cconcerned as to what else has been incorrectly reported in their larger review.\u201d<\/p>\n\n\n\n<p>Gayford, in response, says that he and coauthors were referring to the rarity of the fossil, not criticizing Cooper\u2019s work \u2014 and adds that this highlights the inherent challenges of estimating sizes from the scant fossil record. And, he says, research journals bear some of the burden for outsize claims. \u201cThey are less likely to publish detailed, methodologically sound but not particularly amazing conclusions. And that has a knock-on effect for what people might focus their research on.\u201d<\/p>\n\n\n\n<p>One way to address this, he says, is to note that size in and of itself doesn\u2019t matter quite so much when it comes to whether a creature is worth studying. \u201cThe point is for people to understand that it\u2019s not the size or the weight of an animal that makes it interesting,\u201d Gayford says. \u201cIt\u2019s still a huge, awesome animal that we can learn a lot about.\u201d<\/p>\n\n\n\n\t\t\t<\/div>\r\n<br>\r\n<br><a href=\"https:\/\/www.sciencenews.org\/article\/extinct-giants-size-estimates\">Source link <\/a>","protected":false},"excerpt":{"rendered":"<p>Extreme Climate Survey Science News is collecting reader questions about how to navigate our planet&#8217;s changing climate. What do you want to know about extreme heat and how it can lead to extreme weather events? That\u2019s just one example. Size estimates of many of the planet\u2019s extinct giants have been called into question in the [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":141896,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"tdm_status":"","tdm_grid_status":"","fifu_image_url":"https:\/\/i0.wp.com\/www.sciencenews.org\/wp-content\/uploads\/2024\/09\/091724_cg_extinct-size_inline_mobile.png?fit=680%2C450&ssl=1","fifu_image_alt":"","footnotes":""},"categories":[606],"tags":[5043,15158,962,16114,14902],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/news.talkwithrattan.com\/index.php\/wp-json\/wp\/v2\/posts\/141895"}],"collection":[{"href":"https:\/\/news.talkwithrattan.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/news.talkwithrattan.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/news.talkwithrattan.com\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/news.talkwithrattan.com\/index.php\/wp-json\/wp\/v2\/comments?post=141895"}],"version-history":[{"count":1,"href":"https:\/\/news.talkwithrattan.com\/index.php\/wp-json\/wp\/v2\/posts\/141895\/revisions"}],"predecessor-version":[{"id":141897,"href":"https:\/\/news.talkwithrattan.com\/index.php\/wp-json\/wp\/v2\/posts\/141895\/revisions\/141897"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/news.talkwithrattan.com\/index.php\/wp-json\/wp\/v2\/media\/141896"}],"wp:attachment":[{"href":"https:\/\/news.talkwithrattan.com\/index.php\/wp-json\/wp\/v2\/media?parent=141895"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/news.talkwithrattan.com\/index.php\/wp-json\/wp\/v2\/categories?post=141895"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/news.talkwithrattan.com\/index.php\/wp-json\/wp\/v2\/tags?post=141895"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}