{"id":781097,"date":"2026-07-24T03:39:17","date_gmt":"2026-07-24T03:39:17","guid":{"rendered":"https:\/\/www.newsbeep.com\/us\/781097\/"},"modified":"2026-07-24T03:39:17","modified_gmt":"2026-07-24T03:39:17","slug":"jurassic-pliosaur-liopleurodon-was-big-but-not-as-big-as-once-feared","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us\/781097\/","title":{"rendered":"Jurassic Pliosaur Liopleurodon Was Big, but Not as Big as Once Feared"},"content":{"rendered":"

For several decades, Liopleurodon ferox<\/a> \u2014 a short-necked marine reptile that patrolled the seas of what is now England and France some 163 million years ago \u2014 has held a reputation as one of the largest predators to ever swim the oceans, with some estimates putting its length at a jaw-dropping 25 m. By re-examining every known specimen of Liopleurodon ferox, paleontologists at the University of Portsmouth<\/a> found that the species was far shorter, but its massive skull still made it a fearsome apex predator.<\/p>\n

\"An<\/p>\n

An artist\u2019s impression of a pliosaur. Image credit: Megan Jacobs, University of Portsmouth.<\/p>\n

\u201cLiopleurodon ferox is a well-known thalassophonean pliosaurid from the Middle Jurassic (Callovian) Oxford Clay Formation of England and equivalent strata in northwest France,\u201d said University of Portsmouth paleontologist Edward Bartlett and his colleagues.<\/p>\n

\u201cIt is among the earliest of thalassophoneans to be known from near-complete skeletons.\u201d<\/p>\n

\u201cConsequently, Liopleurodon ferox has become a benchmark for systematic studies and size comparisons of thalassophoneans. However, a complicated taxonomic history stemming from the diagnosis of the holotype, an isolated caniniform tooth originally described in 1873, has led to the referral of many Callovian-Tithonian pliosaurid specimens to the genus.\u201d<\/p>\n

\u201cThis has resulted in a wide range of size estimates from 6.39 m to the astonishing 25 m presented in the 1999 BBC TV series Walking with Dinosaurs<\/a>.\u201d<\/p>\n

In their research, Dr. Bartlett and co-authors analyzed 37 specimens attributed to Liopleurodon ferox.<\/p>\n

They calculated a total body length ranging from about 2.46 to 8.09 m, with the more complete skeletons clustering around 4.8 to roughly 6 m.<\/p>\n

The average animal, they concluded, was likely close to 5 m long \u2014 still a fearsome predator, but a fraction of the mythical 25-m figure.<\/p>\n

\u201cOur study is the first comprehensive reappraisal of every specimen assigned to Liopleurodon ferox,\u201d Dr. Bartlett said.<\/p>\n

\u201cBy bringing together all of the available material, we can finally provide a robust estimate of its size and body proportions.\u201d<\/p>\n

\u201cAlthough it was smaller than some famous reconstructions, it was still the dominant marine predator in the Jurassic Oxford Clay seas.\u201d<\/p>\n

To build their revised model, the paleontologists turned to two well-preserved skeletons \u2014 one housed in T\u00fcbingen, Germany, and another at the Natural History Museum in London \u2014 along with a separate, complete skull used to calibrate cranial proportions.<\/p>\n

They found that the skull makes up about 24% of the animal\u2019s skeletal length, a notably larger share than earlier estimates suggested, hinting that Liopleurodon ferox could tackle relatively large prey compared with other pliosaurs living alongside it.<\/p>\n

Even scaled down, Liopleurodon ferox remains the largest known animal from the Oxford Clay Formation ecosystem.<\/p>\n

\u201cOur study is the first comprehensive reappraisal of every specimen assigned to Liopleurodon ferox,\u201d Dr. Bartlett said.<\/p>\n

\u201cBy bringing together all of the available material, we can finally provide a robust estimate of its size and body proportions.\u201d<\/p>\n

But the researchers also flag something more surprising: several fragmentary fossils from the same rock formation appear to belong to pliosaurs considerably larger than any confirmed Liopleurodon ferox, with estimated lengths reaching as high as 12.2 m.<\/p>\n

Because these specimens lack the diagnostic features needed to assign them to a species, their identity remains a mystery, though they suggest that true giants were swimming<\/a> in Middle Jurassic seas alongside Liopleurodon ferox.<\/p>\n

\u201cIndeterminate Oxford Clay Formation pliosaurid specimens estimated at 7.02-12.2 m total body length demonstrate that gigantism in pliosaurs (over 10 m) evolved during the late Middle Jurassic,\u201d the scientists said.<\/p>\n

The findings<\/a> appear in the Journal of Vertebrate Palaeontology.<\/p>\n

_____<\/p>\n

Edward O. Bartlett et al. Re-evaluating body size in the Middle Jurassic pliosaur Liopleurodon ferox Sauvage, 1873. Journal of Vertebrate Paleontology, published online July 16, 2026; doi: 10.1080\/02724634.2026.2691149<\/p>\n","protected":false},"excerpt":{"rendered":"For several decades, Liopleurodon ferox \u2014 a short-necked marine reptile that patrolled the seas of what is now…\n","protected":false},"author":2,"featured_media":781098,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[32],"tags":[79401,9333,1076,5168,594,3209,332586,332587,332588,332589,332590,39887,79,1049],"class_list":["post-781097","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-apex-predator","tag-england","tag-europe","tag-fossil","tag-france","tag-jurassic","tag-liopleurodon","tag-liopleurodon-ferox","tag-oxford-clay-formation","tag-pliosaur","tag-pliosauridae","tag-reptile","tag-science","tag-united-kingdom"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/781097","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=781097"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/781097\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/781098"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=781097"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=781097"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=781097"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}