Following Robinson (1975), many other authors subsequently reused or redrew the Newman & Tarlo reconstruction under the name of Liopleurodon in academic papers, popular articles, and books, to the point where it has become ubiquitous (Taylor 1981; Carroll 1988; Benton 1990a&b; Martill & Hudson 1991; O’Keefe 2002; Ellis 2003; and Yang 2013 come to mind – I’m sure there are many more). Sometimes the outline of the tail fin was reduced or removed, sometimes the soft tissue outline was removed entirely, sometimes the pliosaur was given extra teeth (the original appears devoid of any maxillary teeth), and sometimes its mouth was redrawn in a open position, but the source is always obvious even when it isn’t directly cited. It is quite understandable that this reconstruction has been reused so frequently and for so long. It was the first published illustration of a full body skeletal reconstruction attributed to Liopleurodon, and has remained the only one for 54 years to the present day. So, what do we really know of the ‘Stewartby Pliosaur’ specimen that inspired this reconstruction, and is it really Liopleurodon? A selection of the many books and papers that have reused, modified, or redrawn the Newman & Tarlo (1967) pliosaur reconstruction (original at far left) under the name of Liopleurodon (except, in this picture, Knutsen (2012) (top right) who uses it as a generic pliosaur). The ‘Stewartby Pliosaur’ Beyond that, their nose had two separate chambers that functioned like ears—they used them to pinpoint the exact location of the smell. The study of Liopleurodon is a means to understand the marine ecosystem of the Jurassic period precisely and the Mesozoic Era as a whole. FAQs Was Liopleurodon Bigger than Mosasaurus? They remained at the top of the food chain until the Cretaceous period, which ushered in a more powerful species that likely led to their decline and ultimate disappearance.

The first fossils of this ancient creature were discovered in 1873 in the Boulogne sur Mer region of France. Fossilized tooth of Liopleurodon | Madzia via Wikipedia CC BY-SA 4.0 A highly recommended online toy store featuring a wide variety of Papo, Schleich, Safari Ltd., CollectA, and other figures. Figure from Newman & Tarlo (1967) showing the articulated hind flipper of the ‘Stewartby Pliosaur’ ( Liopleurodon ferox). It’s a photocopy of a photocopy, hence the terrible quality, so if anyone has a scan I’d be glad to hear from you. Making sense of the Newman & Tarlo reconstruction According to sources, the Liopleurodon gave birth to one offspring at a time, and they were likely the size of a baby whale. Also, most of these marine reptiles had similar diets, which consisted of cephalopods and other sea creatures. Some were also known to be scavengers when the situation called for it.Although scientists once exaggerated the size of the Liopleurodon, they have now settled for a more reasonable size. After receiving these fossils for examination, Henri Émile Sauvage, a paleontologist, named them the Liopleurodon ferox. Otherwise called “smooth-sided tooth,” this now-extinct reptile was an apex predator that roamed the oceans between the Middle Jurassic and Late Jurassic periods. Mosasaurs were much bigger and had more powerful jaws than their predecessors, which gave the Liopleurodon real competition.

While some reptiles during the Jurassic period laid eggs, Liopleurodon was one of the few species that gave birth to their young ones alive. Ultimately, these carnivorous reptiles started to decline until they finally disappeared about 150 million years ago, around the beginning of the Cretaceous period. Interactions with Other Species

McHenry (2009) suggested that the reconstruction “ may have been based upon StretosaurusTarlo, 1959″ (p.258) and added that “From vertebral counts of the different body segments and general proportions of the skull it undoubtedly represents a large pliosaurid, perhaps‘ Stretosaurus’( Pliosaurus macromerus)” (p. 370). McHenry also noted that “Tarlo… seemed to imply that the reconstruction was partly based upon the Stretham specimen…”(p.359), and subsequently refers to the reconstruction as the “‘Newman and Tarlo Stretosaurus‘ reconstruction, or the ‘ Stretosaurus’ reconstruction” (e.g. p. 370) and says the reconstruction is “ apparently based upon the Stewartby and Stretham specimens” (p. 370). I’ve bolded key parts to highlight that there’s no direct evidence for this assertion – not that I disagree with it. It is a spectacular figure and is by far the most accurate pliosaur toy reviewed on The Dinosaur Toy Blog so far. All of the Walking with Dinosaurs figures are almost perfectly symmetrical, which is a let down in most of the figures which appear to be just ‘standing around’. However, this is not so much of an issue in the aquatic Liopleurodon. The figure is 24cm long. We know Halstead attributed the reconstruction to Liopleurodon in 1982 (Halstead 1982), so we can be reasonably confident the reconstruction was based on material regarded by him as Liopleurodon at that time, which would have included the lectotype of ‘ Stretosaurus‘. It would also make sense for Tarlo to use the ‘Stretham Pliosaur’ specimen in the Newman & Tarlo reconstruction for two other reasons. First, he described and was intimately familiar with it (Tarlo, 1957, 1959, 1960), and second, in Tarlo’s words, “The Streatham specimen is one of the most important Pliosaur[sic] skeletons to have come out of the Kimeridge [sic][and]…most of the post-cranial skeleton can be described” (Tarlo 1959, p. 41). And, of course, the specimen certainly fulfils the criterion of “other giant pliosaur remains” as stipulated by Newman and Tarlo.

Based on findings, researchers deduced that these reptiles did not lay eggs but gave birth to their young ones live. The Jurassic period is popularly called the age of the dinosaurs because of how prevalent these animals were at that time. L. B. Tarlo (who later went by the name of L. B. Halstead) repurposed part of this iconic reconstruction in at least one other publication, captioned as Liopleurodon (Halstead 1982). However, It was apparently Jane Ann Robinson (1975) who first reused the reconstruction under that genus. Robinson (1977) cites a personal communication with Halstead, so they were certainly acquainted with each other by 1977, so it is possible, likely even, that Robinson consulted with Tarlo/Halstead a couple of years earlier when she reused and captioned the reconstruction as Liopleurodon. This brawl is one of the reasons scientists believe that most youngsters did not make it to adulthood.Their first fossils were recovered in the 19th century, and these items have proved pivotal in knowing more about this apex predator. Tarlo, L. B. 1959. Stretosaurus gen. nov., a giant pliosaur from the Kimmeridge Clay. Palaeontology, 2, 39-55.

Still, since there are only a few postcranial fossils to work with, it is almost impossible to provide the accurate size of this reptile. Noè, L. F. 2001. A taxonomic and functional study of the Callovian (Middle Jurassic) Pliosauroidea (Reptilia, Sauropterygia). Unpublished PhD thesis, University of Derby.Since then, some corrections have been made to the Liopleurodon’s actual shape; you can find a reconstructed skeleton at the Museum of Paleontology in Tubingen, Germany.