The paddles at the front (the pectoral paddles) were longer than those at the back (the pelvic paddles). It probably had six teeth in each premaxilla, and the teeth preserved there were formed like large fangs. Smart Destinations from Boston, USA, CC BY-SA 2.0, via Wikimedia Commons. Recognizing them as the remains of a plesiosaur, larger than any he had seen in Europe, Cope wrote to Turner asking him to deliver the rest of the specimen, at the ANSP's expense. Peloneustes had a large head, a streamlined body. The team measured the distance between bite marks on the larger Tanystropheus and compared them with the jaws of various predators sharing the habitat. Elasmosaurus (eh-LAZZ-mo-SAWR-us) lived during the late Cretaceous period and went extinct during the K-T mass extinction, 65 million years ago. Elasmosaurids probably ate small bony fish and marine invertebrates, as their small, non-kinetic skulls would have limited the size of the prey they could eat. Turner died unexpectedly at Fort Wallace on July27, 1869, without seeing the completion of the work he began, but Cope continued to write him, unaware of his death until 1870. High diversity, low disparity and small body size in plesiosaurs (Reptilia, Sauropterygia) from the TriassicJurassic boundary. Also, Cope initially thought it consisted of two specimens of different animals in an 1868 letter to LeConte, Cope had referred to the supposed "smaller specimen" as Discosaurus carinatus. Paleontologists have uncovered dozens of plesiosaur species from rocks spanning 135 million years of plesiosaur history, but one of the most beautiful is that of Nichollssaura borealis. Thanks for reading Scientific American. This sensitivity would determine the distance at which they could detect approaching displacement waves and would, hence, account for the super-long neck of elasmosaurs like Thalassomedon and Elasmosaurus. She lives in Salt Lake City, Utah. . It was based on Schrder's Pliosaurus(?) Kronosaurus (Kroe-noe-sore-uss) was one of the sea reptiles known as pliosaurs, a member of the plesiosaur group, but in the Pliosauridae family (including Macroplata, Peloneustes and Liopleurodon). Put all this together and we can infer that the longest-necked plesiosaurs were probably doing lots of relatively straight, long-distance swimming in open water. Or could it help the neck move more easily in one direction? The back vertebrae had rib facets level with the neural canal, and the front and back part of the transverse processes here had distinct ridges on their margins. [22] Elasmosaurus differed from all other plesiosaurs by having 72 neck (or cervical) vertebrae; more may have been present but were later lost to erosion or after excavation. One of the potential problems of a long neck in plesiosaurs, as envisaged by Henry de la Beche . Time in Universe Once Flowed Five Times Slower, Screens More Versatile Than LED: Fins, Droplets, Squash Bugs Are Attracted to and Eat Each Other's Poop to Stock Their Microbiome, How Urea May Have Been the Gateway to Life, Octopus Sleep Is Surprisingly Similar to Humans and Contains a Wake-Like Stage, Turning Old Maps Into 3D Digital Models of Lost Neighborhoods, Orangutans Can Make Two Sounds at the Same Time, Similar to Human Beatboxing, Study Finds, Do Hummingbirds Drink Alcohol? But when they did swim, how did they do it? [41] Welles moved this specimen to the new genus and species Alzadasaurus riggsi in 1943. Living things have a knack for learning how to make parts of their bodies into multi-purpose tools and there is no reason why plesiosaurs would be any different. You also have the option to opt-out of these cookies. [73] However, Ketchum and Benson's analysis instead included it in the Leptocleidia,[74] and its inclusion in that group has remained consistent in subsequent analyses. [98], The soft, muddy sea floor probably received very little sunlight, but it teemed with life due to steady rains of organic debris from plankton and other organisms farther up the water column. Turner did not live to see his Elasmosaurus captivate the imagination of the world. Continue reading with a Scientific American subscription. So now that we have a general idea about the anatomy and biology of some of these long-necked plesiosaurs, how did they use their incredible necks? [63], Persson assigned another species to Elasmosaurus alongside his 1959 description of "E."helmerseni remains from Sweden, namely E. [21], Though the only known specimen of Elasmosaurus (holotype specimen ANSP10081) is fragmentary and missing many elements, related elasmosaurids show it would have had a compact, streamlined body, long, paddle-like limbs, a short tail, a proportionately small head, and an extremely long neck. Shiqiu Liu, CC BY 2.5, via Wikimedia Commons. The cited variability in the number of heads on the neck ribs arises from his inclusion of Simolestes to the Elasmosauridae, since the characteristics of "both the skull and shoulder girdle compare more favorably with Elasmosaurus than with Pliosaurus or Peloneustes." [25][44], An elasmosaurid specimen was found by Handel Martin in Logan County, Kansas in 1889. [14][66] He subsequently abandoned this idea in his 1869 description of Elasmosaurus, where he stated he had based it on Leidy's erroneous interpretation of Cimoliasaurus. ScienceDaily, 5 July 2017. Muraenosaurus was 20 feet (6 metres) long with a very long neck, and a wide body. [62] In 1997 Carpenter reconsidered the differences between the two species, and found them sufficient to place E.morgani in its own genus, which he named Libonectes. [15][2], Elasmosaurus had four sacral vertebrae (the fused vertebrae that form the sacrum connected to the pelvis), a number typical of elasmosaurids. Society for Experimental Biology. Graphical abstract. The head and the front of the neck are missing, but judging from the vertebrae which are preserved it looks as if the animal had a very long neck with 50 or more vertebrae. Credit: iScience (2022). No, L., Taylor, M., Gmez-Prez, M. 2017. It was discovered that the 'flat tail' was its neck. [20], In 2017 Sachs and Joachim Ladwig suggested that a fragmentary elasmosaurid skeleton from the upper Campanian of Kronsmoor in Schleswig-Holstein, Germany, and housed in the Naturkunde-Museum Bielefeld, may have belonged to Elasmosaurus. This technique was highly advantageous as it would not have alarmed the school, which would have promptly dispersed. Elasmosaurus measured around 46 feet (14 metres) in length and weighed over 2.2 tons (2,000 kilograms), making it the longest ever plesiosaur species. They included: Plesiosaurus 7.6 feet (2.3 metres) long with a long neck, 4 wide, paddle-shaped flippers, and a tapered body. And wouldnt that make them clumsy and slow swimmers that had a hard time changing direction? Even though there hasnt been a Plesiosaur Renaissance to match the dinosaur equivalent of the late 20th century, expert anatomists have nevertheless given plesiosaurs stiffer, straight necks that operated in coordination with the rest of the body rather than as independent, snaky appendages that could dart one way while the body was moving another. [61], In 1949 Welles named a new species of Elasmosaurus, E.morgani. They are distinguished by having two holes in the rear upper part of their skulls and two holes behind the eyes, like all Diapsids. ", "Computer Simulations Imply Forelimb-Dominated Underwater Flight in Plesiosaurs", "The four-flipper swimming method of plesiosaurs enabled efficient and effective locomotion", "Elasmosaur (Reptilia: Sauropterygia) neck flexibility: Implications for feeding strategies", "An integrated approach to understanding the role of the long neck in plesiosaurs", "Functional morphology and hydrodynamics of plesiosaur necks: Does size matter? Analytical cookies are used to understand how visitors interact with the website. [91] Another study found the long necks of elasmosaurs would normally increase drag during forward swimming but this was cancelled out by their large torsos, and hence large body sizes may have facilitated the evolution of longer necks. of Scania (S. 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The short neck of his backwards elasmosaur would reduce drag as the animal propels itself through the water, while the long tail could be used for propulsion via undulations. Meet The Ancient Sea Reptile With A Comically Long Neck Plesiosaurs had several remarkable physical traits, but without a doubt, the most impressive thing about them is the long neck. All three had roughly triangular heads and jaws densely-packed with curved, spike-like teeth a grin suited for nabbing food and swallowing the morsels whole. The usual number of tail vertebrae in elasmosaurids is 30. This cookie is set by GDPR Cookie Consent plugin. Naturally, there are caveats to studies like these. How did plesiosaurs swim with such long necks? | Geology Page Most aquatic predators have a tendency to evolve larger skulls and shorter necks to help them deal with armored prey like crustaceans or larger vertebrates. They also noted that conceptual sketches of the Palaeozoic Museum show that the model Elasmosaurus was originally envisioned with a long "tail", though later updated with a long neck. This extremely long neck provided some advantages, but it might have also been an obstacle for efficient swimming. Add to these disadvantages other major biological issues to overcome, such as breathing and swallowing down a massive neck and pumping blood from the heart to the head, and you have a very difficult adaptation to manage, let alone wield successfully. But some plesiosaurs do not fit any of these models. In other words, no swinging the neck out sideways to grab fish or rearing back into a swan-like S pose. They werent exactly saurian whales interlocking teeth arent as good as baleen for filtering but plesiosaurs probably dipped their heads to trap shoaling fish from the water column or scoop crustaceans from the bottom, sand and silt filtering out of their jaws.