Name: Maraapunisaurus ‭(‬huge lizard‭)‬.
Phonetic: Ma-rah-pu-ne-sore-us.
Named By: Kenneth Carpenter-‭ ‬2018
Synonyms: Amphicoelias fragillimus.
Classification: Chordata,‭ ‬Reptilia,‭ ‬Dinosauria,‭ ‬Saurischia,‭ ‬Sauropoda,‭ ‬Rebbachisauridae.
Species: M.‭ ‬fragillimus‭ (‬type‭)‬.
Diet: Herbivore.
Size: Highly speculative given that the genus is based upon partial remains which have now become lost.‭ ‬Older estimates from the time when Maraapunisaurus fossils were attributed to the Amphicoelias genus and reconstructed as a diplodocid suggested‭ ‬anywhere between‭ ‬40‭ ‬and‭ ‬60‭ ‬meters long.‭ ‬Later reconstruction of Maraapunisaurus as a rebbachisaurid sauropod dinosaur suggest a little over‭ ‬30‭ ‬meters long.‭ ‬Original vertebrae had a preserved height of‭ ‬1.5‭ ‬meters,‭ ‬possibly being as much as‭ ‬2.7‭ ‬meters high when complete.
Known locations: USA,‭ ‬Colorado‭ ‬-‭ ‬Morrison Formation.
Time period: Late Jurassic.
Fossil representation: Partial vertebra and femur.‭ ‬All specimens are now lost,‭ ‬only existing in original illustrations.

       Maraapunisaurus was originally described as a species of the sauropod dinosaur Amphicoelias,‭ ‬and based upon the discovery of a partial vertebra reported to be of massive proportions,‭ ‬as well as a distal end of a femur that was also of equally massive proportions.‭ ‬These bones are among the‭ ‬largest dinosaur fossils ever reported,‭ ‬but‭ ‬there is a problem‭; ‬they have vanished and no one knows where they are.
       It would seem quite ridiculous that such large bones should be able to just disappear,‭ ‬but one detail that we know about them is that they were fossilised in mudstone,‭ ‬a very weak rock that can be damaged and eroded easily.‭ ‬We also know that at the time of their original description in the nineteenth century the fossils were probably not treated with preservatives to‭ ‬make them hard and resilient‭ (‬some palaeontologists did,‭ ‬but others did not,‭ ‬the whole process of preserving fossils was still in its infancy‭)‬.‭ ‬It is possibly that the fossils could have simply crumbled and broken apart after they were taken from the ground,‭ ‬and‭ ‬this‭ ‬is a theory postulated by Kenneth Carpenter when he named the Maraapunisaurus genus in‭ ‬2018.
       Whereas Amphicoelias was described as a relative to Diplodocus,‭ ‬and hence a diplodocid sauropod,‭ ‬Carpenter‭ (‬2018‭) ‬considers Maraapunisaurus to actually be a rebbachisaurid sauropod dinosaur.‭ ‬Rebbachisaurid sauropods were unknown at the time of the original Amphicoelias description‭ (‬the type genus Rebbachisaurus was named in‭ ‬1954,‭ ‬over seventy-five years after Amphicoelias was named.‭)‬,‭ ‬and the‭ ‬2018‭ ‬naming and assessment of Maraapunisaurus as a rebbachisaurid sauropod certainly fits better with the shape of the original vertebrae.‭ Using the genus Limaysaurus as a body double (Limaysaurus is one of the most completely known rebbachisaurids) and scaling the bones to match the known material for ‬Maraapunisaurus has also lead to a reconstructed length of a little over thirty meters,‭ ‬a more believable estimate.

Further reading
-‭ ‬Maraapunisaurus fragillimus,‭ ‬N.G.‭ (‬formerly Amphicoelias fragillimus‭)‬,‭ ‬a basal Rebbachisaurid from the Morrison Formation‭ (‬Upper Jurassic‭) ‬of Colorado.‭ ‬-‭ ‬Geology of the Intermountain West.‭ ‬5:‭ ‬227‭–‬244.‭ ‬-‭ ‬Kenneth Carpenter‭ ‬-‭ ‬2018.


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