“Brachiosaurus” nougaredi II – Oh no, What is with its sacrum!?

Recent studies on newer old sauropod phylogenies came across the original description of Ferganasaurus and what in the world is with its sacrum. As you can clearly see in Figure 5 (shown below), half of the sacrum is complete, and all the vertebrae are preserved. By doing a little math, I come up with a total length of 78 cm for the sacrum, and a width of 46 cm. Anyone see similar proportions to the sacrum of “Brachiosaurus” nougaredi (from here on out B. nougaredi). The B. nougaredi sacrum is about 145 cm when complete, and about 100 cm wide. Scale the Ferganasaurus sacrum to the same width, and its length becomes 156. Oh my god, look at the similarities in proportions. The B. nougaredi sacrum was originally cited as 80 cm in length, so if I do more math and scale Ferganasaurus up again, the Ferganasaurus sacrum is now just under 136 cm long. Now comes a problem, If these species are actually within the same genus, or what is more likely, family, then the family spans 50 million years, which is quite a lot for two genera. However, as the describers of Ferganasaurus are Alifanov and Averianov, which have recently scooped Kulindadromeus, I’m not certain that they didn’t bump back the age at least 10 million years to help with their publicity. An age of 170 million years is odd for the closest relative of Neosauropoda, as the oldest definite of the group itself are 157 million years old. This means that there would have been a ghost lineage of around 15 million years, unless of course Cetiosauriscus is a neosauropodan. Below are the figures of Lapparent, 1960 and Alifanov and Averianov, 2003, comparing the sacrums.Ferganasaurus weird sacrum B. nougaredi sacrum modified

References:

  • Alifanov, V.R.; Averianov, A.O. (2003). “Ferganasaurus verzilini gen. et sp. nov., a New Neosauropod (Dinosauria, Saurischia, Sauropoda) from the Middle Jurassic of Fergana Valley, Khirgizia”. Journal of Vertebrate Paleontology 23(2): 358–372.
  • de Lapparent, A.F. (1960). “Les dinosauriens du “continental intercalaire” du Sahara central” (“The dinosaurs of the “continental intercalaire” of the central Sahara.”) Mémoires de la Société Géologic de France, Nouvelle Série 88A 39(1–6): 1–57.
  • Alifanov, V.R.; Saveliev, S.V. (2014). “Two new ornithischian dinosaurs (Hypsilophodontia, Ornithopoda) from the Late Jurassic of Russia”, Paleontological Journal 4: 72–82.
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About ijreid

I am an amateur palaeontologist thats hobbies include studying extinct amniotes, specifically dinosaurs, birds, and mammals. Occasionally, I focus my time on detailed and accurate illustrations of dinosaurs, and I have completed drawings of Dysalotosaurus, Micropachycephalosaurus, Zhuchengtyrannus, Troodon, Eotyrannus, Europelta, and Achillobator. I do not believe in copyrights, and think that the world would be better if everything was open access.
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