Haplocheirus

Name: Haplocheirus ‭(‬Simple hand‭)‬.
Phonetic: ‭H‬ap-low-ky-rus.
Named By: J.‭ ‬N.‭ ‬Choiniere,‭ ‬X.‭ ‬Xu,‭ ‬J.‭ ‬M.‭ ‬Clark,‭ ‬C.‭ ‬A.‭ ‬Forster,‭ ‬Y.‭ ‬Guo‭ & ‬F.‭ ‬Han‭ ‬-‭ ‬2010.
Classification: Chordata,‭ ‬Reptilia,‭ ‬Dinosauria,‭ ‬Saurischia,‭ ‬Theropoda,‭ ‬Alvarezsauroidea.
Species: H.‭ ‬sollers‭ (‬type‭)‬.
Diet: Insectivore‭?
Size: 2‭ ‬meters long.
Known locations: China,‭ ‬Junggar Basin‭ ‬-‭ ‬Shishugou Formation.
Time period: Oxfordian of the Jurassic.
Fossil representation: Almost complete individual on slab.

       At the time of its description Haplocheirus was the oldest‭ ‬known‭ ‬alvarezsaur by an impressive sixty-three million years before the previous record holder.‭ ‬This places Haplocheirus firmly within the Oxfordian stage of the Jurassic revealing that the alvarezsaurs began at least this far back rather than the early Cretaceous period as previously thought.‭ ‬On a side note,‭ ‬Haplocheirus also happened to predate the famous‭ ‘‬dino-bird‭’ ‬Archaeopteryx by fifteen million years,‭ ‬further confirming the idea that while Archaeopteryx was the first feathered bird like dinosaurs discovered,‭ ‬it was not the first to have feathers.
       Haplocheirus was a primitive alvarezsaur,‭ ‬something that is not just revealed by its early appearance its features as well.‭ ‬First is the sheer size of Haplocheirus which at around two meters is bigger than the known later and more refined forms.‭ ‬Second is that the more advanced forms of the Cretaceous have a single specially developed digit on each hand.‭ ‬Haplocheirus also has a well-developed thumb,‭ ‬but it also retains the use of two additional fingers on each hand.‭ ‬It seems that in time as the alvarezsaurs became more specialised these two fingers still present in Haplocheirus became redundant to the point that they became vestigial appendages.
       As a small dinosaur Haplocheirus would have had to of been careful not to end up being a meal for Jurassic era Asian theropods such as Sinraptor and Monolophosaurus,‭ ‬both known from the same formation as Haplocheirus.

Further reading
- A basal alvarezsauroid theropod from the early Late Jurassic of Xinjiang, China. - Science 327(5965):571-574. - J. N. Choiniere, X. Xu, J. M. Clark, C. A. Forster, Y. Guo & F. Han - 2010.



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