Aurornis

Name: Aurornis ‭(‬Daybreak bird‭)‬.
Phonetic: Or-ror-niss.
Named By: Pascal Godefroit,‭ ‬Andrea Cau,‭ ‬Hu Dong-Yu,‭ ‬François Escuillié,‭ ‬Wu Wenhao‭ & ‬Gareth Dyke‭ ‬-‭ ‬2013.
Classification: Chordata,‭ ‬Avialae.
Species: A.‭ ‬xui‭ (‬type‭)‬.
Diet: ‭ ‬Insectivore/Carnivore.
Size: About‭ ‬50‭ ‬centimetres long.
Known locations: China,‭ ‬Liaoning Province‭ ‬-‭ ‬Tiaojishan Formation‭? ‬See main text.
Time period: Oxfordian of the Jurassic‭? ‬See main text.
Fossil representation: Single individual preserved on a slab.

       Just after its description and at the time of writing,‭ ‬there is some uncertainty as to exactly how old Aurornis are.‭ ‬The type specimen was acquired from a fossil dealer in China and was labelled as coming from the Tiaojishan Formation which is Oxfordian‭ (‬late Jurassic‭) ‬in age.‭ ‬However the describers now recognise the possibility that the holotype may have actually come from the Yixian Formation which is Barremian/Aptian‭ (‬early Cretaceous‭) ‬in age.
       If the original description of Aurornis as a Jurassic organism is correct then it may hint at an earlier bird evolution than previously thought.‭ ‬If it comes from the Oxfordian then Aurornis were similar to but appeared ten million years before the world famous Archaeopteryx,‭ ‬a genus that many choose to use to mark the dividing line between where dinosaurs turned into birds.‭ ‬However,‭ ‬there is still a lot of on-going debate about Archaeopteryx,‭ ‬with some labelling them as a bird like dinosaurs while others treat them as the first birds.
       One key difference between Archaeopteryx and Aurornis is that Aurornis had a much more primitive bone structure,‭ ‬which means that is was less likely to have the ranges of motion necessary for‭ ‘‬flight strokes‭’‬.‭ ‬Aurornis also had a covering of feathers all over the body,‭ ‬but lacked larger flight capable feathers.‭ ‬This in turn suggests that the feathers on Aurornis served an insulatory and display purpose.‭
       At fifty centimetres long Aurornis were fairly big for a potential bird ancestor,‭ ‬but still quite small when compared to predatory dinosaurs in the same ecosystem.‭ ‬Given their size,‭ ‬Aurornis may have hunted for smaller invertebrates like insects and worms that lived amongst the litter of the forest floor.

Further reading
-‭ ‬A Jurassic avialan dinosaur from China resolves the early phylogenetic history of birds,‭ ‬Pascal Godefroit,‭ ‬Andrea Cau,‭ ‬Hu Dong-Yu,‭ ‬François Escuillié,‭ ‬Wu Wenhao‭ & ‬Gareth Dyke‭ ‬-‭ ‬2013.



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