Anchiornis: Prehistoric Animal of the Week

Anchiornis huxleyi was a small, feathered dinosaur that lived in what is now China during the Jurassic period a little over 160 million years ago.  It's genus name translates to "Near Bird" in reference to its striking similarity to birds.  Its species name honors Thomas Henry Huxley who was one of the first scientists to propose birds and (other)dinosaurs were related.

Life reconstruction of Anchiornis huxleyi by Christopher DiPiazza

Anchiornis was tiny.  In fact, it may be the smallest non-avian dinosaur known to date.  From head to tail it was only about a foot long, roughly the same size as a pigeon.  It probably ate small animals like lizards and insects when alive but I wouldn't be surprised if it ate some plant material as well.  Anchiornis would have co-existed with its close relative, Eosinopteryx. 

Fossil of Anchiornis complete with feathers

 Like birds, thanks some beautifully preserved fossils, we know that Anchiornis was fully feathered.  And by fully feathered I mean it was fully feathered.  In fact, Anchiornis had more plumage on its body than most modern birds do!  In addition to all the regular body parts one would expect to find feathers on an animal such as this, Anchiornis also had feathers covering most of its face, long, primary feathers running all down each of its legs and it even had small feathers covering its feet and toes.  As strange as this sounds, its actually not unheard of in the modern bird world either.  Owls, for instance, have light, wispy feathers on their toes growing out from between their scales.  Certain breeds of domestic chicken and dove also have primary feathers on their legs and feet.  What Anchiornis used its interesting plumage for is uncertain.  The feathers themselves weren't the right shape for flying, despite having so many.  Because they were all down its legs and feet, running on the ground would have also been a huge hassle for this dinosaur.  It is likely that Anchiornis was mostly arboreal and possibly was able to glide or parachute short distances when it had to.

Cochin Chicken

Foot of a Eurasian Eagle Owl

Anchiornis is one of the few dinosaurs in which the feathers have preserved so nicely, that paleontologists can look at them under a microscope and actually tell what color they probably were in life (which I have written all about before on here).  They can do this thanks to the fact that tiny cells, called melanosomes, preserved.  The shape of the cells reflects the color of the structure that they are on.  All the scientists had to do was look at the shapes of the melanosomes on Anchiornis and then find a match to melanosomes on modern birds.  What they found out was that Anchiornis would have been mostly a dark gray/black on most of its body, had white wing and leg feathers with black tips and had a reddish brown crest and flecks on its head.  Keep in mind the real colors of this animal when alive may not be exactly this since there could have been other cells that have since rotted away over the past 160 million years that when added to the ones that were observed could have given off a different pigment in life.  For now, however, this is our most likely image of the animal. 

That's all for this week!  Not sure if I will be able to get a post up Thursday because I will likely be packing for Gary and I's big trip to New Mexico to take part in an excavation of Triassic dinosaur fossils!  We will be sure to keep you posted though.  As always feel free to comment below or on our facebook page.

References

Hu, D; Hou, L.; Zhang, L. & Xu, X. (2009). "A pre-Archaeopteryx troodontid theropod from China with long feathers on the metatarsus". Nature 461 (7264): 640–643.

Li, Q.; Gao, K.-Q.; Vinther, J.; Shawkey, M.D.; Clarke, J.A.; D'Alba, L.; Meng, Q.; Briggs, D.E.G. et al. (2010). "Plumage color patterns of an extinct dinosaur". Science 327 (5971): 1369–1372.

Xu, X.; Zhao, Q.; Norell, M.; Sullivan, C.; Hone, D.; Erickson, G.; Wang, X.; Han, F. et al. (2009). "A new feathered maniraptoran dinosaur fossil that fills a morphological gap in avian origin". Chinese Science Bulletin 54 (3): 430–435.