In Depth
In terms of size, Anchiornis was a very small dinosaur indeed, though this is not the claim to fame for the genus. Anchiornis is known to have been feathered and one specimen is so well preserved that palaeontologists have been able to determine what colour and pattern these feathers were in life. Anchiornis seems to have been mostly black with white stripes running along its wings of its fore arms, while the face had black and red speckles. This was all crowned off with an orange Mohawk style feather crest on top of its head. As of 2010, our understanding of dinosaur colours is most complete for Anchiornis, though the tail is still unknown at the time of writing. The first dinosaur to make headlines for the discovery of colour was Sinosauropteryx, which is now known to have had a banded orange and white tail.
Anchiornis had feathers but is still thought of by palaeontologists as a dinosaur rather than a bird, though one that wasn’t far from becoming one. As with all feathered dinosaurs, Anchiornis had maniraptorian origins, and shows features seen in both dromaeosaurs and troodontids. Although Anchiornis had a similar feather arrangement as Microraptor, the actual form and arrangement of the feathers on Anchiornis are not that well suited to flight, suggesting more of an insulation/display function for them.
Despite the lack of suitable feathers, Anchiornis had very long fore limbs that were equivalent to four fifths of the total length of the rear limbs, and wrists more like those of birds than dinosaurs. These are both developments that later descendants could carry forward to fully functional flight capable wings, but in Anchiornis they were probably more for grasping and climbing Mesozoic trees to keep out of the way of predators.
Anchiornis would have shared its habitat with other dinosaurs such as Tianyulong, Xiaotingia and Eosinopteryx. The skies though would have still been ruled by pterosaurs, with Darwinopterus, Qinglongopterus, Changchengopterus, Dendrorhynchoides and Jianchangnathus to name just a few of the pterosaurs known from the Tiaojishan Formation.
Further Reading
- A new feathered maniraptoran dinosaur fossil that fills a morphological gap in avian origin, Xing Xu, Qi Zhao, Mark Norell, Corwin Sullivan, David Hone, Gregory Erickson, XiaoLin Wang, FengLu Han & Yu Guo - 2009. - Plumage color patterns of an extinct dinosaur, Quanguo Li, Ke-Qin Gao, Jakob Vinther, Matthew D. Shawkey, Julia A. Clarke, Liliana D’Alba, Qingjin Meng, Derek E. G. Briggs & Richard O. Prum - 2010. – On the absence of sternal elements in Anchiornis (Paraves) and Sapeornis (Aves) and the complex early evolution of the avian sternum. – Proceedings of the National Academy of Sciences. 111 (38): 13900–13905. – X. Zheng, J. O.Conner, X. Wang, M. Wang, X. Zhang & Z. Zhou – 2014. – Comment on the absence of ossified sternal elements in basal paravian dinosaurs. – Proceedings of the National Academy of Sciences. 111 (50): E5334–E5334. – C. Foth – 2014. – Bizarre structures point to dromaeosaurs as parasites and a new theory for the origin of avian flight. – Journal of Paleontological Sciences. 6: 1–27. – G. Fraser – 2014. – Additional information on the primitive contour and wing feathering of paravian dinosaurs. – Palaeontology. 61 (2): 273–288. – Evan T. Saitta, Rebecca Gelernter & Jakob Vinther -2018. – Exceptional dinosaur fossils reveal early origin of avian-style digestion. – Scientific Reports. 8 (1): 14217. – Xiaoting Zheng, Xiaoli Wang, Corwin Sullivan, Xiaomei Zhang, Fucheng Zhang, Yan Wang, Feng Li & Xing Xu – 2018.
