Sinornithosaurus ‭(‬Chinese bird lizard‭)

Short Info

Sinornithosaurus ‭(‬Chinese bird lizard‭)

Phonetic : Sine-or-nith-oh-sore-s

Named By : Xu,‭ ‬Wang‭ & ‬Wu‭ ‬-‭ ‬1999

Diet : Carnivore

Size : Estimated 1.2 metres long

Type of Dinosaur : Small Theropod

Type Species : S.millenii‭ (‬type‭)‬,‭ ‬S.‭ ‬haoiana

Found in : China,‭ ‬Liaoning Province‭ ‬-‭ ‬Yixian Formation

When it Lived : Early Cretaceous, 122-120 million years ago

Sinornithosaurus (derived of a mix from Latin and Greek meaning ‘Chinese bird lizard’) is a genus of feathered dinosaurs that date back to in the beginning of Cretaceous Period (early Aptian) of the Yixian Formation in what is today China. This was also the 5th feathered dinosaur genus that was discovered in 1999. The first specimen was taken from the Sihetun area of the western part of Liaoning. It was discovered inside the Jianshangou beds of the Yixian Formation and was dated at 124.5 millions of years old. Additional samples have been discovered in the more recent Dawangzhangzi bed, dating back to approximately the 122 million year old age.


Sinornithosaurus millenii 2I, Laikayiu, CC BY-SA 3.0, via Wikimedia Commons


Xu Xing described Sinornithosaurus and carried out a phylogenetic analysis that showed that it was basic, or primitive, among the Dromaeosaurs. He also proved that the skull’s features and shoulder are like Archaeopteryx along with other Avialae. These two findings prove how the first dromaeosaurs looked more like birds than later dromaeosaurs.

Sinornithosaurus was one of the smallest of dromaeosaurids. It measured the length of around 90 centimetres (3.0 feet). In 2010 Gregory S. Paul gave the higher estimates of 1.2 metres and 3 kilograms.

Aspects of Sinornithosaurus preserve impressions of feathers covering the entire body and creating wings. They were identical by shape from those seen on birds that were found in the same deposits of geological origin. They were also known as “contour” feathers. (contour) feathers were typically between 3-4.5 cm in length and comprised two kinds of feathers that were composed of a variety of filaments that were connected to form “tufts”, similar to modern feathers made of down. The second type, which included the arms consisted from lines of filaments (barbs) connected by the principal shaft (rachis) which made them similar to modern feathers for birds. However, unlike the wings feathers of flying birds they did not have secondary branches that had tiny hooks (barbules) which feathers for flight have that allow flight feathers to become a continuous vane. Certain scientists have suggested feathers may have permitted Sinornithosaurus to glide over shorter distances after leaping off of trees.

A study in 2010 indicated that Sinornithosaurus could have had feathers that varied in color with respect to various body regions according to examination of microscopic structures of cells found in preserved fossils.

Source: Wikipedia