Sinornithosaurus was a genus of feathered dromaeosaurid dinosaurs that lived during the Early Cretaceous, 130-125 million years ago in what is now China. The name means "Chinese bird-lizard," which was a close relative of Velociraptor. In 1999, it was the fifth non-avian feathered dinosaur discovered. Paleontologists found the fossils in the Jianshangou beds of the Yixian Formation, dated to 124.5 million years ago.
Sinornithosaurus was the most famous dino-bird fossil discovered in China's Liaoning Quarry because it is the most complete. Sinornithosaurus had different types of feathers on other parts of its body. The head was short and hairy, the arms and tail were long and distinctly bird-like, with intermediate length tufts along its back. Considering that Sinornithosaurus had unique large, sickle-shaped claws on each of its hind legs used to tear at its prey, it bears a more remarkable resemblance to the other dino-birds of the Mesozoic Era.
One study indicated that the body of Sinornithosaurus was completely covered with feathers. In a 2010 study, it was found that the feathers of Sinornithosaurus had significant color in different regions of its body. Later, in 2012, the study showed that the feathers of Sinornithosaurus were reddish brown, yellow, black and gray spread throughout its body.
Sinornithosaurus was an agile and active carnivore during its time. It probably hunted in groups. Its tail acted as a counterweight, allowing great precision and releasing the powerful claws on its feet.
Sinornithosaurus was estimated to be 90-120 cm long and weighed 3 kg.
Well, there are a lot of rumors around Sinornithosaurus about it being venomous. Perhaps because Sinornithosaurus has three lines of evidence: apparently long teeth in the upper jaw, grooves in those teeth that could conduct venom, and a pouch in the skull that is said to be the perfect place for a venom gland. However, an argument ensued between Gianechini and his colleagues; these features had nothing to do with venom.
First, the "elongated" teeth appeared to have slightly protruded from their sockets and did not have extraordinarily long fangs.
Second, the "poison grooves" on the teeth were not consistent with what was seen or did not stand up to scrutiny either.
Third, there is no evidence of a special pocket in the skull for a venom gland.
Sinornithosaurus was an agile and active carnivore during its time, hunting small prey such as birds.
Sinornithosaurus was the most famous dino-bird fossil discovered in China's Liaoning Quarry in 1999 because it is the most complete.
Sinornithosaurus had deadly features such as unique large, sickle-shaped claws on each of its hind legs used to tear its prey.