Pronunciation: SIEN-or-nith-o-SOR-us
Meaning: Chinese bird lizard
Author/s: Xu (1999)
Synonyms: None known
First Discovery: Liaoning, China
Discovery Chart Position: #455
Sinornithosaurus millenii
Sinornithosaurus was discovered in the Jianshangou beds of the Yixian Formation, an area of China that regularly comes up trumps with tiny but beautifully preserved fossils. It was also the fifth bird-like dinosaur of 1999 to sport "protofeathers", but had two kinds; (1) down-like tufts on its head, neck and hind limbs, probably for insulation, and (2) quills on its forearms and tail, similar to those seen in modern flightless birds.
Identifying those structures as feathers immediately put creationists in a flap, and even some bird experts took umbrage, suggesting these "feathers" were merely misidentified hairs and that palaeontologists were seeing what they wanted to see. "Feathers and 'flight' evolved in tandem from tree-dwelling critters down", they said, "how can feathered-but-flightless dinosaurs be the ancestors of birds when the first birds are older than so-called feathered dinosaurs?". Those are valid points, to be fair. But regardless, these filaments vary in colour across different regions of the body based on analysis of microscopic cell structures (melanosomes) in their fossilized fluffy bits, and they were attached to a body which seems to have attained the prerequisites for powered, flapping flight.
In 2009, Empu Gong claimed that Sinornithosaurus was venomous because of the long, fang-like, mid-jaw teeth with full-length vertical grooves on the rear edge and a cavity in the jaw bone that housed a soft-tissue venom gland — a design found in confirmed venomous critters like Gila lizards. After their "killing claws" use as claws for killing was recently called into question, dromaeosaurids could do with an alternative strategy for taking down prey. However, grooves in one form or another are present on the teeth of many theropod dinosaurs and in a 2010 review, Gianechini suspected that its long "fangs" are merely regular teeth that have popped out of their sockets, and they couldn't locate chambers for venom glands at all.
Identifying those structures as feathers immediately put creationists in a flap, and even some bird experts took umbrage, suggesting these "feathers" were merely misidentified hairs and that palaeontologists were seeing what they wanted to see. "Feathers and 'flight' evolved in tandem from tree-dwelling critters down", they said, "how can feathered-but-flightless dinosaurs be the ancestors of birds when the first birds are older than so-called feathered dinosaurs?". Those are valid points, to be fair. But regardless, these filaments vary in colour across different regions of the body based on analysis of microscopic cell structures (melanosomes) in their fossilized fluffy bits, and they were attached to a body which seems to have attained the prerequisites for powered, flapping flight.
In 2009, Empu Gong claimed that Sinornithosaurus was venomous because of the long, fang-like, mid-jaw teeth with full-length vertical grooves on the rear edge and a cavity in the jaw bone that housed a soft-tissue venom gland — a design found in confirmed venomous critters like Gila lizards. After their "killing claws" use as claws for killing was recently called into question, dromaeosaurids could do with an alternative strategy for taking down prey. However, grooves in one form or another are present on the teeth of many theropod dinosaurs and in a 2010 review, Gianechini suspected that its long "fangs" are merely regular teeth that have popped out of their sockets, and they couldn't locate chambers for venom glands at all.
Etymology
Sinornithosaurus is derived from the Greek "Sinai" (Chinese), "ornis-" (bird) and "sauros" (lizard), named for its bird-like features, including feathers. Incidentally, Sinai is also a biblical peak where Moses, after teasing the Israelites with freedom, stood and commanded them not to lie, steal, kill, commit adultery or work Sundays (amongst other things). What happened to that?
The species epithet, millenii, was named for the impending year 2000 millennium.
Discovery
The first remains of Sinornithosaurus were discovered in the Yixian Formation (Jehol Group) at the Sihetun locality, Liaoning Province, China. The holotype (IVPP V12811) is an almost complete skeleton, preserved on a slab with feather impressions.
A specimen known as "Dave" (NGMC 91) was a particularly handsome chap, but when its encasing slab was split the bones shattered and only a silhouette was left! Initially identified as a juvenile specimen of Sinornithiosaurus millenni, "Dave" was tossed between Cryptovolans and Microraptor but its original classification is generally accepted.
Preparators
S-H Xie
