Ornithodesmus

Ornithodesmus (meaning "bird link") is a genus of small, dromaeosaurid dinosaur from the Isle of Wight in England, dating to about 125 million years ago. The name, along with that of the type and only species, O. cluniculus, was originally assigned to a bird-like sacrum (a series of vertebrae fused to the hip bones), initially believed to come from a bird and subsequently identified as a pterosaur. More complete pterosaur remains were later assigned to Ornithodesmus. More recently, a detailed analysis determined that the original specimen in fact came from a small theropod, specifically a dromaeosaur, making it one of the first dromaeosaurs known to science. All pterosaurian material previously assigned to this genus has been renamed Istiodactylus.

==Discovery and naming== Ornithodesmus cluniculus was first described by Harry Govier Seeley in 1887, based on a set of six fused vertebrae from the hip (sacrum), specimen number BMNH R187. The specimen was found by the Rev.William Fox in Wessex Formation sediments from Brook Bay, on the Isle of Wight. After his death, the so-called "Fox collection" fell into the hands of the British Museum of Natural History, in London (now the Natural History Museum, London). Seeley believed that BMNH R187 belonged to some kind of primitive bird, noting that it "approximates towards Dinosaurs in a way of which no bird had previously given evidence". Accordingly, he gave it the genus name Ornithodesmus, meaning "bird link", from Greek ὄρνις (ornis), "bird", en δεσμός (desmos), "link". The specific name he gave it, cluniculus, means "little buttock" in Latin, a reference to the small thigh muscles indicated by the size and anatomy of the specimen.