Chinese Dinosaur Discovery with Two Types of Fossilised Feathers
Scientists have debated the origins of birds for many years and the most widely accepted theory is that they evolved from meat-eating dinosaurs. The debate over the relationship between Aves (birds) and Theropod dinosaurs (meat-eaters) is actually quite old, the first discussion papers on this subject were published in Victorian times. John Ostrom, the distinguished professor of vertebrate palaeontology at Yale University’s Peabody Museum of Natural History, published a number of papers analysing the evolution of flight. For John Ostrom, the commonly held believe at the time, of a sluggish, overgrown reptile being the typical view of a dinosaur, simply did not reflect the evidence in the fossil record. He was a driving force in the “Dinosaur Renaissance” of the early 1970s, depicting dinosaurs as perfectly adapted animals, active, agile and energetic.
Landmark Moment in Modern Palaeontology
His description of the Dromaeosaur Deinonychus (Deinonychus antirrhopus) is regarded as one of the landmark moments in the history of modern palaeontology. Now thanks to the amazing fossil discoveries of Liaoning in China, palaeontologists have a number of fossil specimens of different feathered dinosaurs that imply an evolutionary link between small Theropods and birds.
Feathered Dinosaur Fossil From China
However, a new report on a particular feathered dinosaur from China, about the same size as Deinonychus, suggests that some dinosaurs may have had a number of different feather types adorning their bodies. Some feathers may have been to help insulate them and keep them warm (indicating active warm-blooded animals), whilst other feathers may have served as ornamentation to help them attract a mate and signal to others within their herd (or should that be flock)?
In a paper published on the primitive Therizinosaurid (sometimes known as a Segnosaur), Beipiaosaurus, it is stated that two distinct types of feather have been found on the animal’s remains one for insulation, the other type perhaps used to signal for a mate, some of the earliest evidence of this type of feather found in the dinosaur fossil record.
Beipiaosaurus – Bizarre Member of the Dinosauria
Beipiaosaurus was named after the city of Beipiao, a city in Liaoning province in northern China. The first fossils of this dinosaur were discovered in this area in 1996. It was a very unusual looking dinosaur (we often think Therizinosaurs seem to be made up of a mixture of different animal parts):
Beipiaosaurus was approximately 2-3 metres tall, heavily built and a plant-eater. The fossils date from the mid Cretaceous (Aptian faunal stage), approximately 120 million years ago. Beipiaosaurus had a relatively large head for a Therizinosaur (later animals such as Nothronychus had proportionately smaller heads), a long neck and a broad body. The shin bones are longer than the thigh bones and this dinosaur had three-toed feet. Scientists have identified fine, proto-feathers associated with fossils of this dinosaur, but the discovery of the elongated, broad, filamentous feathers has excited palaeontologists, who believed that such coverings existed but had rarely found traces of them.
It is believed that dinosaurs had these broad, showy feathers at some point in the past because more advanced forms have already been discovered on dinosaur remains.
The primitive feathers on Beipiaosaurus are similar to the earliest forms seen on ancient birds. The fossil remains of Beipiaosaurus are approximately 25 million years younger than the fossils of Archaeopteryx, the earliest bird yet discovered. There are similarities between the wider, filamentous feathers on Beipiaosaurus and those of Archaeopteryx. If scientists are correct in assuming that birds evolved from Theropods then the discovery of similar feathers on Beipiaosaurus proves that dinosaurs did have feathers of this type and indeed there may be other fossils of dinosaurs dating from before Archaeopteryx which would also show this feather type. They are waiting to be discovered.
Interestingly, in the report published in the scientific journal “The Proceedings of the National Academy of Sciences” by the Chinese research team, their study of the Beipiaosaurus specimen reveals information on where on the animal the various feather types grew. Feathers from the animal have been identified on the fossilised remains of half a skeleton, including the head, neck and part of the tail. Those that were used for communication (the wide, filamentous feathers) grew most densely on the back of the neck and at the end of the creature’s tail. Ideal locations for a signalling device. We can imagine a flock of Therizinosaurs bobbing their heads at each other just as flamingos do. Or perhaps they waived their tails to communicate or combined both head and tail movements in a sort of dinosaur semaphore. The presence of such feathers will enable scientists to speculate on elements such as animal social interaction, hierarchy and herd behaviour, unfortunately, the hard evidence for this is rarely preserved in the fossil record.