Scientists finally discover the origin of ‘bird-hipped’ dinosaurs 

If you are someone who’s fascinated by prehistoric creatures like dinosaurs and are often intrigued to know more about them, this brand-new piece of information will definitely impress you. After years of analysis, scientists have finally found the origin of ‘bird-hipped’ dinosaurs, the group which includes the famous species like the Triceratops. Here’s what all they discovered. 

‘Bird-hipped’ dinosaurs evolved from silesaurs 
Turns out, ‘bird-hipped’ dinosaurs evolved from a group of animals known as silesaurs, the species that were identified nearly two decades (2003) earlier. Wondering who came up with this final hypothesis? Palaeontologists based at the University of Cambridge (in UK) and Universidade Federal de Santa Maria (in Brazil) who were long involved in the process of solving a long-standing mystery in the field: Where did ‘bird-hipped’ dinosaurs come from? And now, finally, they have their suitable findings that they published in the Zoological Journal of the Linnean Society.  

Okay, so if the silesaurs were identified twenty years ago, why did it take so long for the researchers to conclude that the ‘bird-hipped’ dinosaurs (also called ornithischians) were their descendants? Because there is still a gap of almost 25 million years in the fossil record, thus making it harder to locate the exact branch of the dinosaur family tree to which ornithischians belong.  

In case you’re wondering when the silesaurs lived, that would be in the Late Triassic Period, the age preceding the Jurassic Period. And, as many of you would know, ‘bird-hipped’ dinosaurs evolved in the Early Jurassic Period (225 million years ago), proving that silesaurs modified their anatomy and turned into ornithischians, while the ages were in transition. 

‘Bird-hipped’ dinosaurs closely linked to ‘lizard-hipped’ dinosaurs 
Silesaurs, the recently revealed ancestors of ornithischians are known to have had the hip structure of the ‘lizard-hipped’ dinosaurs, also called saurischians. Can you guess what this means? That’s right, the ‘bird-hipped’ dinosaurs were in fact a close relative of the ‘lizard-hipped’ dinosaurs. How cool is that!  

Classification of dinosaurs has always been primarily based upon the shape of their hip bones, meaning they were either lizard-hipped or bird-hipped and at times even both! This classification was first made in 1888 by the then famous palaeontologist Harry Seeley. However, fast forward to 2017, David Norman and his research assistants from Cambridge’s Department of Earth Sciences proposed that these classification needs to be rearranged, redefined and renamed especially when there was more fossil record at hand. They had also stated that both ornithischians and saurischians had a common ancestor that can shed further light into the evolutionary history of dinosaurs.  

Silesaurs at a glance  
Silesaurs, the ancestor of both ‘bird-hipped’ and ‘lizard-hipped’ dinosaurs are known to have had long and slender legs, giving it an upright dinosaur-like posture. Also called the ‘Silesian lizard,’ their hip bones were arranged like -lizard-hipped’ dinosaurs, but it had a toothless, beak-like region in front of its lower jaw like the ‘bird-hipped’ dinosaurs. Moreover, like ‘bird-hipped’ dinosaurs, silesaurs had leaf-shaped teeth in their crown region and could sit on trees. Can you guess what this means? Yes, saurischians and ornithischians are close cousins with a common ancestor silesaurs, with only a few characteristic differences between the two.