A new species of carnivorous bird-like dinosaur being named Hesperornithoides miessleri has been discovered by an international team of paleontologists from the United States and the United Kingdom.
Hesperornithoides miessleri. Image credit: Gabriel Ugueto.
Hesperornithoides miessleri roamed our planet approximately 150 million years ago (Jurassic period).
Nicknamed Lori, the ancient creature was about the size of a chicken and lived in a world populated by giant dinosaurs such as Stegosaurus, Diplodocus, and Allosaurus.
The partial, well-preserved skull and postcranial skeleton of Hesperornithoides miessleri were found in 2001 at the Jimbo Quarry in the Morrison Formation near Douglas, Wyoming.
“I remember the first time I laid my eyes on this little dinosaur. Even back then, I knew it was a significant discovery,” said team member Dean Lomax, a paleontologist and visiting scientist at the University of Manchester.
“But, it wasn’t until 2015 when our dino team formed and we began to study ‘Lori’ in much more detail than ever before.”
The skull and skeleton of Hesperornithoides miessleri. Scale bar – 1 cm. Image credit: Levi Shinkle.
One of the other key findings of the study relates to the origin of bird flight.
Hesperornithoides miessleri is a highly terrestrial proto-bird, suggesting that many features scientists associate with being bird-like evolved in dinosaurs that lived out their lives on the ground.
“We found that Lori is a primitive member of a group of dinosaurs that includes Troodon, but perhaps more importantly we discovered that the smaller details of the family tree of bird-like dinosaurs isn’t quite as resolved as some researchers would claim,” said team leader Scott Hartman, a PhD candidate at the University of Wisconsin-Madison.
“For example, it only takes a few changes in the dataset for Hesperornithoides miessleri to be found as a closer relative of Velociraptor than of Troodon.”
“One robust finding we did come up with is that even as the interrelationships changed, the primitive members of all these groups were non-flying ground dwelling dinosaurs.”
“That means that some small relatives of Velociraptor such as Microraptor that looks like it could have glided evolved this separately from the modern bird family.”
The discovery is detailed in a paper published this month in the journal PeerJ.
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S. Hartman et al. 2019. A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight. PeerJ 7: e7247; doi: 10.7717/peerj.7247
