Research reveals new information on the evolution of dinosaur senses

Dec 19, 2012

An international team of scientists, including PhD student Stephan Lautenschlager and Dr Emily Rayfield of the University of Bristol, found that the senses of smell, hearing and balance were well developed in therizinosaurs and might have affected or benefited from an enlarged forebrain. These findings came as a surprise to the researchers as exceptional sensory abilities would be expected from predatory and not necessarily from plant-eating animals.

Therizinosaurs are an unusual group of which lived between 145 and 66 million years ago. Members of this group had evolved into up to 7m (23ft) large animals, with more than 50cm (20in) long, razor-sharp claws on their forelimbs, elongated necks and a coat of primitive, down-like feathers along their bodies. Although closely related to carnivorous dinosaurs such as and , and in spite of their bizarre appearance, therizinosaurs were probably peaceful .

Inspired by this paradox, the international team of palaeontologists decided to take the first close look inside the heads of these enigmatic dinosaurs.

They studied the brain and inner ear anatomy of therizinosaurs using high-resolution CT scanning and 3D computer visualisation to find out more about their sensory and and how these had evolved with the transition from meat- to plant-eating.

The focus of the study was the skull of Erlikosaurus andrewsi – a 3-4m (10-13ft) therizinosaur, which lived more than 90 million years ago in what is now Mongolia.

Lead author, Stephan Lautenschlager of Bristol's School of Earth Sciences said: "Our results suggest that therizinosaurs would have used their well-developed sensory repertoire to their advantage which, for herbivorous animals, must have played an important role in foraging, in the evasion of predators or in .

"This study sheds a new light on the evolution of dinosaur senses and shows it is more complex than we thought."

Co-author, Professor Lindsay Zanno of the North Carolina Museum of Natural History and the North Carolina State University agrees: "Once you've evolved a good sensory toolkit, it's probably worth hanging on to, whether you're hunting or being hunted."

Fellow author Lawrence Witmer, Chang Professor of Paleontology at the Ohio University Heritage College of Osteopathic Medicine said: "Of course the actual brain tissue is long gone from the fossil skulls but we can use to visualize the cavity that the brain once occupied and then generate 3D computer renderings of the olfactory bulbs and other brain parts."

This study has important ramifications for our understanding of how sensory function evolved in different dinosaur groups and whether it was developed as a response to their environment or simply inherited by their ancestors. In particular, in the light of the transition from dinosaurs to birds, these results should prove to be very interesting.

The study by Stephan Lautenschlager and Emily Rayfield (Bristol), Perle Altangerel (National University of Ulaanbaatar), Lindsay Zanno (North Carolina) and Lawrence Witmer (Ohio) is published today in PLoS One.

Explore further: New hadrosaur noses into spotlight

add to favorites email to friend print save as pdf

Related Stories

Meat-eating dinosaurs not so carnivorous after all

Dec 20, 2010

Field Museum scientists used statistical analyses to determine the diet of 90 species of theropod dinosaurs. Their results challenge the conventional view that nearly all theropods hunted prey, especially ...

Study discovers eating habits of Diplodocus

Jul 30, 2012

A team of researchers from the University of Bristol, Natural History Museum of London, the University of Missouri and Ohio University has discovered the eating habits of Diplodocus using a three-dimensional ...

Recommended for you

New hadrosaur noses into spotlight

Sep 19, 2014

Call it the Jimmy Durante of dinosaurs – a newly discovered hadrosaur with a truly distinctive nasal profile. The new dinosaur, named Rhinorex condrupus by paleontologists from North Carolina State Univer ...

Militants threaten ancient sites in Iraq, Syria

Sep 19, 2014

For more than 5,000 years, numerous civilizations have left their mark on upper Mesopotamia—from Assyrians and Akkadians to Babylonians and Romans. Their ancient, buried cities, palaces and temples packed ...

New branch added to European family tree

Sep 17, 2014

The setting: Europe, about 7,500 years ago. Agriculture was sweeping in from the Near East, bringing early farmers into contact with hunter-gatherers who had already been living in Europe for tens of thousands ...

User comments : 0