New York: Modern penguins' brains look different than their ancestors' brains, but the changes were not caused by their loss of flight, says a new study.
Leaving the sky for the ground gave ancient penguins their unique locomotion style, but losing the ability to fly did not cause major changes in their brain structure, the findings showed.
"What this seems to indicate is that becoming larger, losing flight and becoming a wing-propelled diver does not necessarily change the (brain) anatomy quickly," said lead researcher James Proffitt from The University of Texas at Austin, US.
The findings were published in the Journal of Anatomy.
The researchers conducted the study in a penguin skull kept at the Canterbury Museum in Christchurch, New Zealand.
The skull is from a penguin that lived in New Zealand over 60 million years ago during the Paleocene epoch.
According to Proffitt, it likely lived much like penguins today. But while today's penguins have been diving instead of flying for tens of millions of years, the change was relatively new for the ancient penguin.
"It is the oldest (penguin) following pretty closely after the loss of flight and the evolution of flightless wing-propelled diving that we know of," Proffitt said.
The shape of bird skulls is influenced by the structure of the brain. To learn about early penguin brain anatomy, Proffitt used X-ray CT-scanning to digitally capture fine features of the skull's anatomy, and then used computer modeling software to create a digital mold of the brain, called an endocast.
The researchers thought that loss of flight would impact brain structure -- making the brains of ancient penguins and modern penguins similar in certain regions.
However, after analysing the endocast and comparing it to modern penguin brain anatomy, no such similarity was found, Proffitt said.