Dinosaurs had flight-ready brains, according to articles in ScienceDaily 31 July 2013, and ABC News in Science and BBC News 1 August 2013. Birds have relatively large brains in relation to their overall body size compared with reptiles. This phenomenon is called “hyperinflation” and is considered necessary for birds to have sufficient brain power for flight. Amy Balanoff, a research associate at the American Museum of Natural History, and colleagues have carried out CT scans of the skulls of Archaeopteryxand a number of dinosaurs in order to assess their brain size compared with their overall body size. Using the scan results, they produced digital reconstructions of their brains and assessed the overall size of major sections of the brain such as olfactory bulbs, cerebrum, optic lobes, cerebellum, and brain stem. A relatively large cerebrum, optic lobes and cerebellum are necessary for the brain to have sufficient circuitry for the vision and muscle coordination involved in flight.

The researchers then compared the results with living birds. They found some dinosaurs had brains at least as large as Archaeopteryx. Living birds also have a structure named the wulst, which is used in information processing and motor control. Researchers found evidence of this structure in Archaeopteryx, but not in dinosaurs. In spite of this, Amy Balanoff concluded: “If Archaeopteryx had a flight-ready brain, which is almost certainly the case given its morphology, then so did at least some other non-avian dinosaurs”.

ABC, BBC, ScienceDaily

Editorial Comment: How could you know if a brain was “flight-ready”? The only way is to study brain cell circuits in flying creatures today. Size alone will not tell you this. It is reasonable to presume that those dinosaurs with big brains, had enough brains to know they should not try jumping off some high point to see if they could stay airborne, which means they knew they had no feathers, no matter how National Geographic illustrates them. Archaeopteryx presumably not only had sufficient brain, its fossil bones and feathers show it was flight ready also. Balanoff’s comment about body structures, reminds us that our brains should also be big enough to conclude that it is impossible to know what was going on in the brains of any creatures we only know as fossil bones. Maybe these scientists have accidently stumbled across another theory as to why dinosaurs are extinct – they evolved flight-ready brains before flight-ready bodies, and then fell out of trees trying to fly. (Ref. neurology, neuroanatomy, reptiles, birds)

Evidence News 7 August 2013