UAlbany researcher floats new dinosaur extinction theory

PHOTOGRAPHER: Zachary Matson

Gordon Gallup

A University at Albany evolutionary psychologist thinks the demise of dinosaurs might have been hastened by something a bit tamer than a massive asteroid: toxic plants.

Gordon Gallup, of Berne, who has worked at the university for more than 40 years, argues in a paper recently published in the journal “Ideas in Ecology and Evolution” that dinosaurs may have been doomed by an inability to develop taste aversions to toxic plants, which started to proliferate around the time dinosaurs started their gradual slide toward extinction.

As an evolutionary psychologist, Gallup began studying taste aversion – the response humans and animals quickly form in response to consuming something that later causes sickness – earlier in his career. Through research in that field, he came to believe the formation of taste aversions coincided with the development of the first toxic plants, angiosperms, during epochs dominated by dinosaurs.

If dinosaurs were incapable of forming taste aversions, Gallup theorizes, they slowly “ate themselves into oblivion,” as they continued to gorge on toxic plants for millions of years before and after the asteroid strike that has long been considered the major cause of dinosaur extinction.

Gallup called the scenario a “biotic revenge,” since the largest plant-eating dinosaurs may have been “among the prime movers for the emergence of plant toxicity in the first place,” he said.

So, the plants became toxic in response to the insatiable appetites of massive dinosaurs, which were, in turn, incapable of developing their own response mechanism to the newly-toxic plants, Gallup’s theory goes.

“The reason they went extinct is because of a psychological deficit,” Gallup said of the dinosaurs. “An inability to form a classically-conditioned association between the taste of novel food and getting sick later on.”

In the 1980s, intrigued by the idea that there may be a connection between taste aversions and the demise of the dinosaurs, Gallup conduct research on caimans – a form of crocodile. Bringing 10 caimans to the UAlbany campus, he fed them beef and chicken and forced illness after the feedings. Rather than associating the illness with the foods, the caimans kept snacking on the meat, suggesting they were unable to form a taste aversion and, in his mind, bolstering the idea that dinosaurs were doomed by a lack of taste aversion.

But after setting aside the dinosaur theory for decades, Gallup and a former student, Michael Frederick, decided to dive back into recent literature around dinosaur extinction. While the prevailing theory — that the dinosaurs were driven to extinction by the asteroid — remained strong, more recent research suggested dinosaurs were already trending toward oblivion before the asteroid impact and continued to do so for millions of years afterward, he said.

Gallup, who specializes in the evolution of intelligence and human reproductive competition, said he suspected paleontologists would be skeptical of a theory proffered by a pair of psychologists. But he also said his outsider status in the world of dinosaur academia may give him a useful perspective.

“The other advantage, I think, to being outside of paleontology is that you can think outside the box,” he said. “You don’t have these blinders on as a result of having been trained in paleontology, and you can consider things paleontologists might never have considered.”

Gallup suggested two areas of future research for refining, strengthening or invalidating his theory: Analyze the remains of amber-encased insects from the time dinosaurs were going extinct, along with the bones of dinosaurs themselves. Also, he said, take a look at the fecal fossils of dinosaur droppings.

“If you could extract those insects and test for plant toxins, I would predict that they would be high by virtue of feeding on dinosaurs that were eating toxic plants,” he said.