In the foreground, the carnivorous lizard Palaeosaniwa pursues a pair of hatchling Edmontosaurus, as the snake Cerberophis and the lizard Obamadon look on. In the background, T. rex faces off against Triceratops.
Artwork by Carl Buell
The small, insect-eating lizard was discovered in the badlands of northeastern Montana—its fossil preserved in an area called the Hell Creek formation. Less than a foot long, it had elaborate teeth with three cusps on each tooth and a slender jaw. Some 65 million years ago, it went extinct. And now, it is named for the 44th president of the United States: Obamadon gracilis.
The ancient lizard species bearing President Obama’s name was discovered when researchers from Yale and Harvard universities re-examined fossil collections all across the country, as part of an effort to understand what happened to lizards and snakes during the mass extinction that killed off the dinosaurs.
In the process, Yale paleontologist Nicholas Longrich said the team encountered several new species that were previously unknown or misclassified lurking in museum collections. There was one ferocious carnivorous lizard in need of a name, but that one didn’t turn out to be presidential. The small one with the slender jaw seemed just right. There was one problem. This was before November.
“I was seriously thinking, if the election had gone the other way, I would have yanked it,” Longrich said. “It might have seemed like we were mocking it, naming a lizard that goes extinct after that, seemed kind of cruel.”
Longrich and colleagues described the Obamadon in a paper published Monday in the Proceedings of the National Academy of Sciences. But far from a debutante party for a presidential lizard, the name is an aside in a paper that provides new evidence that the mass extinction 65.5 million years ago, thought to have been triggered by the crash-landing of the massive Chicxulub asteroid, may not have spared lizards and snakes nearly as much as scientists previously believed.
“This is a bit speculative, but the ecosystem basically collapses when there’s not enough sunlight to make new leaves. No new plants growing, everything kind of starves, and in that situation I would imagine, maybe what you’ve got going on is dead, rotting plant material, dying, rotting dinosaurs, and probably a lot of maggots and beetles and grubs that are eating all that dead material,” Longrich said. “Animals that can eat the insects are maybe what’s surviving, so insectivores which tend to be smaller” can survive.
Those small lizards and snakes would have fared better, but overall the reptiles would have been hard hit. The researchers estimate that the extinction was dramatic: 83 percent of the species of snakes and lizards would have been lost. But in some ways, they also see what is often seen as a dramatic ending—the mass extinction—as “a form of creative destruction,” as they write in the paper. Lizards and snakes retained just enough diversity that they could get back on their feet.
“The lizards that dominate today get their start after the extinction—they radiate in the aftermath,” Longrich said. “But that said, the radiation takes a long time. Mammals bounce back really fast and gain ground,” and reptiles never regain their niche.