Were Dinosaurs Endangered Before K-T Disaster?

“The extinction of . . . dinosaurs . . . is a perpetual topic of fascination, and lasting debate has focused on whether dinosaur biodiversity was in decline before end-Cretaceous volcanism and bolide [large exploding meteor] impact,” write the authors of a statistical survey of dinosaur diversity published in Nature Communications.1 Evolutionists debate the significance of the study.

Although the authors do not deny the popular evolutionary belief that a meteor caused dinosaur extinction, they suggest that certain types of large plant-eating dinosaurs in North America may have already been on their way out.

”Did sudden volcanic eruptions or an asteroid impact strike down dinosaurs during their prime?” lead author Stephen Brusatte asks. “We found that it was probably much more complex than that, and maybe not the sudden catastrophe that is often portrayed.” He explains, “We know a large asteroid or comet hit the planet about 65.5 million years ago, right when the dinosaurs completely disappeared from the fossil record. . . . We now also know that at least some groups of dinosaurs were undergoing long-term declines in biodiversity during the final 12 million years of the Cretaceous, at least in North America.”

The authors explain that a creature’s biodiversity indicates its evolutionary well-being.

The authors explain that a creature’s biodiversity indicates its evolutionary well-being. In other words, a highly diverse kind of creature is conducting successful evolutionary experiments, filling many ecological niches, and preparing to evolve into other kinds of creatures. Less diverse kinds, on the other hand, were losing their grip on the tree of life, soon to fade from significance on the evolutionary scene.

But how is diversity measured? Usually dinosaur diversity is assessed by counting the number of species, but “results can be biased by uneven sampling of the fossil record,” Brusatte says. “We wanted to go beyond a simple species count.” Therefore, this statistical analysis evaluated diversity not by counting the number of species but by quantifying anatomical variations within each.

They found triceratops and duck-billed2 dinosaur fossils from North America’s upper Cretaceous rocks were more anatomically uniform than similar dinosaurs in Asia. “Something was going on with large herbivores in the late Cretaceous, at least in North America. Maybe it was the fact that the local environments were in flux,” Brusatte says. The rest of the world’s dinosaurs displayed plenty of anatomic diversity, so Brusatte suggests these big North American herbivores were the first victims of a more general decline. He says, “Maybe, given a few more million years we would have seen declines in other dinosaur groups higher up in the food chain.”

”Dinosaurs were hugely diverse,” co-author Richard Butler adds. “Different groups were probably evolving in different ways and the results of our study show that very clearly.”

Other evolutionists question both the significance and interpretation of this analysis. Paleobiologist Paul Upchurch of University College London points out a more extensive survey may demonstrate many similar declines during dinosaur history. He says, “The decline in disparity during the final 12 million years might merely be ‘evolutionary business as usual’ and have little to do with the true final extinction.” Furthermore, “Only some dinosaur groups show reduced disparity . . . while other groups continue to do well. So this study could actually be taken as evidence in favor of a sudden extinction.”

Diminished diversity “does not automatically mean that dinosaurs were doomed to extinction,” co-author Mark Norell admits. "Dinosaur diversity fluctuated throughout the Mesozoic, and small increases or decreases between two or three time intervals may not be noteworthy within the context of the entire 150-million-year history of the group.”

For those who interpret the fossil record in the context of biblical history, unverifiable evolutionary assumptions should be apparent on both sides of this argument. Biodiversity within a species (which is observed) does not show new kinds of animals can evolve from other kinds (an unobserved phenomenon). Furthermore, while variations within created kinds occur and may relate to the adaptive ability to fill various ecological niches, less biodiversity does not necessarily mean a pre-Flood group of creatures was an endangered species. Perhaps they just lived in a habitat that did not demand a lot of adaptation. Nothing in this study demonstrates anything in support of the unbiblical notion of the evolutionary rise of new kinds of animals.

Finally, while dinosaurs are now apparently extinct,3 their extinction is not recorded in the fossil record; what is recorded are the deaths of many dinosaurs. The global Flood caused massive death among all kinds of creatures, and many were buried and preserved in the fossil record. But representative dinosaurs, like all kinds of land animals and birds (Genesis 6:19–20 ), were present aboard the massiveNoah’s Ark. They, like many other animals, later became extinct, often because of harmful human activity.