Science: Cretaceous Fairy Tales

(2 of 2)

If the size of some dinosaurs did not do the trick, maybe their culinary habits did. They could have been fussy eaters, for example. "If they ate mainly one plant, just as the koala bear lives on eucalyptus," says James Hopson, a dinosaur expert at the University of Chicago, "they would be in trouble if that plant were no longer available." Or maybe dinosaurs were not picky enough. Perhaps they died from indiscriminately eating poisonous plants. Ronald K. Siegel, a psychopharmacologist at the UCLA school of medicine, points out that alkaloidproducing angiosperms began evolving toward the end of the dinosaur era. These plants produce toxic chemicals, but they also taste so bitter that most modern creatures know to eschew rather than chew them. If the dinosaurs lacked a palate, however, some of them may have died on an overdose of the poisons. Others have suggested that because the angiosperms replaced ferns, a possible dinosaur dietary staple containing laxative oils, the reptiles may have been the first creatures to succumb to constipation.

Unlike theories about catastrophic impacts, or changing climates and sea levels, these fanciful concepts all fail to account for the hundreds of other species that perished at the end of the Cretaceous. Says Physicist Luis Alvarez of the University of California, Berkeley: "The problem is not what killed the dinosaurs but what killed almost all the life at the time." Muller believes that comets are a far more plausible explanation for the death of the dinosaurs, but he wryly allows one other possibility. Says he: "Maybe there just wasn't enough room for them on the ark."