A dinosaur hobbyist who made his name as a Microsoft multimillionaire has published a scientific paper alleging "serious errors and irregularities" in dinosaur research involving some of the world's top palaeontologists. The research, some of it dating to the 1990s, analysed skeletons of different ages to estimate how quickly dinosaurs grew. For example, a 2001 paper, published in the journal Nature , estimates that the giant dinosaur Apatosaurus had a growth spurt of 5,500kg in a year. The papers, particularly a 2004 paper in Nature on the growth of Tyrannosaurus rex , were influential in offering an explanation for why some dinosaurs were much larger than their relatives and slashed decades off the estimated life span of the creatures. The accuser is Nathan Myhrvold, a former chief technology officer at Microsoft. The lead author of the papers in question is Gregory Erickson, a professor of anatomy and palaeobiology at Florida State University. The problems … appear to be consistent with scientific misconduct NATHAN MYHRVOLD Myhrvold's article, published on Monday by the journal PLOS One , says Erickson's papers contained mistakes, including graphs that did not match the data and curves that did not match the reported equations. And Myhrvold's revised estimates put the maximum growth rate of Apatosaurus at about a tenth of what Erickson and his colleagues had reported. Erickson declined to be interviewed, but issued an e-mail statement noting that the papers were the work of teams of scientists and were peer-reviewed. Myhrvold's "reinterpretation of our data, although reaching moderately different conclusions on a species-by-species basis, strongly supports the cardinal conclusions that we reached regarding how dinosaurs grew", the statement said. "The bottom line is that the empirical findings of our research group stand, and we stand behind them." Myhrvold, a physicist, said he was not accusing Erickson or his collaborators of deliberately falsifying or manipulating data, because he could not know how the errors occurred. But in a letter to Nature , Science , PLOS One and other journals that published Erickson's work, he raised the possibility. "At the very least these problems are serious errors that merit correction in the literature," he wrote. "The problems also appear to be consistent with scientific misconduct, which may factor into any resulting investigation." Some of Erickson's co-authors agree that the papers have errors that should be corrected. "I'll be interested to see how Greg responds scientifically to Nathan's claims," said Kristina Curry Rogers, a professor of geology at Macalester College in St. Paul, Minnesota, who was a co-author of the 2001 paper in Nature . "If he has data to the contrary, then he can present that. If he does not, then he can explain that."