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Dinosaur growth rates revisited



From: Ben Creisler
bcreisler@gmail.com

New in PLoS ONE:

Nathan P. Myhrvold (2013)
Revisiting the Estimation of Dinosaur Growth Rates.
PLoS ONE 8(12): e81917.
doi:10.1371/journal.pone.0081917
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0081917


Previous growth-rate studies covering 14 dinosaur taxa, as represented
by 31 data sets, are critically examined and reanalyzed by using
improved statistical techniques. The examination reveals that some
previously reported results cannot be replicated by using the methods
originally reported; results from new methods are in many cases
different, in both the quantitative rates and the qualitative nature
of the growth, from results in the prior literature. Asymptotic growth
curves, which have been hypothesized to be ubiquitous, are shown to
provide best fits for only four of the 14 taxa. Possible reasons for
non-asymptotic growth patterns are discussed; they include systematic
errors in the age-estimation process and, more likely, a bias toward
younger ages among the specimens analyzed. Analysis of the data sets
finds that only three taxa include specimens that could be considered
skeletally mature (i.e., having attained 90% of maximum body size
predicted by asymptotic curve fits), and eleven taxa are quite
immature, with the largest specimen having attained less than 62% of
predicted asymptotic size. The three taxa that include skeletally
mature specimens are included in the four taxa that are best fit by
asymptotic curves. The totality of results presented here suggests
that previous estimates of both maximum dinosaur growth rates and
maximum dinosaur sizes have little statistical support. Suggestions
for future research are presented.