There are more species of beetle than of any other type of animal—so many, in fact, that one evolutionary biologist famously claimed that God has an inordinate fondness for them. Scientists have named more than 380,000 different species so far. Yet a new study of the fossil record may have researchers wondering not why beetles are so diverse today, but how they’ve been so doggedly persistent through time. The team considered more than 5500 fossils of beetles collected at more than 200 sites worldwide (including the 45-million-year-old fossil of a weevil unearthed in Colorado, shown). It grouped those beetles into families (the biological classification just above genera, which are groups of species) and then sorted them into bins of time that each lasted 25 million years. During the past 300 million years, there have been 214 families of beetles, but only 35 of those have completely died out, the researchers report online today in the Proceedings of the Royal Society B. Of the 179 families that remain, about 69% have at least one representative in the fossil record. The biggest surprise, the researchers note, is that some families of beetles, once they appeared, have never gone away—even surviving mass extinctions such as those that claimed the dinosaurs and many other species 66 million years ago. At first glance, the researchers say, the persistence of beetles can likely be ascribed to their wide range of dietary habits, their ability to move to find ecologically suitable habitat when necessary, and their adaptability in case environmental conditions have dramatically changed.
*Correction, 18 March, 10:27 a.m.: The image that originally accompanied this article (a mislabeled stock photo of a bug, not a beetle) has been replaced.