By Darren Naish at Scientific American

A novel phylogenetic hypothesis for Dinosauria!? Shock! Horror!—Say it isn’t so!!!

Today sees the publication of a significant new technical paper on dinosaur phylogeny. And it’s a game-changer or watershed study, one of those that will get cited a phenomenal amount and result in a distinct pre- and post-2017 marker in the literature. The paper concerned – published in Nature and authored by Matthew Baron, David Norman and Paul Barrett – argues that the consensus view of dinosaur phylogeny is inaccurate, that Saurischia of convention (the sauropodomorph + theropod clade) is not monophyletic, and that theropods are closer to ornithischians than they are to sauropodomorphs (Baron et al. 2017). This is surprising stuff in view of the apparently robust, conventional and well-supported view that Saurischia of traditional is natural, a hypothesis that has been well bolstered by substantial study and the gradual accruing of data.

First things first: science is about scepticism, and no hypothesis is ever a definitive ‘last word’ on a subject. While the data here looks good – good enough that it appears to represent reality – it’s only as good as the data available right now, and at this early stage it’s impossible to predict whether this novel model will survive to eternity. I don’t say that to put a downer on the study but to remind people not to complain too much when cherished hypotheses are overturned or found wanting.

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