Untangling the dinosaur family tree

LANGER, MAX C.; EZCURRA, MARTÍN D.; RAUHUT, OLIVER W. M.; BENTON, MICHAEL J.; KNOLL, FABIEN; MCPHEE, BLAIR W.; NOVAS, FERNANDO E.; POL, DIEGO; BRUSATTE, STEPHEN L.

NATURE

NATURE PUBLISHING GROUP

Lugar: Londres; Año: 2017 vol. 551

0028-0836

The size and scope of the Baron et al. dataset (457 anatomical features scored for 74 early dinosaurs and close relatives) are important advances on previous studies of early dinosaur phylogeny. It combines previously published and new morphological characters, setting a standard for the field, which we applaud. With that said, however, the results of the new study differ so radically from all previous cladistic analyses, and decades of pre-cladistic research, that they deserve close scrutiny. Our main concern is that the authors were able to personally study fewer than half of the taxa in their analysis; the others were scored mostly based on published literature, which is problematic, because many characters relate to fine anatomical details, requiring first-hand study to be reliably documented. The taxon sample of Baron et al. is larger than any previous analysis and this represents one of the strongest aspects of the study. However, the lack of some important taxa (for example, the early thyreophoran Scutellosaurus, the possible theropod Daemonosaurus, the newly described Ixalerpeton and Buriolestes, and a broader sample of averostran theropods) may have a substantial effect on character optimizations near the base of the dinosaur tree, and thus on the interrelationships of early dinosaurs.