Figure 1.

Comparison of probabilistic APT dates (red bars, cal3; blue bars, Hedman; see the text) for key nodes in dinosaur phylogeny: Dinosauria I (Nyasasaurus as sister to Dinosauria), Dinosauria II (Nyasasaurus nested within Dinosauria), Avialae I (Archaeopteryx as first bird), Avialae II (Aurornis as first bird) and Neornithes (crown birds). Asterisks mark minimum bound or ‘traditional’ palaeontological estimate. Molecular and morphological clock dates for Neornithes are shown in the lower right corner (A–J; electronic supplementary material, table S3): circles indicate mean and horizontal bars the 95% HPD. Silhouettes were taken from public domain images on phylopic.org (Aurornis, Gareth Monger; Eoraptor, Scott Hartman; Vegavis, Matt Martyniuk), or modified with kind permission from works by Sergio Pérez (Archaeopteryx) and Nobu Tamura (Nyasasaurus).