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[dinosaur] Tip-dating suggests Cretaceous origin of Telluraves



A new paper not yet mentioned.

N.M.A. Crouch, K. Ramanauskas, and B. IgiÄ (2018)
Tip-dating and the origin of Telluraves
Molecular Phylogenetics and Evolution (advance online publication)
DOI: 10.1016/j.ympev.2018.10.006

Despite a relatively vast accumulation of molecular data, the timing of diversification of modern bird lineages remains elusive. Accurate dating of the origination of Telluravesâa clade of birds defined by their arborealityâis of particular interest, as it contains the most species-rich avian group, the passerines. Historically, neontological studies have estimated a Cretaceous origin for the group, but more recent studies have recovered Cenozoic dates, closer to the oldest known fossils for the group. We employ total-evidence dating to estimate divergence times that are expected to be both less sensitive to prior assumptions and more accurate. Specifically, we use a large collection of morphological character data from arboreal bird fossils, along with combined molecular sequence and morphological character data from extant taxa. Our analyses recover a Late Cretaceous origin for crown Telluraves, with a few lineages crossing the K-Pg boundary. Following the K-Pg boundary, our results show the group underwent rapid diversification, likely benefiting from increased ecological opportunities in the aftermath of the extinction event. We find very little confidence for the precise topological placement of many extinct taxa, possibly due to rapid diversification, paucity of character data, and rapid morphological differentiation during the early history of the group.
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Of note is that this study includes the assembly of one of the largest morphological phylogenetic datasets for crown-group birds to date (782 characters). Unfortunately, the supplementary material doesn't appear to be available yet. Strangely, none of the raptorial telluravian clades (Accipitriformes/morphae, Strigiformes, and Falconiformes) were sampled, nor was Cariamiformes. Given that these groups are among the earliest-diverging lineages of Telluraves and have been suggested to represent the ancestral ecology of the group, one wonders how they might influence the analysis.