A new Paleogene fossil and a new dataset for waterfowl (Aves: Anseriformes) clarify phylogeny, ecological evolution, and avian evolution at the K-Pg boundary

Despite making up one of the most ecologically diverse groups of living birds, comprising soaring, diving and giant flightless taxa, the evolutionary relationships and ecological evolution of Anseriformes (waterfowl) remain unresolved. Although Anseriformes have a comparatively rich, global Cretaceous and Paleogene fossil record, morphological datasets for this group that include extinct taxa report conflicting relationships for all known extinct taxa. Correct placement of extinct taxa is necessary to understand whether ancestral anseriform feeding ecology was more terrestrial or one of a set of diverse aquatic ecologies and to better understand avian evolution around the K-T boundary. Here, we present a new morphological dataset for Anseriformes that includes more extant and extinct taxa than any previous anseriform-focused dataset and describe a new anseriform species from the early Eocene Green River Formation of North America. The new taxon has a mediolaterally narrow bill which is ..., PA 725 was CT scanned at the University of Chicago by April Neander, using the facilities of the Department of Organismal Biology and Anatomy. A two-part multiscan was conducted in order to achieve the highest resolution possible. The scan sheet is available on Morphobank (O’Leary and Kaufman 2012) under Project 4001 (http://morphobank.org/permalink/?P4001) and all the CT tiffs are available on DRYAD. Originally 2000 projections were created for the scan, but due this fossil requiring a two-part multiscan because of its size, over half of the projections contained nothing but air. We trimmed the number of projections to the number that contains the fossil, which is 511, and resliced the scan in imageJ so that the fossil is visible in lateral view. CT scans were segmented by the authors at the University of Texas at Austin using Aviso. All segmentation files are available on Morphobank., No programs are required, although we suggest imageJ to view slices easily., # Data from: A new Paleogene fossil and a new dataset for waterfowl (Aves: Anseriformes) clarify phylogeny, ecological evolution, and avian evolution at the K-Pg boundary

CT Tiffs of 2 part multiscan of PA 725 (Holotype specimen of Paakniwatavis grandei).

## Description of the data and file structure

This data comprises a tiff stack of the 2 part multiscan of PA 725. To quickly view and scroll through the tiffs, we recommend using ImageJ to open the tiff stack.

## Sharing/Access information

PA 725 was CT scanned at the University of Chicago by April Neander, using the facilities of the Department of Organismal Biology and Anatomy. A two-part multiscan was conducted in order to achieve the highest resolution possible. The scan sheet is available on Morphobank (OLeary and Kaufman 2012) under Project 4001 ([http://morphobank.org/permalink/?P4001](http://morphobank.org/permalink/?P4001) and all the CT tiffs are available on DRYAD. CT scans were segmented by the authors at the Universit...