DOI: 10.5061/dryad.v15dv4208
title: 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

description: 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 not known in any previously described anseriform fossils other
 than portions of the pseudotoothed Pelagornithidae. The matrix created to
 assess the placement of this taxon comprises 41 taxa and 719 discrete
 morphological characters describing skeletal morphology, musculature,
 syringeal morphology, ecology, and behavior. We additionally combine the
 morphological dataset with published sequences using Bayesian methods and
 perform ancestral state reconstruction for ecological and behavioral
 characters. We recover the new Eocene taxon as a stem anseranatid across
 all analyses, and find that the new taxon represents a novel ecology
 within known Anseriformes and the Green River taxa. Results indicate that
 Anseriformes were likely ancestrally aquatic herbivores with rhamphothecal
 lamellae and provide insight into avian evolution during and following the
 K-Pg mass extinction.
description: 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.
description: No programs are required, although we suggest imageJ to view
 slices easily.
description: # 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 University of Texas at Austin using Aviso. All segmentation files are available on Morphobank. ## Code/Software We recommend use of imageJ for visualizing slices and Aviso for segmentation.