Cretaceous Antarctic bird skull elucidates early avian ecological diversity
Data files
Aug 13, 2025 version files 4.55 GB
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README.md
11.01 KB
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SD01_Avialae_matrix.nex
19.40 KB
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SD02_phylogenetic_analyses_outputs.zip
2.65 GB
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SD03_Galloanserae_matrix.nex
42.75 KB
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SD04_scan_data_volume_details.csv
1.01 KB
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SD05_polygon_details.csv
8.17 KB
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SD06_taphonomic_data_reconstruction.mp4
101.03 MB
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SD07_taphonomic_reconstruction.pdf
133.75 MB
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SD08_surface_files_original_material_only.zip
145.37 MB
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SD09_surface_files_full_reconstruction.zip
127.25 MB
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SD10_original_material.blend
602.86 MB
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SD11_retro_deformation.blend
788.33 MB
Abstract
Fossils representing Cretaceous lineages of crown clade birds (Aves) are exceptionally rare but are crucial to elucidating changes in key anatomical systems across early avian divergences. Among the earliest known putative crown birds is Vegavis iaai, a foot-propelled diver from the latest Cretaceous (69.2–68.4 Ma) of Antarctica with controversial phylogenetic affinities. Initially reported as a stem anatid (ducks and closely related species), Vegavis has since been recovered as a stem member of Anseriformes (waterfowl) or outside Aves altogether. Here we report a new, nearly complete skull of Vegavis that preserves novel information on its feeding ecology and phylogenetic affinities. Vegavis exhibits a definitively avian beak (absence of teeth, reduced maxilla) and brain shape (hyperinflated cerebrum, ventrally shifted optic lobes). The temporal fossa is well excavated and expansive, indicating that this bird had hypertrophied jaw musculature. The beak was narrow and pointed, and the mandible lacked retroarticular processes. Together, these features comprise a feeding apparatus unlike any other known anseriform but like extant birds that capture prey underwater (e.g., grebes, loons). The Cretaceous occurrence of Vegavis, with a feeding ecology unique among known extant Galloanserae (water- and landfowl), is further indication that the earliest anseriform divergences were marked by evolutionary experiments unrepresented in the extant diversity.
Christopher R. Torres, Julia A. Clarke, Joseph R. Groenke, Matthew C. Lamanna, Ross D. E. MacPhee, Grace M. Musser, Eric M. Roberts & Patrick M. O'Connor. 2025. Nature 638 146-151.
This package includes our phylogenetic character matrices and the results of our phylogenetic analyses (SD01-SD03), details about how CT scan data were collected (SD04), and files derived from CT scan data (SD05-SD11).
Contents
SD01_Avialae_matrix.nex - Our morphological character matrix in Nexus format (.NEX) focused on Avialae with PAUP and BAYES command blocks (see Supplemental Information for character descriptions). .NEX files can be viewed in a text editor or the Mesquite software (www.mesquiteproject.org).
SD02_phylogenetic_analyses_outputs.zip - Compressed folder of files output from our phylogenetic analyses. File types within: .TXT files contain the logs from PAUP analyses in plain text format; readable by any text editor. .TRE files contain topological and (for MrBayes analyses) branch length data pertaining to the phylogenetic trees produced by phylogenetic analyses in nexus format. .CKP files contain checkpoint information from MrBayes analyses in nexus format. .LSTAT files contain marginal likelihoods estimated during MrBayes analyses in tab delimited text format. .MCMC files contain run diagnostics from MrBayes analyses in tab delimited text format. .PARTS files contain tables of taxon bipartitions from MrBayes analyses in tab delimited text format. .TSTAT files contain summary statistics pertaining to the taxonomy bipartitions from MrBayes in tab delimited format. .PSTAT files contain parameter values for MrBayes analyses in tab delimited text format. .P files contain parameters for substitution models used in MrBayes analyses in tab delimited text files. .T and .TRPROBS files contain the topology and branch length data estimated by MrBayes analyses in nexus format. .VSTAT files contain statistics pertaining to branch and node parameters estimated by MrBayes analyses in tab delimited text format. Phylogenetic trees contained in nexus files are viewable using the freely available FigTree software (tree.bio.ed.ac.uk/software/figtree/).
- Subfolders SD02a-j - outputs from our phylogenetic analyses using the character matrix focused on resolving relationships among Avialae (i.e., SD01_Avialae_matrix.nex):
- SD02a - PAUP analysis, including only previously-described Vegavis material (Extended Data Fig. 6d)
- SD02b - MrBayes analysis, including only previously-described Vegavis material (Extended Data Fig. 6c)
- SD02c - PAUP analysis, including only the new Vegavis specimen (Extended Data Fig. 6f)
- SD02d - MrBayes analysis, including only the new Vegavis specimen (Extended Data Fig. 6e)
- SD02e - PAUP analysis, including both previously-described and the new Vegavis specimen as separate tips (Extended Data Fig. 6h)
- SD02f - MrBayes analysis, including both previously-described and the new Vegavis specimen as separate tips (Extended Data Fig. 6g)
- SD02g - PAUP analysis, including both previously-described and the new Vegavis specimen as a combined tip (Extended Data Fig. 6b)
- SD02h - MrBayes analysis, including both previously-described and the new Vegavis specimen as a combined tip (Extended Data Fig. 6a)
- SD02i - PAUP analysis, including both previously-described and the new Vegavis specimen as a combined tip and including Gansus yumenensis (Extended Data Fig. 6i)
- SD02j - MrBayes analysis, including both previously-described and the new Vegavis specimen as a combined tip and including Gansus yumenensis (Extended Data Fig. 6j)
- Subfolders SD02k-r - outputs from our phylogenetic analyses using the character matrix focused on resolving relationships among Galloanserae (i.e., SD03_Galloanserae_matrix.nex) with the taxon Anachronornis excluded:
- SD02k - PAUP analysis, including only previously-described Vegavis material (Extended Data Fig. 6d)
- SD02l - MrBayes analysis, including only previously-described Vegavis material (Extended Data Fig. 6c)
- SD02m - PAUP analysis, including only the new Vegavis specimen (Extended Data Fig. 6f)
- SD02n - MrBayes analysis, including only the new Vegavis specimen (Extended Data Fig. 6e)
- SD02o - PAUP analysis, including both previously-described and the new Vegavis specimen as separate tips (Extended Data Fig. 6h)
- SD02p - MrBayes analysis, including both previously-described and the new Vegavis specimen as separate tips (Extended Data Fig. 6g
- SD02q - PAUP analysis, including both previously-described and the new Vegavis specimen as a combined tip (Extended Data Fig. 6a)
- SD02r - MrBayes analysis, including both previously-described and the new Vegavis specimen as a combined tip (Extended Data Fig. 6b)
- Subfolders SD02s-z - outputs from our phylogenetic analyses using the character matrix focused on resolving relationships among Galloanserae (i.e., SD03_Galloanserae_matrix.nex) with the taxon Anachronornis included:
- SD02s - PAUP analysis, including only previously-described Vegavis material (Extended Data Fig. 6l)
- SD02t - MrBayes analysis, including only previously-described Vegavis material (Extended Data Fig. 6k)
- SD02u - PAUP analysis, including only the new Vegavis specimen (Extended Data Fig. 6n)
- SD02v - MrBayes analysis, including only the new Vegavis specimen (Extended Data Fig. 6m)
- SD02w - PAUP analysis, including both previously-described and the new Vegavis specimen as separate tips (Extended Data Fig. 6p)
- SD02x - MrBayes analysis, including both previously-described and the new Vegavis specimen as separate tips (Extended Data Fig. 6o)
- SD02y - PAUP analysis, including both previously-described and the new Vegavis specimen as a combined tip (Extended Data Fig. 6j)
- SD02z - MrBayes analysis, including both previously-described and the new Vegavis specimen as a combined tip (Extended Data Fig. 6i)
SD03_Galloanserae_matrix.nex - Our morphological character matrix in Nexus format (.NEX) focused on Galloanserae with PAUP and BAYES command blocks (see Supplemental Information for character descriptions). .NEX files can be viewed in a text editor or the Mesquite software (www.mesquiteproject.org).
SD04_scan_data_volume_details.csv - Details about how the positions of the CT scan datasets used in this study were transformed/rotated for alignment to a reference CT scan dataset (i.e., the 2018 scan of Block A of AMNH FARB 30899). See Supplemental Information for how we aligned these datasets. Columns:
- SCAN REFERENCE - the name of the CT scan dataset being transformed
- MORPHOSOURCE VOLUME FILE MEDIA ID - the ID number corresponding to the CT scan dataset on www.MorphoSource.org
- MORPHOSOURCE MEDIA URL - the URL address for the CT scan dataset on www.MorphoSource.org
- TRANSLATION X - translational adjustment along the X axis (in mm)
- TRANSLATION Y - translational adjustment along the Y axis (in mm)
- TRANSLATION X - translational adjustment along the Z axis (in mm)
- ROTATIONAL DEGREES - total rotation (in degrees)
- ROTATION X - rotational adjustment about the X axis (in degrees)
- ROTATION Y - rotational adjustment about the Y axis (in degrees)
- ROTATION Z - rotational adjustment about the Z axis (in degrees)
SD05_polygon_details.csv - Details about how the positions of mesh files corresponding to independent skeletal elements (included in SD08_surface_files_full_reconstruction.zip) were adjusted for alignment to the reference CT scan dataset (i.e., the 2018 scan of Block A of AMNH FARB 30899). Columns:
- POLYGON REFERENCE - the element being transformed
- CATEGORY - the type of element being transformed (Bone = skeletal element; Impression or Void = negative space corresponding to inferred skeletal element; Matrix = non-skeletal region of the dataset corresponding to rock)
- MORPHOSOURCE MEDIA ID - the ID number corresponding to the CT scan dataset on www.MorphoSource.org
- MORPHOSOURCE MEDIA URL - the URL address for the CT scan dataset on www.MorphoSource.org
- VOLUME FILE REFERENCE - the CT scan dataset from which the mesh file was derived
- LABEL FILE REFERENCE - the label file derived from the CT scan dataset that includes the mesh file
- SMOOTHING PROTOCOL - the settings in the segmentation editing software Avizo (FEI) used when smoothing the surface contour of the mesh
- TRANSLATION X - translational adjustment along the X axis (in mm)
- TRANSLATION Y - translational adjustment along the Y axis (in mm)
- TRANSLATION X - translational adjustment along the Z axis (in mm)
- ROTATIONAL DEGREES - total rotation (in degrees)
- ROTATION X - rotational adjustment about the X axis (in degrees)
- ROTATION Y - rotational adjustment about the Y axis (in degrees)
- ROTATION Z - rotational adjustment about the Z axis (in degrees)
SD06_taphonomic_data_reconstruction.mp4 - A video file cut-through of our 3D realignment of scan data showing a, uCT XY slice reconstruction of the 2014 Block A and Block B data in unified coordinate space, and b, slice reconstruction with polygons of segmented cranial elements. Scale bars = 2 cm.
SD07_taphonomic_reconstruction.pdf - 3D PDF of realigned CT scan data and surface files (see Supplemental Information).
SD08_surface_files_original_material_only.zip - Compressed folder of polygon files (.PLY) of only originally preserved elements (Fig. 1, Extended Data Figs. 2-4). Spatial positioning is preserved relative to surface files in SD09_surface_files_full_reconstruction.zip. Files can be opened using the open source program Meshlab (https://www.meshlab.net).
SD09_surface_files_full_reconstruction.zip - Compressed folder of polygon files (.PLY) of reconstructed skull with mirrored elements (Extended Data Fig. 5) Spatial positioning is preserved relative to surface files in SD08_surface_files_original_material_only.zip. Files can be opened using the open source program Meshlab (https://www.meshlab.net).
SD10_original_material.blend - A Blender file of only originally preserved elements (Fig. 1, Extended Data Figs. 2-4). Blender is a free, open-source program that can be downloaded at https://www.blender.org.
SD11_retro_deformation.blend - A Blender file of reconstructed skull with mirrored elements (Extended Data Fig. 5). Blender is a free, open-source program that can be downloaded at https://www.blender.org.
Sharing/Access Information
Related data are available on MorphoSource (https://www.morphosource.org/concern/biological_specimens/000553312)
See main text and supplemental information.