Nuclei and nucleoli in embryo-like fossils from the Ediacaran Weng’an Biota Zongjun Yin, John A. Cunningham, Kelly Vargas, Stefan Bengtson, Maoyan Zhu, Philip C. J. Donoghue. This dataset contains three dimensional synchrotron x-ray tomographic (SRXTM) datasets and analyses of nuclei and nucleoli in embryo-like fossils from the Ediacaran Weng’an Biota. The data accompanies the following paper: Yin Z, Cunningham JA, Vargas K, Bengtson S, Zhu M, Donoghue PCJ. 2017. Nuclei and nucleoli in embryo-like fossils from the Ediacaran Weng’an Biota. Precambrian Research. DOI: 10.1016/j.precamres.2017.08.009 Each .7z archive zip file contains the data relating to a single specimen. All specimens featured in this work, their museum number and quarry that they were extracted from are as follows: Tianzhushania Specimen name Museum number Quarry 01 THKD04x SMNH X 4407 Datang 02 Bris_0012g SMNH X 4410 Datang 03 THHD05i SMNH X 4403 Datang 04 Bris_0001g SMNH X 4413 Datang 05 Bris_0001c SMNH X 4412 Datang 06 Bris_0002c SMNH X 4414 Datang 07 Bris_0002g SMNH X 4416 Datang 08 Bris_0004d SMNH X 4411 Datang 09 Bris_0001j SMNH X 4409 Datang 10 THHD04vi SMNH X 4408 Datang 11 THMD04iii SMNH X 4405 Datang 12 Bris_0004a SMNH X 4415 Datang 13 THJD04xii SMNH X 4406 Datang 14 WA-B3-H09d NIGPAS-166378 54 Quarry 15 WA-B3-H07f NIGPAS-166379 54 Quarry 16 CWTo NRM-PZ X 6771 Datang 17 CWT_10a NRM-PZ X 6772 Datang 18 CWTr NRM-PZ X 6773 Datang Spiralicellula 01 THID04ix SMNH X 4404 Datang 02 PD1511_48 NIGPAS-166380 Nanbao 03 Bris_0037L NRM-PZ X 6774 Datang 04 PD1511_53 NIGPAS-166381 Nanbao 05 Bris_0032d NRM-PZ X 6775 Datang SMNH and NRM refer to the Swedish Museum of Natural History / Naturhistoriska riksmuseet. NIGPAS refers to Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences The volume and size data of cells and LIS for the following specimens were obtained from the published paper "Fossilized nuclei and germination structures identify Ediacaran 'animal embryos' as encysting protists" by Huldtgren et al (2011). Science 334: 1696-1699. DOI:10.1126/science.1209537 Tianzhushania: THKD04x Bris 0012g THHD05i Bris 0001g Bris 0001c Bris 0002c Bris 0002g Bris 0004d Bris 0001j THHD04vi THMD04iii Bris 0004a THJD04xii Spiralicellula: THID04IX Specimens were scanned using synchrotron radiation X-ray tomographic microscopy (SRXTM). SRXTM analyses were carried out at the ID19 beamline at the European Synchrotron Research Facility, Grenoble, France, for specimens WA-B3-H09d and WA-B3-H07f. SRXTM analyses were carried out at the X02DA TOMCAT beamline of the Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland, for all other specimens. Raw tomographic data for each specimen consist of a stacked series of 2D .tif files that represent maps of X-ray attenuation. The individual slices can be viewed with standard graphics software. The datasets can be studied in 3D using tomographic reconstruction software such as Avizo (www.vsg3d.com/), Spiers (www.spiers-software.org/), VG Studio Max (www.volumegraphics.com) etc. Working files included for each specimen consist of Avizo files (.hx and .am files, which can be opened in Avizo (www.vsg3d.com/)). Additionally the labels (segmentations) have been included as an exported stack of 2D .tif images providing compatibility with freeware such as Spiers (www.spiers-software.org/). 3D models are also provided as .stl files, widely compatible with 3D freeware packages such as MeshLab (http://meshlab.sourceforge.net/) or Blender (https://www.blender.org/), or with proprietary software, e.g. Avizo (www.vsg3d.com/), Geomagic (http://www.geomagic.com/en/), Mimics (http://biomedical.materialise.com/mimics). All specimens figured in Fig 1 and Fig 2 have their tomographic data and working files with 3D models (stl), segmentation and statistics deposited. Specimens not figured in Fig 1 and Fig 2 have their tomographic data and working files with segmentation and statistics deposited. Specimens originally published in Huldtgren et al (2011) have their tomographic data only. Voxel size for specimens Spiralicellula PD1511_48 and Spiralicellula PD1511_53 is 0.325 x 0.325 x 0.325 µm. Voxel size for specimens Tianzhushania WA-B3-H09d and Tianzhushania WA-B3-H07f is 0.75 x 0.75 x 0.75 µm. Voxel size for all other specimens is 0.36 x 0.36 x 0.36 µm. Synchrotron settings for the specimens scanned at the Swiss Light Source are as follows: Specimen name Museum number energy projections exposure scintilator Tianzhushania THKD04x SMNH X 4407 20 keV 1501 600 ms x20 Bris_0012g SMNH X 4410 20 keV 1501 200 ms x20 THHD05i SMNH X 4403 20 keV 1501 375 ms x20 Bris_0001g SMNH X 4413 19 keV 1501 600 ms x20 Bris_0001c SMNH X 4412 18 keV 1501 310 ms x20 Bris_0002c SMNH X 4414 19 keV 1501 590 ms x20 Bris_0002g SMNH X 4416 19 keV 1501 590 ms x20 Bris_0004d SMNH X 4411 19 keV 1501 600 ms x20 Bris_0001j SMNH X 4409 19 keV 1501 600 ms x20 THHD04vi SMNH X 4408 20 keV 1501 375 ms x20 THMD04iii SMNH X 4405 20 keV 1501 375 ms x20 Bris_0004a SMNH X 4415 19 keV 1501 600 ms x20 THJD04xii SMNH X 4406 19 keV 1501 310 ms x20 CWTo NRM-PZ X 6771 19 keV 1501 200 ms x20 CWT_10a NRM-PZ X 6772 20 keV 1501 750ms x20 CWTr NRM-PZ X 6773 18 keV 1501 175 ms x20 Spiralicellula THID04ix SMNH X 4404 17 keV 1501 360ms x20 PD1511_48 NIGPAS-166380 18 keV 1501 200 ms x20 Bris_0037L NRM-PZ X 6774 15 keV 1501 185 ms x20 PD1511_53 NIGPAS-166381 20 keV 1501 220 ms x20 Bris_0032d NRM-PZ X 6775 17 keV 1501 350 ms x20