README Written by Eric M. Arndt on March 24, 2015 This collection contains experimental data for the paper "Mechanistic Origins of Bombardier Beetle (Brachinini) Explosion-Induced Defensive Spray Pulsation," by Eric M. Arndt, Wendy Moore, Wah-Keat Lee, and Christine Ortiz, which was accepted by Science on March 16, 2015, and which is in press at the time of preparation of this readme. Data sets are organized by beetle, with beetle numbers corresponding to those listed in Tables S1 and S2 of the paper supplement. Images stacks are ZIP-compressed. The total size of all files (compressed) is 62.9 GB. For Beetle 1, the raw 30-frame-per-second (fps) x-ray and 30-fps closed-circuit TV (CCTV) videos are provided as TIFF image stacks. For Beetles 2-4, the raw 250-fps x-ray and 30-fps CCTV videos are provided as TIFF image stacks. For Beetle 5, the raw and processed 1000-fps x-ray videos are provided as TIFF image stacks. An AVI video (25-fps playback) of the recorded spray as well as the Matlab processing script (file path redacted) are also provided. CCTV video was not recorded. For Beetles 6-14, the raw and processed 2000-fps x-ray videos are provided as TIFF image stacks. AVI videos (25-fps playback) of all recorded sprays as well as the Matlab processing scripts for each data set (file paths redacted) are also provided. CCTV video was not recorded. 250-fps and 2000-fps X-ray video footage of 400-mesh TEM grids are also provided as TIFF image stacks for purposes of length calibration. Note that for Beetles 2-14 as well as the calibration data, the raw x-ray images are 16-bit TIFF files and therefore may require special viewing software (e.g. ImageJ). The Excel spreadsheet Data_summary.xlsx is a catalog of the data and provides x-ray and (where available) CCTV frame numbers for all sprays. The citable handle for this collection is hdl.handle.net/1721.1/96123. Some users running Mac OS X have reported difficulties in extracting some of the ZIP archives using the default extractor in Finder. A suggested fix is to use a different zip utility or to use the command line unzip.