(a) Highly oriented 2D pattern taken from a turkey tendon, covering a wide q-range as indicated. The inset enlarges the details of the SAXS region for the periodic peaks along the qz direction. Two prominent arcs located along the qx axis are selectively marked with the corresponding lateral dL-spacing of 11.4 Å. (b) The intensity line-cut profile extracted along the qz axis, with the periodic peaks selectively numbered. The inset shows that all the peak positions fall nearly perfectly on the linear regression line, for the d-spacing indicated.