Table 3. Mineral density as calculated from the Micro-CT scans.

Segment	Treatment	T.A. (mm2) or T.V. (mm3)*	Obj.A. (mm2) or Obj.V. (mm3)*	Obj.A./T.A. or Obj.V./T.V.* (%)	Obj.Th. (mm) or Obj.S. (mm2)*	T. M. D. (gHA/cm3)
merus	ambient	11.734	0.368	3.13	0.063	0.631
	reduced pH	11.734	0.489	4.17	0.076	0.694
	reduced pH/increased temp	11.734	0.387	3.30	0.062	0.663
carapace	ambient	5.056	0.191	3.78	0.061	0.562
	reduced pH	5.056	0.186	3.67	0.063	0.634
	reduced pH/increased temp	5.056	0.155	3.06	0.058	0.613
dactyl*
low density	ambient	2.997	2.089	69.70	14.359	1.294
	reduced pH	3.063	2.019	65.91	14.132	1.344
	reduced pH/increased temp	2.844	1.490	52.38	17.929	1.455
high density	ambient	2.997	0.747	24.91	12.488	1.877
	reduced pH	3.063	0.879	28.70	13.978	1.879
	reduced pH/increased temp	2.844	1.011	35.54	25.348	1.853

The carapace and merus were quantified via a 2D analysis by integrating 2D slices in the region of interest as defined by the total area (T.A.), while the dactyl was 3D analyzed in the total volume (T.V.) of interest. Area metrics presented refer to the merus and carapace. Volume metrics refer to the dactyl as indicated by the*. Obj.A or Obj.V. is the total object area or volume obtained inside the T.A. or T.V., respectively. Obj.A./T.A. is the object area divided by the total area, and Obj.V./T.V. is the object volume divided by the total volume; both metrics have the same units. Obj.Th. is the thickness of the object and Obj.S. is the surface area of the object’s volume. T.M.D. is the true mineral density calculated by correlating attenuation coefficients from images of sample and hydroxyapatite (HA) rods of known densities. The units for T.M.D are the same for the merus, carapace, and dactyl.