Table 1.

SEM-EDS quantitative data for the emu claw sheath (electronic supplementary material, figure S2), fossil Citipati claw sheath (figure 3) and sediment associated with the fossil (electronic supplementary material, figure S3), in decreasing abundance. Data are presented by weight (ms%) and molar (mol%) percentages. Intriguingly, iron is present in the sediment but is not detected in the fossil claw sheath, indicating little transfer between the oviraptorid claw sheath tissues and entombing sediments. Note the difference in relative abundance of calcium (italicized) in the fossil claw sheath compared to the extant emu claw sheath (see Discussion).

emu			Citipati			sediment
element	ms%	mol%	element	ms%	mol%	element	ms%	mol%
C	75.48	81.85	O	36.76	48.37	O	41.39	44.49
O	20.08	16.34	Ca	31.57	16.58	C	24.68	35.34
S	3.22	1.31	C	11.88	20.82	Si	18.64	11.41
CI	0.67	0.25	P	11.85	8.05	Al	7.2	4.59
Na	0.29	0.16	Si	4.76	3.57	Ca	2.37	1.02
K	0.26	0.09	Al	1.94	1.52	Fe	2.04	0.63