Supplementary Table. Measured comatulid brachials from the site RR13A on the western Rodrigues Ridge with main quantitative data. The smallest brachials (D<0.80 mm) were not measured. D: maximum diameter, H: height, epi: episyzygial brachial, hypo: hyposyzygial brachial, musc: muscular synarthry (mu/musc: on both proximal and distal facets), pin: pinnule socket, sax: axial synarthry, syz: syzygy with radiate crenularium. Values in mm except ratio.

Catalogue n°	H	D	H/D	Figure	articulations	type	
OPH213	2.65	3.95	0.67	Fig. 7B	sax/musc	axillary	
OPH241 a	1.16	3.31	0.35	Fig. 7A	sax/musc/pin	epi	
OPH214 b	1.23	3.18	0.39	not figured	sax/musc/pin	epi	
OPH214 c	0.73	1.95	0.37	not figured	sax/musc?	epi?	
OPH214 d	0.71	1.78	0.40	not figured	sax/musc	hypo	
OPH217 a	1.02	2.37	0.43	not figured	syz/musc/pin	epi	
OPH217 a	0.98	2.25	0.44	Fig. 7D	syz/musc	hypo	
OPH217 b	0.95	2.06	0.47	not figured	syz/musc/pin	epi	
OPH217 c	0.94	2.03	0.46	not figured	syz/musc/pin	epi	
OPH217 d	1.16	1.96	0.60	not figured	syz/musc/pin	epi	
OPH215 b	1.12	1.92	0.58	Fig. 7E	syz/musc/pin	epi	
OPH217 e	1.10	1.81	0.61	not figured	syz/musc/pin	epi	
OPH217 f	0.93	1.78	0.52	not figured	syz/musc	hypo	
OPH217 g	1.06	1.60	0.66	not figured	syz/musc/pin	epi	
OPH215 c	1.03	1.50	0.69	Fig. 7C	syz/musc/pin	epi	
OPH217 h	0.77	1.48	0.52	not figured	syz/musc	hypo	
OPH217 i	0.76	1.34	0.57	not figured	syz/musc	hypo	
OPH217 j	1.01	1.26	0.80	not figured	syz/musc/pin	epi	
OPH217 k	0.65	1.08	0.60	not figured	syz/musc	hypo	
OPH217 l	0.70	0.98	0.90	not figured	syz/musc	epi	
OPH217 m	0.87	0.93	0.93	not figured	syz/musc/pin	epi	
OPH217 n	0.51	0.80	0.64	not figured	syz/musc	hypo	
OPH218 a	1.08	2.73	0.40	not figured	mu/musc/pin	free	
OPH218 b	1.18	2.69	0.44	not figured	mu/musc/pin	free	
OPH218 c	1.90	2.61	0.73	not figured	mu/musc/pin	free	
OPH218 d	2.05	2.58	0.79	not figured	mu/musc/pin	free	
OPH218 e	2.12	2.50	0.85	not figured	mu/musc/pin	free	
OPH218 f	2.16	2.49	0.87	not figured	mu/musc/pin	free	
OPH218 g	2.03	2.42	0.84	not figured	mu/musc/pin	free	
OPH216	1.73	2.32	0.75	Fig. 7F	mu/musc/pin	free 	
OPH218 h	1.60	2.15	0.74	not figured	mu/musc/pin	free	
OPH218 i	1.76	2.07	0.85	not figured	mu/musc/pin	free	
OPH218 j	1.90	2.04	0.93	not figured	mu/musc/pin	free	
OPH218 k	1.97	2.00	0.98	not figured	mu/musc/pin	free 	
OPH218 l	1.71	1.84	0.93	not figured	mu/musc/pin	free	
OPH218 m	1.74	1.69	1.03	not figured	mu/musc/pin	free	
OPH218 n	1.30	1.26	1.03	not figured	mu/musc/pin	free