Table 1. Compactness parameters, K and lifestyle readings for the humerus, radius and ulna of the four South African Lystrosaurus species, compared to the dicynodontoid Daptocephalus leoniceps.

Species	Acc. No.	MD	Min	Max	S	P	Cc	Cp	Cg	K	Lifestyle
Humerus
L. maccaigi	NMQR 3663a	40	0.3730496	0.999999	0.2038591	0.6227462	0.399	0.913	0.717	0.62	0
L. curvatus	NMQR 3922a	29	0.3879353	0.9234601	0.0748487	0.6072952	0.474	0.931	0.715	0.61	0
L. murrayi	BP/1/3236	30	0.2971604	0.85865	0.118658	0.4562598	0.334	0.825	0.716	0.45	0
L. declivis	NMQR 1485a	28	0.2884796	0.8827366	0.1255311	0.5596468	0.296	0.865	0.669	0.55	0
D. leoniceps	NMQR 3633a	39	0.1910163	0.985676	0.4026052	0.1560593	0.517	0.898	0.798	0.15	0
Radius
L. curvatus	NMQR 3651b	18	0.2316513	0.999999	0.1180121	0.6902793	–	–	0.61	0.69	0
L. murrayi	NMQR 659b	12	0.1359149	0.9222332	0.0856374	0.387408	–	–	0.783	0.38	0
L. declivis	NMQR 1485c	18	0.0857202	0.9095449	0.0772092	0.5071929	–	–	0.679	0.51	0
Ulna
L. maccaigi	NMQR 3663b	41	0.3048958	0.999999	0.1806802	0.497793	–	–	0.772	0.49	–
L. curvatus	NMQR 3651c	20	0.4636301	0.9041376	0.1178336	0.6704773	–	–	0.691	0.67	–
L. murrayi	NMQR 659c	19	0.3233334	0.9169428	0.083876	0.4531913	–	–	0.78	0.45	–
L. declivis	NMQR 1485c	23	0.0650608	0.9073332	0.1125244	0.4720466	–	–	0.684	0.47	–

Notes.

Abbreviations

Acc. No

accession number

Cc

compactness at the bone center

Cg

global compactness

Cp

compactness at the bone periphery

Max

maximum compactness

MD

maximum diameter

Min

minimum compactness

K

cortical thickness

P

transition area between the medullary cavity and compact cortex

S

value proportional to the width of the transition zone between the medullary cavity and cortex

A 0 lifestyle reading for the humerus and radius in all taxa indicates an aquatic lifestyle (Canoville & Laurin, 2010; Laurin, Canoville & Germain, 2011). There is currently no available model to determine lifestyle using the ulna.