TABLE 1. Forelimb muscle belly and tendon lengths and masses as predicted from Cuff et al. (2016a). Serrat. vent. cerv. = m. serratus ventralis cervicus, Serrat. vent. thor. = m. serratus ventralis thoracis, Abd. dig. 1 = m. abductor digiti 1. Ext. = extensor, Flex. = flexor.
Muscle | Belly length (m) |
Tendon length (m) |
Belly mass (kg) |
Tendon mass (kg) |
Latissimus dorsi | 0.646 | 1.776 | ||
Trapezius cervicis | 0.379 | 0.229 | ||
Trapezius thoracis | 0.275 | 0.242 | ||
Rhomboideus capitis | 0.428 | 0.232 | ||
Rhomboideus cervicis | 0.230 | 0.444 | ||
Rhomboideus thoracis | 0.204 | 0.156 | ||
Omotransversarius | 0.350 | 0.169 | ||
Cleidocephalicus | 0.405 | 0.484 | ||
Cleidobrachialis | 0.336 | 0.140 | 0.509 | |
Serrat. vent. cerv. | 0.244 | 0.523 | ||
Serrat. vent. thor. | 0.240 | 0.552 | ||
Pectoralis superficialis | 0.372 | 0.567 | ||
Pectoralis profundus | 0.642 | 1.923 | ||
Supraspinatus | 0.344 | 0.045 | 1.001 | 0.001 |
Infraspinatus | 0.261 | 0.203 | 0.699 | 0.038 |
Deltoideus acromion | 0.184 | 0.162 | ||
Deltoideus spinous | 0.195 | 0.113 | 0.190 | 0.000 |
Teres major | 0.286 | 0.002 | 0.554 | 0.001 |
Subscapularis | 0.254 | 0.022 | 0.670 | 1.000 |
Teres minor | 0.091 | 0.035 | ||
Coracobrachialis | 0.644 | 0.133 | ||
Triceps longus | 0.348 | 0.130 | 1.562 | 0.006 |
Triceps lateralis | 0.277 | 0.101 | 0.582 | 0.005 |
Triceps medius | 0.253 | 0.136 | 0.197 | 0.010 |
Triceps accessory | 0.281 | 0.123 | ||
Biceps brachi | 0.257 | 0.102 | 0.531 | 0.012 |
Brachialis | 0.297 | 0.059 | 0.138 | 0.003 |
Anconeus | 0.165 | 0.072 | ||
Ext. carpi radialis | 0.310 | 0.163 | 0.201 | 0.008 |
Ext. digitorum communis | 0.236 | 0.014 | 0.186 | 0.074 |
Ext. digitorum lateralis | 0.415 | 0.169 | 0.054 | 0.008 |
Ext. carpi ulnaris | 0.264 | 0.163 | 0.077 | 0.005 |
Flex. carpi ulnaris ulnar | 0.262 | 0.021 | 0.139 | 0.003 |
Flex. carpi ulnaris humeral | 0.295 | 0.108 | 0.162 | 0.002 |
Brachioradialis | 2.410 | 0.218 | ||
Supinator | 0.147 | 0.002 | 0.039 | 0.004 |
Pronator teres | 0.216 | 0.128 | ||
Pronator quadratus | 0.254 | 0.073 | 0.071 | 0.004 |
Flex. carpi radialis | 0.259 | 0.081 | 0.058 | 0.002 |
Flex. digitorum complex | 0.284 | 0.177 | 0.499 | 0.087 |
Abd. dig. 1 | 0.418 | 0.223 | 0.039 | 0.003 |
TABLE 2. Hindlimb muscle belly and tendon lengths and masses as predicted from Cuff et al. (2016b). Gastroc. = gastrocnemius, Dig. = digitorum, Supefic. = superficialis.
Muscle | Belly length (m) |
Tendon length (m) |
Belly mass (kg) |
Tendon mass (kg) |
Biceps femoris | 0.420 | 1.537 | ||
Caudofemoralis | 0.373 | 0.345 | 0.515 | 0.019 |
Sartorius | 0.654 | 0.775 | ||
Tensor fascia latae | 0.190 | 0.293 | 0.542 | 0.043 |
Vastus lateralis | 0.389 | 0.962 | ||
Rectus femoris | 0.419 | 0.650 | 0.693 | 0.079 |
Vastus medius | 0.350 | 0.029 | 0.487 | 0.004 |
Vastus intermedius | 0.486 | 0.002 | 0.168 | 0.000 |
Semitendinosus | 0.464 | 0.134 | 0.684 | 0.005 |
Semimembranosus | 0.718 | 0.043 | 1.369 | 0.003 |
Gracilis | 0.257 | 0.088 | 0.534 | 0.016 |
Gluteus superficialis | 0.184 | 0.153 | ||
Gluteus medius | 0.249 | 1.063 | ||
Gluteus profundus | 0.231 | 0.005 | 0.090 | 0.001 |
Piriformis | 0.090 | 0.023 | 0.093 | 0.002 |
Gemelli | 0.154 | 0.146 | ||
Quadratus femoris | 0.125 | 0046 | ||
Obturator externus | 0.124 | 0.168 | ||
Obturator internus | 0.118 | 0.078 | 0.178 | 0.008 |
Pectineus | 0.268 | 0.093 | ||
Adductor magnus | 0.392 | 1.181 | ||
Adductor brevis | 0.214 | 0.211 | ||
Iliacus | 0.564 | 0.538 | ||
Psoas major | 0.558 | 0.058 | 0.785 | 0.074 |
Psoas minor | 0.373 | 0.072 | 0.242 | 0.002 |
Gastroc. lateralis | 0.334 | 0.072 | 0.377 | 0.021 |
Gastroc. medius | 0.291 | 0.137 | 0.302 | 0.021 |
Superfic. dig. flexor | 0.293 | 0.373 | 0.119 | 0.311 |
Soleus | 0.268 | 0.024 | 0.123 | 0.002 |
Dig. extensor longus | 0.291 | 0.269 | 0.084 | 0.105 |
Tibialis cranialis | 0.284 | 0.111 | 0.213 | 0.004 |
Popliteus | 0.189 | 0.095 | 0.054 | 0.003 |
Dig. extensor lateralis | 0.215 | 0.320 | 0.026 | 0.003 |
Peroneus longus | 0.222 | 0.166 | 0.185 | 0.062 |
Peroneus brevis | 0.200 | 0.242 | 0.041 | 0.004 |
Deep digital flexor medial | 0.298 | 0.299 | 0.165 | 0.062 |
Deep digital flexor lateral | 0.324 | 0.465 | 0.137 | 0.040 |
Tibialis caudalis | 0.272 | 0.180 | 0.117 | 0.011 |
TABLE 3. Vertebral muscle belly and tendon lengths and masses as predicted from Cuff et al. (2016a, b). Longis. = longissimus, Iliocost. = iliocostalis, Multifid. = multifidus.
Muscle | Belly length (m) |
Tendon length (m) |
Belly mass (kg) |
Tendon mass (kg) |
Rectus capitis | 0.112 | 0.098 | ||
Splenius cervicis | 0.395 | 0.366 | ||
Serratus dorsalis cranialis | 0.127 | 0.228 | 0.124 | 0.033 |
Serratus dorsalis caudalis | 0.085 | 0.001 | 0.080 | 0.020 |
Semispinalis capitis biventer | 4.009 | 0.325 | ||
Semispinalis capitis complexus | 0.470 | 0.325 | ||
Spinalis cervicis | 0.314 | 0.336 | ||
Spinalis thoracis | 0.641 | 0.877 | ||
Longissimus capitis | 0.323 | 0.064 | ||
Longissimus cervicis | 0.405 | 0.143 | ||
Longissimus thoracis | 0.827 | 0.916 | ||
Iliocostalis thoracis | 0.640 | 0.195 | ||
Multifidis throacis | 0.713 | 0.355 | ||
Longis. lumborum | 2.342 | 0.987 | ||
Iliocost. lumborum | 1.494 | 0.630 | ||
Multifid. lumborum | 0.381 | 0.661 |
TABLE 4. Body composition of Panthera atrox from reconstructed muscles and dissections of extant P. leo specimens (Davis, 1962). “Muscle recon” is the sum of the reconstructed forelimb, hindlimb, and vertebral muscles. Additional muscle is the remaining expected muscle using the body compositions for modern lions (Davis, 1962) i.e., 57.1% - “Muscle recon”.
Body | Forelimb muscles |
Hindlimb muscles |
Vertebral muscle |
Muscle recon |
Additional muscle |
Bone | Adipose | Organs | Skin and fur | Blood and waste | |
Mass (kg) | 207 | 35.2 | 32.2 | 16.9 | 84.4 | 33.7 | 25.7 | 5.5 | 24.4 | 23.8 | 9.56 |
Percentage (%) | 100 | 17.0 | 15.6 | 8.18 | 40.8 | 16.3 | 12.4 | 2.67 | 11.8 | 11.5 | 4.62 |
TABLE 5. Panthera leo limb segment masses from the different mass estimate methods. “Flesh” is the weight calculated for the segment volumes (multiplied by 1060 kg m-3) from CT segmentation. “Reconstruction” was based on the muscle and bone reconstruction, although muscle masses for the manus and pes were calculated as total tendon mass for distal muscles. Convex hull bones (“CHB”) is the convex hull range of masses and the convex hull muscles (“CHM”) is the convex hull range of masses from the muscled reconstructions. The masses for both convex hull methods were calculated from the volumes using only the mean density [893.36 kg m−3 multiplied by 1.206 (Sellers et al., 2012)]. Ratios of each of these estimates are shown in the final four columns on the right side of the table. Dig_Man = digits of the manus, Dig_Pes = digits of the pes.
Flesh | Reconstruction | CHB Mean | CHM Mean | Flesh/Recon | Recon/CHB | CHM/Recon | Flesh/CHM | |||
Bone mass | Muscle mass | Total | ||||||||
Humerus | 7.47 | 0.44 | 3.94 | 4.38 | 1.19 | 7.29 | 1.71 | 3.69 | 1.67 | 1.02 |
Ulna/Radius | 2.39 | 0.16 | 1.40 | 1.56 | 0.86 | 2.25 | 1.53 | 1.81 | 1.44 | 1.07 |
Manus | 0.55 | 0.18 | 0.29 | 0.47 | 0.42 | 1.18 | 1.12 | |||
Dig_Man | 0.44 | 0.07 | 0.07 | 0.29 | 6.16 | 0.24 | ||||
Femur | 10.9 | 0.62 | 7.23 | 7.85 | 1.50 | 10.6 | 1.39 | 5.23 | 1.35 | 1.03 |
Tibia | 2.35 | 0.53 | 1.13 | 1.66 | 1.28 | 2.54 | 1.41 | 1.30 | 1.53 | 0.92 |
Pes | 0.75 | 0.41 | 0.27 | 0.68 | 0.73 | 1.10 | 0.93 | |||
Dig_Pes | 0.30 | 0.13 | 0.13 | 0.29 | 2.31 | 0.45 |
TABLE 6. Centre of mass (COM) validation test for extant lion limb segments. “Original COM” was derived from CT scan data for each segment, “CHM COM” from the convex hull models fitted to the muscled limbs, and “Difference” is the “Original COM” minus “CHM COM”. Italicised numbers are long axis lengths from which the percentage (%) of segment lengths were calculated. Positive x, y, and z are anterior, dorsal, and medial, respectively, relative to the origin at the proximal end of the segment. Centre of mass (COM) was expressed as % of length (from the proximal end) relative to the total proximodistal length of the segment.
Original COM | CHM COM | Difference | Original % of length | CHM % of length | |||||||||
x | y | z | X | y | z | x | y | z | |||||
Humerus | 0.0003 | -0.1120 | 0.005226 | -0.0067 | -0.1223 | 0.011691 | 0.0070 | 0.0103 | -0.0065 | 45.6 | 49.8 | ||
Ulna/Radius | -0.0023 | -0.1093 | 0.001969 | 0.0016 | -0.0935 | 0.002054 | -0.0038 | -0.0158 | -0.0001 | 42.7 | 36.6 | ||
Femur | -0.0201 | -0.0943 | -0.0177 | -0.0164 | -0.1098 | -0.0216 | -0.0037 | 0.0154 | 0.0039 | 32.1 | 37.4 | ||
Tibia | -0.0219 | -0.1497 | -0.0004 | -0.0230 | -0.1607 | -0.0009 | 0.0011 | 0.0111 | 0.0005 | 50.3 | 54.0 |
TABLE 7. Reconstructed and convex hull masses for various segments of the body of Panthera atrox. Bone mass was calculated from estimated bone density (1150 kg m-3) based on relative bone mass (25.7 kg - Table 4) divided by total bone volume (0.0223 m3). Muscle mass was calculated from the muscle and tendon that forms the majority of the segment (e.g., M. biceps brachii has tendons that extend to the scapula and the ulna, but these are all counted to the mass of the humeral segment as that is the majority of the muscle and tendon) (Table 1, Table 2, Table 3), with tendons for the distal muscles being placed in the manus and pes segments. Convex hull bones’ (CHB) and convex hull muscles’ (CHB) masses were calculated from the volumes multiplied by relative density (893.36 kg m−3 multiplied by 1.091, 1.206, and 1.322 (Sellers et al., 2012) respectively). Dig_Man and Dig_Pes are the digits for the manus and pes, respectively. The Recon/CHB is the ratio of reconstructed mass to CHB mass, and CHM/Recon is the ratio of the CHM mass to the reconstructed mass. Rad = radius, Dig_Man = digits of the manus, Fib = fibula, Dig_Pes = digits of the pes.
Reconstruction | Convex Hull Bones | Convex Hull Muscles | Recon/CHB | CHM/Recon | |||||||||
Bone Mass | Muscle Mass | Total | Mean | Lower | Upper | Mean | Lower | Upper | |||||
Humerus | 1.03 | 7.65 | 8.88 | 2.88 | 2.60 | 3.15 | 10.16 | 9.19 | 11.14 | 3.02 | 1.17 | ||
Ulna/Rad | 0.73 | 1.94 | 2.67 | 2.03 | 1.83 | 2.22 | 4.44 | 4.02 | 4.87 | 1.32 | 1.66 | ||
Manus | 0.34 | 0.20 | 0.54 | 0.92 | 0.84 | 1.01 | 1.28 | 1.16 | 1.40 | 0.59 | 2.35 | ||
Dig_Man | 0.17 | 0.17 | 0.60 | 0.55 | 0.66 | 0.70 | 0.63 | 0.76 | 0.28 | 4.12 | |||
Femur | 1.12 | 13.5 | 14.63 | 2.90 | 2.62 | 3.18 | 17.60 | 15.92 | 19.29 | 5.05 | 1.20 | ||
Tibia/Fib | 0.87 | 1.99 | 2.86 | 1.89 | 1.71 | 2.07 | 4.33 | 3.92 | 4.75 | 1.51 | 1.52 | ||
Pes | 0.90 | 0.61 | 1.50 | 1.60 | 1.45 | 1.76 | 2.16 | 1.96 | 2.37 | 0.94 | 1.44 | ||
Dig_Pes | 0.28 | 0.28 | 0.68 | 0.62 | 0.75 | 0.92 | 0.83 | 1.01 | 0.41 | 3.27 |
TABLE 8. Centre of mass for Panthera atrox limb segments. Positive x, y, and z are anterior, dorsal, and medial, respectively, relative to the origin at the proximal end of the segment. Centre of mass (COM) was expressed as % of length (from the proximal end) relative to the total proximodistal length of the segment.
Segment | x | y | z | COM % of length |
Humerus | 0.002 | -0.119 | 0.009 | 0.372 |
Ulna | -0.002 | -0.117 | 0.001 | 0.360 |
Manus | -0.010 | -0.118 | -0.001 | 0.622 |
Digits | -0.015 | -0.045 | -0.009 | 0.414 |
Femur | -0.012 | -0.144 | -0.018 | 0.380 |
Tibia | -0.017 | -0.200 | -0.014 | 0.537 |
Pes | -0.020 | -0.114 | -0.010 | 0.464 |
Digits | 0.001 | -0.045 | -0.017 | 0.370 |
TABLE 9. Moments of inertia (relative to the centre of mass; Table 8) for the limb segments of Panthera atrox. Units are kg m2.
Humerus | Ulna | Manus | Digits | |||||||||||
x | y | z | x | Y | z | x | y | z | x | y | z | |||
0.1068 | 0.0616 | 0.1476 | 0.0551 | 0.0081 | 0.0576 | 0.0040 | 0.0015 | 0.0034 | 0.0012 | 0.0007 | 0.0010 | |||
Femur | Tibia | Pes | Digits | |||||||||||
x | y | z | x | Y | z | x | y | z | x | y | z | |||
0.3373 | 0.1221 | 0.4066 | 0.0460 | 0.0085 | 0.0482 | 0.0151 | 0.0025 | 0.0150 | 0.0020 | 0.0011 | 0.0015 |