Table 1.
Pectoral and forelimb muscles of adults of representative amphibian and reptilian taxa
| Amphibia (Caudata): Ambystoma ordinarium (Michoacan stream salamander) | Amphibia (Anura): Rhinella arenarum (Argentine common toad) | Reptilia (Testudines): Trachemys scripta (Red-eared slider turtle) | Reptilia (Lepidosauria): Timon lepidus (Ocellated ‘lizard’) | Reptilia (Crocodylia): Caiman latirostris (Brown-snouted caiman) | Reptilia (Aves): Gallus domesticus (Chicken) |
|---|---|---|---|---|---|
| Serratus anterior (part of serrati sensuHowell, 1937a) | Serratus anterior (part of serrati sensuHowell, 1935, 1937b) | Serratus anterior | Serratus anterior (serratus ventralis sensuKardong & Zalisko, 1998 and Kardong, 2002) | Serratus anterior (serratus ventralis sensuMeers, 2003) | Serratus anterior |
| – | ‘Rhomboideus’ | – | – | ‘Rhomboideus’ | ‘Rhomboideus’ |
| Levator scapulae (thoracico-scapularis sensuJouffroy, 1971; levator scapulae superioris sensu Heterington & Tugaoen 1990; opercularis sensuWalthall & Ashley-Ross, 2006 and Piekarski & Olsson, 2007; includes the collumellaris and the opercularis sensuDuellman & Trueb, 1986 and Carroll, 2007) | Levator scapulae superioris (levator scapulae sensuHowell, 1935, 1937b) | Levator scapulae | Levator scapulae | Levator scapulae | – |
| – | Opercularis (colummelaris sensuCarroll, 2007) | – | – | – | – |
| – | – | – | Sternocoracoideus (sternocoracoid superior and inferior sensuHowell, 1937b) | – [according to authors such as Fürbringer, 1876; Walker, 1973; Holmes, 1977 and Dilkes, 2000; the sternocoracoideus is not present as an independent muscle in turtles and in crocodylians] | Sternocoracoideus [according to authors such as Dilkes, 2000; the sternocoracoideus is present in birds] |
| – | – | – [according to Walker, 1973 the costocoracoideus is not present as a distinct muscle in turtles] | Costocoracoideus (costoscapularis sensuHowell, 1936a, 1937b and Holmes, 1977; costosternocoracoideus sensuHolmes, 1977 and Dilkes, 2000) | Costocoracoideus (costosternocoracoideus sensuHolmes, 1977 and Dilkes, 2000) | – [according to authors such as Dilkes, 2000; the costocoracoideus is not present as an independent muscle in birds] |
| Pectoralis | Pectoralis | Pectoralis (pectoralis major sensuWyneken, 2001) | Pectoralis [according to authors such as Fürbringer, 1876; Walker 1973, Holmes, 1977 and Dilkes, 2000; the pectoralis is present in all the major extant reptilian clades] | Pectoralis | Pectoralis (includes pectoralis pars thoracica sensuMaxwell & Larsson, 2007) |
| Supracoracoideus (coracohumeralis sensuHowell, 1935, 1937b) | Supracoracoideus (coracohumeralis sensuHowell, 1935, 1937b) | Supracoracoideus | Supracoracoideus (coracohumeralis sensuHowell, 1936a) | Supracoracoideus | Supracoracoideus (pectoralis secundus sensuJollie, 1962) |
| Deltoideus scapularis [the deltoideus scapularis sensuJouffroy, 1971 corresponds to the dorsalis scapulae sensuSmith, 1926; Howell, 1937b; Romer, 1944; Walthall & Ashley-Ross, 2006; Diogo & Abdala, 2007; and Diogo, 2007] | Deltoideus scapularis (dorsalis scapulae sensuHowell, 1935, 1937b) | Deltoideus scapularis (dorsal, or scapular, part of deltoideus sensuWalker, 1973 and Wyneken, 2001) | Deltoideus scapularis (dorsalis scapulae sensuHowell, 1936a; Diogo & Abdala, 2007; and Diogo, 2007) [according to Holmes, 1977 and Dilkes, 2000 the deltoideus scapularis is present in turtles, crocodylians, birds and lepidosaurs] | Deltoideus scapularis (dorsalis scapulae sensuFürbringer, 1876) | Deltoideus scapularis (part of acromialis sensuRibbing, 1938; part of deltoideus sensuJollie, 1962) |
| – | – | – | – [but see text] | Scapulo-humeralis posterior (scapulo-humeralis caudalis sensuMeers, 2003) | Scapulo-humeralis posterior (scapulo-humeralis caudalis sensuDilkes, 2000 and Maxwell & Larsson, 2007) |
| Procoracohumeralis [see text] | Procarocohumeralis | Deltoideus clavicularis (ventral, or clavicular, part of deltoideus sensuWalker, 1973 and Wyneken, 2001) | Deltoideus clavicularis (procoracohumeralis sensuDiogo & Abdala, 2007 and Diogo, 2007) | Deltoideus clavicularis (scapularis inferior sensuFürbringer, 1876) | Deltoideus clavicularis (part of acromialis sensuRibbing, 1938) |
| – | – | – | – [but see text] | Humeroradialis | Humeroradialis (deltoides propatagialis sensuRomer, 1944; tensor patagii sensuJollie, 1962; tensor propatagii sensuSullivan, 1962, 1967; tensor propatagialis sensuMeers, 2003) |
| – | – | – | Scapulo-humeralis anterior | – | Scapulo-humeralis anterior (scapulohumeralis cranialis sensuDilkes, 2000 and Maxwell & Larsson, 2007) |
| Subcoracoscapularis [present in urodeles according to Smith, 1926; Romer, 1944 and Kardong, 2002; but see text] | Subcoracoscapularis (subscapularis sensuEcker,1889) | Subcoracoscapularis (subscapularis sensuWalker, 1973; Holmes, 1977; Dilkes, 2000 and Wyneken, 2001) | Subcoracoscapularis (subscapularis + subcoracoideus sensuHolmes, 1977 and Dilkes, 2000) | Subcoracoscapularis (subscapularis sensu Dilkes and Meers, 2003) | Subcoracoscapularis (subscapularis + subcoracoideus sensuSullivan, 1962, 1967, Dilkes, 2000 and Maxwell & Larsson, 2007) |
| – | – | Teres major | – [but see text] | Teres major | – |
| Latissimus dorsi | Latissimus dorsi | Latissimus dorsi | Latissimus dorsi | Latissimus dorsi | Latissimus dorsi |
| Triceps brachii | Triceps brachii | Triceps brachii | Triceps brachii | Triceps brachii | Triceps brachii |
| Humeroantebrachialis (part of biceps sensuRomer, 1944 and of brachialis sensuHowell, 1937b) | Humeroantebrachialis | Brachialis (brachialis inferior sensuRomer, 1944; Walker, 1973; Holmes, 1977; Dilkes, 2000 and Wyneken 2001) | Brachialis (brachialis inferior sensuRomer, 1944; Holmes, 1977 and Dilkes, 2000) | Brachialis (brachialis inferior sensuRomer, 1944; Holmes, 1977 and Dilkes, 2000) | Brachialis (brachialis inferior sensuHolmes, 1977 and Dilkes, 2000) |
| – [but coracoradialis present in other urodeles, see text] | Coracoradialis | Biceps brachii | Biceps brachii (humeroantebrachialis sensuDiogo & Abdala, 2007; and Diogo, 2007; short and long heads of biceps brachii sensuJouffroy, 1971) | Biceps brachii | Biceps brachii |
| Coracobrachialis (corresponds to the coracobrachialis longus/superficialis sensuWalthall & Ashley-Ross, 2006; Diogo & Abdala, 2007; and Diogo, 2007) | Coracobrachialis | Coracobrachialis (coracobrachialis magnus + coracobrachialis brevis sensuWalker, 1973 and Wyneken, 2001; which correspond respectively to the coracobrachialis longus + coracobrachialis brevis sensuHolmes, 1977 and Dilkes, 2000) | Coracobrachialis (coracobrachialis superficialis/longus + coracobrachialis profundus/ brevis sensuHowell, 1936a; Romer, 1944; Jollie, 1962; Holmes, 1977 and Dilkes, 2000) | Coracobrachialis (coracobrachialis brevis sensuHolmes, 1977 and Dilkes, 2000) | Coracobrachialis (coracobrachialis longus + coracobrachialis brevis, or coracobrachialis cranialis plus coracobrachialis caudalis, or coracobrachialis anterior + coracobrachialis posterior, sensuJollie 1962, Holmes, 1977 and Dilkes, 2000) |
| Pronator quadratus (pronator profundus sensuRibbing, 1907; Walthall & Ashley-Ross, 2006; Diogo & Abdala, 2007; and Diogo, 2007) | Pronator quadratus (pronator profundus sensuRibbing, 1907) [Ribbing, 1907 states that the ‘abductor pollicis’sensuGaupp, 1896 corresponds to the pronator quadratus, and not to the abductor pollicis brevis, sensu the present work] | Pronator quadratus (probably corresponds to part of the pronator profundus sensuWalker, 1973; the other part corresponding to the pronator accessorius sensu the present work; pronator profundus sensuAbdala et al. 2008) | Pronator quadratus (pronator profundus sensuMoro & Abdala, 2004; Abdala & Moro, 2006; Diogo & Abdala, 2007; and Diogo, 2007) | Pronator quadratus (pronator profundus sensuStraus, 1942) | Pronator quadratus |
| – | – | Pronator accessorius (probably corresponds to part of the pronator profundus sensuWalker, 1973; the other part corresponding to the pronator quadratus sensu the present work | Pronator accessorius | – | – |
| Contrahentium caput longum (ulnocarpalis sensuMcMurrich, 1903a,b;, Straus, 1942; and Bunnell, 1942) | Contrahentium caput longum (ulnocarpalis + intercarpalis sensuGaupp, 1896) | – | – [interestingly, our dissections indicated that a few ‘lizards’ may eventually have a small muscle that somewhat resembles the contrahentium caput longum of Ambystoma: see text] | – | – |
| Flexor accessorius lateralis (caput dorsale of flexor palmaris profundus sensuStraus, 1942; seemingly corresponds to the palmaris profundus III sensuMcMurrich, 1903a) | Flexor accessorius (sensuRibbing, 1907; palmaris profundus sensuGaupp, 1896; Straus, 1942 and Manzano et al. 2008b) | – [absent as an independent muscle in extant amniotes: see text] | – | – | – |
| Flexor accessorius medialis (caput volare of flexor palmaris profundus sensuStraus, 1942) | – | – [absent as an independent muscle in extant amniotes: see text] | – | – | – |
| Flexor digitorum communis (palmaris superficialis sensuMcMurrich, 1903a; flexor primordialis communis sensuRibbing, 1907) | Flexor digitorum communis (flexor primordialis communis sensuRibbing, 1907; flexor digitorum communis longus sensuManzano, 1996 and Manzano et al. 2008b) | Flexor digitorum longus (flexor primordialis communis + flexor accessorius communis sensuRibbing, 1907) | Flexor digitorum longus (palmaris communis sensuHolmes, 1977 and Dilkes, 2000; flexor digitorum communis sensuDiogo & Abdala, 2007; and Diogo, 2007; it probably also includes the ‘pronator radii teres’sensuMcMurrich, 1903a and Holmes, 1977; at least in taxa such as Sphenodon and ‘lizards’) | Flexor digitorum longus (palmaris communis sensuHolmes, 1977 and Dilkes, 2000) | Flexor digitorum longus (flexor accessorius communis sensuRibbing, 1938; palmaris communis sensuHolmes, 1977 and Dilkes, 2000) |
| – | – [but see text] | ‘Palmaris longus’ | – [but some lepidosaurs do have a ‘palmaris longus’] | – | – |
| Flexor carpi ulnaris (part of flexor antebrachii et carpi ulnaris sensuDiogo & Abdala, 2007; and Diogo, 2007) | Flexor carpi ulnaris | Flexor carpi ulnaris (part of the flexor carpi ulnaris sensuWalker, 1973 and Abdala et al. 2008) | Flexor carpi ulnaris (part of flexor antebrachii et carpi ulnaris sensuDiogo & Abdala, 2007 and Diogo, 2007) [according to Dilkes, 2000; the flexor carpi ulnaris is present in all major extant groups of reptiles] | Flexor carpi ulnaris | Flexor carpi ulnaris |
| Epitrochleoanconeus (flexor antebrachii ulnaris sensuMcMurrich, 1903a and Ribbing, 1907) | Epitrochleoanconeus (epitrochleo-cubitalis sensuGaupp, 1896 and Manzano et al. 2008b; flexor antebrachii ulnaris sensuMcMurrich, 1903a and Ribbing, 1907) | Epitrochleoanconeus (flexor antebrachii ulnaris sensuRibbing, 1907, 1938; part of the flexor carpi ulnaris sensuWalker, 1973 and Abdala et al. 2008) | Epitrochleoanconeus | Epitrochleoanconeus | Epitrochleoanconeus (flexor antebrachii ulnaris sensuRibbing, 1938; entepicondylo-ulnaris sensuMaxwell & Larsson, 2007) |
| Flexor antebrachii et carpi radialis (flexor carpi radialis sensuMcMurrich, 1903a,b;) | Flexor carpi radialis | Flexor carpi radialis [as described by Walker, 1973; Holmes, 1977 and Abdala et al. 2008; in turtles the pronator teres (which Holmes designates as a ‘head of the flexor carpi radialis’) and the flexor carpi radialis are usually present as distinct muscles] | Flexor carpi radialis (part of flexor carpi radialis sensuHolmes, 1977 and Dikes 2000) | Flexor carpi radialis (part of flexor carpi radialis sensuHolmes, 1977 and Dilkes, 2000 and of pronator teres sensuMeers, 2003) | Flexor carpi radialis (part of flexor carpi radialis sensuHolmes, 1977 and Dilkes, 2000; seems to correspond to the pronator superficialis sensuSullivan, 1962; Shellswell & Wolpert, 1977; Meyers, 1996 and Dilkes, 2000) |
| – | Pronator teres (flexor antebrachii radialis sensuRibbing, 1907; seems to correspond to the flexor antebrachii lateralis superficialis and profundus sensuGaupp, 1896; although Ribbing, 1907 stated that it actually corresponds to the flexor antebrachii medialis sensuGaupp, 1896) | Pronator teres (pronator radii teres Holmes, 1977) | Pronator teres (flexor antebrachii radialis sensuRibbing, 1907; part of flexor carpi radialis sensuHolmes, 1977 and Dilkes 2000) | Pronator teres (part of flexor carpi radialis sensuHolmes, 1977 and Dilkes, 2000 and of pronator teres sensuMeers, 2003) | Pronator teres (part of flexor carpi radialis sensuHolmes, 1977 and Dilkes, 2000; seems to correspond to the pronator profundus sensuSullivan, 1962; Shellswell & Wolpert, 1977; Meyers, 1996 and Dilkes, 2000) |
| Flexores breves superficiales (flexores digitorum breves superficiales sensuMcMurrich, 1903a; b) | Flexores breves superficiales | Flexores breves superficiales (flexor brevis superficialis sensuWalker, 1973; flexores digiti brevis superficiales sensuAbdala et al. 2008) | Flexores breves superficiales (part of flexores digitorum breves superficiales sensuMcMurrich, 1903a,b; flexores breves sublimes sensuHolmes, 1977; flexores digiti brevis superficialis sensuAbdala & Moro, 2006) | Flexores breves superficiales (part of flexores breves sublimes sensuHolmes, 1977; flexores digitorum breves superficiales and probably also flexor digiti quinti and/or transversus palmaris sensuMeers, 2003) | Flexores breves superficiales [see text] |
| – [but according to authors such as McMurrich, 1903a,b;, the lumbricales are present in other urodeles, such as Ambystoma tigrinum] | Lumbricales | Lumbricales (lumbricalis sensuAbdala et al. 2008) | Lumbricales | Lumbricales | – [see text] |
| Contrahentes digitorum (part of flexores digitorum breves medii sensuMcMurrich, 1903a,b;) | Contrahentes digitorum (part of flexores digitorum breves medii sensuMcMurrich, 1903a,b; probably includes the adductor pollicis sensuManzano et al. 2008b) | Contrahentes digitorum (includes adductor digiti minimi sensuWalker, 1973) | Contrahentes digitorum (part of flexores digitorum breves medii sensuMcMurrich, 1903a,b; and Lewis, 1989; include the flexor digitorum V transversus I and II of e.g. Abdala & Moro, 2006) | Contrahentes digitorum (part of flexores digitorum breves medii sensu authors such as McMurrich, 1903a,b; flexores digitorum intermedii sensuHolmes, 1977 and Meers, 2003) | Contrahentes digitorum |
| Flexores breves profundi (flexores digitorum breves profundi sensuMcMurrich, 1903a,b;) | Flexores breves profundi | Flexores breves profundi | Flexores breves profundi (flexores digitorum breves profundi sensuMcMurrich, 1903a,b; flexores digiti brevis profundus sensuAbdala & Moro, 2006) | Flexores breves profundi (flexores digitorum profundus, and possibly also flexor digitorum intermedius digiti V, sensuMeers, 2003; : see contrahentes digitorum) | Flexores breves profundi (flexores digitorum breves profundi sensuRibbing, 1938 and Holmes, 1977) |
| – [seemingly absent in Ambystoma ordinarium; see text] | Abductor pollicis brevis [see text] | Abductor pollicis brevis | Abductor pollicis brevis (abductor brevis pollici sensuAbdala & Moro, 2006) | Abductor pollicis brevis (abductor metacarpi I sensuMeers, 2003) | Abductor pollicis brevis [the ‘abductor alulae’sensuMeyers, 1996 corresponds to the ‘abductor indicis’sensuSullivan, 1962 and Shellswell & Wolpert, 1977 and goes to digit 1 (i.e. digit 2 according to embryology), thus seemingly corresponding to the abductor pollicis brevis sensu the present work] |
| Abductor digiti minimi (extensor lateralis digiti IV sensuWalthall & Ashley-Ross, 2006 and Diogo et al. 2009a) | Abductor digiti minimi (abductor primus digiti V sensuGaupp, 1896) | Abductor digiti minimi (abductor digitorum V sensuAbdala et al. 2008) | Abductor digiti minimi (abductor digitorum V sensuAbdala & Moro, 2006) | Abductor digiti minimi (abductor metacarpi V sensuMeers, 2003) | – |
| Intermetacarpales | Intermetacarpales (transversi metacarpi sensuGaupp, 1896; transversi metacarporum sensuBurton, 1998; transversus metacarpi superficialis + transversus metacarpi profundus profundus sensuManzano, 1996) | Intermetacarpales | Intermetacarpales (intermetacarpales I and II sensuAbdala & Moro, 2006; Diogo & Abdala, 2007; and Diogo, 2007) | Intermetacarpales (part of interossei dorsalae sensuMeers, 2003) | Intermetacarpales |
| – [see text] | Dorsometacarpales | Dorsometacarpales (possibly correspond to part of interossei dorsales sensuWalker, 1973; see intermetacarpales above) | Dorsometacarpales | Dorsometacarpales (part of interossei dorsalae sensuMeers, 2003) | Dorsometacarpales |
| Extensor antebrachii et carpi radialis (including extensor radialis longus + extensor radialis brevis sensuStraus, 1941a,b;) | Extensor antebrachii et carpi radialis | Extensor antebrachii et carpi radialis (extensor radialis superficialis, extensor carpi intermedius and extensor radialis profundus sensuHaines, 1939 and Walker, 1973; extensor carpi radialis sensuAbdala et al. 2008) | Extensor antebrachii et carpi radialis (including extensor radialis longus + extensor radialis brevis sensuStraus, 1941a,b; extensor carpi radialis sensuAbdala & Moro, 2006) | Extensor antebrachii et carpi radialis (extensor radialis superficialis, extensor carpi intermedius and extensor radialis profundus sensuHaines, 1939) | Extensor antebrachii et carpi radialis (including extensor carpi radialis sensuRibbing, 1938) [the extensor antebrachii et carpi radialis sensu the present work includes, very likely, the ‘extensor metacarpi radialis’ and the ‘supinator’sensuMeyers, 1996] |
| – [not present as an independent muscle in Ambystoma; see text] | – | Brachioradialis (tractor radii sensuHaines, 1939; Walker, 1973; Wyneken, 2001; and Abdala et al. 2008) | – [but seemingly present in Sphenodon; see text] | Brachioradialis (seems to correspond to the supinator sensuMeers, 2003) | – [but see text] |
| Extensor antebrachii et carpi ulnaris (extensor ulnaris sensuStraus, 1941a,b;) | Extensor carpi ulnaris | Extensor antebrachii et carpi ulnaris (extensor ulnaris sensuHaines, 1939; extensor carpi ulnaris sensuWalker, 1973 and Abdala et al. 2008) | Extensor antebrachii et carpi ulnaris (extensor carpi ulnaris + extensor antebrachii ulnaris sensuHaines, 1939; extensor ulnaris sensuStraus, 1941a,b; extensor carpi ulnaris + anconeus quartus sensuHolmes, 1977) | Extensor antebrachii et carpi ulnaris (flexor ulnaris sensuMeers, 2003; extensor carpi ulnaris + anconeus quartus sensuHolmes, 1977) | Extensor carpi ulnaris (seemingly corresponds to the extensor metacarpi ulnaris sensuShellswell & Wolpert, 1977 and Meyers, 1996) |
| – [but according to authors such as Haines, 1939; the anconeus is present in at least some urodeles, such as Salamandra: see text] | Anconeus (epicondylo-cubitalis sensuGaupp, 1896; extensor antebrachii ulnaris sensuRibbing, 1907) | – [but the anconeus is seemingly present in at least some other turtles, such as Testudo, Pelomedusa, Chelodina and Emys: see text] | – [but the anconeus is seemingly present in at least some lepidosaurs, such as Sphenodon: see text] | – | Anconeus (anconeus quartus sensuHolmes, 1977; seemingly corresponds to the ectepicondylo-ulnaris sensuMeyers, 1996 and Maxwell & Larsson, 2007) |
| Extensor digitorum (extensor digitorum communis sensuRibbing, 1907 and Walthall & Ashley-Ross, 2006; Diogo & Abdala, 2007; and Diogo, 2007; humerodorsalis sensuHaines, 1939) | Extensor digitorum (extensor digitorum communis longus sensuGaupp, 1896 and Manzano et al. 2008b; extensor digitorum communis sensuRibbing, 1907; humerodorsalis sensuHaines, 1939) | Extensor digitorum (humerodorsalis sensuHaines, 1939; extensor digitorum communis sensuWalker, 1973; extensor digitorum longus sensuAbdala et al. 2008) | Extensor digitorum (humerodorsalis sensuHaines, 1939; extensor digitorum longus sensuAbdala & Moro, 2006; extensor digitorum communis sensuDiogo & Abdala, 2007; and Diogo, 2007) | Extensor digitorum (extensor digitorum longus sensuHolmes, 1977 and Dilkes 2000; extensor carpi ulnaris longus sensuMeers, 2003) | Extensor digitorum (extensor digitorum longus sensuRibbing, 1938; Holmes, 1977 and Dilkes, 2000; extensor longus communis sensuDilkes, 2000) |
| Extensores digitorum breves | Extensores digitorum breves [probably correspond to the extensores breves superficiales, and, possibly, also to the extensores breves medii, sensuGaupp, 1896] | Extensores digitorum breves (extensores digiti brevis sensuAbdala et al. 2008) | Extensores digitorum breves (extensor digitorum brevis communis sensuHolmes, 1977; extensores digiti brevis sensuAbdala & Moro, 2006) | Extensores digitorum breves (extensor digitorum brevis communis sensuHolmes, 1977) | Extensores digitorum breves (extensores breves digitorum superficiales and seemingly also extensores breves digitorum profundi sensuRibbing, 1938; extensor digitorum brevis communis sensuHolmes, 1977) |
| Abductor et extensor digiti I (supinator manus sensuBrooks, 1889; Ribbing, 1907; Haines, 1939; Howell, 1936a,b; and Straus, 1941a,b;) | Abductor pollicis longus (abductor indicis longus sensuGaupp, 1896 and Manzano et al. 2008; supinator manus sensuHaines, 1939) | Abductor pollicis longus (supinator manus sensuHaines, 1939 and Walker, 1973) [according to Haines, 1939; Walker, 1973 and Abdala et al. 2008; turtles usually have an abductor pollicis longus running from the ulna to the metacarpal I] | Abductor pollicis longus (supinator manus sensuHaines, 1939 and Holmes, 1977; abductor longus pollicis sensuAbdala & Moro, 2006; abductor et extensor digiti I sensuDiogo & Abdala, 2007 and Diogo, 2007) | Abductor pollicis longus (supinator manus sensuHolmes, 1977) | Abductor pollicis longus (abductor digit 1 sensuRibbing, 1938; supinator manus sensuHolmes, 1977) |
The nomenclature of the muscles shown in bold follows that of the text; in order to facilitate comparisons, in some cases names often used by other authors to designate a certain muscle/bundle are given in front of that muscle/bundle, between round brackets; additional comments are given between square brackets. Data compiled from evidence provided by our own dissections and comparisons and by an overview of the literature (see text, Tables 2 and 3, and Figs 1–10).