Muscular anatomy of the forelimbs of the lesser grison (Galictis cuja), and a functional and

Transcription

1 Muscular anatomy of the forelimbs of the lesser grison (Galictis cuja), and a functional and phylogenetic overview of Mustelidae and other Caniformia Journal of Mammalian Evolution Marcos D. Ercoli, Alicia Álvarez, M. Ignacio Stefanini, Felipe Busker, Miriam. M. Morales Correspondence Marcos D. Ercoli, División Mastozoología, Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Av. Ángel Gallardo 470, C1405DJR, Buenos Aires, Argentina. T: ; E: marcosdarioercoli@hotmail.com

2 specimen 1 specimen 2 specimen 3 Intraspecific variation left right left right left right M. cutaneus trunci Etra thin strip inserting into superficial and lateral surface of the arm Etra thin strip inserting into superficial and lateral surface of elbow Thin band emerging from the ventral margin, partially fused with the posterior margin of mm. pectorales, and inserting between the m. pectoralis profundus and m. latissimus dorsi, merging with the latter M. trapezius pars cervicalis Cranial origin on C3 Cranial origin on C4 Insertion reaching proimolateral aspect of metacromion, and enters in contact with m. omotransversarius Tendinous origin in middle zone, cranial to the tendinous intersection M. trapezius pars thoracis Partial subdivision into two bellies, the anterior larger and the posterior one smaller Proimal insertion partially fleshy M. cleidocephalicus pars mastoidea Fleshy fibers present in the origin M. cleidocephalicus pars cervicalis More caudal origin on C3 More caudal origin on atlas or ais Presence of rudimentary clavicle in insertion M. cleidobrachialis Absence of contact with m. pars deltoideus acromialis M. rhomboideus capitis Partially fused with the m. rhomboideus cervicis at the insertion Attachment fibers eclusively fleshy M. rhomboideus profundus Some tendinous fibers originate on the m. splenius The tendinous origin attain the entire posterior margin of the atlas, immediately caudal to the origin of m. omotransversarius M. rhomboideus cervicis Subdivision into two bellies? M. omohyoideus

3 Absence of insertion onto the basihioid bone M. deltoideus Origin of m. deltoideus pars scapularis is continuous distally with the m. pars deltoideus acromialis Absence of origin on the basis of metacromion for the m. deltoideus pars acromialis M. supraspinatus Presence of a sesamoid bone at the insertion of the cranial belly No fibers shared between m. supraspinatus and m. subscapularis Insertion of cranial belly onto the cranial aspect of lesser tubercle; secondary insertion onto the other bellies of m. supraspinatus and bicipital groove vicinity M. latissimus dorsi Origin from the rib of T10?? Origin from the rib of T13?? More cranial origin reaching the raphe at the level of T3 M. pectoralis superficiales Total differentiation of proimal and distal portions of the caudal belly? Cranial origin of the proimal portion of caudal belly via tendinous fibers Proimal portion of caudal belly reduced at its insertion Etended area of insertion of proimal belly; overlapping laterally with distal belly M. pectoralis profundus Lack of fusion between dorsocaudal margin of m. pectoralis profundus and the ventral margin of the m. latissimus dorsi Distal differentiation between bellies nearby to their insertion Origin of cranial belly from lateral aspect of the cranial sector of third sternebra? Origin of cranial belly from the lateral aspect of the whole sternebra?? Origin of the cranial belly etended from third sternebra to the laterocranial end of fifth sternebra?? Cranialmost origin of caudal belly reaching the caudal half of third sternebra? Cranialmost origin of caudal belly reaching the caudal end of third sternebra??

4 Cranialmost origin of caudal belly reaching the caudal end of fourth sternebra?? Lacking of insertion of cranial belly onto the base of greater tubercle of humerus Lacking of insertion of cranial belly onto the lesser tubercle of humerus M. triceps brachii, caput laterale Proimal fusion between lateral and accesory triceps heads Origin entirely fleshy Origin including some tendinous fibers M. triceps brachii, caput accesorium Well defined fascia present in origin Origin including some tendinous fibers M. triceps brachii, caput mediale, principal Both bellies are indistinguishable and are fused to the m. triceps brachii caput accesorium M. triceps brachii, caput mediale, intermedius Sturdy, subdivided distally in two bellies M. triceps brachii, caput mediale accesorium Markedly reduced Origin etending to the base of the entepicondylar foramen bridge M. subscapularis Caudal belly covered by a tendinous fascia in most of its etension M. infraspinatus Tendinous origin etends across the entire dorsal margin of infraspinous fossa Tendinous origin confined to the caudal angle of the infraspinous fossa M. teres major Reduced insertion; continuing with the m. triceps brachii caput mediale, "intermedius" Broad insertion; separated from m. triceps brachii caput mediale, "intermedius" Broad insertion; continuing with m. triceps brachii caput mediale, "intermedius" M. teres minor Some tendinous fibers originate from the m. infraspinatus Absence M. articularis humeris Diffuse origin from tissues surrounding shoulder Punctual origin from tissues, from the cranial

5 margin of the m. subscapularis M. brachialis Tendinous fibers in origin Tendinous fibers reaching the radius near the ulnar insertion M. brachioradialis Origin reaching the middle of the humeral shaft; additional tendinous origin from insertion fibers of the m. brachialis Origin etends to the proimal and caudolateral section of humerus, near humeral neck Some fibers taking origin from m. brachialis M. fleor carpi ulnaris Humeral belly larger than the ulnar one at the insertion onto the accesory bone M. pronator teres Subdivision into bellies poorly defined and only in type of fibers Tendinous fibers in the origin of proimal belly Rudimentary and tendinous third belly present M. palmaris longus Origin eclusively tendinous Lack of well defined tendons for digits Tendon for digit II present Tendon for digit V present Presence of small muscle bundle partially differentiated on the tendinous surface; it reaches digit I via a tendon M. etensor digitorum communis Without subdivision Late subdivision of tendons corresponding to digits II and III M. etensor digitorum lateralis Lateral belly becomes a tendon at the level of middle forearm Lateral belly becomes a tendon at the level of distal third of forearm Medial belly originates through tendon Medial belly originates through some tendinous fibers Differentiation of the two bellies distal to the origin Tendon of insertion onto digit III fused with tendon of insertion of m. digitorum communis M. fleor digitorum profundus Early fusion between both bellies of caput

6 humerale lateral Origin of caput ulnare etends to the base of olecranon Presence of a sesamoid bone in the tendon of insertion of caput ulnare, at the level of the point of fusion whit common tendon M. fleor digitorum superficialis The origin of belly for digit II largely independent Belly for digit II reduced Insertion tendon onto digit II not subdivided? M. etensor digiti I et II Origin etends to the lateral aspect of olecranon M. etensor carpi radialis longus et brevis Common origin of both muscles; differentiation at the level of wrist Differentiation of both muscles at the level of distal third of forearm Both muscles independent Insertion tendon for digit III gives off an etra slender slip to the digit II M. lumbricales Absence of lumbrical for digit II? Some bundles reaching middle phalan M. abductor digiti V Composed by a single belly Broad insertion through fleshy and tendinous fibers Broad insertion through tendinous fibers Reduced insertion via small tendon M. opponens digiti V Insertion tendon passing over and becoming lateral to the tendion of m. fleor digitorum prfundus Origin from metacarpal V and its sesamoid only indirect, through ligaments Fused at origin with mm. fleores breves profundi of digit V Fused to the metacarpo-phalangeal joint, near the insertion Insertion onto the proimopalmar aspect, instead lateroproimal, of middle pahalan M. abductor et opponens digiti I Additional insertion via fleshy fibers onto the medial aspect of the ventral surface of metacarpal I M. adductores digitorum, II Belly for digit II absent Mm. fleores breves profundi

7 Additional origin via tendon from distal sector of accesory bone M. abductor digiti IV Broad origin occupying the proimal half of the?? medial aspect of metacarpal V M. serratus ventralis Differentiation of cervical and thoracic sectors at the rib of T2 Differentiation of cervical and thoracic sectors at the rib of T2-T3 Differentiation of cervical and thoracic sectors at the rib of T3 Presence of and eighth fascicle within cranial portion, originating from the rib of T3 Overlap of adjacent fascicles at the level of T2 Caudalmost origin reaching the rib of T7?