The functional and phylogenetic implications of the myology of the lumbar region,

Transcription

1 The functional and phylogenetic implications of the myology of the lumbar region, tail, and hind limbs of the lesser grison (Galictis cuja) Journal of Mammalian Evolution Marcos D. Ercoli, Sebastián Echarri, Felipe Busker, Alicia Álvarez, Miriam M. Morales, and Guillermo F. Turazzini Correspondence Marcos D. Ercoli, Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Av. Ángel Gallardo 470, C1405DJR, Buenos Aires, Argentina. T: ; E:

2 Specimen 1 Specimen 2 Specimen 3 Intraspecific variation Left Right Left Right Left Right M. sacrocaudalis ventralis medialis First bundles are well distinguishable Bundles strongly fused First bundle originates on the anterior aspect of the first vertebra of the sacrum First bundle originates on the posterior aspect of the first vertebra of the sacrum M. sacrocaudalis ventralis lateralis Broadly fused with the m. sacrocaudalis ventralis medialis M. sacrocaudalis dorsalis lateralis Some fibers originate anteriorly on the accesory processes of the last thoracic vertebra Mm. intertransversarii ventralis caudae Conformed by two bellies that reach the seventh and eighth caudal vertebrae Conformed by multiple packages; it runs to the last caudal vertebrae Strongly fused with the m. coccygeus M. iliocaudalis The two origin areas are clearly differentiated Insertion is by a thin tendon that reaches the fifth caudal vertebra Some fibers insert anteriorly, at the level of the third caudal vertebra M. psoas minor Origin on the first and second lumbar vertebra?? Origin on the second and third lumbar vertebra?? M. iliacus Conformed by a small number of fibers?? M. psoas major The origin is anteriorly epanded reaching the antepenultimate lumbar vertebra (including this third element)?? M. quadratus lumborum Broad fusion of bundles that originate in thoracic region?? Partial fusion of bundles that originate in thoracic region?? The last bundles takes origin in the transverse process of the last and penultimate lumbar vertebrae?? Lumbar bundles virtually indistinguishable?? The bundles originated on the anticlinal vertebra are absent?? The origin area of the last bundles reach the base of the transverse process?? Broad fusion between the anterior lumbar bundles of the m. quadratus lumborum and the m. psoas major?? M. gluteus superficialis Posterior subdivision present, seem like the m. gluteofemoralis The origin of the posterior bundles are independent and tendinous; on the transverse process of the first caudal vertebra and the surrounding fascia M. gluteus medius Dorsal and ventral packages well differentiated

3 Broad fusion between m. gluteus medius and m. piriformis M. gluteus medius and m. piriformis distally fused M. gluteus medius and m. pririformis fully independent M gluteus profundus Subdivided in three packages, the etra package insert directly on the dorsal end of the greater trochanter Sharing of some fibers with the m. tensor fascia latae M. biceps femoris Fusion with anterior edge of m. semitendinosus lacking Area of origin epanded anteriorly, dorsal to m. quadratus femoris origin Independent insertion respect to m. biceps femoris M. abductor cruris caudalis Two areas of origin: one dorsal on the mm. intertransversarii dorsales caudae, and the second one on the anterior half of the transverse process of the first caudal vertebra, below mm. intertransversarii dorsales caudae. The fibres from both origins fuse each other early M. semitendinosus Both bellies partially differentiated at insertion Origin via aponeurosis in the third caudal vertebra absent M. semimembranosus A small "third belly" is present between principal bellies M. sartorius Etended origin on the anterior edge of the wing of ilium and by fleshy fibers from the anterior edge of the m. gluteus medius and m. gluteus superficialis M. quadratus femoris Broad insertion on the medial margin of the trochanteric fossa M. vastus medius Partially fused with m. vastus intermedius, ecept in half of its way Totally fused with m. vastus intermedius M. gracilis Origin area differentiated in two bellies early fused M. pectineus Subdivided in two sheets, one deep (or lateral) and other medial (or superficial) M. adductor longus The two bellies are practically indistinguishable M. adductor magnus The insertion area etend proimally, covering the distal quarter of the femoral diaphysis M. gastrocnemius Proimal fusion between the m. gastrocnemius caput laterale and the m. fleor digitorum superficialis A group of fleshy and tendinous fibers with anomalous position. It takes origin on the first quarter of the eternal surface of the m. gastrocnemius caput laterale and m. fleor digitorum superficialis, then it involves the m. gastrocnemius caput laterale and inserts on

4 the lateral and proimal surfaces of the fibula on the m. fibularis longus M. soleus Partially divided in two packages M. fleor digitorum superficialis Insertion on the calcaneus completely independent to that of the m. gastrocnemius After it crosses the tarsal joint, its continues like a flat and well defined tendon that fuses with the origin of the m. fleor digitorum brevis A large number of fibers remains partially independent and above the ventral surface of the m. fleor digitorum brevis M. fibularis longus Origin area is relatively reduced M. fibularis brevis Partial fusion of the bellies near their origin Anterior belly large than the posterior one Proimal to the lateral maleollus, the muscular fibers of the anterior belly become a flat tendon Proimal to the lateral maleollus, the muscular fibers of the posterior belly become early a flat tendon Proimal to the lateral maleollus, the muscular fibers of the posterior belly become early a flat tendon The tendon of the posterior belly forms a ring for the passage of the anterior one Bellies fused and a sesamoid bone is present in this joint M. tibialis cranialis Insert on the medial-dorsal fascia of tarsus instead of the medial aspect of the ventral tubercle of metatarsal I M. etensor digiti I longus Insertion through a tendon moderately differentiated, on the etensor tubercle of the distal phalange of the II digit instead of the digit I M. etensor digitorum brevis Insertion by a group of tendinous fibers which do not form a defined tendon The most medial belly continues like a group of tendinous fibers or aponeurosis, and reach the m. etensor digiti I longus at the level of the tarsal-metatarsal joint Tendon of the digit I is clearly diferentiated and distally fused with the m. etensor digiti I longus Tendons for the digits II, III and IV are clearly diferentiated and the insertion in the digit I is absent A group of lateral fibers as an aponeurosis insert on the tarsometatarsal joint of the fifth digit, fusing with m. fibularis brevis and then indirectly with the m. etensor digitorum longus and m. etensor digitorum lateralis The principal tendon for the digit II is distally subdivided in two

5 tendons M. abductor digiti V A medial group of fibers forms a tendon that inserts in the medial surface of the distal phalange of the fifth digit M. fleor digitorum brevis Tendons split early Tendon for the digit V inserts on the proimal phalange instead the intermediate M. quadratus plantae Somes tendinous fibers originate at a small area in the posterior and distal margin of the fibula Some fibers originate on the m. abductor digiti V Some fibers originate independently on the ventral-medial surface of the calcaneus tubercle Mm. lumbricales Four lumbricales are present, including an etra belly between digits I and II Lateral lumbrical hypertrophied. It insert distally, in the fleor tubercle of the distal phalange of digit V Mm. adductores digitorum A small group of fibers split between the bellies for digit II and V and insert between the tendons of digits III and IV of the mm. fleores?? breves profundi Mm. fleor breves profundi Lateral belly of the mm. fleor breves profundi digiti II is subdivided in two bellies Lateral belly of the mm. fleor breves profundi digiti IV is subdivided in two bellies Three bellies conform the mm. fleores digitorum profundi III Bellies of the mm. fleores digitorum profundi IV are fused Bellies of the mm. fleores digitorum profundi II and III are fully fused. They only separate from each other near the insertion site on each digit Bellies of the mm. fleores digitorum profundi III and IV are fully fused The medial packages of the mm. fleor breves profundi digiti II originate on the proimal end of the metatarsal I and on its lateral projection Additional proimal area of origin on the medioventral surface of the calcaneus of the medial belly of the mm. fleor breves profundi digiti I placed, where it is attached by means of a thin tendon The lateral belly of the digit IV is larger than the medial one, and originates on the proimo-medial aspect of the metatarsal V Some fibers of the medial and lateral part of the mm. fleor breves profundi digiti V reach the calcaneus