Forelimb anatomy of new world monkeys: Myology and the interpretation of primitive anthropoid models

Abstract

The forelimbs of 12 genera of New World monkeys, two genera of Old World monkeys, and a gibbon were dissected. Of the 54 muscles examined, 19 exhibited significant intergeneric variation. We present arguments for which morphologies are primitive and which are derived within platyrrhines and within anthropoids. We conclude that the forelimbs of Cebus apella and Callicebus moloch represent good models of the ancestral anthropoid morphology. Thus among living anthropoids they are most appropriate for comparisons with early fossil anthropoids. They are also useful for determining whether myological anomalies of human aneuploids are atavistic. Wagner tree analyses were conducted to assess the value of these myological characters in phylogenetic studies of platyrrhines. In most respects the Wagner trees were consonant with phylogenies previously proposed, although some hypothesized trees are less parsimonious than others in explaining our data. There is an unexpected number of derived features shared by Aotus and the Atelines. There are marked dissimilarities in forelimb musculature between Aotus and Callicebus.

Systematic and comparative morphologies of the extrinsic cardiac nervous system in lemurs (Primates: Strepsirrhini: Infraorder Lemuriformes, Gray, 1821) with evolutionary morphological implications

“…The terminologies used for the somatic structures followed those used in previous publications by Jouffroy (1962), El-Assy (1965-66), Stevens et al (1981), Dunlap et al (1985), and Kawashima and Thorington (2011).…”

An unusual elbow muscle in the red howler monkey: does it deserve invention of a new name musculus contrahens cubiti?

“…In humans, such proximal origin of additional head has been found near the insertion of m. deltoideus (Gruber, 1848, cited after Rodriguez-Nedenführ et al, 2001. Dunlap et al (1985) described a similar additional head of the m. brachioradialis in squirrel monkeys (Saimiri sciureus): its origin was found on the pectoral crest of the humerus, medial to the insertion of the m. pectoralis major (s. superficialis). Apparently, the presence of two heads of the m. brachioradialis, one running from the lateral epicondyle and the other from the pectoral crest, is the usual condition in squirrel monkeys.…”

“…Summarizing the available literature, we can state that a similar muscle has not been reported neither as the normal condition, nor as an anomaly in either howlers (Sirena, 1871;Schön, 1968;Youlatos, 1999), or in other platyrrhines (Dunlap et al, 1985;Youlatos, 2000), or even in non-human primates as a whole (Diogo and Wood, 2012). Additionally, never have we met a single reference of this muscle in any non-primate mammal, and nothing whatsoever in the recent review by Diogo and Abdala (2010).…”

Descripción Anatómica del Músculo Braquiorradial del Tití Gris (Saguinus leucopus Günther, 1877) y el Hallazgo de una Cabeza Accesoria como Variante Anatómica

“…Entre la musculatura cráneo-lateral del antebrazo de primates (posterior en humanos) se encuentra el músculo braquiorradial, el cual, presenta diferentes distribuciones de su origen e inserción entre las especies descritas (Ackermann, 2003; Aversi-Ferreira et al, 2010;Champneys, 1871;Cribillero et al, 2009;Diogo & Wood, 2012;Dunlap et al, 1985;Hepburn, 1892;Hill, 1959;Kimura & Takai, 1970;Michilsens et al, 2009;Primrose, 1900;Standring, 2008;Stevens et al, 1977;Testut & Latarjet, 1984;Youlatus, 2000); por lo tanto, el objetivo del presente estudio es caracterizar la anatomía de este músculo en el Saguinus leucopus.…”

“…Su postura y locomoción son cuadrú-pedas, para movilizarse principalmente con saltos, y suspenderse y adherirse a las ramas y troncos de los árboles (Defler), lo que se puede llevar a cabo gracias a la fuerza que suplen los músculos al sistema esquelético (Kardong, 2011), que al igual que todos los de su género tienen adaptaciones morfológicas, como la presencia de garras en sus manos para desgarrar la corteza de los árboles y alimentarse del látex que fluye de ellos (Ankel-Simons, 2007; Morales- Jiménez et al, 2008). Por lo tanto, el conocimiento de las condiciones morfológicas de estos animales permitirán posteriores estudios funcionales (Marques et al, 2006), en especial si estudiamos sus músculos.Entre la musculatura cráneo-lateral del antebrazo de primates (posterior en humanos) se encuentra el músculo braquiorradial, el cual, presenta diferentes distribuciones de su origen e inserción entre las especies descritas (Ackermann, 2003; Aversi-Ferreira et al, 2010;Champneys, 1871;Cribillero et al, 2009;Diogo & Wood, 2012;Dunlap et al, 1985;Hepburn, 1892;Hill, 1959;Kimura & Takai, 1970;Michilsens et al, 2009;Primrose, 1900;Standring, 2008;Stevens et al, 1977;Testut & Latarjet, 1984;Youlatus, 2000); por lo tanto, el objetivo del presente estudio es caracterizar la anatomía de este músculo en el Saguinus leucopus. …”