M. rectus capitis lateralis.

<p>A) Dorsolateral view on the M. rectus capitis lateralis (rcl). The muscle originates ventrally from C3-C5 (indicated by asterisks), wraps around the neck and inserts on the cranium. The M. rectus capitis lateralis is located superficially from the M. splenius capitis (sc) and M. rectus capitis dorsalis (rcd). Coordinate system indicates ventral (V), cranial (Cr), dorsal (D) and caudal (Ca). Scale bar represents one centimetre. B) Connection diagram from lateral view of M. rectus capitis lateralis in <i>T</i>. <i>f</i>. <i>pratincola</i>; origin and insertion sites are connected with lines representing the muscle slips, broken lines indicate tendinous parts. C) Connection diagram from dorsal view of M. rectus capitis lateralis in which the muscle attachment sites are indicated with red circles and are interconnected by a line representing the muscle slips. The blue lines represent ventrally located slips, which are thus actually behind the field of vision in a dorsal view. D) Dorsal view on the skull with indicated insertion sites of the M. rectus capitis lateralis. Foramen magnum (FM) and condylus occipitalis (CO) are indicated. Scale bar represents one millimetre (adapted from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0134272#pone.0134272.ref005" target="_blank">5</a>]). E-G) Origins of the M. rectus capitis lateralis indicated with red ellipses in the three-dimensional models of the vertebrae of <i>T</i>. <i>f</i>. <i>pratincola</i> from ventral view (cranial is on top) of vertebrae (C3-C5). Scale bars in E-G represent one millimetre (adapted from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0134272#pone.0134272.ref005" target="_blank">5</a>]).