Assertion: amphisbaena's neck | /r/HasAspect | a pair of ribs
Facets:
Source sentences:
text: Though they share many traits with other squamates, there are a few traits unique to them and they include: pectoral girdle and forelimbs absent but some may have a “rudimentary” pelvic girdle or hindlimbs in the form of a bony spur, 120 to 500 vertebrae, each neck and trunk vertebra has a pair of ribs making them extremely flexible, in the cranium the supraoccipital is excluded from the margin of the foramen magnum by exoccipitals, flexible ligamentous symphysis between the dentaries allows the right and left jaw to widely spread apart, left lung absent or largely reduced, dominant right lung, ophthalmic branch of the trigeminal nerve is enclosed within the brain case and enters the orbit through the optic foramen (in other squamates the nerve is not enclosed and enters the orbit posteriorly), the left arterial arch is larger than the right (in all other tetrapods it is the reverse), and the absence of ciliary-body muscles in the eye (Pough et al.