Assertion: viper's fang | /r/CapableOf | snap into biting position
Facets:
Source sentences:
text: Head: Broad, flat and round-snouted, with center-ridged (or keeled) scales; forward-set moderately large eyes with vertical pupils (much like those of the Southwestern rattlesnakes); distinctive supraorbital horns (which may not always be present in all populations or even individuals); hinged hollow fangs that snap into a biting position when the snake opens its mouth.
text: Broad, flat and round-snouted, with center-ridged (or keeled) scales; forward-set moderately large eyes with vertical pupils (much like those of the Southwestern rattlesnakes); distinctive supraorbital horns (which may not always be present in all populations or even individuals); hinged hollow fangs that snap into a biting position when the snake opens its mouth.