Assertion: mastodon's jaw | /r/HasProperty | opened to about a 90° angle
Facets:
value: to free the upper canines
type: PURPOSE
Source sentences:
text: In addition, the jaw could be opened to about a 90° angle to free the upper canines for action; however, some paleontologists suggest that since the muscles in the jaw would have had to stretch significantly to enable such a wide gape, they would have been relatively weak compared with those of modern cats.