Assertion: echidna's spine | /r/HasProperty | up to 50 mm long
Facets:
Source sentences:
text: The spines, which may be up to 50 mm long, are modified hairs, mostly made of keratin.
text: Their body, except for the underside, face and legs, is covered with cream coloured spines, which can be up to 50 millimetres long, there is fur between these spines, with colours that vary from golden to dark red brown and black.