Assertion: exoskeleton | /r/CapableOf | spring up in short course of time
Facets:
value: very
type: DEGREE
value: before the cambrian period
type: TEMPORAL
Source sentences:
text: It is known, however, that in a very short course of time, just before the Cambrian period, exoskeletons made of various materials – silica, calcium phosphate, calcite, aragonite, and even glued-together mineral flakes – sprang up in a range of different environments.