Assertion: feather's structure | /r/HasProperty | recognized as the precursors of feathers
Facets:
value: commonly
type: TEMPORAL
Source sentences:
text: Filamentous structures, which are commonly recognized as the precursors of feathers, have been reported in the small-bodied, basal tyrannosauroid Dilong paradoxus from the Early Cretaceous Yixian Formation of China in 2004.