Assertion: mollusk's gill | /r/CapableOf | become adapted for filter feeding
Facets:
value: by the early silurian
type: TEMPORAL
Source sentences:
text: The protobranchs feed in a different way, scraping detritus from the seabed, and this may be the original mode of feeding used by all bivalves before the gills became adapted for filter feeding.
text: By the Early Silurian, the gills were becoming adapted for filter feeding, and during the Devonian and Carboniferous periods, siphons first appeared, which, with the newly developed muscular foot, allowed the animals to bury themselves deep in the sediment.