Assertion: vertebrate | /r/CapableOf | evolve flatter body
Facets:
value: for swimming
type: PURPOSE
Source sentences:
text: The first vertebrate may have been a sediment-dwelling animal that evolved a flatter body for swimming, a mobile larva of some sort that began retaining its larval features into adulthood, or a stationary filter-feeder that evolved into a free-swimming animal.