Assertion: billed duck | /r/HasProperty | a sister species
Facets:
value: to a clade
type: TRANSITIVE-OBJECT
Source sentences:
text: A molecular phylogenetic study published in 2009 that compared mitochondrial DNA sequences from ducks, geese and swans in the family Anatidae found that the Indian spot-billed duck was a sister species to a clade containing the Mexican duck, the American black duck, the mottled duck and the mallard.