bi-valve is a type of sex position for cows.
Some examples of univalves are snails and slugs.
sand burrowing mollusc
one has three cusps (tri) and the other has two (bi)
there is actually more than one valve in the heart. there is the semilunar, bi-cuspid, tri-cuspid
I think it's bivalvular
BisonBitternBighornBinturongBilbies
it is called a bivalve
If it has the bi-metal spring actuated valve it has a donut. If it has a vacuum operated valve it has no donut.
birds
from various animals and animal bi-products!
Bi-cuspid means having two cusps or flaps. It is used in relation to the heart valves. Mitral valve is a bicuspid valve.
Animals will sometimes mount another animal in a show of dominance not for sex.