It's possible that the comb jelly also evolved its nervous system after diverging from the common ancestor.
Caption: The comb jelly Mnemiopsis leidyi rests at the base of the tree of animal life, according to analyses of its genome.
Leidy's comb jelly eats the myriad tiny animals known collectively as zooplankton.
from The Leidy's comb jelly, a jellyfish native to the the Americas western Atlantic coast, devastated the Black Sea fisheries.
A harbinger, perhaps, of what the Leidy's comb jelly may do if it makes its way down from the north.
It's not just their appearance that is wondrous: Slice a comb jelly embryo in two and you get two half-adults that can fertilize themselves to give birth to a perfectly whole offspring.
It's even possible that the sophisticated comb jelly lineage may have evolved before the brainless, gutless, muscle-less sea sponges.
This specimen from the Arctic is probably a new species of comb jelly
, (Unlike true jellyfish, in the phylum Cnidaria, comb jellies don't have stinging cells.