This is interesting. Two ova + two sperm = fraternal twins. One ovum + one sperm + splitting = identical twins. Now there’s a new twist in the tale: two sperm + one ovum + splitting = semi-identical twins.
I’m a little surprised that this hasn’t been described before – perhaps it has for other animals?
In other biology news, a monster cane toad. Who can tell me the error in the first paragraph?