The humeral spot (black spot) is more pronounced on altus but visible at certain angles on falcatus.
Altus has a shorter top jaw by a little. Or under bite.
Falcatus jaws are even.
Your fish has a under bite.
But other then a little difference in jaw structure. They both act the same and obtain the same size in aquaria. And falcatus are more popular so that may be a alternate replacement for you.
How long did you have it?
What was its diet?
Sorry for the loss I wish you would have shown the fish sooner.
Cuda's are my favorite fish I currently own 12.