Very very strange.....

you dont think maybe it grew around a twig or something ?

and it fell off later ?

that is very strange.

i do have a mango seedling with 2 sprouts coming from the same seed, when i transplanted, they did not want to seperate... but none were twisted.

Definitely not a twig or any physical object causing it. I've keep an eye on this seedling daily ever since it sprouted, because I usually have to bring it in and outside every time the weather warms or cools, as I'm in zone 8b. Another sprout actually popped up since taking that pic.

I can confirm now that it actually does appear to be two trunks twisted together. They may actually be starting to separate at the area where the bottom left leaf is. The top half inch or inch or so seems to be straight, but I'll definitely keep an eye on it and see how it goes.

very cool

I guess I should start a 'mangoes behaving badly' thread, because this one not only busted/sprout out of the side of the cup I was propagating it in, but it too has two fused trunks.

I have had polyembryonic seeds grow 2 stalks, with yours I suspect they grew toward each other under the surface of the dirt and erupted together?

At least one of these mangoes were suppose to be monoembryonic, being a seedling of a Kent mango.

Well if the seeds were planted vertically I could see them growing together if they were poly.

You could uproot the seed that will tell you for sure if its 2 separate trees or a split on the trunk.

In either case letting it grow will be interesting.