Was this worthy of suspension?

So I'm in tenth grade.
I got suspended for one day on Friday, and the one day is tomorrow.
My parents grounded me and I still can't figure what I did wrong?
So I have a really close friend and her name is Safiya.
I love Safiya, but she admittedly has huge teeth. They are very white and straight, they're just very big.
I still think she's beautiful but a lot of people make fun of her for it behind her back.
I think that's mean cuz she can't control that.
Like all the time when I tell people about her they'll say "Oh the girl with the teeth" and I tell them " You seriously couldn't have found any other way to identify her?"
But basically, I hate when people make fun of her teeth.
So there's another girl in our grade who we both don't like. Her name is Maria, in short we just don't like her.
Maria is in my fifth period, and on Friday we were looking at skulls since it's a science class.
We were looking at a pic of a T Rex skull.
She said "Wow that looks like the skull of Safiya."
Everyone immediately knew who she was talking about and they all started laughing. My face got red, and out of anger I screamed at her
"Shut up Maria! Your body is shaped like a damn IPhone!"
We both got sent to the principals office, and I got suspended cause Maria cried over it. I don't know what she got but I hope she got suspended too.
I tried saying that Safiya would have cried too if she heard what Maria said, but I still got suspended which I still don't get.
What did I do wrong?

You screamed and swore and said "shut up" in the middle of class. I'm guessing the teacher was offended by your behavior.
There are better ways to defend your friend. Use your brain.

Honestly kid, you did a good job! You stood up for your friend. But obviously being in school at a young age, where they are trying to set a better example for you guys, certain snap might come off as being a no no for the rest of the students, even though you guys know alot more than what the teachers would like.

Great fiction story, publish it and make money, look forward to seeing more of your work .oh one more thing there's no school tomorrow