Question: What kind of Salamanders do I have??? Help ASAP please!

Hello, all! This is my very first time posting, so I apologize if I am not in the right forum or just not doing this correctly. But I have a huge question that I greatly need assistance on ASAP! I've been an axolotl owner for about a year now. So about a month ago I purchased two (what I thought were) axolotls from a guy who didn't know anything about axolotls, salamanders, etc... They looked like Axolotls when I got them, but I noticed one of them started to lose it's gills, like they were shrinking. I posted on Reddit asking what they were and people were telling me they were a type of salamander. I just want to know what kind it is? I live in the USA (Utah to be precise). I know they are salamanders for sure now because I took the little guy without gills out of the water to see if he could breath and he can, so I transferred him to a terrarium with dampened Sphagnum moss and a water bin/rock/cave combo thing and he is totally outta the water burrowing in the moss! I have attached some photos. They are quite little 411. Everything I read said that they usually morph when they're bigger, but my little one just went for it young! Please let me know if you know what kind of salamander this is and any pointers will be much appreciated since I am totally new to this species! Thank you XOXO

First off i would just like to say that axolotls are also a type of salamander, even though they are aquatic

These look like they are probably tiger salamanders. Also, many people have been sold axolotls that ended up being tiger salamanders because when they are larvae they look similar and if the origin of them is unknown ( wild caught vs. captive bred ) someone could easily confuse the two.
Once terrestrial you can keep them as described in the following care sheets.
Caudata Culture Articles - Tiger Salamander 101
Caudata Culture Species Entry - Tiger salamander

As for the one that is still aquatic, continue to keep it like an axolotl. However if it starts to show signs of morphing provide and area where it can easily climb out of the water. You can do so by adding a cork float, turtle dock etc..

Hope this helps!
-Seth

I'm sorry! I just wanted to make it clear that I haven't taken care of tiger salamanders, etc. Just experience with Axolotls specifically. You've been a lot of help, thank you so much! So is it possible to tell the coloring these ones will get or is it kind of a surprise? I saw some are just blackish grey and some have colored spots.

Just a surprise. Most likely you will have gotten Barred tiger salamanders which have bold black and yellow stripes all over the body and tail. Easterns show up occasionally, and they typically have small oval markings of color all over the body that can be yellow, but other colors show up as well. Here is the care-sheet: Caudata Culture Species Entry - Tiger salamander

And the 101 guide: Caudata Culture Articles - Tiger Salamander 101