Help with an ID

Hello.
I bought these cacti a few months ago at Redcliff show and want to find out more about them and how to care for them but for that I need to know their species. They were all from the same tray, so after looking through some photos I believe they are all Mammillaria. But I've only just started learning about succulents and cacti and was wondering if anyone could please ID these cacti for me.

Hi brooklyn.

They definitely all look like mammillarias. Some of these are very difficult to identify at a young age so you may have to wait for a few years to know for sure what they are.

However, the bottom one is undeniably Mammillaria fragilis.

Second last maybe mammillaria marksiana. Couldn't be sure until it goes to flower.

First one might be a young mammillaria hahniana. Once this one ages you will know for sure. M. Hahniana is easily identifiable as it has quite a unique look to it.

Thanks for the ID. I've been researching those cacti and was wondering if you meant the second one was mammillaria hahniana. The first one isn't fluffy but the second one is so I assume you mean the second one. In that case any idea on the first one?
Thanks

You are correct. The second one is hahniana. I numbered them wrong.

Top one I am not sure about. It looks like it could be an very young echinocactus grusonii.