I collected this several years back, but can't remember what they are. Any identification and background on them would be great. They were collected in Minnesota.

Here are the links to the images, sorry it didn't work the last time.

https://imgur.com/8QLTBqR
https://imgur.com/eIMRA54
https://imgur.com/PSHYyZn
https://imgur.com/9OsQbKq

not sure on the 1st, the second one looks like plastic cogs, the 3rd is a section through a shell eg nautilus, the 4th is a piece of coral.