What are these frames at the bottom of the TFTD X-Com soldier sprite sheets?

[The Martian]

I was going over the TFTD unit sprites and noticed these on the "Diving Suit" & "Ion Armor / Magnetic Ion Armor" but not the "Plastic Aqua Armor":

Does anyone know what these frames are?

[Nord]

These are unused in vanilla game. For armored zombies, as you can see.

[The Martian]

Thank you for the information Nord.

That is a relief to know, I was a bit worried that stripping the zombie frames off the sprite sheet would cause an error if the game called for them.

I've always found the unused images in both X-Com games to be rather interesting. From what I've read the developers didn't have much time to implement features when making TFTD but I've noticed that they did a lot more image work compared to the original game.

For example most objects have HandObs in TFTD:
UFO has 128 HandOb image frames.
TFTD has 440 HandOb image frames.

MicroProse artist Terry Greer recalled: "A decision was made to use the original engine, reskin the graphics and create a whole new story. By keeping changes to the absolute minimum a sequel could be created in just a few months. Also, by not inventing any new game features or game technology it would make the scheduling one largely led purely by asset creation – which makes it whole lot easier when it comes to estimating task durations and scheduling."