Parietal eyelid(s) 'across' or 'up/down'?

[Nik_2213]

Lizards, reptiles, tuatara and fossils with parietal 'third' eyes do not seem to have legacy bone attachments / processes for their third eye's lid muscles.

In fact, IIRC, the 'parietal eye' seems 'inside out' and 'fixed' compared to said beasties' 'ordinary' eyes.
Perhaps Vertebrae Eye 1.0 ?
YMMV...

If any lizards etc parietal eye had not evolved away from 'imaging', would you expect their third eye's lid(s) to open 'across' rather than 'up/down' ??

 

[Greg Bernhardt]

Moving to Biology. Have you worked out anything since writing this post?

 

[Nik_2213]

In the end, I went with one eye either side of narrow head, one on the brow, all lidded horizontally.

https://www.deviantart.com/the-nik-files/gallery/67694419/WIRS

WIRS#5, 'The Heptonstall Horror', but they don't make an appearance until the end of chapter #10.

I'm currently trawling for a 'proper' Latin name for them...
;-)