Which kind of tick is this and what is that thing around its back?
As your link suggests, it looks like a female tick of the genus Ixodus. It is likely female because the scutum or shield only covers part of the dorsal surface. E.g.,



which comes from Bristol University Tick ID. The translucent posterior portion may just be from light passing through.

If you are able to zoom in closer on different parts, you can key out what species it is.