An entry in Fortnightly Topic Challenge #42: Wordless Connecting Walls
Rules: Organize the following sixteen images into four groups of four, based on categories into which they fit. The sixteen images are also connected by one overarching theme.
(Bonus points if you can not only find the categories, but fully name everything.)
Hint to start you off:
One of the categories is something you'd find in the Senate, or on certain animals.
The four groups could be considered as four general "types" of the overarching theme.
Google Drive link to a bigger version, for my fellow visually impaired people.