This mite is a Brachychthoniidae and possibly Eobrachychthonius, one of the few oribatids that retain a lateral ocellus that is a simple eye between the seta and bothridium (shown in orange).
Eobrachychthonius belongs to the order of the Oribatida, better known as beetle mites or moss mites. Most of them are heavily armored by thick body plates which help to reduce the chance that something eats them. Internally, many are filled with toxins to the same end. Poison dart frogs get their toxins from oribatid mites (and ants), so the defenses don’t always work to their advantage, but often enough for them to have persisted form over 450 million years!
Mites secrete an outermost layer of waxes and proteins called the cerotegument (as shown in green on legs and bright brown or blue on remaining body parts). The cerotegument of species found in dry microhabitats has pustulate ornamentation which look a bit like Bucky Balls at high magnification – very similar to some of the types of brochosomes found on Cicadellidae. Likely the cerotegument are water-repellent structures analogous to those found on the upper side of the leaves of water lilies.
The ‘ear’ or ‘antenna’ is a special seta called a sensillus that can be moved and is sensitive to airborne vibrations. The very deep base (the ‘screw-threaded-tube’) for the sensillus is called a bothridium. It provides extra support for the sensillus to allow it to vibrate but not to snap off. There is another sensillus and bothridium on the other side of the mite’s ‘head’. Almost all oribatid species have a pair of sensilli.
Unusual for oribatids, Brachychthoniidae can be rather colourful: in the species Eobrachychthonius latior the sclerites are orange in adults and immatures are violet. Suprapleural plates that may be present appear to be infolded, therefore it is not sure if this mite belongs to the genus Eobrachychthonius. The mouthparts on either side of the chelicerae are called pedipalps – homologous to the pincers of scorpions/ pseudoscorpions, but used as feelers by oribatids. A slim adherent structure on the head looks like a bit of fungus.