A Cretaceous mite with ultra-long setae possibly reveals the early survival strategy of Chyzeriidae

Chyzeriidae Womersley, 1954, is a family of trombidiform mites characterized by unique body structures and habits, though it has not been well studied. A new genus and species, Cretachyzeria macroseta gen. et sp. nov., in the subfamily Pteridopinae of Chyzeriidae, found in Cretaceous amber in Myanmar, provides the first formally described fossil species in this family. A phylogenetic study of Chyzeriidae based on postlarval morphology supported the morphological classification.

The dorsal setae of Cretachyzeria macroseta gen. et sp. nov. are extremely long and dense, resembling the quills of a porcupine. This unusual morphological structure likely served specific biological functions. We hypothesize that these long setae functioned as a specialized defense, protecting the fragile abdomen and aiding in predator deterrence in its complex environment.

Given the geological time frame of this fossil mite and the wide distribution of extant Chyzeriidae, we propose that the family existed prior to the breakup of Pangaea.