A new fossil plesiomorphic flat bug (Aradidae) suggests widespread flower visiting in Heteroptera during the Mesozoic

Abstract

Abstract The phenomenon of flower visiting (anthophily) and the pollination, though becoming prevalent with the rise of flowering angiosperms, hypothesized to have originated from the antagonistic relationship of florivory between insects and gymnosperms in the Upper Jurassic. Though not commonly known, this behaviour has been documented in several instances among the representatives of the suborder Heteroptera, i.e., the true bugs. Here, we describe Shaykayatcoris michalskii gen. nov., sp. nov., the first known representative of the plesiomorphic flat bug (Aradidae) subfamily Prosympiestinae in the Upper Cretaceous Burma Terrane amber fauna (Lowermost Cenomanian, ca. 99 Mya). Besides expanding the knowledge on the heteropteran insect fauna of the Lagerstätte, the discovery of this new true bug provides intriguing insights into the evolutionary history of true bugs. First, the new record corroborates that the subfamily Prosympiestinae is a Gondwanan relict group among the representatives of flat bugs. Second, this insect presents the first known incidence of iridescent colouration in flat bugs with a tentative role of camouflage, suggesting a more exposed lifestyle compared to the apomorphic lineages of flat bugs, which have adapted to live under tree bark. Third, the iridescence and the high amount of pollen among the syninclusions suggest that the insect was likely to be anthophilous. The suspected presence of anthophily in such a specialised heteropteran insect group like Aradidae suggests that anthophily was more widespread among the Mesosoic true bugs than it can be observed in the case of extant taxa.