A unique camouflaged mimarachnid planthopper from mid-Cretaceous Burmese amber

Abstract

Predation is a major driving force for the evolution of functional forms. Avoidance of visual predators has resulted in different kinds of anti-predator defences, such as: camouflage, crypsis, disruptive coloration, and masquerade or mimesis. Camouflage is one of the forms involving shape, colouration, structure and behaviour when the visual pattern and orientation of an animal can determine whether it lives or dies. Inferring the behaviour and function of an ancient organism from its fossilised remains is a difficult task, but in many cases it closely resembles that of its descendants on uniformitarian grounds. Here we report and discuss examples of morphological and behavioural traits involving camouflage named recently as a flatoidinisation syndrome, shown by the inclusion of a planthopper in mid-Cretaceous Burmese amber. We found a new genus and species of an extinct Cretaceous planthopper family Mimarachnidae showing peculiar complex morphological adaptations to camouflage it on tree bark. Due to convergence, it resembles an unrelated tropiduchid planthopper from Eocene Baltic amber and also a modern representatives of the planthopper family Flatidae. Flattening of the body, the horizontal position of the tegmina at repose, tegmina with an undulating margin and elevated, wavy longitudinal veins, together with colouration and more sedentary behavioral traits enable these different insects to avoid predators. Our discovery reveals flatoidinisation syndrome in mid-Cretaceous Burmese amber which may provide insights into the processes of natural selection and evolution in this ancient forest.

New mimarachnids (Hemiptera, Fulgoromorpha, Fulgoroidea) in mid-Cretaceous Burmese amber

“…In addition, Mimaplax ekrypsan Jiang, Szwedo & Wang, 2019 used more complicate camouflaged configuration to avoid possible predation. It is possible that mimarachnids have evolved with a range of anti-predation defenses in Burmese amber forests, such as disruptive coloration, wing spots, and "flatoidinisation syndrome" (a specialized and complex camouflage, uniting shape, colour, and behaviour) (Jiang et al 2019) to help them to avoid being attacked by predators.…”

“…They are medium-sized to large planthoppers and are characterized by the following characters: mesonotum with double median carinae, remnants of sensory pits in the adults, tegmina and hind wings with simplified venation and irregular network of veinlets, and basal cell absent or weak (Brysz and Szwedo 2019). Historically, species of this family were considered as members of the "cixiidae-like" planthoppers (Bourgoin and Szwedo 2008), and some mimarachnids are specialized insects with peculiar and striking forms (Shcherbakov 2007;Jiang et al 2018Jiang et al , 2019Zhang et al 2018).…”

High morphological disparity of neuropteran larvae during the Cretaceous revealed by a new large species

“…The unique specimen is from the Cretaceous deposits in the Hukawng Valley of Myanmar, from a former amber mine located near Danai (Tanai) town (26°21″ 33.41″ N, 96°43 0 11.88″ E; palaeolatitude 5.0 ± 4.7°S) (Kania et al 2015;Thu & Zaw, 2017;Westerweel et al 2019; see the locality in fig. 1 of Jiang et al 2019). More than 600 families of invertebrates, vertebrates, protists, plants and fungi have been reported from Kachin amber (Yu et al 2019;Ross, 2021).…”

Mimicry in Cretaceous Bugs

“…Among Mesozoic insects, liverwort-mimicking larvae from the Cretaceous mimicked their surroundings to prevent predation, thus qualifying as mimesis or masquerade, as contrasted to true aggressive mimicry in berstids, which involved resemblance between iScience Article predators and their prey with the aim of deceiving the latter (Liu et al, 2018). Further examples of camouflage are documented from Cretaceous amber lacewings (Liu et al, 2018;Pé rez-de la Fuente et al, 2018;Wang et al, 2016) and planthoppers (Jiang et al, 2019), but these cases again involve mimesis of inanimate objects and not resemblance of prey species as is the case in berstids. Moreover, mimesis in these lacewings is based on a constructed concealment rather than morphological modifications (i.e., physical mimicry) of the body as is documented here.…”