Mimicry and secondary defense are staples among predator–prey interactions. Among insects, the stick and leaf insects are masters of camouflage. Nonetheless, a meager understanding of their origin and early mimetic evolution persists. Here, we report the earliest mimetic and defensive strategies of a stick insect from the Middle Jurassic of China, Aclistophasma echinulatum gen. et sp. nov., exquisitely preserving abdominal extensions and femoral spines. The distribution of these characteristics mapped onto the phylogeny of Phasmatodea reveals that abdominal extensions and femoral spines developed multiple times during the evolution of stick insects, and indicates that the origin of abdominal extensions predates other modifications, while tergal extensions predate other expansions of the body, such as those of the sterna and pleura, as well as defensive femoral spines. The new fossil provides clues into early antipredator defensive strategies, allows inferences as to the potential environment and predators, and reveals the mimetic and defensive mechanisms of stick insects from 165 million years ago.

A phylogeny of the lacewing family Nymphidae based on morphology and DNA sequences is presented including representatives of all living genera and selected fossil genera. Widely distributed Jurassic and Cretaceous genera gave rise to recent taxa now restricted to Australasia. Two previously defined clades (i.e. Nymphinae and Myiodactylinae) were recovered and reflect the diverging adult and larval morphology of members of these two subfamilies. From Chinese Cretaceous deposits, a new genus (Spilonymphes gen. nov.) is described with one new species, as well as new species described in the genera Baissoleon Makarkin and Sialium Westwood. Nymphidae are a small family of distinctive neuropterans characterized by a medially divided arolium, leading to their common name of split-footed lacewings. The family is considered one of the more plesiomorphic clades of Myrmeleontiformia, sister to a group comprising at least Myrmeleontidae (antlions) and Ascalaphidae (owlflies) (Asp€ ock et al., , 2012Asp€ ock, 2002;Engel and Grimaldi, 2008) or also including Nemopteridae (spoon-winged lacewings) (New, 1984;Oswald, 1998;. Extant Nymphidae are restricted entirely to the Australasian region, the greatest diversity being found in eastern mainland Australia with a few species found in western Australia and New Guinea (New, 1987). A single species has been described from the Philippines (i.e. Myiodactylus chrysopoides Nav as) but the type has been lost and no specimens are known to confirm this anomalous record (New, 1981). Eight extant genera containing 33 species are described with an additional 14 extinct genera containing 23 species, from both Mesozoic and Palaeogene deposits.Diagnostic features of nymphid imagos include elongated filiform antennae, ocelli absent, legs with a bifid arolium, wings with trichosors present, nygmata absent and thyridiate (incomplete) crossveins present of varying length along the subcostal space. Nymphidae are one of the few families of lacewings that lay eggs on silken stalks (New, 1982(New, , 1983a. Arguably, the most specialized arrangement of eggs on silken stalks found in Neuroptera is produced by the relatively derived genus Nymphes Leach. Eggs are laid with every second egg produced with a silken stalk, and intermediate eggs produced perpendicular to the previous one and used to connect the stalked eggs such that the egg mass is arranged in a large "U"-shaped pattern. Immature stages are distinctive and are known for the genera Osmylops Banks, Nymphes and Norfolius Nav as (New, 1982(New, , 1983a(New, , 1989aNew and Lambkin, 1989). Immatures typically have a large armoured head with six stemmata and broadly separated jaws that often articulate beyond 180° (MacLeod, 1964). The jaw has a large single tooth midway along its length, separating it from most other neuropteran larvae. Antennae are shorter than half the length of the mandible with the flagellum being distinctly *Corresponding author: E-mail address: rendong@mail.cnu.edu.cn This is an open access article under the terms of the...

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