title: Under cover at pre-angiosperm times: a cloaked phasmatodean insect from the Early Cretaceous Jehol biota.
abstract: BACKGROUND
  Fossil species that can be conclusively identified as stem-relatives of stick- and leaf-insects (Phasmatodea) are extremely rare, especially for the Mesozoic era. This dearth in the paleontological record makes assessments on the origin and age of the group problematic and impedes investigations of evolutionary key aspects, such as wing development, sexual size dimorphism and plant mimicry.
  
  
  RESULTS
  A new fossil insect species, Cretophasmomima melanogramma Wang, Béthoux and Ren sp. nov., is described on the basis of one female and two male specimens recovered from the Yixian Formation (Early Cretaceous, ca. 126±4 mya; Inner Mongolia, NE China; known as 'Jehol biota'). The occurrence of a female abdominal operculum and of a characteristic 'shoulder pad' in the forewing allows for the interpretation of a true stem-Phasmatodea. In contrast to the situation in extant forms, sexual size dimorphism is only weakly female-biased in this species. The peculiar wing coloration, viz. dark longitudinal veins, suggests that the leaf-shaped plant organ from the contemporaneous 'gymnosperm' Membranifolia admirabilis was used as model for crypsis.
  
  
  CONCLUSIONS
  As early as in the Early Cretaceous, some stem-Phasmatodea achieved effective leaf mimicry, although additional refinements characteristic of recent forms, such as curved fore femora, were still lacking. The diversification of small-sized arboreal insectivore birds and mammals might have triggered the acquisition of such primary defenses.
authors.affiliation: Key Laboratory of Insect Evolution and Environmental Changes, Capital Normal University, Beijing, P. R. China.
authors.forename: Maomin
authors.initials: M
authors.lastname: Wang
authors.affiliation: Sorbonne Universités - CR2P - MNHN, CNRS, UPMC-Paris6, Paris, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Béthoux
authors.affiliation: Johann-Friedrich-Blumenbach-Institute of Zoology and Anthropology, Georg-August-University Göttingen, Göttingen, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Bradler
authors.affiliation: Laboratory of Palaeoecology, Xishuangbanna Tropical Botanical Garden, CAS, Menglun, Mengla, Xishuangbanna, Yunnan, P. R. China.
authors.forename: Frédéric M B
authors.initials: FM
authors.lastname: Jacques
authors.affiliation: Key Laboratory of Insect Evolution and Environmental Changes, Capital Normal University, Beijing, P. R. China; Institute of Geology, Department of Palaeontology, Technical University Bergakademie Freiberg, Freiberg, Germany.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Key Laboratory of Insect Evolution and Environmental Changes, Capital Normal University, Beijing, P. R. China.
authors.forename: Dong
authors.initials: D
authors.lastname: Ren
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D005075:Biological Evolution; D002681:China; D032462:Cycadopsida / Q000033:anatomy & histology; D005260:Female; D005580:Fossils; D007313:Insecta / Q000033:anatomy & histology* / Q000145:classification; D008297:Male; D010163:Paleontology; D010802:Phylogeny; D018515:Plant Leaves / Q000033:anatomy & histology; D018547:Plant Stems / Q000033:anatomy & histology; D014921:Wings, Animal / Q000033:anatomy & histology*