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| Ankyloleon caudatus Badano, Fratini, Maugeri, Palermo, Pieroni, Cedola, Haug, Weiterschan, Velten, Mei, Di Giulio & Cerretti, 2021 DOI: 10.1111/syen.12482 Scale bar: 500 μm. |
Abstract
Fossils sometimes show unusual morphological features absent in living organisms, making it difficult to reconstruct both their affinity and their function. We describe here a new lacewing larva, Ankyloleon caudatus gen. et sp.n. (Neuroptera) from the Cretaceous amber of Myanmar, characterized by an abdomen unique among insects, with ‘tail-like’ terminal segments bearing a ventral pair of vesicles. Phase-contrast X-ray microtomography reveals that these structures were dense and equipped with a median duct, suggesting that they were likely pygopods used for locomotion, holding the position through adhesive secretions. Our phylogenetic analyses, combining genomic and morphological data from both living and fossil lacewings, proved critical to placing Ankyloleon gen. n. on the lacewing tree of life as an early representative of the antlion clade, Myrmeleontiformia. These results corroborate the view that derived myrmeleontiform lacewings ‘experimented’ with unusual combinations of features and specializations during their evolutionary history, some of which are now lost.
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| Ankyloleon caudatus gen. et sp. n. holotype (MZURPAL00111): (A) dorsal view and (B) ventral view. Scale bar: 500 μm. |
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| Phylogeny of Neuroptera, highlighting the relationships of Ankyloleon. Based on the ML analysis of partitioned combined dataset including genomic and morphological data, see also Fig. S4. Fossil taxa are in bold characters. (i-vii) selected representatives of the diversity of lacewing larvae (not in scale): (i) Osmylidae larva indet. (photo by G. Montgomery); (ii) Dilar sp., Dilaridae; (iii) Mantispa styriaca (Poda), first instar, Mantispidae; (iv) Chrysoperla mediterranea Hölzel, Chrysopidae; (v) Ankyloleon caudatus gen. et sp. n. reconstruction; (vi) Nemoptera bipennis (Illiger) Nemopteridae; (vii) Libelloides ictericus (Charpentier) Ascalaphidae and (viii) Brachynemurus ferox (Walker), Myrmeleontidae. |
Davide Badano, Michela Fratini, Laura Maugeri, Francesca Palermo, Nicola Pieroni, Alessia Cedola, Joachim T. Haug, Thomas Weiterschan, Jürgen Velten, Maurizio Mei, Andrea Di Giulio, Pierfilippo Cerretti. 2021. X-ray Microtomography and Phylogenomics provide insights into the Morphology and Evolution of an enigmatic Mesozoic Insect Larva. Systematic Entomology. 46(3); 672-684. DOI: 10.1111/syen.12482
