New Transitional Fleas from China Highlighting Diversity of Early Cretaceous Ectoparasitic Insects

SummaryFleas are a group of highly specialized blood-feeding ectoparasites whose early evolutionary history is poorly known [1, 2]. Although several recent discoveries have shed new light on the origin of the group [3, 4], a considerable gap exists between stem fleas and crown fleas. Here we report a new transitional flea, Saurophthirus exquisitus sp. nov., assigned to a new family Saurophthiridae fam. nov., from the Lower Cretaceous Yixian Formation of northeastern China. Saurophthirids are more similar to crown fleas than other stem fleas in having a relatively small body size, relatively short and slender piercing-sucking stylet mouthparts, comparably short and compact antennae, rows of short and stiff bristles on the thorax, and highly elongated legs. The new finding greatly improves our understanding of the morphological transition to the highly specialized body plan of extant fleas. However, saurophthirids also display several features unknown in other fleas, and some of these features are suggestive of a possible ectoparasitic relationship to contemporaneous pterosaurs, though other possibilities exist. The new fossils, in conjunction with previous discoveries, highlight a broad diversity of ectoparasitic insects in the mid-Mesozoic

A total-evidence approach to dating with fossils, applied to the early radiation of the Hymenoptera

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Comments On The Proposed Revocation Of Article 74.7.3 Of The Code Lectotype Designation)

Volume: 58Start Page: 300End Page: 30

Testing cladograms by fossil record: the ghost range test

A method of the ghost range calculation is proposed to assess the congruence between a cladogram and the fossil record and to compare cladograms on this basis. The method is tested on a set of cladograms developed recently to reveal the phylogeny of the hymenopterous insects (Order Vespida), and the results are discussed

Xyela (Pinicolites) lata Smith (Vespida: Xyelidae), a living fossil sawfly from western North America

Volume: 73Start Page: 231End Page: 23

Zippelia engeli RASNITSYN & MÜLLER 2023, sp. nov.

Zippelia engeli sp. nov. Holotype. SNHMB. G 8194; Burmese (Kachin) amber, midCretaceous; well preserved small larva with ventral aspect partially obscured with air bubble. Etymology. Species is named after Dr Michael S. Engel in appreciation of his identification of the symphytan nature of the holotype. Diagnosis. As for the genus. Description (Zippel et al., 2022: figs. 2, 3). Early larva. Body surface finely reticulate except that head capsule apparently smooth; no vestiture discernible except for strong setae on basal segments of maxillary palp mentioned by Zippel et al. (2022). Body length 3.9 mm. Head capsule 0.40 mm long, 0.25 mm high, antenna 0.28 mm, with segments growing gradually narrower and longer toward apex, with scape and pedicel transverse, somewhat elongate dorsally, and apical segment almost needle-like. Clypeus apparently short, with transverse impression. Mandibles short, with teeth apparently short and of similar length. Maxillary and labial palps both some 1.3 mm long (palpiger included), rather thick, conical. Mid leg 0.38 mm long (coxa to pretarsus lengths in mm respectively 0.085, 0.06, 0.055, 0.055, 0.055, 0.055), with three apical segments almost cylindrical. Abdominal tergum 10 with lateral teeth slightly longer than wide, rounded apically, medial tooth slightly bent upward, with wider base and narrow main part, 0.23 mm long, narrowly rounded apically, much longer than main part of tergum (visible length 0.14 mm). Subanal lobe 1.25× as long as wide basally, tapering toward truncated apex, with apicolateral processes as long as lobe apex wide, with two segments of equal length, much longer than wide, basal one subcylindrical, apical one conical.Published as part of RASNITSYN, ALEXANDR P. & MÜLLER, PATRICK, 2023, Identity of the insect larva described by Zippel et al. (2022) in the mid-Cretaceous Burmese (Kachin) amber (Hymenoptera, Tenthredinoidea, Blasticotomidae = Xyelotomidae syn. nov.), pp. 13-16 in Palaeoentomology 6 (1) on page 14, DOI: 10.11646/palaeoentomology.6.1.4, http://zenodo.org/record/775490

Zippelia RASNITSYN & MÜLLER 2023, gen. nov.

Genus <i>Zippelia</i> gen. nov. <p> <b>Type species.</b> <i>Zippelia engeli</i> <b>gen. et sp. nov.</b></p> <p> <b>Species included.</b> Type species only.</p> <p> <b>Etymology.</b> Genus name is derived from the name of the first author of the original larval description.</p> <p> <b>Diagnosis.</b> Larva (probably an early one because of small size). Body segments soft, smooth, naked, with only head capsule and ninth and particularly tenth abdominal terga sclerotised. Head position oblique (semiprognathous). Stemma small, touching antennal foramen dorsally. Antenna setiform, 7-segmented, touching mandibular base or nearly so. Mandibles with at least three teeth. Maxillary and labial palps 4- and 3-segmented, respectively, with large palpigers. 9 spiracles visible (on pronotum and abdominal segments 1–8). Legs setiform, 6-segmented, with terminal segment (pretarsus) long but apparently soft, not claw-like.Abdominal terga with three (basal ones) through no (8 th to 10 th) transverse folds. Separated lateral lobes bearing spiracles and so nonhomologous to those in other symphytan larvae; delimited area below them apparently participating in incipient prolegs distinct at least in segments 5–8 (basal segments are not visible from below). Sternal area (between incipient prolegs) variable in having two, one or no transverse folds. Tergum 9 distinctly sclerotised, convex, tergum 10 strongly sclerotised, concave, pentagonal, with two lateral prongs and long posteromedial tooth, recalling incipient concavity of terga 9–10 in larval Blasticotomidae. Sternum 10 with elongate subanal lobe bearing lateroapically two-segmented appendages long enough to be visible dorsally.</p>Published as part of <i>RASNITSYN, ALEXANDR P. & MÜLLER, PATRICK, 2023, Identity of the insect larva described by Zippel et al. (2022) in the mid-Cretaceous Burmese (Kachin) amber (Hymenoptera, Tenthredinoidea, Blasticotomidae = Xyelotomidae syn. nov.), pp. 13-16 in Palaeoentomology 6 (1)</i> on page 14, DOI: 10.11646/palaeoentomology.6.1.4, <a href="http://zenodo.org/record/7754902">http://zenodo.org/record/7754902</a&gt

New fossil records of Xyelidae (Hymenoptera) from the Middle Jurassic of Inner Mongolia, China

A new genus and two new species of Xyelidae Newman, 1834 (Hymenoptera Linnaeus, 1758), Platyxyela tenuis sp. nov. and Scleroxyela daohugouensis gen. et sp. nov. are described and illustrated from the Middle Jurassic Daohugou Beds of Ningcheng, Inner Mongolia, China. Platyxyela tenuis sp. nov. (Xyelinae Newman, 1834, Liadoxyelini Rasnitsyn, 1966) can be distinguished from its congeners by short forewing length and ovipositor sheath strongly narrowed toward acute apex. Scleroxyela daohugouensis gen. et sp. nov. is placed within Macroxyelinae Ashmead, 1898, Xyeleciini Benson, 1945 based on pterositigma completely sclerotised and costal space sclerotised before ptrostigma, 1-Rs half as long as 1-M, and 1m-cu short. It is the fi rst recorded species of Xyeleciini in Daohugou Beds. Furthermore, an updated key of identifi cation of subfamilies and tribes of Xyelidae is provided. Our fi ndings of new morphological data provide insights into the early evolution of Hymenoptera, as well as eff ectively enrich our understanding of the diversity of Xyelidae in the Mesozoic.</p

New fossil records of Xyelidae (Hymenoptera) from the Middle Jurassic of Inner Mongolia, China – Corrigendum

A new genus and two new species of Xyelidae Newman, 1834 (Hymenoptera Linnaeus, 1758), Platyxyela tenuis sp. nov. and Scleroxyela daohugouensis gen. et sp. nov. are described and illustrated from the Middle Jurassic Daohugou Beds of Ningcheng, Inner Mongolia, China. Platyxyela tenuis sp. nov. (Xyelinae Newman, 1834, Liadoxyelini Rasnitsyn, 1966) can be distinguished from its congeners by short forewing length and ovipositor sheath strongly narrowed toward acute apex. Scleroxyela daohugouensis gen. et sp. nov. is placed within Macroxyelinae Ashmead, 1898, Xyeleciini Benson, 1945 based on pterositigma completely sclerotised and costal space sclerotised before ptrostigma, 1-Rs half as long as 1-M, and 1m-cu short. It is the fi rst recorded species of Xyeleciini in Daohugou Beds. Furthermore, an updated key of identifi cation of subfamilies and tribes of Xyelidae is provided. Our fi ndings of new morphological data provide insights into the early evolution of Hymenoptera, as well as eff ectively enrich our understanding of the diversity of Xyelidae in the Mesozoic.</p