Short communication
New wood soldier flies from mid-Cretaceous Myanmar amber (Diptera, Stratiomyomorpha, Xylomyidae)

https://doi.org/10.1016/j.cretres.2022.105142Get rights and content

Abstract

Two new wood soldier flies, Clemoxyla aculeolata gen. et sp. nov. and Archeoxyla gigantea gen. et sp. nov., are described from mid-Cretaceous Myanmar (Burmese) amber. Clemoxyla gen. nov. is most characteristic of the broadened cell d and presence of short M1+2 stem after the cell d. The apical palpus of Archeoxyla gen. nov. is obviously expanded that is distinct from other known fossil xylomyid genera. Based on the analysis of key features of body and venation, the genus Cretarthropeina Solórzano Kraemer and Cumming, 2019 is transferred from Xylomyidae to Stratiomyidae as the sixth soldier fly from mid-Cretaceous Myanmar amber. In addition, a key to the genera of all known fossil and extant xylomyids is provided.

Introduction

The Xylomyidae Verrall, 1901, commonly called wood soldier flies, is a small family of the infraorder Stratiomyomorpha, comprising 143 extant species in four genera (Pape et al., 2011; Woodley, 2011; Fachin and Amorim, 2014). Extant wood soldier flies are easily recognized by their slender body, conical antennae, wings with closed cells m3 and cua, and spurs on the mid and hind tibiae (Fachin and Amorim, 2014; Fachin and Assis-Pujol, 2016). Like the extant Xylomyidae, the fossil xylomyids have low diversity including six described genera with nine species up to date (Table 1). The earliest xylomyid-like fossil Xylomya? shcherbakovi Mostovski was described from the Early Jurassic Kazakhstan based on a fragmentary wing, however, the systematic position of the species has not been further confirmed since it was established (Mostovski, 1999; Grimaldi, 2016). The earliest accepted xylomyid fossil was described from Lower Cretaceous Lebanese amber, with the diagnostic character of the absence of R2+3 (Grimaldi et al., 2011). Comparing to other localities, the xylomyids in mid-Cretaceous Myanmar (Burmese) amber are remarkably diverse, currently representing five species in four genera (Table 1). Additionally, an unnamed xylomyid was described from the Cretaceous Spanish amber of which only thorax and abdomen were partially preserved (Grimaldi et al., 2011). In Cenozoic xylomyids, three Eocene species have been described respectively from Baltic amber and Florissant, Colorado, which were attributed to two extant genera (Solva and Xylomya) (Table 1) (Loew, 1850; Cockerell, 1914; Melander, 1949). According to the current distributions of xylomyid fossils, it is clear that Xylomyidae had undergone a rapid and significant generic differentiation during the Cretaceous.

Herein, we describe two new genera and two new species from mid-Cretaceous Myanmar amber, which provide significant morphological details to clarify the early evolutionary development of Xylomyidae. The systematic position of the genus Cretarthropeina Solórzano Kraemer and Cumming is assessed, and transferred to the family Stratiomyidae. Additionally, a key to the fossil and extant genera of Xylomyidae is provided.

Section snippets

Material and methods

All specimens are deposited in the Key Lab of Insect Evolution & Environmental Changes, Capital Normal University, Beijing, China (CNUB; Dong Ren, Curator). The specimens were examined and photographed using a Nikon SMZ 25 microscope with a Nikon DS-Ri 2 digital camera system. Line drawings were prepared with Adobe Illustrator CC and Adobe Photoshop CC graphics software.

The amber specimens of this paper were collected from Kachin (Hukawng Valley) of northern Myanmar, approximately 15 km

Systematic palaeontology

  • Order Diptera Linnaeus, 1758

  • Suborder Brachycera Macquart, 1834

  • Infraorder Stratiomyomorpha Hennig, 1973

  • Family Xylomyidae Verrall, 1901

  • Genus Clemoxyla gen. nov. (Fig. 1, Fig. 2)

  • LSID: urn:lsid:zoobank.org:act:0F35E039-E4F5-400B-A85F-656E6DFE61C0

  • Type species: Clemoxyla aculeolate gen. et sp. nov.

  • Etymology. Taken from the Greek word “clem-” (meaning “branch”) and “xyla” (abbreviation of the type genus Xylomya), referring to a short stem of M1+2 present after cell d. Gender is feminine.

  • Diagnosis.

Discussion

Up to date, six genera including seven species of Xylomyidae have been described from Myanmar amber. Well-preserved morphological details in amber provide a new insight in understanding the early evolution of xylomyids. Among the Xylomyidae, two-segmented maxillary palpus, a groundplan feature of lower Brachycera (Woodley, 1989), occurs in two genera of Solva and Arthropeina and all known xylomyid fossils, of which the basal palpomere is normally slender and clavate (Woodley, 2009, 2011). It is

Conclusion

Two new genera and two new species, described from Myanmar amber, enhance our knowledge of the Cretaceous Xylomyidae. Clemoxyla gen. nov. shows new characters on venation and tibial apical spurs. Archeoxyla gen. nov. exhibits the high homology with the extant Xylomya and Coenomyiodes for having similarity palpus structure which suggests a significant diversification of Xylomyidae before or during the mid-Cretaceous. The unique genus Cretarthropeina Solórzano, Kraemer and Cumming is transferred

Acknowledgements

We sincerely thank the valuable comments and suggestions from Dr. Eduardo Koutsoukos and two anonymous reviewers to improve this paper. This work was supported by the National Science Foundation of China (Grants 31970383, 31730087), the Beijing Natural Science Foundation (Grant 5192002), and the Academy for Multidisciplinary Studies of Capital Normal University, Capacity Building for Sci-Tech Innovation - Fundamental Scientific Research Funds (Grant 19530050144).

References (29)

  • R.D. Cruickshank et al.

    Geology of an amber locality in the Hukawng Valley, northern Myanmar

    Journal of Asian Earth Science

    (2003)
  • Y.M. Liu et al.

    First soldier fly from the mid-Cretaceous Burmese amber (Diptera, Stratiomyidae)

    Cretaceous Research

    (2017)
  • G.H. Shi et al.

    Age constraint on Burmese amber based on U-Pb dating of zircons

    Cretaceous Research

    (2012)
  • P. Barden et al.

    A new genus of hell ants from the Cretaceous (Hymenoptera: Formicidae: Haidomyrmecini) with a novel head structure

    Systematic Entomology

    (2017)
  • T.D.A. Cockerell

    Three Diptera from the Miocene of Colorado

    The Canadian Entomologist

    (1914)
  • J. Cumming et al.

    Adult morphology and terminology

  • D.A. Fachin et al.

    Taxonomic revision of the Neotropical genus Arthropeina Lindner, 1949 (Diptera: Xylomyidae)

    Zootaxa

    (2014)
  • D.A. Fachin et al.

    Catalogue of Diptera of Colombia: family Xylomyidae

    Zootaxa

    (2016)
  • D.A. Grimaldi

    Diverse orthorrhaphan flies (Insecta: Diptera: Brachycera) in amber from the Cretaceous of Myanmar: Brachycera in Cretaceous amber, part VII

    Bulletin of the American Museum of Natural History

    (2016)
  • D.A. Grimaldi et al.

    Brachyceran Diptera (Insecta) in Cretaceous ambers, part IV, significant new orthorrhaphous taxa

    ZooKeys

    (2011)
  • D.A. Grimaldi et al.

    The Mesozoic Family Eremochaetidae (Diptera: Brachycera) in Burmese amber and Relationships of Archisargoidea

    American Museum Novitates

    (2016)
  • W. Hennig

    Diptera (Zweiflügler)

  • X.D. Lin et al.

    Life habits and evolutionary biology of new two-winged long-proboscid scorpionflies from mid-Cretaceous Myanmar amber

    Nature Communications

    (2019)
  • C. Linnaeus
  • Cited by (2)

    • Plant–insect and –fungal interactions in Taxodium-like wood fossils from the Oligocene of southwestern China

      2022, Review of Palaeobotany and Palynology
      Citation Excerpt :

      Subsequent research has documented possible boring traces by beetles in the Middle Permian (Naugolnykh and Ponomarenko, 2010), and borings contain coprolite and fungal traces as evidence in the Late Permian (Feng et al., 2017; Wei et al., 2019), revealing symbiotic relationships between different arthropods and fungus in deep geological time. Borings from non-coleopteran insects are mostly reported from the Mesozoic, especially during the Cretaceous (e.g., Labandeira et al., 1997; Labandeira, 2014; McLoughlin and Mays, 2022), as numerous amber and wood fossil studies provide evidence of the upsurge of these arthropods, including wood wasps (Ortega-Blanco et al., 2008), termites (Francis and Harland, 2006), mayflies (Moran et al., 2010), and soldier flies (Han et al., 2022). Compared to the other two eras, there are more damage records from angiosperm wood fossils in the Cenozoic (Sutherland, 2003; Greppi et al., 2021).

    View full text