Short communicationNew wood soldier flies from mid-Cretaceous Myanmar amber (Diptera, Stratiomyomorpha, Xylomyidae)
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)
- et al.
Geology of an amber locality in the Hukawng Valley, northern Myanmar
Journal of Asian Earth Science
(2003) - et al.
First soldier fly from the mid-Cretaceous Burmese amber (Diptera, Stratiomyidae)
Cretaceous Research
(2017) - et al.
Age constraint on Burmese amber based on U-Pb dating of zircons
Cretaceous Research
(2012) - et al.
A new genus of hell ants from the Cretaceous (Hymenoptera: Formicidae: Haidomyrmecini) with a novel head structure
Systematic Entomology
(2017) Three Diptera from the Miocene of Colorado
The Canadian Entomologist
(1914)- et al.
Adult morphology and terminology
- et al.
Taxonomic revision of the Neotropical genus Arthropeina Lindner, 1949 (Diptera: Xylomyidae)
Zootaxa
(2014) - et al.
Catalogue of Diptera of Colombia: family Xylomyidae
Zootaxa
(2016) 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)- et al.
Brachyceran Diptera (Insecta) in Cretaceous ambers, part IV, significant new orthorrhaphous taxa
ZooKeys
(2011)
The Mesozoic Family Eremochaetidae (Diptera: Brachycera) in Burmese amber and Relationships of Archisargoidea
American Museum Novitates
Diptera (Zweiflügler)
Life habits and evolutionary biology of new two-winged long-proboscid scorpionflies from mid-Cretaceous Myanmar amber
Nature Communications
Cited by (2)
Plant–insect and –fungal interactions in Taxodium-like wood fossils from the Oligocene of southwestern China
2022, Review of Palaeobotany and PalynologyCitation 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).