Work

A New Species of Orthosyntexis (Hymenoptera: Anaxyelidae) from Mid-Cretaceous Burmese Amber

Year: 2025

Type: article

Abstract: Anaxyelidae, a relict lineage of sawflies, are represented by a single extant species today but displayed remarkable Mesozoic diversity. Here, we describe the Orthosyntexis mascula sp. nov. from mid-Cretaceous Burmese amber. The new species can be readily distinguished by its forewing, with a normally sized, uniformly sclerotized pterostigma; 1-Rs shorter than 1-M; cell 1M more than twice as long as wide; absence of 1r-rs; 1-Cu, distinctly shorter than 2-Cu; 3-Cu shorter than 4-Cu; 2m-cu shorter than 1m-cu; and 3rs-m twice as short as 4-M. In the hind wing, abscissa 2-M+Cu present, 1-M shorter than 2-M, crossvein m-cu absent, and cell R1 closed. Mesotibia with two apical spurs. Examination of high-resolution photographs of Kempendaja jacutensis enables a revised interpretation of its venation, confirming its placement in Anaxyelinae. Comparative analysis of syntexine taxa further reveals that variation in the forewing crossvein 1r-rs consistently corresponds with hind wing venation, suggesting that multiple evolutionary trajectories may have existed within Syntexinae. These findings not only expand the known diversity of Cretaceous Anaxyelidae but also provide new evidence for reconstructing the evolutionary history and internal diversification of Anaxyelidae.

Source: Insects

DOI: 10.3390/insects16101039

Authors: Xiao Li, Gengyun Niu, Meicai Wei

Institution: Jiangxi Normal University

Language: English

Topic: Fossil Insects in Amber

Subfield: Ecology, Evolution, Behavior and Systematics

Field: Agricultural and Biological Sciences

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $3,137

Funders: National Natural Science Foundation of China, Russian Academy of Sciences