Odonata Fabricius 1793

Allenby Odonata gen. and sp. A Figure 3 Material. BBM-P 000021, original PDMA collection number PMF.2023.001.0031. No counterpart. Distal portions of two wings with poorly preserved fragments of apical-most regions. Found by Beverley Burlingame on 4 August 2023 and donated to the Princeton and District Museum and Archives, then to the Beaty Biodiversity Museum, where it is now housed. Description. Distal portion of the wing, as in remarks (below), and the following. Preserved portion hyaline. Pterostigma about four times longer than wide; no brace vein; most cells in much of anterior region about twice (or more) as high as wide; many linear (or nearly so) supplementary sectors between main veins obscuring identities of partially preserved main veins posterior to RP3–4. Range and age. Vermilion Bluffs Member of the Allenby Formation about 4 km southwest of the village of Princeton, British Columbia. Ypresian (see above). Remarks. The wings of BBM-P000021 are more generalised and difficult to assign to a genus and species than are those of other Allenby Formation non-anisopteran odonates. Some of its morphology, however, is informative: its pterostigma is the general size and shape found in many Okanagan Highlands Dysagrionidae; its postnodal and postsubnodal crossveins are not aligned; its C–RA space distad the pterostigma is more than one cell wide and most likely not more than two; it lacks a brace vein; it has a distinctly angled subnodus of normal obliquity; it has numerous linear supplementary sectors; IR2, RP3–4, and likely at least some other incompletely preserved main veins are rather strongly curved distally; and there are narrow cells in the posterior region of the wings, many twice as high as wide. Although all preserved distal portions of the BBM-P000021 wings agree with those of the Dysagrionidae, the character states that might diagnose the species as a member of that family are found in the basal half of their wings, and some Zygoptera also have similar venation, particularly in the distal part of their wings (Archibald et al. 2023b; Simonsen et al. 2024). Therefore, we tentatively associate BBM-P000021 with similar odonates that are also known from the Ypresian, especially regionally, pending more complete future specimens. By the above, BBM-P000021 is similar to the wings of Okanagrion threadgillae Archibald and Cannings (Dysagrionidae) (see Archibald et al. 2021, fig. 20) from Klondike Mountain locality A0307, about 670 m from B4131; Primorilestes madseni Rust et al. (Dysagrionidae), from the early Ypresian Fur Formation of Denmark (Rust et al. 2008, fig. 2); and Tynskysagrion brookeae Bechly et al. (Green River Formation, Wyoming, United States of America, placed by Bechly et al. 2020 in Eodysagrioninae, which they treated as a subfamily of Dysagrionidae but was later excluded from that subfamily by Simonsen et al. 2024). We, therefore, treat BBM-P000021 as Allenby gen. and sp. A, also tentatively in the Dysagrionidae and Cephalozygoptera.

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.