Allenbycimbex morrisae, Archibald & Rasnitsyn, 2023

Archibald, S. Bruce & Rasnitsyn, Alexandr P., 2023, Cimbicidae (Hymenoptera, ‘ Symphyta’) in the Paleogene: revision, the new subfamily Cenocimbicinae, and new taxa from the Eocene Okanagan Highlands, Zootaxa 5278 (1), pp. 1-38 : 7-8

Allenbycimbex morrisae n. sp.

http://zoobank.org/ urn:lsid:zoobank.org:act:158DB20D-4B4D-41C3-B064-CCB1AB5237A9

Fig. 4 .

Material. Holotype RBCM.EH2007.002.0001a, b (part, counterpart). Mostly complete but somewhat deformed by geological shear forces, lacking head, fore and mid legs, hind tarsi, apical half of left wings, and apical half of abdomen; hind wings fragmentary and poorly preserved; wings lack visible colouration either originally or by preservation; collected by Muriel Morris, Allenby Formation; housed in the collections of the RBCM.

Diagnosis. As for genus.

Description. Length as preserved (stretched, see below; incomplete head and abdomen) 8.9 mm, apparently dark (preserved parts: hind tibiae, metasoma possibly paler). Temples somewhat inflated. Antennal club if correctly identified apparently short with truncated apex. Lateral pronotal lobes very wide, notauli apparently widely separated before scutellum (interpretation tentative). Hind coxae large, contiguous; femora not inflated, almost parallel-sided, shorter than abdomen wide; tibia thinner and much longer than femur. Forewing: length ca. 13.5 mm as preserved (distorted), the same in life if it was compressed in width, ca. 10 mm in life if it was stretched in length; maximum width: ca. 3.5 mm as preserved, about the same in life if it was stretched in length or ca. 4.25 if compressed in width; length/width: probably ca. 3.0; no membrane colouration detected (could be an artefact of preservation); pterostigma broad, distinctly wider than C-R basal to it; R+M longer than 1-M; 2r-rs not preserved; 2r-rm curved, joins Rs about same level as 2m-cu joins M, joins M behind 2m-cu for more than half length of 2r-m; 1-M almost straight; 1-M and 1m-cu diverging toward anterior; 3r-m distinctly bowed toward base; cell 2mcu with M shorter than 1m-cu; 2m-cu curved distinctly toward base; cu-a postfurcal; anal cell contracted for distance subequal to width (height) of 1a cell, with no crossvein; basal portion of 2A+3A sharply bent toward 1A, meets 1A at steep angle. Hind wing with m-cu not preserved, r-m and cu-a far distant (for much longer than in Cenocimbex and more similar to that characteristic of Leptostigma n. gen.); other details obscure. Abdomen with 3 segments preserved (apparently sterna 2–4) each narrower than thorax and some 3.5× as wide as long.

Remarks. The fossil was distorted by geological shear forces during diagenesis, either stretching it along the plane of the length of its right forewing or compressing it 90° to that. These possibilities cannot be distinguished. As the forewings are about 90° to each other, we estimated its life shape by both graphically compressing the image along the length of the right forewing and by stretching it’s width so that elements of its venation are of equal length to those of its left wing.

Etymology. The specific epithet is a patronymic formed from the surname of Muriel Morris, recognizing her contribution as collector and donor of the only known specimen.

Figures

FIGURE 4. Allenbycimbex morrisae, holotype RBCM.EH2007.002.0001: A, photograph; B, drawing; C, drawing of right wing; D, drawing of left wing. Scale bar for A and B is 5 mm (as the fossil has been stretched by geologic shear forces, C and D are altered to the presumed unstretched configuration).