Chilgatermes diamatensis, Engel & Pan & Jacobs, 2013

Engel, Michael S., Pan, Aaron D. & Jacobs, Bonnie F., 2013, A termite from the Late Oligocene of northern Ethiopia, Acta Palaeontologica Polonica 58 (2), pp. 331-334 : 332-333

Chilgatermes diamatensis sp. nov.

Figs. 1–2 .

Etymology: The specific epithet is taken from the ancient kingdom of D’mt (a.k.a. Diamat), which ruled portions of modern Eritrea and northern Ethiopia from ca. 700–400 BCE, and which encompassed in its southernmost regions the Chilga deposits.

Holotype: Alate wings, overlapping with only forewing venation discernible; CH 52−70 (a and b), part and counterpart; deposited in the Chilga collections, National Museum of Ethiopia, Addis Ababa, Ethiopia.

Type locality: Sublocality 2 ( CH 52) of Guang River flora, northwestern Ethiopia (Amhara Region, Chilga Woreda, approximately 60 km west of Gondar ( Jacobs et al. 2005).

Type horizon: Late Oligocene (Early Chattian, 28–27 Ma).

Diagnosis.—Alate forewing: Membrane reticulate; all veins originating inside scale; basal suture gently convex, not straight or oblique (straight and oblique in modern Stolotermitidae ); radial field relatively wide, not as narrow as in extant Stolotermitidae , of approximately same width for most of wing length, widening to encompass wing apex in ex−

R

treme apical portion of wing; R (radial vein) simple, extending to about one−third wing length, apparently with a single, short veinlet extending to costal margin in basal third; Rs (radial sector vein) strong, with several (8), largely−simple branches extending to costal margin; M (medial vein) strong, running closer to CuA (anterior cubital vein) than to Rs in proximal third of wing, extensively developed, with numerous (7), mostly dichotomously−branching primary branches extending to posterior wing margin, apicalmost branch terminating just posterior to wing apex, basalmost branch terminating on posterior margin near wing midlength; CuA extensively developed in proximal half of wing, with numerous (at least 10), largely−simple branches.

Description.—As in the diagnosis, with the following minor additions: Total length (as preserved) from basal suture to apex 17.4 mm; maximum width 5.9 mm. Sc (subcostal vein) not evident; apex of Rs stem branching dichotomously just posterior to wing apex, apicalmost superior branch forking near its base, posteriormost fork terminating at wing apex; penultimate branch of CuA forking near posterior wing margin.

Stratigraphic and geographic range.— Type locality only.

Figures

Fig. 1. Termite Chilgatermes diamatensis gen. et sp. nov. (CH 52−70), Chilga Woreda, Ethiopia, Early Chattian (Oligocene). Photomicrographs of part (A) and counterpart (B).Photomicrographs by MSE.

Fig. 2. Reconstruction of forewing venation of termite Chilgatermes diamatensis gen. et sp. nov. (CH 52−70) from Chilga Woreda, Ethiopia, Early Chattian (Oligocene), membrane reticulations omitted. Drawing by Ismael A. Hinojosa−Díaz. Abbreviations: CuA, anterior cubital vein; M, medial vein; R, radial vein; Rs, radial sector vein.