Zigrasimecia ufv-04, 2023

Abstract, Júlio Cezar Mário Chaul, 2023, A revision of the Cretaceous ant genus Zigrasimecia Barden & Grimaldi, 2013 (Hymenoptera: Formicidae: † Zigrasimeciinae), Zootaxa 5325 (3), pp. 301-341 : 327

Zigrasimecia ufv-04

( Fig. 15 )

This morphospecies is most likely related to Z. hoelldobleri , but the unique specimen representing it is covered by hundreds of small bubbles which make impossible a proper examination and an unambiguous identification. Zigrasimecia ufv-04 is relatively small (HW 0.66). It has 32–36 clypeal chaetae. Frontal carina is strongly marked, forming a mildly sinuous margin from torulus to compound eye. Compound eye has around 50 ommatidia. Standing setae on body thick, clubbed and truncate. Petiolar node bilobed, node not particularly anteroposteriorly compressed. The peculiar clubbed setae ( Fig. 15 , C) and the petiole shape are the main characters suggesting the morphospecies Zigrasimecia ufv-04, Zigrasimecia ufv-06, and Z. hoelldobleri are a small group of related species within the genus. It is possible that Zigrasimecia ufv-04 and/or Zigrasimecia ufv-06 could belong to Z. hoelldobleri itself, but confirming that would likely require a better characterization of both morphospecies, which would be possible only through micro-CT scanning or with additional, better-preserved specimens. This morphospecies was excluded to all identification keys due to insufficient characters to differentiate it from Z. hoelldobleri ; in the dichotomous key, it would easily key out as the latter.

A mite is attached to the metabasitarsus of the specimen ( Fig. 15 , e).

Examined material. Worker (ANTWEB1038932). Hukawng Valley, Kachin Province, Myanmar; Lower Cenomanian (ca.98.79 ± 0.62 Ma) [ JCMCC] .

Figures

FIGURE 15. Morphospecies Zigrasimecia ufv-04 (specimen ANTWEB1038932). A, head in full-face view; B, profile of right side of body; C, detail of mandibles and clypeus, black triangles indicate clubbed setae on gena; D, posterodorsolateral view of mesosoma and head; E, phoretic mite on mesotibia, with a simplified scheme below the image. Scale bars are 0.2 mm in A, B and D and 0.05 mm in E.