Zigrasimecia Abstract, 2023
- Dataset
- GBIF Backbone Taxonomy
- Rank
- GENUS
Classification
- kingdom
- Animalia
- phylum
- Arthropoda
- class
- Insecta
- order
- Hymenoptera
- family
- Formicidae
- genus
- Zigrasimecia
description
(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).
materials_examined
Examined material. Worker (ANTWEB 1038932). Hukawng Valley, Kachin Province, Myanmar; Lower Cenomanian (ca. 98.79 ± 0.62 Ma) [JCMCC].
description
(Fig. 16) The specimen is covered by hundreds of bubbles in the amber matrix, which makes it difficult to achieve satisfactory characterization. This morphospecies is overall very similar to Zigrasimecia ufv- 04, sharing with it the abovementioned traits, except for being larger (HW 0.8, ML 0.72) and with the compound eye formed by more ommatidia, at least 90. It has approximately 34 clypeal chaetae. See above a discussion on the possible relatedness of the two morphospecies to Z. hoelldobleri. This morphospecies was excluded from 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.
materials_examined
Examined material. Worker (ANTWEB 1032645). Hukawng Valley, Kachin Province, Myanmar; Lower Cenomanian (ca. 98.79 ± 0.62 Ma) [JCMCC].
description
(Fig. 17) This morphospecies is composed of two specimens that were originally in one single piece (separated for study). The amber matrix is extremely dirty and both specimens appear desiccated (the entire body " sculpturing " appears to be an artifact). The specimens do not have conspicuous standing setae, instead, they have a curved small pilosity on the head which is similar to Zigrasimecia ufv- 11 (see below). They have a subrectangular head. Compound eye has around 50 ommatidia. The frontal carina is poorly developed. The propodeal dorsal and descending surfaces are separated by a strong angle. The petiole is somewhat long and low, the node top surface is round, not bilobed (very distinct from any shape seen in other species or morphospecies). If better-preserved specimens confirm that the traits attributed to this morphospecies are not artifactual (some sclerite shapes could be a result of stretching), it will certainly belong to a new species, as this combination of traits is unique in the genus. This morphospecies was excluded from the dichotomous identification key.
materials_examined
Examined material. Workers (UFV-LABECOL- 010579 and UFV-LABECOL- 010580). Hukawng Valley, Kachin Province, Myanmar; Lower Cenomanian (ca. 98.79 ± 0.62 Ma) [JCMCC].
description
(Fig. 20) Five worker specimens are likely conspecifics and compose morphospecies Zigrasimecia ufv- 11. Images for all specimens are uploaded on Antweb. The specimens share similar shapes of the head, mesosoma, and petiole (petiole apparently badly damaged in ANTWEB 1047907), and all have small, curved, decumbent setae on the head. Currently, a species based on a worker specimen and deposited in the Yunnan Key Laboratory for Palaeobiology, Institute of Palaeontology, Yunnan University, Kunming, China, is being described and images were presented to one of the authors (Yuhui Zhuang, personal communication). The species is similar to Zigrasimecia ufv- 11 and could be conspecific or very close to it, for that reason, I refrain from describing the morphospecies here. Zigrasimecia ufv- 11 was added to both dichotomous and the multi-entry keys, as it will soon be described and is satisfactorily characterized. One specimen (ANTWEB 1047052) deposited at JGDC (added to Antweb as morphospecies “ JGD- 09 ”), could possibly belong to morphospecies Zigrasimecia ufv- 11, but the available images were not sufficient to ascertain that.
materials_examined
Examined material. Hukawng Valley, Kachin Province, Myanmar; Lower Cenomanian (ca. 98.79 ± 0.62 Ma). Four workers (ANTWEB 104703, ANTWEB 104710, ANTWEB 104709, and ANTWEB 1047907) [MBC]. One worker (ANTWEB 1047053) [JCMCC].
description
This worker specimen is similar to Z. caohuijiae, except for the petiolar shape which is more antero-posteriorly compressed, therefore, without the evenly round top of the node in lateral view, and by the mesosomal dorsal surface in dorsal view, which is apparently slightly more compact than in Z. caohuijiae. They share a similar head shape, to a great extent the mesosomal shape, and the petiolar shape in anterior view (petiole with a curved dorsal outline in anterior view rather than flat or bilobed). It was added to multientry key but excluded from the dichotomous; the images are by José Gómez Durán, reproduced with permission.
materials_examined
Examined material. One worker (ANTWEB 1047077). Hukawng Valley, Kachin Province, Myanmar; Lower Cenomanian (ca. 98.79 ± 0.62 Ma) [JGDC].
description
The queen is surely not conspecific to Z. goldingot (one of the two species described based on queens), differing from it by the head rather subrectangular instead of subquadrate, by having 36 clypeal chaetae instead of 22, and by the shape of the mesoscutellum, which is about as long as wide while clearly wider than long in Z. goldingot. When compared to Z. tonsora (the other species described based on a queen), significant differences are not that apparent, in fact, both have similar clypeal chaetae numbers and similar mandibular shapes. Specimen YKLP-AMB- 002 is better preserved than Z. tonsora holotype and has been better imaged due to the micro-CT scanning technique, so a detailed comparison between the two is difficult until we have a better characterization of Z. tonsora. Pilosity might be a main difference between the two, but chances of conspecificity should not be ruled out and direct comparison between them and / or further imaging of Z. tonsora should be attempted in the future. Queen YKLP-AMB- 002 was tentatively added to the multientry but not to the dichotomous key. The images in the multientry key are by Yuhui Zhuang, reproduced with permission.
materials_examined
Examined material. One alate queen (YKLP-AMB- 002). Hukawng Valley, Kachin Province, Myanmar; Lower Cenomanian (ca. 98.79 ± 0.62 Ma) [YKLP].
description
(Fig. 18) The specimen has many bubbles around it which prevents an ascertained identification. It has similar head shape, in full-face view, to Z. caohuijiae. It also resembles that species by its mesosomal and petiolar shape, in profile view. There are, however, standing setae on the body which makes conspecificity to Z. caohuijiae unlikely. The standing setae are thin, filiform, and apparently sparse, resembling that of Z. ferox. The shape of the mesosoma and petiole, though, do not indicate Zigrasimecia ufv- 09 belongs to Z. ferox. Additional specimens, when found, might allow a more complete characterization and help in deciding whether it is worthy of receiving a formal description. This morphospecies was excluded to all identification keys due to the small number of characters that could be extracted from the specimen.
materials_examined
Examined material. Worker (ANTWEB 1047064). Hukawng Valley, Kachin Province, Myanmar; Lower Cenomanian (ca. 98.79 ± 0.62 Ma) [JCMCC].
description
(Fig. 19) The specimen has the entire cuticle wrinkled. It was originally so close to the edge of the amber piece that a few polishing and faceting was possible, so there are not too many views available and the specimen could not be fully studied. It apparently lacks any conspicuous standing pilosity on body, which excludes the possibility of it being Z. boudinoti, Z. chuyansui, Z. ferox, Z. hoelldobleri or Z. thate. The petiole in Zigrasimecia ufv- 10 has a bilobed node. The specimen presents an interesting, potentially important trait, which is a visible promesonotal suture. The poor preservation conditions of the specimen, however, do not allow to exclude that some sort of folding could have resulted in a fake " promesonotal suture ". If further specimens confirm the presence of a promesonotal suture in Zigrasimecia ufv- 10, not only the morphospecies would be confirmed as a new species but it would also make the generic diagnosis outdated, as all Zigrasimecia workers known to date have the mesosoma fused to an almost maximum degree, without signs of a promesonotal suture whatsoever. This morphospecies was excluded from all identification keys due to uncertainty about most of its traits.
materials_examined
Examined material. Worker (ANTWEB 1047051). Hukawng Valley, Kachin Province, Myanmar; Lower Cenomanian (ca. 98.79 ± 0.62 Ma) [JCMCC].