Zigrasimecia goldingot

†Zigrasimecia goldingot; Temporal range: Early Cenomanian, Late Cretaceous K Pa Eo Ol Mi Pl Burmese amber, Kachin State, Myanmar
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Zigrasimeciinae
Genus:	Zigrasimecia
Species:	†Z. goldingot
Binomial name
	†Zigrasimecia goldingot; Zhuang, Ran, Li, Feng & Liu, 2021

Identification

Chaul (2023) - Head roughly subquadrate in full-face view. Pilosity on body composed of inconspicuous, decumbent, small setae; on the dorsum of head setae curving towards the midline. Compound eyes subcircular (in relation to Zigrasimecia tonsora). Reduced number of clypeal chaetae (less than 25). Dorsal propodeal surface relatively short (in relation to Z. tonsora). Petiolar node apex sharp, not forming a proper dorsal surface; transversally the apex is mildly bilobed.

Zigrasimecia goldingot and Z. tonsora are species known only by queens. Below is summarized why the species described from workers are unlikely conspecific to them.

Zigrasimecia goldingot differs strikingly in pilosity from the species Zigrasimecia boudinoti, Zigrasimecia chuyangsui, Zigrasimecia ferox and Zigrasimecia hoelldobleri as it has small and decumbent setae while those four species have conspicuous standing setae on the body. It differs from Zigrasimecia thate and Zigrasimecia perrichoti in the low number of clypeal chaetae (less than 25, rather than more than 30); from Z. thate alone, for not having the flagellate, hook-shaped setae on the frons and vertex; and from Z. perrichoti alone in the subquadrate, rather than subrectangular, head (although different shape of the head is common between queens and workers in many ant species), and for having many small, recurved, decumbent setae on the head, rather than a mostly glabrous head (or maybe with very thin and inconspicuous setae, see description of Z. perrichoti). Finally, Z. goldingot is unlikely conspecific to Zigrasimecia caohuijiae for its petiole with a short and bilobed apex, rather than having the broad and round dorsal surface of the node seen in Z. caohuijiae.

Zigrasimecia tonsora can be differentiated from Z. boudinoti, Z. chuyangsui and Z. hoelldobleri for the type of its standing pilosity, which is shorter, thinner and not as homogeneously distributed on the dorsal surfaces of the head, mesosoma and metasoma as in those species. Also due to pilosity, Zigrasimecia tonsora is unlikely conspecific to Zigrasimecia caohuijiae, Z. perrichoti and Z. thate, as the three are mostly glabrous, except that Z. thate has a patch of hook-shaped, flagellate standing setae on the head (setae on the head of Z. tonsora being simple, thin, and suberect). The type of the pilosity in Z. ferox is similar to Z. tonsora for being short and suberect to erect, however, in Z. ferox the setae appears more sparse and evenly distributed, while it is patchy and denser in Z. tonsora. Z. tonsora differs from most species by having the apical tooth strongly offset (outer margin sinuous distally, Fig. 2, D). Finally, there are two unique traits that isolate Z. tonsora, a V-shaped groove on the frons, and a pair of vertexal ridges (see comment on that last character under Zigrasimecia tonsora).

Keys including this Species

Key to Zigrasimecia species

Distribution

This taxon was described from Burmese amber, Kachin State, Myanmar (Early Cenomanian, Late Cretaceous).

Castes

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

†goldingot. †Zigrasimecia goldingot Zhuang, Ran, Li, Feng & Liu, 2021: 2, figs. 1-2 (q.) MYANMAR (Burmese amber).

Type Material

Holotype YKLP-AMB-001, alate female. Hukawng Valley, Kachin Province, northern Myanmar; upper Albian-lower Cenomanian (ca. 98.79 ± 0.62 Ma).

This material was originally collected from an amber mine located near Noije Bum Village (26° 21' 33.41"N, 96° 43' 11.88"E), Danai Town, northern Myanmar, and later purchased from a local dealer. The amber piece (YKLP-AMB-001) is housed at the Yunnan Key Laboratory for Palaeobiology, Institute of Palaeontology, Yunnan University, Kunming, China.

Description

References