DOI: 10.5061/dryad.0k6djhb7d
title: Data from: Cretaceous crown male ant reveals the rise of modern lineages

description: Most described Mesozoic ants belong to stem groups that existed only
 during the Cretaceous period. Previously, the earliest known crown ants
 were dated to the Turonian (Late Cretaceous, ca. 94–90 million years ago
 (Ma)) deposits found in the USA, Kazakhstan, and Botswana. However, the
 recent discovery of an alate male ant in Kachin amber from the earliest
 Cenomanian (ca. 99 Ma), representing a new genus and species,
 Antiquiformica alata, revises the narrative on ant diversification.
 Antiquiformica can be distinctly differentiated from all known male stem
 ants by its geniculate antennae with elongated scape, extending far beyond
 the occipital margin of the head and half the length of the funiculus, as
 well as its partly reduced forewing venation. Furthermore, the combination
 of a one-segmented waist with a well-developed node, elongated scape
 extending beyond the occipital margin, and reduced forewing venation,
 particularly the completely reduced m-cu and rs-m crossveins and absence
 of rm and mcu closed cells, firmly places the fossil within the extant
 subfamily Formicinae. Fourier transform infrared spectroscopy (FTIR)
 confirmed that the amber containing Antiquiformica alata originated from
 the Kachin mines in Myanmar. This discovery significantly revises our
 understanding of the early evolution of Formicinae. The presence of
 Antiquiformica in Cenomanian amber indicates that the subfamily Formicinae
 emerged at least by the start of the Late Cretaceous, with crown ants
 likely originating earlier during the earliest Cretaceous or possibly the
 Late Jurassic, although paleontological evidence is lacking to support the
 latter hypothesis.
description: # Scan mCT data of Cretaceous ant *Antiquiformica alata* for Wu et al ZR
 [https://doi.org/10.5061/dryad.0k6djhb7d](https://doi.org/10.5061/dryad.0k6djhb7d) The original data of CT scanning allowed us to reconstruct the three-dimensional structure of Cretaceous ant *Antiquiformica alata* Wu, Radchenko & Engel, 2024. ## Description of the data and file structure We assigned a species, *Antiquiformica alata* Wu, Radchenko & Engel, 2024, to Formicinae of Formicidae (Insecta, Hymenoptera) based on an alate male ant in Kachin amber from the mid-Cretaceous (ca. 99Ma) (Wu et al., 2024). The specimen was collected from Noije Bum hill, approximately 18 km southwest of Tanai Village in the Hukawng Valley, northern Myanmar. The specimen is stored in the Key Lab of Insect Evolution and Environmental Changes, College of Life Sciences, Capital Normal University (CNUB; Dong Ren, Curator), Beijing, China. The head structure of the specimen is not very clear, especially the position of the antenna. To better understand the key structures of the head of this fossil ant, we conducted a CT scan of the head. According the result of reconstruction of the head, we can clearly observe that its distinctly geniculate antennae with elongated scape, extended far beyond occipital margin of head and half length of funiculus. These two key features can easily differentiate Antiquiformica from all known Cretaceous stem ants. Therefore, we placed *Antiquiformica alata* Wu, Radchenko & Engel, 2024 within the subfamily Formicinae, a crown clade of Formicidae. This finding suggest that crown ants may have evolved as early as the earliest Cretaceous or even the latest Jurassic. This compressed file contains 993 original images of the holotype of *Antiquiformica alata* Wu, Radchenko & Engel, 2024 captured by CT scans, saved in TIFF format.  Wu Q., Radchenko A.G., Engel M.S., Li X.Q., Yang H.R., Li X.R., Shih C.K., Ren D., Gao T.P. 2024. Cretaceous crown male ant reveals the rise of modern lineages. *Zoological Research*, 45(5): 983-989. ## Code/Software The specimen was scanned at the micro-CT laboratory of the Yunnan Key Laboratory for Paleobiology using an X-ray microscope (3D-XRM, Zeiss Xradia 520 versa, Germany). The scanning parameters were as follows: beam strength: 60 kV/5 w, filter: no, resolution: 2.92 μm, exposure time: 5 s, and number of TIFF images: 993. Volume rendering and three-dimensional (3D) reconstruction were performed using the open-source software Drishti v.2.4 (Limaye, 2012). Limaye A. 2012. Drishti: a volume exploration and presentation tool. *In*: Proceedings of SPIE 8506, Developments in X-ray Tomography VIII. San Diego: SPIE, 85060X.