Fig. 5. 3D reconstructions of the head of †Gerontoformica gracilis specimen CASENT0741232, showing skeleton and musculature of maxilla and labium. (A, F, H, and K) Dorsal view.(B, E, I, and L) Ventral view. (C, G, and J) Sagittal view,in (C) the left instead of right side of the head is shown. (D) Frontal view. (M) Lateral view. (A–C and G) Maxillary musculature. (D–F) Maxilla. (H–J) Labial musculature and salivary duct. (K–M) Labium. Abbreviations: 0hy3, M. tentoriohypopharyngalis; 0hy12, M. hypopharyngosalivaris; 0la5, M. tentoriopraementalis; 0la11, M. praementoparaglossalis; 0la12, M. praementoglossalis; 0la14, M. praementopalpalis externus; 0mx1, M. craniocardinalis externus; 0mx3, M. tentoriocardinalis; 0mx4, M. tentoriostipitalis anterior; 0mx6, M. stipitolacinialis; 0mx7, M. stipitogalealis; 0mx8, M. stipitopalpalis externus; bpb, basiparaglossal brush; cd, cardo; ga, galea; gl, glossa; hy, distal hypopharynx; lb, labrum; lc, lacinia; msf, medial stipital flange; mxc, maxillary comb; pgl, paraglossa; plb, labial palp; plbp, process of the labial palp; pmd, premental ditch; pml, prementum lateral face; pmv, prementum ventral face; pmx, maxillary palp; psm, postmentum; st, stipes; svd, salivary duct. Symbols: blue line, premental ditch.

Published as part of Richter, Adrian, Boudinot, Brendon, Yamamoto, Shûhei & Katzke, Julian, 2022, The First Reconstruction of the Head Anatomy of a Cretaceous Insect, †Gerontoformica gracilis (Hymenoptera: Formicidae), and the Early Evolution of, pp. 1-80 in Insect Systematics and Diversity 6 (5) on page 14, DOI: 10.1093/isd/ixac013, http://zenodo.org/record/7301493