Fig. 2 in The First Reconstruction of the Head Anatomy of a Cretaceous Insect, †Gerontoformica gracilis (Hymenoptera: Formicidae), and the Early Evolution of

Fig. 2. Slices of the µ-CT dataset showing histological preservation in the head of †Gerontoformica gracilis specimen CASENT0741232. (A) Frontal section showing the cells of the mandibular gland. (B) Transverse section showing the optic neuropils of the brain. (C) Transverse section showing the prepharynx slightly posterad the antennal insertions. (D) Frontal section showing the mandibular adductor, arrows indicating the only possible cuticular filaments. (E) Longitudinal section showing antennal muscles, olfactory lobes, and part of the pharyngeal gland. (F) Overview of sagittal section. Abbreviations: 0bu5, M. tentoriobuccalis, only fragments preserved; 0md1, M. craniomandibularis internus; ada, adductor apodeme; ammc?, likely the antennal mechanosensory and motor center; anm, antennal musculature; ba, amber 'bubble' displacing tissue; bpg, basiparaglossal brush; br, brain; bt, buccal tube; la, lamina; lo, lobula; mb, mushroom body; me, medulla; nan, antennal nerve; glo, glomeruli of the olfactory lobe; mdg, mandibular gland; om, fold representing the oral arm; om, ommatidia of the compound eye; ph, pharynx; pph, prepharynx; sog, suboesophageal ganglion; tr, transverse prepharyngeal ridges. Colors: beige/brown, cuticular structures (ada & bpg); green, alimentary canal; orange, muscles; purple, glands; yellow, nervous system.