Tucanoichthys tucano, specimen TCWC 20316.01, 14.4 mm SL, c&s. A. Hyopalatine arch and opercular series, right side in lateral view (image reversed). B. Jaws and anterior part of palatoquadrate. Margin of coronomeckelian outlined by thin white line. Inset image shows close up of upper jaw teeth at junction of premaxilla and maxilla (area surrounded by box with thin grey dashed line). C. Infraorbital bones, right side in lateral view (image reversed). D. Sclerotic ring, right side in lateral view. Abbreviations: An, anguloarticular; Ant, antorbital; Apal, autopalatine; Cm, coronomeckelian; Den, dentary; Ecpt, ectopterygoid; Enpt, endopterygoid; EPC, Ethmo-Palatine cartilage; Hy, hyomandibular; Iop, interopercle; Io1–3, infraorbitals 1–3; MC, Meckel’s cartilage; Mpt, metapterygoid; Mx, maxilla; Op, opercle; Pmx, premaxilla; Pop, preopercle; Q, quadrate; Ra, retroarticular; Sc, sclerotic; ScC, sclerotic cartilage; Sop, subopercle; Sy, symplectic.

  Part of: Mattox GMT, Conway KW (2021) Osteology of Tucanoichthys tucano Géry and Römer, an enigmatic miniature fish from the Amazon basin, Brazil (Teleostei: Characiformes: Characidae). Vertebrate Zoology 71: 645-667. https://doi.org/10.3897/vz.71.e71886