Three-dimensional reconstruction of the atlas (first to third column) and axis (fourth to sixth column) of Siagonodon exigumm sp. nov. in anterior, lateral and posterior views based on µ-CT data. MNRJ 27562 (a), MNHN-RA-2023.0001 (b), MNRJ 27558 (c). Abbreviations: af articular facet; con condile; iI intercentrum I: iII intercentrum II; iIII intercentrum III; na neural arch; od odontoid; odp odontoid process; sp spinal process.

  Part of: Martins A, Folly M, Ferreira GN, Garcia da Silva AS, Koch C, Fouquet A, Machado A, Lopes RT, Pinto R, Rodrigues MT, Passos P (2023) An evolutionary paradox on threadsnakes: Phenotypic and molecular evidence reveal a new and remarkably polymorphic species of Siagonodon (Serpentes: Leptotyphlopidae: Epictinae) from Amazonia. Vertebrate Zoology 73: 345-366.