On a new Melanosuchus species (Alligatoroidea: Caimaninae) from Solimões Formation (Eocene-Pliocene), Northern Brazil, and evolution of Caimaninae Author Souza-Filho, Jonas Pereira De jpdesouzafilho @ hotmail. com; https: // orcid. org / 0000 - 0003 - 0481 - 3204 Author Guilherme, Edson guilherme. edson @ gmail. com; https: // orcid. org / 0000 - 0001 - 8322 - 1770 Author Toledo, Peter Mann De INPE-Instituto Nacional de Pesquisas Espaciais, MCT, São José dos Campos, São Paulo, Brazil. Author Carvalho, Ismar De Souza Departamento de Geologia, CCMN-IGEO, Universidade Federal do Rio de Janeiro, 21.910 - 200, Cidade Universitária-Ilha do Fundão, Rio de Janeiro, Rio de Janeiro, Brazil. ismar @ geologia. ufrj. br; https: // orcid. org / 0000 - 0002 - 1811 - 0588 Author Negri, Francisco Ricardo Laboratório de Paleontologia, Universidade Federal do Acre-Campus Floresta, 69895 - 000, Cruzeiro do Sul, Acre, Brazil. Author Maciente, Andréa Aparecida Da Rocha andreamaciente @ gmail. com; https: // orcid. org / 0000 - 0003 - 3504 - 1833 Author Cidade, Giovanne M. Author Lacerda, Mauro Bruno Da Silva Author Souza, Lucy Gomes De text Zootaxa 2020 2020-12-11 4894 4 561 593 journal article 9356 10.11646/zootaxa.4894.4.5 e798d6b3-ca6a-456a-a0af-ec2c72408720 1175-5326 4316776 19BD5D89-5C9C-4111-A271-98E819A03D8E Melanosuchus and its prolific debates Melanosuchus was originally proposed by Gray (1862) as a monospecific genus to relocate the species Caiman niger described by Spix (1825) . For a synonym list of Melanosuchus niger see Medem (1963) . Regarding the phylogenetic relationships of the genus there are two main propositions: 1) nested within Caiman genus, frequently as sister of C. latirostris (e.g., Poe 1996 ; Brochu 1997 , 1999 ; Souza-Filho et al. 2019 ); or, 2) as sister species of Caiman genus (e.g., Oaks 2011 ; Roberto et al. 2020 ). The validity of the Melanosuchus is still an open debate with some authors suggesting its synonymization with Caiman ( Poe 1996 ) , this discussion, for now, goes beyond the scope of the present contribution. However, we suggest that the propositions made by Fitzhugh (2016) for molecular inferences should be considered in future works addressing this question.