Distribution map of Mcvaughia: triangle – M. bahiana, circle – M. piauhiensis, and square – M. sergipana. Solid blue line in the center represents the São Francisco River today. Dotted blue line represents the past course of São Francisco River. Blue circle represents the São Francisco paleo lake. Light green – Atlantic Forest domain, dark green – Amazon Forest domain, orange – Cerrado domain, and yellow – Caatinga domain. AL – state of Alagoas, BA – state of Bahia, CE – state of Ceará, MA – state of Maranhão, PB – state of Paraíba, PE – state of Pernambuco, PI – state of Piauí, RN – state of Rio Grande do Norte, and SE – state of Sergipe.