AA 3866 then AA 1408 at DFW
Merida → Dallas-Fort Worth → Huatulco
Timetable, Dallas-Fort Worth time
18:05AA 3866 from Merida at the gate
10:49AA 1408 to Huatulco leaves the gate
16 h 44 apart on the timetable, overnight
AA 1408 leaves 16 h 44 after AA 3866 arrives on the timetable: more than half a day, so not a connection we count.