The entirety of Myxosargus nigricormis‘ Wikipedia entry reads (at time of writing): “A species of soldier fly in the family Stratiomyidae.” INaturalist puts its range at most of the eastern United States (and of course Florida).

Soldier flies in general are somewhat large and can look imposing (some mimic wasps), but they are usually harmless to humans. The “wings one on top of the other” resting pose is distinctive to the family.

This individual was identified via the kind people at iNaturalist.