  We report an experimental study of the magnetic order and electronic
structure and transport of the layered pnictide EuMnSb$_2$, performed using
neutron diffraction, angle-resolved photoemission spectroscopy (ARPES), and
magnetotransport measurements. We find that the Eu and Mn sublattices display
antiferromagnetic (AFM) order below $T_\mathrm{N}^\mathrm{Eu} = 21(1)$ K and
$T_\mathrm{N}^\mathrm{Mn} = 350(2)$ K respectively. The former can be described
by an A-type AFM structure with the Eu spins aligned along the $c$ axis (an
in-plane direction), whereas the latter has a C-type AFM structure with Mn
moments along the $a$--axis (perpendicular to the layers). The ARPES spectra
reveal Dirac-like linearly dispersing bands near the Fermi energy. Furthermore,
our magnetotransport measurements show strongly anisotropic magnetoresistance,
and indicate that the Eu sublattice is intimately coupled to conduction
electron states near the Dirac point.
