  We propose a new type of structure for singly heavy baryons of $Qqq\bar{q}q$
in addition to the conventional one of $Qqq$. Based on chiral symmetry of the
light quarks, we show that the $Qqq\bar{q}q$ baryon offers a novel picture for
heavy-quark spin-singlet and flavor-antisymmetric baryons. By making use of the
effective Lagrangian approach, we find $\Lambda_c(2765)$ and $\Xi_c(2967)$ are
mostly $Qqq\bar{q}q$ while $\Lambda_c(2286)$ and $\Xi_c(2470)$ are mostly
$Qqq$. The masses of negative-parity baryons are predicted. We also derive a
sum rule and the extended Goldberger-Treiman relation that the masses of the
baryons satisfy. These are the unique features that the conventional picture of
radial excitation in the quark model does not accommodate. Our findings provide
useful information not only for future experiments but also for future lattice
simulations on diquarks.
