  Recent data on the production of $D$ mesons and $\Lambda_c^+$ baryons in
heavy ion collisions at the Relativistic Heavy Ion Collider and the Large
Hadron Collider exhibit a number of striking characteristics such as enhanced
yield ratios $D_s^+/D^0$, $\Lambda_c^+/D^0$ and their transverse momentum
dependences. In this paper, we derive the momentum dependence of open charm
mesons and singly charmed baryons produced in ultra-relativistic heavy ion
collisions via the equal-velocity quark combination. We present analytic
expressions and numerical results of yield ratios and compare them with the
experimental data available. We make predictions for other charmed hadrons.
