Recent measurements of charm-hadron production in proton-proton collisions at the LHC have found a surprisingly large baryon to meson ratio. We propose that this observation can be explained by the statistical hadronization model (SHM), by employing a largely augmented set of charm-baryon states beyond the current listings of the particle data group. We estimate the additional states using guidance from the relativistic quark model and from lattice QCD. Using charm- and strange-quark fugacity factors to account for the well-known suppression of heavy flavor in elementary collisions, we compute the yields and spectra of D, $D_s$ and ${\Lambda }_c$ hadrons in proton-proton collisions at $\sqrt{s}=5$ TeV. Our main finding is that the enhanced feeddown from excited charm baryons can account for the ${\Lambda }_c/D^0$ ratio measured by ALICE at midrapidity, with some caveat for the forward-rapidity LHCb data. Furthermore, assuming independent fragmentation of charm quarks but with the hadronic ratios fixed by the SHM, the measured transverse-momentum ($p_T$) spectra of D-mesons and ${\Lambda }_c$ can also be described; in particular, the low-$p_T$ enhancement in the observed ${\Lambda }_c$/$D^0$ ratio is attributed to the enhanced feeddown from “missing” charm-baryon states. We comment on the implications of these findings for measurements of $D_s$ and ${\Lambda }_c$ in heavy-ion collisions.