  We report on the experimental observation of Feshbach resonances in large
mass-imbalance mixtures of Erbium (Er) and Lithium (Li). All combinations
between ${}^{168}$Er, ${}^{166}$Er and ${}^7$Li, ${}^6$Li are cooled to
temperatures of a few microkelvin, partially by means of sympathetic cooling
together with Ytterbium (Yb) as a third mixture component. The Er-Li inelastic
interspecies collisional properties are studied for magnetic fields up to 680
G. In all cases resonant interspecies loss features, indicative of Feshbach
resonances, have been observed. While most resonances have sub-Gauss widths, a
few of them are broad and feature widths of several Gauss. Those broad
resonances are a key to the realization of ultracold Er-Li quantum gas mixtures
with tunable interactions.
