Two of the main mechanisms of fluid acquisition in adult mammals are lapping and sucking. Mammals with incomplete cheeks ingest fluid via lapping, which involves rhythmic tongue protrusion to contact the fluid and retraction to transport the fluid stream into the oral cavity. In contrast, mammals with complete cheeks use suction by generating negative pressures to draw fluid into the oral cavity. Here we use XROMM combined with a soft-tissue marker in the tongue to compare jaw and tongue kinematics and coordination during drinking in species with incomplete cheeks (ferret) and complete cheeks (pig and goat). Results demonstrate that lapping uses highly coordinated out-of-phase tongue-jaw movements, such that the tongue is maximally protracted at maximum gape. The goat also shows highly correlated, but in-phase, tongue-jaw movements, such that the tongue is maximally protracted at minimum gape. Further, the tongue never leaves the oral cavity. Surprisingly, tongue-jaw kinematics in the pig differs from the goat in key ways: the tongue often protrudes into the fluid as in lapping, but tongue-jaw coordination is in-phase, as in sucking. Additionally, the pig does not swallow every cycle as in the goat. As tongue-jaw coordination is also weak in the pig, unlike in the goat, these results show fundamental differences in sucking between two closely related species. This also demonstrates that the historical dichotomy of lapping and sucking is not representative of the kinematic diversity underlying mammalian fluid ingestion.