The COVID-19 pandemic caused educational institutions across the world to face a new reality: when teachers and students do not share the same physical space (fractured ecologies; drastic changes in the everyday procedures and routines of teaching become an immediate necessity. In this paper, we trace some of the effects of this new situation in online classes of three experienced university teachers in the early days of the pandemic. We zoom in on dimensions of the classroom interface such as: turn-taking procedures, socialization, peer scaffolding and feedback; strategic footing changes across institutional and conversational roles; joking and humor. Not surprisingly, we found that the systematic absence of multimodal contextualization cues like gaze direction and tracing the origin of sound/speech were a trouble source in these online multiparty settings. We also saw, however, that teachers and students were successful in reinventing themselves and in devising new ways to deal with the changed circumstances. We end the paper with a number of implications for research into the classroom interface, both online and offline.