Many languages show case concord among various DP-internal elements. Some of these languages, such as Warlpiri, additionally allow discontinuous DPs and preserve concord in these split structures. In this talk, we examine novel data from two unrelated languages, Tiwa (Tibeto-Burman; India) and Amahuaca (Panoan; Peru), which show a distinct, previously unanalyzed pattern: case concord is possible in discontinuous DPs but not in continuous DPs. We argue that this pattern of case concord only under discontiguity arises as a result of multiple DP layers and a restricted mechanism of concord we call "D-concord''. We demonstrate that this style of analysis correctly predicts instances of case stacking in Tiwa and the interactions of case concord and differential case marking found in both languages. From these data, we conclude that while the patterns in Warlpiri and the patterns in Tiwa and Amahuaca may both pretheoretically be identified as concord, they arise due to two distinct mechanisms. Thus, case concord only under discontiguity represents a new type of concord altogether.
[Joint work with Emily Clem (UC Berkeley)]