The article presents the data from Kakliniškės 7 settlement site, discovered and excavated in 2020 during the construction of the gas pipeline. The rich and representative collection of pottery and archaeobotanical material gathered in the site have provided valuable data on the hitherto unknown 4th century BC in Lithuania. Pottery such as that found at Kakliniškės 7 has not previously been identified, and is therefore referred to here as Kakliniškės Ware. These are pots with slightly curved walls, rounded shoulders and vertical rims, featuring a striated surface topped with an additional coarse layer. The defined attributes of this new type of pottery have allowed the identification of the same ware in other settlement and burial sites in southeastern Lithuania and the Trans-Nemunas region. All of these settlement sites share some common features; most likely they are the sites of short-lived farmsteads belonging to highly dispersed settlements. Such data allow us to hypothesise a hitherto unidentified cultural group that briefly spread in southern Lithuania in the 4th century BC. This challenges the prevailing model of a static cultural development and a homogeneous material culture in the 1st millennium BC in all of eastern Lithuania. Our data show that the cultural situation here was much more dynamic than previously thought.