Birth-order term borrowing as evidence for historical interaction patterns in the Saruwaged Mountains of Papua New Guinea

![CDATA[Austronesian languages of the Markham River valley and neighbouring Papuan languages feature birth--‐order term systems with up to sixteen members. All Papuan languages on the opposite side of the Saruwaged Mountains from the Markham River valley lack birth--‐order term systems, except the dialect of Nungon spoken in a single village, Kotet, in the Uruwa River valley. The birth--‐order terms of Kotet village are clearly cognate with those of Papuan and Austronesian languages on the other side of the mountain range; no other Nungon dialects contain birth--‐ order term systems. Besides the birth--‐order terms, the Kotet lexicon shows little evidence of borrowing from southern languages. Every Papuan language in the region shows different forms, repetitions within systems, and ordering of the birth--‐ order terms, making their trajectory to Kotet village hard to track. Birth--‐order term systems are a uniquely diffusable, and mutable, lexical category in this part of the Huon Peninsula, Papua New Guinea.]]