Atartas

If this gender is real, then perhaps it is a compound example: Ã-tartas. In this case and surn. One could suspect that it was a concoction. For tar-: tart- cf. Vi̇̀n-taras: Vi̇̀n-tartas, Mi̇̀n-taras: Mi̇̀n-tartas ¹. See also Tárvydas.