Wallace Line by the Sahul Shelf to New Guinea. The biogeographic boundary known as Lydekker's Line, which separates the eastern edge of Wallacea from the Australian region, has a similar origin to the Wallace line. During ice age glacial advances, when the , both Asia and Australia were united with what are now islands on their respective continental shelves as continuous land masses, but the deep water between those two large continental shelf areas was, for over 50 million years, a barrier that kept the flora and fauna of Australia separated from those of Asia. Wallacea consists of islands that were not
Landsker Line having moved only slightly over the past several centuries. A visible boundary which represents the Landsker line is Brandy Brook which runs through Newgale. The next beach north after the brook has the Welsh name Pen-y-Cwm. Landsker Line The Landsker Line is a term used for the language boundary in Wales between the largely Welsh-speaking and largely English-speaking areas in Pembrokeshire and Carmarthenshire. The English-speaking areas, south of the Landsker line and known as Little England beyond Wales, are notable for having been English linguistically and culturally for many centuries despite being far from the England–Wales border During the 11th