Complex sentence: Wrangellia collided and amalgamated with the Alexander Terrane by Pennsylvanian time, by the end of the Triassic Period the Peninsular Terrane had also joined the Wrangellia CT.
Split into simpler sentences: Wrangellia collided and amalgamated with the Alexander Terrane by Pennsylvanian time. By the end of the Triassic Period, the Peninsular Terrane had also joined the Wrangellia CT.