Complex sentence: Certain Limestones in western part of the Republic of Ireland are packed with beautifully preserved goniatite fossils, they are also found in marine bands of the Carboniferous Coal Measures in Europe, and in marine rocks of the Pennsylvanian period in Arkansas.
Split into simpler sentences: Certain limestones in western part of the Republic of Ireland are packed with beautifully preserved goniatite fossils. They are also found in marine bands of the Carboniferous coal measures in Europe, and in marine rocks of the Pennsylvanian period in Arkansas.