Complex sentence: The rock was formerly known as the Psammosteus Limestone after a characteristic fossil fish recorded from it; "Psammosteus anglicus"; the fossil was subsequently shown to have been wrongly identified and is in fact "Traquairaspis symondsi".
Split into simpler sentences: The rock was formerly known as the Psammosteus Limestone after a characteristic fossil fish recorded from it; "Psammosteus anglicus". The fossil remains were subsequently shown to have been wrongly identified and belong in fact to "Traquairaspis symondsi".