Complex sentence: The earliest accepted fossils are known from the Cambrian-aged Burgess Shale ("Thaumaptilon "), similar fossils from the Ediacaran (ala"Charnia") may represent the dawn of sea pens.
Split into simpler sentences: The earliest accepted fossils are known from the Cambrian-aged Burgess Shale ("Thaumaptilon "). Similar fossils from the Ediacaran (ala"Charnia") may represent the dawn of sea pens.