<Tr> <Td> Zuzhuangian </Td> <Td> Delamaran </Td> <Td> Amgan </Td> <Td> Undillian </Td> <Td> </Td> </Tr> <Tr> <Td> Zhungxian </Td> <Td> </Td> <Td> </Td> <Td> Florian </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Templetonian </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> Dyeran </Td> <Td> </Td> <Td> Ordian </Td> <Td> </Td> </Tr>

The precambrian-cambrian boundary represents the first appearance of