Suborder:
|
Paraceltitina
|
Superfamily:
|
Xenodiscoidea
|
Family:
|
Xenodiscidae
|
Genus:
|
Xenodiscus
|
Species:
|
chaotianensis |
Qualifier:
|
ss |
Author:
|
Zhao et al. 1978,p.106
|
Lower Boundary:
|
Pseudosteph./Tap.--Pseudotir./Pleuron., 252.5 million years
|
Upper Boundary:
|
Pseudotir./Pleuron.--Rotodiscoceras beds, 252 million years
|