Abundant Holothurioidea fossils were collected in 1982 from the Shaodong Formation (the lower part of the lower Carboniferous ) in Linwu county of Hunan
T.regularis Zhang. Microahtyx botoni was discovered in the Rockford limestone (lower Mississippian) of Indiana of USA and the Shidengzi Formation (the upper Lower Carboniferous) in Longhui county of Hunan. Thuroholia marginata was discovered in the Rockford limestone and the Escabrosa limestone (also Lower Mississippian) of Arizona. Thuroholia regularis was found in the lower part of the lower Carboniferous from Shaoyang and Wugang of Hunan. Protocaudina symmetrica and Paraeocaudina minularis were discovered in the lower Carboniferous of Wugang. Mortensenites teat
Paracucumarites asymmetricus and Thuroholia crassa were first collected in lower Carboniferous of Linwu county of Hunan.According to this faunae collected
the Shaodong Formation may belong to the Tournaician stage of Early Carboniferous.