Early Cambrian shelly fossils from the White Point Conglomerate, Kangaroo Island, South Australia

Abstract

The lower Cambrian (Series 2) White Point Conglomerate (WPC) on Kangaroo Island, South Australia contains exotic clasts representing a diverse array of lithologies, including metamorphics, chert, sandstone, and abundant carbonates, notably archaeocyath-rich bioclastic limestone. Acetic acid digestion of the WPC bioclastic limestone clasts reveals a diverse shelly fauna. This assemblage includes abundant organophosphatic brachiopods such as Cordatia erinae Brock and Claybourn gen. et sp. nov., Curdus pararaensis, Eodicellomus elkaniformiis, Eohadrotreta sp. cf. E. zhenbaensis, Eoobolus sp., Kyrshabaktella davidii, and Schizopholis yorkensis. Additional shelly taxa include the solenopleurid trilobite Trachoparia? sp., the tommotiids Dailyatia odyssei, Dailyatia decobruta Betts sp. nov., Kelanella sp., and Lapworthella fasciculata, spines of the bradoriid arthropod Mongolitubulus squamifer, and several problematica, such as Stoibostrombus crenulatus and a variety of tubular forms. The upper age limit for the WPC is constrained by biostratigraphic data from the overlying Marsden Sandstone and Emu Bay Shale, which are no younger than the Pararaia janeae Trilobite Zone (Cambrian Series 2, Stage 4). The shelly fossil assemblage from the WPC limestone clasts indicates an upper Dailyatia odyssei Zone (= Pararaia tatei to lower P. janeae trilobite zones), equivalent to the Atdabanian-early Botoman of the Siberian scheme. This contrasts with the previously suggested late Botoman age for the limestone clasts, based on the diverse archaeocyath assemblage. The minor age difference between the WPC and its fossiliferous limestone clasts suggests relatively rapid reworking of biohermal buildups during tectonically-active phases of deposition in the Stansbury Basin.

Brachiopods from the Byrd Group (Cambrian Series 2, Stage 4) Central Transantarctic Mountains, East Antarctica: biostratigraphy, phylogeny and systematics

“…; Betts et al . , ), and the assemblages recently reported from the Shuiyu section along the southern margin of the North China Block (Pan et al . in press).…”

“…The unusual, relatively nondescript paterinate Cordatia erinae has recently been described from allochthonous limestone blocks in the White Point Conglomerate, Kangaroo Island, South Australia, suggesting an age for these clasts equivalent to the upper part of the Dailyatia odyssei Zone of South Australia (Betts et al . ). Specimens of C. erinae have also been recovered from the Dailyatia odyssei Zone across much of the Arrowie Basin (Betts et al .…”

“…Specimens of C. erinae have also been recovered from the Dailyatia odyssei Zone across much of the Arrowie Basin (Betts et al . ).…”

“…Some were figured, and these include an ‘elkaniid‐like lingulid’ (tentatively associated with Eodicellomus elkaniiformis by Betts et al . ) and Lingulella sp. (Rowell et al .…”

“…The oldest assemblage consists of Schizopholis yorkensis (Holmer & Ushatinskaya in Gravestock et al ., ), Eoobolus sp. and Cordatia erinae Brock & Claybourn in Betts et al ., in the Shackleton Limestone at horizon HRA/42, located 191 m above the base of the HRA section and 130.5 m below the fossil‐rich biohermal unit at the top of the Shackleton Limestone (Fig. ).…”