FURONGIAN TRILOBITES FROM THEASIOPTYCHASPIS ANDQUADRATICEPHALUS ZONES OF THE HWAJEOL FORMATION, TAEBAEKSAN BASIN, KOREA

Abstract

This paper describes the upper Furongian trilobites from the Hwajeol Formation and, based on these trilobite faunal assemblages, proposes formally two trilobite biozones, theAsioptychaspis andQuadraticephalus zones. A total of 14 species belonging to ten genera are described: i.e.,Micragnostus sp.,Pseudagnostus planulatus, Koldinioidia sp.,Hamashania pulchera, Hamashania sp. cf.H. busiris, Asioptychaspis subglobosa, Changia sp.,Quadraticephalus elongatus, ptychaspidid genus and species indeterminate,Lophosaukia orientalis, Lophosaukia? sp.,Tsinania canens, Tsinania sp., andHaniwa sosanensis. TheAsioptychaspis Zone is characterized by predominance ofAsioptychaspis subglobosa, while the succeedingQuadraticephalus Zone is dominated byQuadraticephalus elongatus, Lophosaukia orientalis, Haniwa sosanensis, andMicragnostus sp. TheAsioptychaspis andQuadraticephalus zones are well correlated with thePtychaspis- Tsinania andChangia (orQuadraticephalus) zones of North China, respectively. These two trilobite assemblages of the Hwajeol Formation support a strong paleogeographical link between the Taebaeksan Basin and North China Platform during the late Furongian.