Early labechiid stromatoporoids of the Yeongheung Formation (Middle Ordovician), Yeongwol Group, mideastern Korean Peninsula: Part II. Systematic paleontology and paleogeographic implications

Three species belonging to two genera of labechiid stromatoporoids are described from the Yeongheung Formation (Darriwilian, Middle Ordovician), Yeongwol Group of the Taebaeksan Basin, mid-eastern Korean Peninsula. Sixteen stromatoporoid-bearing stratigraphic intervals have been recognized in the Namgyo section. All stromatoporoids occur in the peloidal and bioclastic packstone to grainstone facies. Labechia yeongwolense sp. nov. is the dominant species, occurring throughout the lower and middle parts of the section. In contrast, Labechiella mingshankouensis is restricted to the lower-middle part and Labechiella regularis occurs mostly in the upper part of the section. The occurrence of the early labechiids in the Yeongwol Group is suggestive of a close biogeographic affinity with the Liaoning and Shandong provinces of northeastern China.