Sphenothallus (“Vermes”) from the Tremadocian Dumugol Formation, Korea

Publisher Website
Google Scholar
Abstract
Specimens of Sphenothallus ruedemanni (Kobayashi, 1934), which were originally assigned to Serpulites, are described from the Asaphellus Zone (Tremadocian) of the Dumugol Formation, Korea. Previously, Sphenothallus was known to occur in Middle Ordovician to Permian rocks, thus making Sphenothallus ruedemanni the earliest record of this genus. This species is characterized by a distally expanding tube with smooth to variously wrinkled surface. The tube is presently composed of quartz, chlorite, and/or muscovite, which appear to have replaced calcium phosphate. The zoological affinity of this tube-building animal is still uncertain.