Archaeolithophyllum, and Abundant Calcareous Alga in Limestones of the Lansing Group (Pennsylvanian), Southeastern Kansas

Abstract

Limestones of the Lansing Group (Missourian) in southeastern Kansas contain abundant remains of the calcareous marine alga Archaeolithophyllum. Two species, A. missouriense Johnson and A. lamellosum n. sp., are described and illustrated. The thallus of this genus consists of an undulating, irregularly-shaped crust characterized by a distinctive internal cellular structure similar to that in the coralline (red) algae. A. missouriense is believed to have developed as free or locally attached solitary crusts. A. lamellosum grew as encrusting masses made up of superimposed crusts or thalli, and it is intimately associated with bryozoans and encrusting foraminifers.

Archaeolithophyllum is interpreted as having generally inhabited the inner sublittoral marine environment and as having had the capacity to tolerate appreciable wave agitation. The thalli were semi-rigid crusts capable of providing both a self-supporting skeletal framework and a sediment-binding function at the time of deposition. Because of these properties, species of this alga were significant in the formation of initially porous carbonate buildups or banks.