THE EARLIEST GASTROCHAENOLITES (EARLY PENNSYLVANIAN, ARKANSAS, USA) -AN UPPER PALEOZOIC BIVALVE BORING

Borings of the ichnogenus Gastrochaenolites have been found in limesto ne cobbles of the Morrowan (Early Pennsylvanian) Cane Hill Member of t he Hale Formation in northwestern Arkansas. They were likely excavated by lithophagid bivalves, thus extending the earliest record of obliga te bivalve boring back from the Triassic into the upper Paleozoic. The se borings are herein referred to as G. anauchen n. ichnosp. Lithophag id borings may be rare in the upper Paleozoic because of the absence o r scarcity of suitable substrates, such as scleractinian corals or car bonate hardgrounds. Additional upper Paleozoic bivalve borings will li kely be discovered in other carbonate-rich rocky shore deposits.