Original paper

Rhyncholites and conchorhynch (calcified nautiloid beaks) from the Eocene (Lutetian/Priabonian) Castle Hayne Formation, Southeastern North Carolina

Weaver, Patricia G.; Ciampaglio, Charles N.; Sadorf, Eric M.

Abstract

Four nautiloid upper beaks: two Rhyncolites minimus Van Binckhorst, one Rhyncolites aturensis Pacaud, one Rhyncolites sp. and one lower beak Conchorhynchus furrus Weaver, Ciampaglio & Sadorf n. sp. are described herein for the first time from the Eocene (Lutetian/Priabonian) Castle Hayne Formation of southeastern North Carolina. Rhyncolites americanus Teichert & Spinosa from the Maastrichtian of Mississippi is reinstated as a valid species. The specimens of Rhyncolites minimus are similar in size to those found from California and the Netherlands. The specimen of Rhyncolites aturensis is similar to, but smaller than those of the same species described from France. The specimen of Rhyncolites sp. is so well-worn by dissolution, abrasion or other diagenetic factors that no species assignment is possible. Though preserved nautiloid upper beaks are geographically and stratigraphically wide-spread throughout the Mesozoic to Cenozoic, lower beaks are rarely preserved. Conchorhynchus furrus n. sp. is the first conchorhynch described from the United States. Eocene rhyncholites and the conchorhynch from North Carolina are most likely the calcified beaks of Eutrephoceras Hyatt.

Keywords

cephalopodnautiloidrhyncholiteconcorhyncheocenenorth carolina