CONODONTS FROM A NEW REFERENCE SECTION NEAR THE ORIGINAL TYPE REEF TRAIL MEMBER, BELL CANYON FORMATION (LATEST GUADALUPIAN SERIES): BIOSTRATIGRAPHY, CORRELATION, AND SIGNIFICANCE
Continuing fieldwork has produced three new reference sections critical to better documenting Reef Trail biostratigraphy. An auxiliary section near the original type section has less covered section and only a single, minor offset. In the Patterson Hills (western Guadalupe Mountains National Park), a complete basinal section extends from the underlying Lamar Member through the Reef Trail Member to the overlying Castile Formation. Another basinal section in the Patterson Hills better exposes strata immediately surrounding the Reef Trail-Castile contact. Conodonts from these sections represent the zone of Jinogondolella altudaensis, including J. altudaensis, J. xuanhanensis, J. crofti, J. cf. J. granti, and J. artafrons. Rare specimens represent other conodont genera as well. Morphologically advanced specimens of J. altudaensis characterize the uppermost beds of the Reef Trail Member, just below the Castile Formation in the Patterson Hills. These advanced specimens are transitional to the genus Clarkina. Clarkina postbitteri hongshuiensis, the first representative of the genus, has been recovered from just below the Castile in the Apache Mountains on the opposite side of the Delaware Basin.