The Oñate Formation of Middle Devonian (Givetian) age is exposed in the Mud Springs Mountains of New Mexico, where it is represented by an unusually shaly and extremely fossiliferous facies. Tabulophyllum traversensis (Winchell) found here is the only rugose coral species known thus far from Middle Devonian rocks of New Mexico and is of special interest as evidence of migration between the area of the Oñate occurrence and those in the Cedar Valley Limestone in Iowa and the Traverse Group of Michigan. The occurrence is also of interest because of the association of the Oñate coral with the receptaculitid Sphaerospongia sp. cf. S. tessellata (also known from Canada, Australia, and New York). The corals apparently utilized receptaculitids as a solid substrate for post-larval growth and developed an extremely broad flat base, fixed to the upper surface of Sphaerospongia.
Lower-Middle Devonian rugose coral faunas of Nevada: Contribution to an understanding of the "barren" E Zone and Choteč Event in the Great Basin
