Ceratopsid (horned dinosaur) cranial material is relatively common in the Upper Cretaceous Naashoibito Member of the Kirtland Formation, San Juan Basin, New Mexico. However, the specimens are fragmentary, making identification problematic. Previously, it has been suggested that the Naashoibito specimens represent Torosaurus utahensis, a chasmosaurine taxon originally known from the North Horn Formation of Utah. This identification has been used to support a Lancian age for the Naashoibito Member and the Alamo Wash local fauna of the Kirtland Formation (e.g., Lehman, 1981; Lucas et al., 1987). Others (e.g., Lehman, 1990) have synonomized T. utahensis with Torosaurus latus, a taxon otherwise known only from the late Maastrichtian Lance and Hell Creek formations. Recent work has upheld the validity of T. utahensis (Sullivan et al., 2005). However, Sullivan and colleagues (2005) have also argued that no previously described ceratopsid specimens from the Naashoibito Member are identifiable beyond the level of Chasmosaurinae indeterminate and therefore are not useful for assessing biostratigraphic correlations and ceratopsid biogeography. Here we describe a partial chasmosaurine ceratopsid parietal from the Naashoibito Member of the Kirtland Formation. Although other fragmentary parietals have been recovered from this unit (e.g., Lehman, 1981; Lucas et al., 1987), the new specimen exhibits unusual morphology: an epoccipital element positioned along the midline. This feature has previously been reported only in Triceratops, a taxon not known from south of the Denver Basin. The occurrence of such a feature in a cera-