New Mexico Geological Society Annual Spring Meeting — Abstracts

In the canyon of the Jemez River and its tributaries south of Jemez Springs, Sandoval County, New Mexico, the Lower Permian Abo Formation is up to 190 m thick and divided into the lower, mudstone-dominated Scholle Member (100+ m thick), overlain by the Cañon de Espinoso Member (40-60 m thick), which is characterized by numerous sheet sandstone beds. The Scholle Member has long yielded well known vertebrate fossil assemblages of Coyotean (Wolfcampian) age dominated by sphenacodontid eupelycosaurs, diadectomorphs and temnospondyls (Lucas et al., 2012). At the Spanish Queen Mine locality, it also contains a paleoflora dominated by peltasperms and conifers. We report here the first tetrapod footprint assemblage from the Abo Formation in the Jemez Mountains. This assemblage is from New Mexico Museum of Natural History locality 10325, in a 1.3 m-thick bed of ripple-laminated sandstone of the Cañon de Espinoso Member, about 44 m below the upper contact of the Abo Formation with the overlying Meseta Blanca Formation of the Yeso Group. The footprints are associated with walchian conifer impressions and a low diversity invertebrate ichnoassemblage dominated by Scoyenia. Most of the footprints are of temnospondyls, small (Batrachichnus) and large (cf. Limnopus). Rare footprints at the locality can be assigned to cf. Varanopus (captorhiniomorph reptile) and Ichniotherium (diadectomorph). The occurrence of Ichniotherium is significant, as this ichnotaxon is only present in relatively inland localities of the Abo depositional system. The Jemez Springs footprint locality fits that concept, as it was far from the Abo-Hueco shoreline in southern New Mexico. It thus belongs to the Ichniotherium sub-ichnocoenosis of the Batrachichnus ichnocoenosis of Hunt and Lucas (2006).

References:

1. Hunt, A.P., and Lucas, S.G., 2006, Permian tetrapod ichnofacies: Geological Society of London, Special Publication, v. 265, p. 137–156 .Lucas, S. G., Harris, S. K., Spielmann, J. A., Berman, D. S, Henrici, A. C., Krainer, K., Rinehart, L. F., DiMichele, W. A., Chaney, D. S and Kerp, H., 2012b, Lithostratigraphy, paleontology, biostratigraphy and age of the upper Paleozoic Abo Formation near Jemez Springs, northern New Mexico, USA: Annals of the Carnegie Museum, v. 80, p. 323-350.