The formation is divided into (in ascending stratigraphic order) the Tecolotito Member, which is primarily sandstone; the Los Esteros Member, which is primarily mudstone; and the Tres Lagunas Member, which is primarily sandstone.[1]
The sandstone members are interpreted as alluvial sheets deposited by braided streams. The Los Esteros Member is interpreted as a lacustrine deposit in lakes that formed due to local subsidence from dissolution of underlying Permian salt beds. Paleocurrents were primarily to the south in the Tecolotito Member and northeast in the Tres Lagunas Member but are indeterminate in the Los Esteros Member.[3]
In east-central New Mexico, the Los Esteros Member has also yielded a Otischalkian dinosauromorph assemblage that includes specimens of Silesauridae and Lagerpetidae, including Dromomeron, the latter of unusually large size.[7]
History of investigation
The formation was first named as the Santa Rosa Sandstone by N.H. Darton in July 1919 but the report was not published until 1922.[8] By then the name had already appeared in other publications.[9][10] A type locality was not formally designated until 1972.[11] In 1987, Spencer G. Lucas and Adrian Hunt removed the lower sandstone beds into the Anton Chico Formation and divided the remaining beds into members.[1] W.I. Finch and coinvestigators redesignated the unit as the Santa Rosa Formation in 1988.[12]
Beyl, Alexander; Nesbitt, Sterling; Stocker, Michelle R. (2 January 2020). "An Otischalkian dinosauromorph assemblage from the Los Esteros Member (Santa Rosa Formation) of New Mexico and its implications for biochronology and lagerpetid body size". Journal of Vertebrate Paleontology. 40 (1): e1765788. doi:10.1080/02724634.2020.1765788. S2CID221751762.
Hager, Dorsey; Robitaille, A.E. (1919). "Oil possibilities in eastern New Mexico". California Chamber of Mines and Oil, Mining and Oil Bulletin: 13–16, 35–42.
