Boletín de la Sociedad Geológica Mexicana Volumen 66, núm. 3, 2014, p. 459-469 http://dx.doi.org/10.18268/BSGM2014v66n3a4

Freshwater mollusks of the Valley of Sobaco, Coahuila, Northeastern Mexico – a subfossil ecosystem similar to Cuatrociénegas

Alexander Czaja^1,*, José Luís Estrada-Rodríguez¹, Ulises Romero Méndez¹

 ¹ Department of Biological Sciences, Juárez University of the State of Durango, 35010 Gómez Palacio, Durango, México.
^* aaczaja@hotmail.com

Abstract

In the Valley of Sobaco located in Coahuila, Mexico, were found the remains of an aquatic ecosystem with a Holocene malacofauna showing similarities to modern aquatic communities of the internationally famous site of Cuatrociénegas, located in the state of Coahuila and known as the "Mexican Galapagos", as it hosts a large number of endemic species. In addition of ostracods, algae, foraminifera, diatoms and remains of vascular plants, the Sobaco paleo-pools (pozas) also contain the gastropods Juturnia coahuilae, Pyrgulopsis manantiali, Coahuilix hubbsi, Coahuilix cf. landyei and Assiminea cienegensis, which are endemic species of Cuatrociénegas Valley. Additional discoveries include sub-recent lacustrine microbial tufas (microbialites, stromatolites), as well a pool that still contains water hosting bacterial communities similar to those from Cuatrociénegas.

In this paper we present the taxonomic description of the mollusks from the Sobaco paleo-lake system and a first reconstruction of the paleoenvironment. A comparison of this paleoecosystem with modern aquatic communities of the Cuatrociénegas Valley is also included.

Keywords: Sobaco Valley, Cuatrociénegas Valley, lacustrine ecosystems, Holocene.