Cuatro Ciénegas (2001–2004)

The Cuatro Ciénegas basin (Coahuila, Mexico) in the Chihuahuan desert is believed to have the highest degree of local endemism in macro-biota (vertebrates, invertebrates, plants) in all of North America. Recent studies have revealed that it also harbors an astonishing level of microbial diversity. These endemic species inhabit long-isolated and unique aquatic habitats fed by mildly thermal and highly mineralized springs that emerge from unknown depths to feed surface ponds and streams that eventually empty into harsh evaporative basins. Of special interest are the basin’s diverse and complex forms of “stromatolites”, laminating microbial mats that physically resemble modern coral reefs and are thought to represent analogues of the forms of life that dominated Earth before the evolution of higher animals.

Our work examined the role of P limitation in affecting the C:P ratios, productivity, and community structure of stromatolite microbial communities. We also considered the role of stoichiometric constraints on stromatolite-snail interactions in the context of possible factors related to the Cambrian Explosion.



NASA Astrobiology Program