The Coahuilan connection to the interior highlands

Authors: Christopher W. Hoagstrom

Year: 2012 (xliv)

Abstract

Ancient highlands of southeastern North America are hot spots of fish diversity and the Ouachita Orogen is the main tectonic feature linking them. Some fish clades are distributed along this feature, yet, no study has assessed biogeographical trends for the entire length of the orogen. A preliminary assessment shows the Ouachita Orogen is closely paralleled by a generalized track of North American highland fishes. Several aspects of this formation explain its evolutionary significance: (1) during formation, it conformed to & integrated with more ancient highland areas that also were geologically stable, (2) subsequently, it served as an abrupt boundary (ecotone) between coastal & continental environments with suitable habitat for upland fishes, (3) ancient fragmentation via dissolution & erosion isolated highland areas, but (4) dispersal corridors among areas were periodically re-configured. Landscape stability sustained ancient lineages, ecological diversity encouraged vicariant speciation, & dynamic dispersal corridor evolution allowed emerging lineages to periodically expand & diversify.