Biogeography and body size shuffling of aquatic salamander communities on a shifting refuge

• Published in: Proceedings of the Royal Society. B, Biological sciences Vol. 280; no. 1758; p. 20130200
• Main Authors: Bonett, Ronald M., Trujano-Alvarez, Ana Lilia, Williams, Michael J., Timpe, Elizabeth K.
• Format: Journal Article
• Language: English
• Published: England The Royal Society 07-05-2013
• Subjects: Amphibia; Animal Distribution; Animals; Biological Evolution; Biota; Body Size; Body Size Evolution; Caudata; Cell Nucleus - genetics; Coastal Plain; Community Evolution; Incumbency; Molecular Sequence Data; Phylogeny; Sequence Analysis, DNA; Sequence Analysis, Protein; Sequence Homology; United States; Urodela - classification; Urodela - genetics; Urodela - physiology; United States; North America
• ISSN: 0962-8452; 1471-2945; 1471-2954
• DOI: 10.1098/rspb.2013.0200

Freshwater habitats of coastal plains are refugia for many divergent vertebrate lineages, yet these environments are highly vulnerable to sea-level fluctuations, which suggest that resident communities have endured dynamic histories. Using the fossil record and a multi-locus nuclear phylogeny, we examine divergence times, biogeography, body size evolution and patterns of community assembly of aquatic salamanders from North American coastal plains since the Late Cretaceous. At least five salamander families occurred on the extensive Western Interior Coastal Plain (WICP), which existed from the Late Cretaceous through the Eocene. Four of these families subsequently colonized the emergent Southeastern Coastal Plain (SECP) by the Early Oligocene to Late Miocene. Three families ultimately survived and underwent extensive body size evolution in situ on the SECP. This included at least two major size reversals in recent taxa that are convergent with confamilial WICP ancestors. Dynamics of the coastal plain, major lineage extinctions and frequent extreme changes in body size have resulted in significant shuffling of the size structure of aquatic salamander communities on this shifting refuge since the Cretaceous.