A Speciational History of "living Fossils": Molecular Evolutionary Patterns in Horseshoe Crabs.

Horseshoe crabs' exceptional morphological conservatism over the past 150 My has led to their reputation as "living fossils," but also has served to obscure phylogenetic relationships within the complex. Here we employ nucleotide sequences from two mitochondrial genes to assess molecular evolutionary rates and patterns among all extant horseshoe crab… CONTINUE READING