Diversification of cephalic shield shape and antenna in phyllosoma I of slipper and spiny lobsters (Decapoda: Achelata)

Slipper (Scyllaridae) and spiny (Palinuridae) lobsters show a complex life cycle with planktonic larval phase, named phyllosoma. This unique form within Achelata (Decapoda) is characterized by transparent dorsoventrally compressed body pair of antennae. conspicuous morphology has been attributed to adaptive specialization life. Early studies suggest that phyllosoma remained constant over the evolutionary history Achelata, while recent evidence points out large morphological changes diversification larvae consequence radiation processes exploit different habitats. Given ecological evolutive significance phyllosoma, we used shape variation first stage (phyllosoma I) time-calibrated phylogeny extant study how I occurred along Achelata. Our results conserved pear-shaped cephalic shield antennae in older groups slipper lobsters, yet highly specialized wide rounded short younger lobsters. Analyses revealed two bursts lineage mid late without slowdown times. Both preceded disparity. These joined allopatric distribution species convergence shapes between largely divergent involves nonadaptive processes. However, correlation major direction maximum depth adults occurrence second burst post-extinction competitors presuppose some opportunities might have promoted diversification, fitting characteristic components radiations. Therefore, conclude presents main signature radiation.