A new yeti crab phylogeny: Vent origins with indications of regional extinction in the East Pacific

• Published in: PLOS ONE
• Main Authors: Roterman, Christopher Nicolai, Lee, Won-Kyung, Liu, Xinming, Lin, Rongcheng, Li, Xinzheng, Won, Yong-Jin
• Format: Text
• Language: English
• Published: Public Library of Science 2018
• Subjects: Research Article; Pacific; Southern Ocean
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5856415/; http://www.ncbi.nlm.nih.gov/pubmed/29547631; https://doi.org/10.1371/journal.pone.0194696

The recent discovery of two new species of kiwaid squat lobsters on hydrothermal vents in the Pacific Ocean and in the Pacific sector of the Southern Ocean has prompted a re-analysis of Kiwaid biogeographical history. Using a larger alignment with more fossil calibrated nodes than previously, we consider the precise relationship between Kiwaidae, Chirostylidae and Eumunididae within Chirostyloidea (Decapoda: Anomura) to be still unresolved at present. Additionally, the placement of both new species within a new “Bristly” clade along with the seep-associated Kiwa puravida is most parsimoniously interpreted as supporting a vent origin for the family, rather than a seep-to-vent progression. Fossil-calibrated divergence analysis indicates an origin for the clade around the Eocene-Oligocene boundary in the eastern Pacific ~33–38 Ma, coincident with a lowering of bottom temperatures and increased ventilation in the Pacific deep sea. Likewise, the mid-Miocene (~10–16 Ma) rapid radiation of the new Bristly clade also coincides with a similar cooling event in the tropical East Pacific. The distribution, diversity, tree topology and divergence timing of Kiwaidae in the East Pacific is most consistent with a pattern of extinctions, recolonisations and radiations along fast-spreading ridges in this region and may have been punctuated by large-scale fluctuations in deep-water ventilation and temperature during the Cenozoic; further affecting the viability of Kiwaidae populations along portions of mid-ocean ridge.