Fig 1.
Photographs of known kiwaid squat lobsters (“yeti crabs”).
A) Kiwa puravida modified from Thurber et al. [19] (CC BY 4.0); B) Kiwa sp. Galapagos Microplate; C) Kiwa araonae [28]; D) Kiwa hirsuta modified from Muséum National D’Histoire Naturelle (MNHN) crustacean collection–credit Noémy Mollaret (CC BY 4.0); E) Kiwa tyleri modified from Thatje et al. [23] (CC BY 4.0); (F) Kiwa sp. SWIR courtesy of David Shale. Scale bars are approximate and represent 10 mm.
Fig 2.
Map showing locations of kiwaids and the Cretaceous stem lineage fossil Pristinaspina gelasina in relation to land-masses and mid-ocean ridges.
Kiwaid representations are: i) Kiwa puravida ii) Kiwa sp. GM, iii) Kiwa hirsuta, iv) Kiwa araonae v) Kiwa tyleri vi) Kiwa sp. SWIR. Land shapes and ridge positions are modified from the InterRidge Vents Database 2.1 static map (http://vents-data.interridge.org/maps). Areas of mid-ocean ridge in light blue denote unexplored regions that may support Kiwaidae. Spreading ridge abbreviations are as follows: NEPR = Northern East Pacific Rise; SEPR = Southern East Pacific Rise; GR = Galapagos Rift; GM = Galapagos Microplate; PAR = Pacific-Antarctic Ridge; AAR = Australian-Antarctic Ridge; CR = Chile Rise; ESR = East Scotia Ridge; AmAR = American-Antarctic Ridge; SWIR = Southwest Indian Ridge; CIR = Central Indian Ridge; SEIR = Southeast Indian Ridge; MAR = Mid-Atlantic Ridge. Photograph of K. puravida modified from Thurber et al. [19] (CC BY 4.0) and Kiwa hirsuta modified from Muséum National D’Histoire Naturelle (MNHN) crustacean collection–credit Noémy Mollaret (CC BY 4.0).
Fig 3.
Bayesian tree topology of a 9-partition anomuran crustacean dataset generated in MrBayes 3.2.6.
Node support numbers represent ML bootstrap and ML ultrafast approximate bootstrap percentages generated in IQ-TREE 1.5.4 and Bayesian posterior probabilities from MrBayes. Node support values in red bold highlight topology incongruence between the different phylogenetic approaches. Photographs of the six known kiwaids are superimposed next to their names (highlighted in bold). Photograph of K. puravida modified from Thurber et al. [19] (CC BY 4.0) and Kiwa hirsuta courtesy of IFREMER.
Fig 4.
Bayesian tree topology of a 14-partition anomuran crustacean dataset generated in MrBayes 3.2.6.
Node support numbers represent ML bootstrap and ML ultrafast approximate bootstrap percentages generated in IQ-TREE 1.5.4 and Bayesian posterior probabilities from MrBayes. Node support values in red bold highlight topology incongruence between the different phylogenetic approaches. Photographs of the six known kiwaids are superimposed next to their names (highlighted in bold). Photograph of K. puravida modified from Thurber et al. [19] (CC BY 4.0) and Kiwa hirsuta courtesy of IFREMER.
Fig 5.
Divergence time estimates for a 9-partition anomuran crustacean dataset with a monophyletic Kiwaidae-Chirostylidae clade topological constraint as calculated with a relaxed, unlinked lognormal clock on BEAST 2.4.3.
Node bars represent the 95% highest posterior density (HPD) interval for nodal age. Nodes marked by letters show dates of interest to this study. Dates highlighted in blue are of particular interest. Nodes marked with a red spot are fossil calibrated. Geological periods and epochs are shown at the bottom: P = Palaeocene; E = Eocene; O = Oligocene; M = Miocene; Pl = Plio-Pleistocene; Q = Quaternary. Geological colours correspond to those of the International Chronostratigraphic Chart [49], which conforms to the Commission for the Geological Map of the World (http://www.ccgm.org). Photograph of K. puravida modified from Thurber et al. [19] (CC BY 4.0) and Kiwa hirsuta courtesy of IFREMER.
Fig 6.
Divergence time estimates for a 14-partition anomuran crustacean dataset with a monophyletic Kiwaidae-Eumunididae clade topological constraint as calculated with a relaxed, lognormal clock linked across partitions on BEAST 2.4.3.
Node bars represent the 95% highest posterior density (HPD) interval for nodal age. Nodes marked by letters show dates of interest to this study. Dates highlighted in blue are of particular interest. Nodes marked with a red spot are fossil calibrated. Geological periods and epochs are shown at the bottom: P = Palaeocene; E = Eocene; O = Oligocene; M = Miocene; Pl = Plio-Pleistocene; Q = Quaternary. Geological colours correspond to those of the International Chronostratigraphic Chart [49], which conforms to the Commission for the Geological Map of the World (http://www.ccgm.org). Photograph of K. puravida modified from Thurber et al. [19] (CC BY 4.0) and Kiwa hirsuta courtesy of IFREMER.
Fig 7.
Schematic representing the evolution of ridge positions in the East Pacific and Southern Ocean relevant to the radiation of Kiwaidae in the Cenozoic.
Taken from Matthews et al. [81] and Müller et al. [82] as rendered on the software GPlates 2.0 (https://www.gplates.org/index.html). Red lines denote active spreading segments of mid-ocean ridges and light blue lines represent faults and fracture zones. Darker Blue lines denote subduction zones. Light grey areas represent continental crust and dark grey areas show land masses with the present-day coastline. Abbreviations are: PFR = Pacific-Farallon Ridge; PAR = Pacific-Antarctic Ridge; NAR = Nazca-Antarctic Ridge; AmAR = American-Antarctic Ridge; NEPR = Northern East Pacific Rise, SEPR = Southern East Pacific Rise, GR = Galapagos Rift; NPSC = Nazca-Phoenix Spreading Centre; APR = Antarctic-Phoenix Ridge; WSR = West Scotia Ridge; CR = Chile Rise; ESR = East Scotia Ridge; MAR = Mid-Atlantic Ridge; JFM = Juan Fernandez Microplate; GM = Galapagos Microplate.
Fig 8.
Schematic showing the present-day configuration of mid-ocean ridges in the tropical East Pacific and the location of known kiwaids.
Modified from Matthews et al. [81] and Müller et al. [82] as rendered on the software GPlates 2.0 (https://www.gplates.org/index.html). Grey spots represent hydrothermal vents that have been visually surveyed, according to the InterRidge Vents Database version 2.1 [99], but where no kiwaids have been found. Yellow triangles and blue circles show hydrothermal vents and hydrocarbon seeps (respectively) where kiwaids have been found. i = Kiwa puravida; ii = Kiwa sp. GM; iii = Kiwa hirsuta. Grey areas represent land. Red lines denote active spreading segments of the ridges. Light blue lines represent faults and fracture zones. Darker Blue lines denote subduction zones. Abbreviations are: NEPR = Northern East Pacific Rise; SEPR = Southern East Pacific Rise; GR = Galapagos Rift; JFM = Juan Fernandez Microplate; GM = Galapagos Microplate; PAR = Pacific-Antarctic Ridge; CR = Chile Rise. Photograph of K. puravida modified from Thurber et al. [19] (CC BY 4.0) and Kiwa hirsuta modified from Muséum National D’Histoire Naturelle (MNHN) crustacean collection–credit Noémy Mollaret (CC BY 4.0).