Fig 1.
Sample site map of contemporary elphidiid specimens collected across the NE Atlantic.
Geographic locations of specimens collected across the NE Atlantic [30] which have been morphometrically analysed in this study. Numbers next to labels correspond to sample sites listed in S1 Table.
Fig 2.
SEM and ESEM images of Elphidium williamsoni and elphidiid SSU rRNA genetic types S4 and S5.
(A) Elphidium williamsoni Haynes, 1973 (holotype specimen), (B-C) Elphidium williamsoni (paratypes), (D-F) Contemporary topotypic sequenced specimens, (G-I) Polystomella umbilicatula Walker and Jacob, 1798 syntypes of Williamson, 1858, (J-L) elphidiid genetic type S1 specimens collected from across NE Atlantic, (M) elphidiid genetic type S4 [30] and (N) elphidiid genetic type S5 [30]. Scale bars correspond to 100 μm.
Table 1.
Test characters measured or assessed and used in morphometric analysis.
N = last chamber, N1 = penultimate chamber etc.
Fig 3.
Principal coordinate analysis.
Bi-plot of the PCO analysis based on the morphological characters of Elphidium williamsoni Haynes, 1973 type specimens, contemporary topotypic specimens, Polystomella umbilicatula Walker and Jacob, 1798 syntypes of Williamson, 1858 and the two outlier elphidiid genetic types S4 and S5. These groups are bounded by 95% confidence ellipses. The first two principal coordinates account for 59.9% of the total variance.
Fig 4.
UPGMA cluster analysis dendrogram.
UPGMA cluster analysis tree based on the morphological characters of Elphidium williamsoni, Haynes, 1973, contemporary topotypic specimens, Polystomella umbilicatula Walker and Jacob, 1798 syntypes of Williamson, 1858 and the two outlier elphidiid genetic types S4 and S5.
Fig 5.
Principal coordinate analysis.
Bi-plot of the PCO analysis based on the morphological characters of E. williamsoni Haynes, 1973 type specimens, contemporary topotypic specimens, Polystomella umbilicatula Walker and Jacob, 1798 syntypes of Williamson, 1858, contemporary elphidiid genetic type S1 specimens and the two outlier elphidiid genetic types, S4 and S5. These groups are bounded by 95% confidence ellipses. The first two principal coordinates account for 48.5% of the total variance.
Fig 6.
UPGMA Cluster analysis dendrogram.
UPGMA cluster analysis tree based on the morphological characters of Elphidium williamsoni, Haynes, 1973 type specimens, Polystomella umbilicatula Walker and Jacob, 1798 syntypes of Williamson, 1858, contemporary elphidiid genetic type S1 specimens collected from across the NE Atlantic shelves and the two outlier elphidiid genetic types S4 and S5.
Table 2.
Percentage of correctly allocated specimens by the DFA.
Fig 7.
Taxonomic framework for reconciling molecules and morphology.
The initial protocol requires (i) a candidate specimen with distinctive test morphology, (ii) the potential for DNA extraction and (iii) a comprehensive and detailed literature review, to allow a qualitative morphological comparison of the candidate specimen against the type descriptions and illustrations.