eupolypods ii is a clade of ferns in the order polypodiales , under the class polypodiopsida .

this group generally corresponds with the order blechnales described by j. l. reveal in 1993 .

however , the blechnales families were found to be embedded within the larger definition of the order polypodiales describe by smith et al. , 2006 , so according to their system , the group is treated as an informal clade .

this clade includes some important ferns , including the sensitive fern , onoclea sensibilis , which grows as a virtual weed throughout much of its temperate north american range , and ferns of the genus thelypteris , a genus that has shown remarkable speciation .

it also includes one of the more common horticultural ferns , the ostrich fern , matteuccia struthiopteris .

eupolypods ii

eupolypods ii <EOT> the following diagram shows a likely phylogenic relationship between the families of eupolypods ii , based on lehtonen , 2011 , and rothfels & al . , 2012 .

plastid phylogenomics resolve deep relationships among eupolypod ii ferns with rapid radiation and rate heterogeneity .

challenges inherent in resolving the eupolypod ii phylogeny . eupolypods ii phylogram modified from schuettpelz and pryer ( 2007 ) , in ( a ) unrooted and ( b ) rooted form . ( i ) outgroup taxa are on long branches . ( ii ) backbone internodes are very short , suggesting an “ancient rapid radiation . ” ( iii ) the ingroup is marked by significant heterogeneity in rates of evolution , with the members of aspleniaceae on much longer branches than other eupolypod ii taxa .

wherever possible , we included generic and familial types , to facilitate future taxonomic revisions . based on data from schuettpelz and pryer ( 2007 ) and liu et al . ( 2007 ) , our broad outgroup sample included 10 representatives from the sister group to the eupolypods ii ( eupolypods i , see fig . 2 ) . to better evaluate the effect of uncertainty in outgroup placement on the ingroup topology and to better understand the divergence between eupolypods i and ii , we also included two representatives from each of the two potentially successive sister groups to the eupolypods ( notholaena and cryptogramma from pteridaceae ; dennstaedtia and pteridium from dennstaedtiaceae ; see fig . 2 and schuettpelz and pryer 2007 ) . our total sample has 81 terminal taxa ( appendix 1 ) .

plastid phylogenomics resolve deep relationships among eupolypod ii ferns with rapid radiation and rate heterogeneity . - pubmed - ncbi

eupolypods were separated into two clades , corresponding with eupolypods i and ii [ 23 ] . diplaziopsidaceae was resolved as sister to eupolypods ii . christenhusz et al . [ 8 ] included diplaziopsis , homalosorus and hemidictyum within the diplaziopsidaceae , but here hemidictyum was supported as sister to aspleniaceae as in schuettpelz & pryer [ 18 ] and in kuo et al . [ 20 ] . hemidictyum is therefore considered here as a member of aspleniaceae and only diplaziopsis and homalosorus are within diplaziopsidaceae , as in a recent analysis of the matk gene [ 20 ] . family - level relationships mostly remained poorly supported or unresolved within both of the two large eupolypod clades .

eupolypods i is a clade of ferns in the order polypodiales , class polypodiopsida . [ 2 ] in the classification of christenhusz & chase ( 2014 ) this is equivalent to the family polypodiaceae . [ 1 ] it probably diverged from eupolypods ii ( = aspleniaceae of christenhusz & chase 2014 [ 1 ] ) during the mid - cretaceous . the divergence is supported by both molecular data and an often overlooked morphological characteristic which lies in the vasculature of the petiole . most species that make up the eupolypods i clade have three vascular bundles . the only exceptions are the grammitid ferns which have one , and the genus hypodematium which has two . this differs from eupolypods ii which mostly have two vascular bundles ( except the well - nested blechnoid ferns which generally have at least three ) . [ 3 ]

the following phylogram for the eupolypods i is based on lehtonen , 2011 [ 4 ] and christenhusz et al . , 2011 . [ 5 ]

the eupolypods ii , together with its sister group , eupolypods i , comprise the large eupolypod clade , which encompasses two - thirds of living fern species ( fig . 2 ; pryer et al . 2004 ; schneider et al . 2004b ; smith et al . 2006 ) . the ancestors of eupolypods i and ii diverged from each other in the early cretaceous ( pryer et al . 2004 ; schneider et al . 2004b ; schuettpelz and pryer 2009 ) . the eupolypod ii clade started to diversify shortly thereafter ( its crown group is approximately 100 million years old ; schuettpelz and pryer 2009 ) and has subsequently grown into a lineage - rich clade comprising nearly 30 % of extant fern diversity . eupolypods ii includes some of the most familiar groups of ferns ( the lady ferns , ostrich fern , sensitive fern , marsh ferns , and spleenworts ) , as well as some of the most species - rich genera : thelypteris s . lat . ( ∼950 species ) ; asplenium ( ∼700 species ) ; diplazium ( ∼350 species ) ; athyrium ( ∼220 species ) ; and blechnum s . lat . ( ∼150 species ) .

not surprisingly , given the clade ' s size and age , eupolypod ii taxa are morphologically disparate and seemingly incohesive . however , early workers did tend to recognize the close affinities among many of the taxa in this clade , although frequently with members of eupolypods i interdigitated among them ( holttum 1947 ; sledge 1973 ; mickel 1974 ; tryon and tryon 1982 ) . the cohesiveness of the eupolypods ii started to become apparent with the earliest applications of molecular phylogenetic techniques to ferns ( wolf et al . 1994 ; hasebe et al . 1995 ; sano et al . 2000a ) and has been strongly supported in recent broad studies ( schneider et al . 2004b ; schuettpelz and pryer 2007 ; kuo et al . 2011 ) . none of these studies , however , found support for the backbone relationships within eupolypods ii , and only kuo et al . ( 2011 ) attempted to sample its major lineages . it remains one of the few areas of the fern tree - of - life where the backbone relationships remain elusive ( smith et al . 2006 ; schuettpelz and pryer 2007 ) .

relative plastid substitution rates among clades / branches of the eupolypod ii ferns , based on the “83 - gene matrix , ” resulting from the random local clock analyses in beast v1 . 8 . 1 . numbers above the branches indicate relative , median rates with no measured units , scaled by dividing all rates by that of the crown node of eupolypods ii . colors of branches represents to relative rate . light red indicates a relative rate of 0 , whereas a trend of blue color marks a relative rate approaching 3 . 0 .

eupolypods ii is a clade of ferns in the order polypodiales , under the class polypodiopsida . this group generally corresponds with the order blechnales described by j . l . reveal in 1993 . however , the blechnales families were found to be embedded within the larger definition of the order polypodiales describe by smith et al . , 2006 , so according to their system , the group is treated as an informal clade .

hypotheses on the backbone relationship of eupolypod ii ferns with special reference to the positions of rhachidosoraceae and athyriaceae . ( a ) topology resolving rhachidosoraceae as sister to the thelypteridaceae - blechnaceae clade in ; ( b ) topology resolving rhachidosoraceae as sister to the aspleniaceae - diplaziopsidaceae clade in ) ; ( c ) topology showing athyriaceae as nonmonophyletic in , ) and ; and ( d ) topology showing unresolved relationships within eupolypod ii ferns in based on 25 low - copy nuclear genes .

shaw j , lickey eb , beck jt , farmer sb , liu w , et al . ( 2005 ) the tortoise and the hare ii : relative utility of 21 noncoding chloroplast dna sequences for phylogenetic analysis . amer j bot 92 : 142–166 .

comparison of variability in nonoverlapping 1 , 000 - bp sliding windows for eupolypod ii ferns . genes with interests are indicated , that is , genes with pi > 0 . 1 are marked in black and genes with pi < 0 . 1 are marked in red .

the ml phylogram of 40 species based on 83 - gene matrix and codon partitioned strategy and bayesian divergence time estimation based on 83 - gene matrix with unpartitioned strategy . ( a ) maximum likelihood bootstrap values ( bss ) are 100 % and bayesian posterior probabilities ( pps ) are 1 . 0 , unless otherwise indicated . numbers above the branches indicate bss and pps based on whole plastome matrix , and bss ( unpartitioned , parititionfinder , gene partitioned ) and pps based on 88 - gene matrix , while numbers below the branches as bss ( unpartitioned , codon partitioned , parititionfinder , gene partitioned ) and pps based on 83 - gene matrix ; ( b ) chronogram with secondary calibration nodes indicated by numbers ; ( c ) bar chart indicating stem clade ages and hpd intervals of each family of eupolypods ii . blue bars indicate 95 % highest posterior density ( hpd ) intervals of the age estimates ; grey bars indicate the time - scale of eupolypod ii radiation .

carl j . rothfels , anders larsson , li - yaung kuo , petra korall , wen - liang chiou , kathleen m . pryer ( 2012 ) . " overcoming deep roots , fast rates , and short internodes to resolve the ancient rapid radiation of eupolypod ii ferns " . systematic biology 61 ( 1 ) : 70 .

in pteridaceae , all subfamilies accepted by christenhusz et al . [ 8 ] were found to be monophyletic , although the monophyly of cheilanthoidea had poor support . by contrast , numerous pteridoid genera , including adiantum , were not monophyletic . the need for a generic redefinition within pteridoids has already been well recognized by earlier studies [ 8 ] , [ 18 ] , [ 23 ] – [ 27 ] . the relationship between pteridoids and dennstaedtioids was still ambiguous to date [ 23 ] , and the present study also did not provide conclusive results . pteridaceae was positioned as a sister group to eupolypods by parsimony , whereas ml supported dennstaedtiaceae as sister to eupolypods . both hypotheses received less than 50 % support . the genus dennstaedtia was paraphyletic as in previous studies [ 18 ] , [ 28 ] , due to the inclusion of the monophyletic microlepia .

carl j . rothfels , anders larsson , li - yaung kuo , petra korall , wen - liang chiou , kathleen m . pryer ; overcoming deep roots , fast rates , and short internodes to resolve the ancient rapid radiation of eupolypod ii ferns , systematic biology , volume 61 , issue 3 , 1 may 2012 , pages 490 , urltoken

the trees obtained here were generally consistent with the prevailing view of the molecular phylogeny of ferns [ 1 ] , [ 18 ] – [ 20 ] . the taxonomic sampling employed here was almost seven - times broader than in the previous best - sampled fern phylogenetic analysis , hence providing a broader picture of fern phylogenetics , and enabling the investigation of the monophyly of currently accepted genera and families . however , despite the broad sampling , numerous fern groups remained poorly sampled and some phylogenetic relationships could not be completely resolved . for example , the families belonging to the eupolypods ii group are well supported as monophyletic entities , but the relationships between them remained poorly established . the relationships among some of the early diverging polypods ( saccolomataceae , cystodiaceae ) were not unambiguously resolved and questions about a pteridoid - dennstaedtioid relationship still remained unanswered . similarly to previous studies [ 1 ] , [ 20 ] , [ 27 ] – [ 30 ] , the phylogenetic position of horsetails ( equisetaceae ) remained controversial .

arthropteris and psammiosorus were mixed , but together formed a well - supported sister lineage to all other tectariaceae . the proposed subfamilies of polypodiaceae [ 8 ] were monophyletic in the ml analysis , except that synammia was resolved as sister to drynarioideae rather than being a member of polypodioideae . the parsimony analysis did not support monophyletic polypodiaceae , resulting in a largely unresolved topology within the eupolypods i . the current generic classification failed to delimit natural groups within drynarioideae , microsoroideae and polypodioideae . the subfamily loxogrammoideae was resolved as sister group to the remaining polypodiaceae in the ml analysis .

as stated above , earlier studies ( e . g . , schuettpelz and pryer 2007 ) indicate that the eupolypod ii phylogeny is likely to include several key challenges for phylogenetic inference , specifically a series of long branches among very short backbone internodes ( an ancient rapid radiation ) , lineage - specific rate heterogeneity , and a distantly related outgroup . given these concerns , we sought to explicitly evaluate our topology and support values against these potential artifacts , with particular emphasis on the support values along the backbone of the tree .

the eupolypod ii clade is cosmopolitan in distribution , with the subgroups primarily temperate to tropical , and the larger subclades each well represented in both areas . however , many of the phylogenetically enigmatic taxa in this clade are limited to the himalayas or southeast asia , and critical members of several genera are rare and / or infrequently collected . this pattern of rarity and endemism , in conjunction with the richness and geographical breadth of the clade as a whole , is undoubtedly a contributing factor to the incomplete sampling of these ferns in previous phylogenetic studies .

this trend of shared morphological syndromes across very deep splits in the tree by some members of the “woodsiaceae” is in contrast to the interdigitation , among those same taxa , of a series of distinct morphologically unique groups , including the aspleniaceae , blechnaceae , onocleaceae , and thelypteridaceae . the coarse picture of eupolypod ii morphological evolution , then , is marked by two seemingly opposing patterns . on the one hand are the autapomorphy - rich clades , whose individual phylogenetic coherence is strong , but whose deep relationships were obscure based on morphological data . and , on the other , the morphologically consistent yet phylogenetically incoherent members of the “woodsiaceae” .

dna was extracted from silica - dried or herbarium material , using either ( i ) a modified carlson - yoon protocol ( < 0 . 01 g dried plant material , silica beads , 750 μ l carlson buffer , and 20 μ l mercaptoethanol added to a 2 - ml tube and ground for 45 s using a mini - beadbeater ( biospec products ) , followed by incubation at 65 о c for 45 min ; yoon et al . 1991 ) or ( ii ) the protocol of pryer et al . ( 2004 ) or ( iii ) the protocol of kuo et al . ( 2011 ) . for material extracted under the carlson - yoon protocol , the extracted dna was purified by illustra gfx pcr dna and gel band purification kit ( ge healthcare ) .

to evaluate any effects that uncertainty in root - branch placement might have on apparent levels of support within the ingroup , we compared ingroup backbone mlbs values from the analysis of our complete data ( full outgroup ) with those from each of six different variations in outgroup composition : ( i ) ingroup only ; ( ii ) ingroup + dryopteris ; ( iii ) ingroup + dryopteris and didymochlaena ; ( iv ) ingroup + dryopteris and notholaena ; ( v ) ingroup + dryopteris and notholaena and pteridium ; and ( vi ) ingroup + our full eupolypod i sample ( fig . 5 ) . this outgroup sampling regime was selected to successively bisect the longest outgroup branches , with a particular emphasis on breaking the proximate root branch ( the branch connecting the ingroup to the first outgroup node ) .

our approach to resolving the eupolypod ii phylogeny couples a considerably expanded taxon sample with moderate character sampling . our objectives include identifying well - supported major ( approximately “family - level” ) clades and determining the backbone relationships among these clades . given the anticipated phylogenetic challenges and potential for artifacts in our data , we explicitly evaluate our phylogenetic hypothesis against these analytical pitfalls , placing strong emphasis on the use of the reduced consensus technique ( wilkinson 1996 ) to isolate the effects of signal weakness from those of signal conflict ( e . g . , wiens 2003 ; cobbett et al . 2007 ) . our study aims for a comprehensive and well - supported phylogeny of this important group of ferns , and for novel inferences about the behavior of our choice of methods , gleaned from their performance on this data set .

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in the past two decades , molecular systematic studies have revolutionized our understanding of the evolutionary history of ferns . the availability of large molecular data sets together with efficient computer algorithms , now enables us to reconstruct evolutionary histories with previously unseen completeness . here , the most comprehensive fern phylogeny to date , representing over one - fifth of the extant global fern diversity , is inferred based on four plastid genes . parsimony and maximum - likelihood analyses provided a mostly congruent results and in general supported the prevailing view on the higher - level fern systematics . at a deep phylogenetic level , the position of horsetails depended on the optimality criteria chosen , with horsetails positioned as the sister group either of marattiopsida - polypodiopsida clade or of the polypodiopsida . the analyses demonstrate the power of using a ‘supermatrix’ approach to resolve large - scale phylogenies and reveal questionable taxonomies . these results provide a valuable background for future research on fern systematics , ecology , biogeography and other evolutionary studies .

citation : lehtonen s ( 2011 ) towards resolving the complete fern tree of life . plos one 6 ( 10 ) : e24851 . urltoken

copyright : © 2011 samuli lehtonen . this is an open - access article distributed under the terms of the creative commons attribution license , which permits unrestricted use , distribution , and reproduction in any medium , provided the original author and source are credited .

funding : this study received funding from the kone foundation and the academy of finland grants to sl . the funders had no role in study design , data collection and analysis , decision to publish , or preparation of the manuscript .

the combined four - gene ( atpa , atpb , rbcl , rps4 ) data set included a total of 5 , 166 sequences ( dataset s1 ) , hence the matrix of all 2 , 957 taxa by four genes had 6662 missing gene sequence entries ( c . 56 % missing data ) . most taxa ( 91 % ) were represented by the rbcl gene , but the least sampled gene ( atpa ) was available for only approximately 18 % of the taxa . less than 10 % of the sampled taxa were represented by all four genes , and 54 % were represented only by a single gene . in most of the fern families at least some taxa were sampled for all markers , with two small families ( diplaziopsidaceae and rhachidosoraceae ) represented by the rbcl gene only and four other families ( psilotaceae , schizeaceae , cystodiaceae and lomariopsidaceae ) lacking one of the studied genes . the parsimony analysis of these data retained 124 equally parsimonious trees of 74 , 910 steps ( dataset s2 ) . the final ml optimization likelihood score was −391724 . 512141 ( figure 1 , dataset s3 ) .

parsimony and ml trees were largely consistent with each other and with the prevailing view of the fern familial relationships [ 1 ] , [ 18 ] – [ 20 ] . the parsimony analysis positioned horsetails ( equisetopsida ) as a sister group to the marattiopsida - polypodiopsida clade , whereas ml placed them as sister to polypodiopsida . these controversial groupings received low support values . within the tree fern clade , ml and parsimony largely disagreed at the family level . metaxyaceae was positioned as a sister to other tree ferns in the parsimony analysis , whereas in the ml tree the family was placed as sister to dicksoniaceae . the clade composed of thyrsopteridaceae and associated families in the ml tree also included cibotiaceae and dicksoniaceae in the parsimony analysis . similarly , the two methods disagreed in the exact phylogenetic position of dennstaedtiaceae and many small families , including saccolomataceae , cystodiaceae , hypodematiaceae , cystopteridaceae and woodsiaceae . however , most of the incongruent groupings received less than 50 % bootstrap support in both analyses , consistently with the observation that their relationships were also uncertain in previous studies [ 18 ] , [ 23 ] .

a recently published linear fern classification [ 8 ] was largely supported at the family level . at the generic level , however , improved sampling revealed several patterns that were inconsistent with previously published results and current fern taxonomy . some of the most relevant results are shortly described here , otherwise readers are directed to trees available as supplementary information ( dataset s2 , s3 ) and at treebase ( urltoken ) . in ophioglossaceae , the results contradicted those published by hauk et al . [ 21 ] notably regarding the position of cheiroglossa , which is here nested within ophioglossum . in addition , o . lusitanicum l . was here grouped together with helmintostachys zeylanica ( l . ) hook . in the present study , the genus odontosoria ( lindsaeaceae ) was polyphyletic , and sphenomeris was grouped with the tapeinidium - osmolindsaea - nesolindsaea clade , thus contradicting the results of a recent study on lindsaeaceae phylogenetics [ 22 ] .

aspleniaceae was divided into three well - supported lineages , corresponding to hemidictyum and two broadly - defined genera : hymenasplenium and asplenium [ 8 ] , [ 18 ] . several well - supported clades were also present within thelypteridaceae , although not exactly matching the current generic classification . similarly , previous studies have suggested that the current classification of blechnaceae is unnatural [ 8 ] . in this study , the family was divided into three well - supported clades that did not correspond to the currently accepted generic limits ( woodwardia ; salpichlaena - stenochlaena - blechnum p . p . ; blechnum p . p . - brainea - sadleria - pteridoblechnum ) . within athyriaceae , diplazium was strongly supported as monophyletic , but cornopteris was nested within athyrium with a high level of support .

the two subfamilies of dryopteridaceae [ 8 ] were monophyletic ( with the exception of dryopteris inaequalis ( schlecht . ) kuntze , which was placed in elaphoglossoideae ) in the ml analysis , albeit with a very poor support . in the parsimony analysis , on the other hand , the subfamily elaphoglossoideae was divided into two groups with unresolved relationships with dryopteridoideae . the subfamily elaphoglossoideae included pleocnemia winitii holttum , the only member of its genus included in this study . previous studies have considered pleocnemia as a member of tectariaceae [ 8 ] , [ 23 ] , [ 30 ] . at a generic level , polystichum included cyrtomium and cyrtogonellum , arachnioides included leptorumohra and lithostegia , and acrorumohra was nested in dryopteris ( excluding d . inaequalis ) .

the observed uncertainty might , to some extent , reflect the large number of missing entries in the supermatrix . more than half of the taxa were represented by a single gene , rbcl being clearly the best - sampled marker . those markers not as thoroughly sampled were , however , sampled rather evenly across the different fern lineages , so that very few families completely lacked data of one or more genes . furthermore , smith et al . [ 16 ] were able to resolve several difficult problems in the phylogeny of green plants by sampling the rbcl gene only , and it has been shown that supermatrix approach can handle even 90 % missing data without loss of accuracy if the data available contain enough informative characters [ 11 ] , [ 17 ] , [ 32 ] – [ 35 ] .

the advances in fern systematics over the past decades have provided a rather good taxonomic understanding at the family level , and the recently proposed fern classification [ 8 ] was largely supported by the current study . generic delimitation , however , has remained ambiguous in a number of fern families [ 8 ] , [ 23 ] . the analyses presented here shed new light on several unresolved issues , and can be used as a starting point to a more robust classification at this taxonomic level . a good example was that of blechnaceae , a family composed of three well supported clades that ( apart from woodwardia ) do not correspond well with the currently accepted generic classification .

until recently , most of the molecular systematic studies of ferns were based on classical fern taxonomy . the most convenient way of overcoming the impact of outdated taxonomies , as well as detecting contaminated or misidentified sequences [ 11 ] , [ 40 ] , [ 41 ] , is through the use of supermatrix analysis of all available data . the results presented here corroborated most recent findings in molecular fern systematics , but also provided a much wider view for future studies in fern evolution , taxonomy , and beyond . instead of relying on the classical fern taxonomy , pteridologists can now select proper outgroups and delimit their ingroups in an appropriate way from an evolutionarily perspective . as yet , only about one - fifth of the extant fern diversity is currently covered by genbank , but the road is open for a fully sampled fern tree of life , and ultimately , for a natural fern classification .

sequence data was retrieved from genbank release 176 ( feb . 23 , 2010 ) using phylota browser ( urltoken ) . phylota assembles blast clustering for all sequences in the genbank release file [ 42 ] . clusters corresponding to four protein coding plastid genes , rbcl , rps4 , atpa , and atpb , were downloaded for root node “moniliformopses” . this data set was further supplemented by downloading rbcl data of japanese ferns [ 43 ] and adding several fern sequences produced with standard methods and primers [ 3 ] , [ 19 ] , [ 44 ] – [ 49 ] in our laboratory and submitted to genbank , but not yet available on the queried release ( genbank accession numbers hq157300–hq157307 , hq157324–hq157330 , hq157332–hq157334 , hq245099–hq245103 , hq680978 ) . when multiple sequences were available for one taxon , the most complete one was retained and the other sequences excluded . a few sequences in the preliminary test analyses were positioned into highly questionable taxonomic groups , and these apparently misidentified or contaminated sequences were also excluded from the final analyses . the finally accepted fern sequences ( 2 , 656 taxa ) were further supplemented with 301 outgroup taxa representing lycophytes ( 205 taxa ) , angiosperms ( 61 taxa ) and gymnosperms ( 35 taxa ) .

multiple sequence alignments were produced for each data set with muscle [ 50 ] using default settings followed by one round of refinement . due to variable sequence completeness all the alignments had high amounts of missing data at the 5′ and 3′ ends . these ambiguous regions were eliminated from the final data sets after visual inspection , as well as ambiguously aligned segment within the rps4 gene . however , possible errors in the sequences ( such as stop - codons ) were not investigated . indels inserted during the sequence alignment were treated as missing data in the corresponding phylogenetic analyses . because all the markers included were plastid genes they were expected to share a common evolutionary history and were analyzed simultaneously . aligned sequence matrices were concatenated with sequencematrix software [ 51 ] . in total , the data set consisted of 2 , 957 taxa ( rbcl 2 , 681 ; rps4 1 , 134 ; atpb 825 ; atpa 526 taxa ) and 4 , 406 aligned base pairs of molecular data ( rbcl 1 , 332 ; rps4 379 ; atpb 1 , 188 ; atpa 1 , 507 bp ) . the aligned data matrices and resulting trees are available at treebase ( urltoken , [ 52 ] ) .

phylogenetic analyses were performed for the concatenated supermatrix under equally weighted parsimony criteria using tnt [ 53 ] and maximum likelihood criteria using raxml [ 54 ] . in the parsimony analyses 500 ‘new technology’ [ 55 ] , [ 56 ] search replications were used as a starting point for each hit . these replications saved no more than 10 trees per replication , and were run until the best score was hit 10 times , using tbr - swapping , random and constraint sectorial searches , five ratchet iterations , and five rounds of tree fusing ( xmult = repl 500 hits 10 css rss ratchet 5 fuse 5 hold 10 ) . the memory was set to hold 80 , 000 trees . branch support was evaluated by running 500 bootstrap replicates . tbr - swapping , sectorial search , and five rounds of tree fusing were employed in each replicate ( resample = boot replications 500 savetrees [ xmult = rss css fuse 5 ] ) . maximum likelihood ( ml ) analyses were performed using the parallel pthreads - version of the computer program raxml 7 . 2 . 8 [ 54 ] , [ 57 ] running in 2×2 . 26 ghz quad - core intel xeon macintosh with 8 gb of ram . the search was initiated with 500 rapid bootstrap replications followed by a thorough ml search on the original alignment ( - t 16 - f a - x 12345 - p 12345 - # 500 - m gtrgamma ) . free model parameters were estimated by raxml under the gtr + γ model . this is the most commonly used model for real data sets , and provides good performance for large data sets [ 58 ] .

congruence among the data sets was examined by running parsimony bootstrap analyses for each gene separately [ 59 ] . visual inspection of the family - level nodes did not reveal well - supported ( > 70 % support ) conflict at this phylogenetic level , with the exception of nested position of lonchitidaceae within lindsaeaceae in the atpa analysis ( data not shown ) . at lower phylogenetic levels the highly variable taxon sampling made the assessment of phylogenetic conflict highly problematic , and simultaneous analysis of all data sets was considered appropriate based on family - level congruence .

concatenated supermatrix in nexus - format ( file can be opened after unzipping for example with mesquite [ 60 ] ) .

the strict consensus tree of parsimony analysis with bootstrap support values in nexus - format ( file can be opened for example with figtree [ 61 ] ) .

the ml tree with bootstrap support values in nexus - format ( file can be opened for example with figtree [ 61 ] ) .

i thank all the researchers who have produced and shared dna sequences via genbank . the willi hennig society is acknowledged for making tnt publicly available . two anonymous reviewers are acknowledged for their constructive comments on earlier draft version of this manuscript .

conceived and designed the experiments : sl . performed the experiments : sl . analyzed the data : sl . contributed reagents / materials / analysis tools : sl . wrote the paper : sl .

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institute of ecology and evolutionary biology , national taiwan university , no . 1 , section 4 , roosevelt road , taipei 10617 , taiwan

broad phylogeny of ferns . approximate number of species per clade is given in parentheses . modified from smith et al . ( 2006 ) .

five plastid loci were selected for analysis : atpa , atpb , matk , rbcl , and the trng - trnr intergenic spacer ( henceforth “ trng - r ” ) . all loci , except for matk , were amplified according to either the “standard” or “difficult” reaction protocols ( below ) depending on the source of the material ( standard for most extractions ; difficult for those from herbarium specimens greater than 10 years old ) , using the primers listed in table 1 . the standard amplification reaction used standard taq polymerase with the following cycle : a 3 min initial denaturation at 95 о c , followed by 35 cycles of 30 s denaturation at 95 о c , 1 min annealing at 54 о c , and 2 min elongation at 72 о c , followed by a final elongation of 10 min at 72 о c . the difficult amplification reaction , using phusion high fidelity dna polymerase ( finnzymes ) , was 1 min initial denaturation at 98 о c , followed by 35 cycles of 10 s denaturation at 98 о c , 30 s annealing at 58 о c , and 1 min elongation at 72 о c , followed by a final elongation of 8 min at 72 о c . amplification of all matk sequences followed the protocol of kuo et al . ( 2011 ) .

notes : f = forward ; r = reverse ; a = used in amplifications ; s = used in sequencing reactions . while most primers were applied across the phylogeny , superscripts following primer names indicate lineage specificity : a aspleniaceae ; b athyriids ; c blechnaceae ; d cystopteris / gymnocarpium ; e depariids ; f diplaziids ; g diplaziopsis / homalosorus ; h rhachidosorus ; i onocleaceae ; j pteridaceae ; k thelypteridaceae ; l woodsia and allies .

pcr products from carlson - yoon extractions were purified using multiscreen plates in a vacuum manifold ( millipore ) and sequenced by macrogen inc . ( south korea ) . for material extracted under the protocol of pryer et al . ( 2004 ) , each pcr product was cleaned using 0 . 5 μ l of exonuclease i and 1 μ l of shrimp alkaline phosphatase ( usb , cleveland , oh ) ; reaction tubes were incubated at 37 о c for 15 min and then heated to 80 о c for 15 min to inactivate the enzymes , prior to sequencing on a applied biosystems 3730 xl at the duke igsp sequencing facility ( duke university ) . material extracted under the protocol of kuo et al . ( 2011 ) was sequenced at genomics ( taipei , taiwan ) . we completed our sampling with an additional 100 previously published sequences from genbank ( appendix 1 ) .

sequences were manually aligned in mesquite 2 . 72 ( maddison and maddison 2009 ) . indels ( limited to matk , trng - r , and the ends of the atpa alignment ) were assessed by eye , and ambiguously aligned areas were excluded prior to phylogenetic analysis . any gaps associated with unambiguous indel regions were treated as missing data . in one rapidly evolving region of the trng - r alignment , we were unable to confidently align the pteridaceae sequences to those of the other taxa . in order to retain this otherwise unambiguous region , we excised those portions of the pteridaceae sequences , replacing them with question marks .

notes : missing data include both uncertain bases ( e . g . , ? , r , y ) and gaps ( - ) . support values are listed as mlbs or bayesian pps .

to obtain a point estimate of the phylogeny , we performed 10 tree bisection - and - reconnection heuristic searches of the concatenated ( unpartitioned ) data , each from a different random - addition - sequence starting tree , under ml using a gtr + i + g model as implemented in paup * 4 . 0b10 for unix ( swofford 2002 ) . the values for the exchangeability parameters , base frequencies , gamma shape parameter , and proportion of invariant sites were fixed at their ml values as optimized under a garli 0 . 951 ( zwickl 2006 ) tree search , using default genetic algorithm and termination settings .

our approach to phylogeny evaluation involved permutations of both the models and the implementation of those models ( i . e . , programs ) . the models were deliberately selected according to their varying degrees of susceptibility for each of the risk factors in question , in an attempt to isolate potential model - based biases . the choice to additionally vary the programs used was in part due to constraints of implementation—no single program offered all the models we wished to compare . this approach has the added benefit of demonstrating a further level of robustness : if our phylogenetic results are insensitive to both the differing models and the myriad of incompletely quantified differences among programs , we can be all the more confident in our conclusions . additionally , varying both the models and their implementation more closely matches the options available to empirical phylogeneticists seeking to resolve ancient rapid radiations . this approach suffers a clear liability , however , in that the effects of model differences and implementation differences are conflated . in the event of differing results , we may not be able to isolate the effects of one from the other ; therefore , the added value to empirical phylogeneticists comes at the cost of reduced utility of our results to program developers and theorists .

the specific evaluations performed are described more thoroughly in the results section . computation - intensive analyses were run on either the duke shared cluster resource ( urltoken ) or the uppsala multidisciplinary center for advanced computational science ( uppmax ) . when appropriate , multiple tree files were summarized onto a target phylogram with sumtrees 2 . 0 . 2 ( sukumaran and holder 2010 ) for subsequent inspection or manipulation in figtree 1 . 3 . 1 ( rambaut 2006 ) .

tree - wide mean ml bootstrap support ( mlbs ) values ( summed bootstrap values on the ml tree divided by the number of internodes in that tree ) for the individual loci ranged from 74 % ( atpb ) to 84 % ( matk ) . the concatenated data have a mean mlbs of 92 % and strongly support ( i . e . , have ≥ 70 % mlbs and ≥ 0 . 95 posterior probability [ pp ] ) 90 % of the partitions ( table 2 ) . across data sets , ml and bayesian inference consistently inferred strong support for a comparable number of bipartitions ( table 2 ) , a result that offers further empirical corroboration for the approximate equivalence of 70 % mlbs and 0 . 95 pp ( hillis and bull 1993 ; alfaro et al . 2003 ) .

there are two well - supported conflicts among the individual - locus ml trees . the first involves a tip relationship ( matk unites deparia pterorachis with d . unifurcata , with 72 % mlbs , whereas rbcl places d . pterorachis as sister to the rest of the genus , with 75 % support ) that is peripheral to the focus of this study . the second is deeper in the tree : matk has 80 % mlbs for a clade uniting thelypteridaceae with the athyrioids , blechnaceae , and onocleaceae , to the exclusion of woodsia and allies , whereas both atpa and atpb place woodsia and its allies within that clade ( 92 % in atpa ; 71 % in atpb ) . given that we confirmed this conflict to not be attributable to laboratory or identification errors , and because the loci involved are linked and the taxa are long - diverged , we do not ascribe this conflict to differences in evolutionary history and proceeded to concatenate all the data for subsequent analyses .

each of our ten ml best - tree searches of the concatenated data in paup * ( from different random - addition - sequence starting trees ) inferred the same tree ( fig . 3a ) , suggesting that tree space is unimodal for our data set . most partitions in this topology point estimate were strongly supported by both ml bootstrapping and bayesian pps ( table 2 ) ; the different ml programs ( paup * , garli , and raxml ) inferred very similar mlbs levels ( data not shown ) .

phylogeny evaluation : rate heterogeneity and the bayesian star - tree paradox artifact . a ) unrooted ml phylogram of the concatenated data , with the backbone internodes highlighted and labeled . b ) accounting for the impact of rate heterogeneity on backbone support values . the four values listed for each backbone internode are : mlbs on full data , mlbs with aspleniaceae ( asplenium and hymenasplenium ) pruned from trees , mlbs with aspleniaceae removed from analysis , and posterior support from beast . c ) controlling for the bayesian star - tree paradox artifact using the polytomy prior in phycas . the four pps listed for each internode are from : mrbayes 3 . 1 . 1 ( susceptible to the star - tree artifact ) , phycas with c = 1 , phycas with c = e , and phycas with c = 10 . d ) controlling for the bayesian star - tree paradox artifact using the yang branch - length prior . the four pps listed for each internode are from : mrbayes 3 . 1 . 1 ( susceptible to the star - tree artifact ) , mrbayes 3 . 1 . 2 with branch - length prior mu1 / mu0 = 0 . 01 , mrbayes 3 . 1 . 2 with branch - length prior mu1 / mu0 = 0 . 001 , and mrbayes 3 . 1 . 2 with branch - length prior mu1 / mu0 = 0 . 0001 .

for certain branches , we observed very high bayesian pps from the mrbayes analysis , but much lower levels of support from the ml bootstrapping ( fig . 4a ) ; these support discrepancies are disproportionately represented among short branches ( fig . 4b ) . this pattern is consistent with artificially high bayesian support due to the star - tree paradox artifact—most implementations of bayesian phylogenetic inference do not consider polytomies among the option set for the mcmc sampler and thus can return high pps for branches that are unsupported by the data ( lewis et al . 2005 ; yang and rannala 2005 ; yang 2008 ; see early hints in cummings et al . 2003 ) .

discrepancies between ml and bayesian support values . a ) ml phylogram of the concatenated data , internal branches only ( all tip branches have been deleted ) . branches are colored according to the magnitude of the difference between their pp ( from mrbayes 3 . 1 . 1 ) and their percent mlbs ( from 5000 pseudoreplicates in paup * ) . b ) internal branches rotated to be vertical and sorted by length . colors follow figure 4a .

to ensure that this “star - tree paradox” artifact was not influencing our assessment of support , we compared the results from our original mrbayes 3 . 1 . 1 analysis ( ronquist and huelsenbeck 2003 ; mrbayes 3 . 1 . 1 is potentially vulnerable to the star - tree paradox artifact ) with those of a non - bayesian analysis ( ml bootstrapping in paup * from our initial assessment of support ) , as well as with two implementations of bayesian inference that use different approaches to reduce their vulnerability to the star - tree paradox artifact .


calliostoma granti , common name the multibeaded maurea , is a species of sea snail , a marine gastropod mollusk in the family calliostomatidae .

some authors place this taxon in the subgenus calliostoma ( maurea ) .

calliostoma granti

calliostoma granti <EOT> - - - - - - - - - - - - - - - species : calliostoma granti ( a . w . b . powell , 1931 ) - id : 5062000454

( of calliostoma granti ( powell , 1931 ) ) marshall , b . a . 1995 . a revision of the recent calliostoma species of new zealand ( mollusca : gastropoda : trochoidea ) . the nautilus 108 : 83 - 127 . [ details ]

( of calliostoma ( maurea ) granti ( powell , 1931 ) ) marshall , b . a . 1995 . a revision of the recent calliostoma species of new zealand ( mollusca : gastropoda : trochoidea ) . the nautilus 108 : 83 - 127 . [ details ]

calliostoma adamsi brazier , 1895 : synonym of calliostoma comptum a . adams , 1855

calliostoma purpureocinctum hedley , 1894 : synonym of calliostoma comptum a . adams , 1855

( of calliostoma ( maurea ) granti ( powell , 1931 ) ) maxwell , p . a . ( 2009 ) . cenozoic mollusca . pp 232 - 254 in gordon , d . p . ( ed . ) new zealand inventory of biodiversity . volume one . kingdom animalia : radiata , lophotrochozoa , deuterostomia . canterbury university press , christchurch . [ details ]

calliostoma formosensis e . a . smith , 1907 : synonym of calliostoma formosense e . a . smith , 1907

calliostoma poupineli ( montrouzier in souverbie & montrouzier , 1875 ) : synonym of calliostoma comptum a . adams , 1855

calliostoma formosum ( mcandrew & forbes , 1847 ) : synonym of calliostoma occidentale ( mighels & c . b . adams , 1842 )

calliostoma expansum schepman , 1908 : synonym of enida japonica a . adams , 1860

calliostoma euglyptum ( a . adams , 1855 ) - sculptured topsnail , sculptured top shell

calliostoma rubroscalpta lee , y . c . & w . l . wu , 1998

calliostoma bisculptum e . a . smith : synonym of cantharidus bisculptus e . a . smith

calliostoma limatulum marshall , 1995 : synonym of selastele limatulum b . a . marshall , 1995

calliostoma onustum odhner , 1924 : synonym of selastele onustum b . a . marshall , 1995

calliostoma virescens renier , s . a . in coen , g . s . , 1933

calliostoma katoi is a species of sea snail , a marine gastropod mollusk in the family calliostomatidae .

calliostoma akoya is a species of sea snail , a marine gastropod mollusk in the family calliostomatidae .

calliostoma coppingeri major castellanos , z . j . a . de & f . fernandes , 1976

calliostoma pulchrum ( c . b . adams , 1850 ) - beautiful topsnail , beautiful top shell

calliostoma swinneni poppe , g . t . , s . tagaro & h . dekker , 2006

calliostoma trotini poppe , g . t . , s . tagaro & h . dekker , 2006

calliostoma trepidum hedley , 1907 : synonym of laetifautor deceptus ( e . a . smith , 1899 )

calliostoma polychroma ( a . adams , 1851 ) : synonym of cantharidus polychroma ( a . adams , 1851 )

calliostoma rubropunctatum ( a . adams , 1851 ) : synonym of laetifautor rubropunctatus ( a . adams , 1851 )

calliostoma occidentale ( mighels and c . b . adams , 1842 ) - boreal topsnail , north atlantic top shell

calliostoma is a genus of small to medium - sized sea snails with gills and an operculum , marine gastropod molluscs within the family calliostomatidae , the calliostoma top snails ( according to the taxonomy of taxonomy of gastropoda by bouchet & rocroi ( 2005 ) ) . previously this genus was placed within the family trochidae . calliostoma is the type genus of the family calliostomatidae .

calliostoma burnupi e . a . smith , 1899 : synonym of dactylastele burnupi ( e . a . smith , 1899 )

calliostoma deceptum e . a . smith , 1899 : synonym of laetifautor deceptus ( e . a . smith , 1899 )

calliostoma regalis ( verrill & s . smith , 1880 ) : synonym of calliotropis regalis ( verrill & smith , 1880 )

calliostoma poupineli montrouzier , r . p . in souverbie , s . m . & r . p . montrouzier , 1875

calliostoma is a large genus of medium - sized sea snails with gills and an operculum , marine gastropod molluscs known as top shells .

calliostoma hayamanum kuroda , t . & t . habe in kuroda , t . , t . habe & k . oyama , 1971

perron , f . e . ( 1975 ) . " carnivorous calliostoma ( prosobranchia : trochidae ) from the northeastern pacific " . veliger 18 : 52–54 .

marshall , b . a . ( 1995 ) . " a revision of the recent calliostoma species of new zealand " . the nautilus 108 : 83–127 .

clench w . & turner r . ( 1960 ) . " the genus calliostoma in the western atlantic " . johnsonia 4 ( 40 ) : 1 - 80 .

remarks . calliostoma delli tends to be broader than high ; one of the figured paratypes ( fig . 14 ) is unusually narrow , compared to most specimens on the type lot .

clench , w . j . and r . d . turner ( 1960 ) . " the genus calliostoma in the western atlantic " . johnsonia 4 ( 40 ) : 1–80 .

quinn , j . f . jr . ( 1992 ) . " new species of calliostoma and notes on some poorly known species from the western atlantic " . the nautilus 106 : 77–114 .

marshall , b . a . 1995 : a revision of the recent calliostoma species of new zealand ( mollusca : gastropoda : trochoidea ) , the nautilus , 108 ( 4 ) ( p . 90 )

( of venustas punctulata multigemmata powell , 1952 ) marshall , b . a . 1995 . a revision of the recent calliostoma species of new zealand ( mollusca : gastropoda : trochoidea ) . the nautilus 108 : 83 - 127 . [ details ]

( of maurea ( mucrinops ) punctulata ampla powell , 1939 ) marshall , b . a . 1995 . a revision of the recent calliostoma species of new zealand ( mollusca : gastropoda : trochoidea ) . the nautilus 108 : 83 - 127 . [ details ]

the top shells ( which are called calliostoma ) are marine gastropod molluscs . they can be found world - wide . the name of this genus is derived from the greek words kallos ( beautiful ) and stoma ( mouth ) , referring to the pearly aperture .

contrary to what is the case in most other top shells , calliostoma deposits its eggs in gelatinous ribbons that are only fertilized after being deposited . the young emerge as small snails ( lebour , 1936 ) without passing through a free - living planktonic stage as a veliger larva .

currently , calliostoma is being treated in worms as a broad genus . it is expected to be broken up and ( some ) subgenera will be elevated to the status of genus . at this moment ( 2013 ) , information is too fragmentary to assign all species in a revised genus .

holotype for calliostoma atlantoides quinn , 1992 catalog number : usnm 860261 collection : smithsonian institution , national museum of natural history , department of invertebrate zoology preparation : dry locality : st . lucia , caribbean sea , north atlantic ocean depth ( m ) : 417 to 589 vessel : pillsbury r / v

the symbols k . a . c . f . m . an . are used to indicate the geographical range of the species . they have been adopted to give an approxomation of the range of each species within new zealand .

powell , a . w . b . 1979 : new zealand mollusca : marine , land and freshwater shells , collins , auckland ( p . 62 )

note : localities are approximate , and represent only some of the known localities for the species .

- note : several protected species are illustrated here only for identification purposes . they are not for sale . - the photos in our gallery are in most cases just a sample from our stock , except when only one specimen is offered . we try to match the original color but it can vary if your screen is not correctly adjusted ( gamma correction ) .

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html public " - / / w3c / / dtd html 4 . 01 transitional / / en "

some authors consider it the sole member of the non - accepted subgenus akoya .

html public " - / / w3c / / dtd xhtml 1 . 0 transitional / / en " " urltoken "

description . shell large , thin , silky white , nonumbilicate , spire whorls convex . protoconch of one and one - fourth whorls , teleoconch whorls seven , first teleoconch whorl with three spiral cords , noded to produce square cancellations : sculpture changing by the second whorl to three prominently projecting spiral cords , the uppermost cord beaded , the other two smooth . mature sculpture of three prominent cords , subsutural cord the least prominent , remaining close to the suture and losing its beading by about the third whorl ; second cord sharply defined and separated from the subsutural cord by a broad , smooth area ; third cord equally strong and projecting to form the peripheral extent of the whorl . basal keep sharp ; suture laid directly on its lower surface , not forming a channel . basal cording of about three fine cords on the outer edge and two to three bordering the columellar wall ; intermediate area of base smooth except for fine spiral striae . columellar wall thickened , slanted , forming a spur at the base ; outer lip thin . operculum corneous , multispiral . animal and radula as in c . chilena .

dimensions : height 29 . 6 mm . diameter 30 . 9 min ( holotype , fig . 13 ) : height 24 . 3 mm , diameter 23 . 2 mm ( paratype , fig . 14 ) ; height 29 . 0 mm , diameter 26 . 0 ( paratype . fig . 15 ) .

material . chile : los vilos ( lacm , type lot , figs . 13 - 15 ) , papudo , zapallar , algarrobo , punta penablanca ( lacm ) , pichilemu , constitución . specimens examined : 114 .

type material . thirty - three specimens from the type locality , collected 29 may 1977 , by andrade , shrimp trawler goden wind , holotype , lacm 1980 ; paratypes , lacm 1981 ; paratypes , mnhn 200489 ; paratypes , mzicb 15 . 528 ; paratypes , usnm 784738 .

type locality . 400 m off los vilos , chile ( 31°56 ' s : 71°54 ' w ) .

distribution . los vilos ( 31°56 ' s ) to constitución , chile ( 35°20 ' s ) . depth range 200 - 450 m .

diagnosis . a species of the subgenus otukaia characterized by having three spiral cords prominent at all growth stages . it differs from the similarly sculptured c . blacki ( dell , 1956 ) from new zealand ( see dell , 1956 : 46 , pl . 7 , fig . 6 ) in being lower spired , and in having a weaker subsutural ( first ) cord and a stronger second cord .

etymology . we are pleased to name this species in honor of dr . richard k . dell of the national museum of new zealand , wellington . ”

mclean , j . h . and h . andrade . 1982 . large archibenthal gastropods of central chile : collections from an expedition of the r / v anton bruun and the chilean shrimp industry . los angeles county museum , contributions in sciences , 342 : 1 - 20 . urltoken ; = 2316

unconfirmed _ type : mclean , j . & andrade , h . 1982 . contributions in science ( natural history museum of los angeles county ) . 342 : 1 - 20 , figs . 1 - 56 .

holotype : quinn , j . f . 1992 . the nautilus . 106 ( 3 ) : 102 .

unconfirmed type : mclean , j . & andrade , h . 1982 . contributions in science ( natural history museum of los angeles county ) . 342 : 1 - 20 , figs . 1 - 56 .

depth range based on 1 specimen in 1 taxon . water temperature and chemistry ranges based on 1 sample . environmental ranges depth range ( m ) : 274 - 274 temperature range ( °c ) : 12 . 462 - 12 . 462 nitrate ( umol / l ) : 16 . 704 - 16 . 704 salinity ( pps ) : 35 . 456 - 35 . 456 oxygen ( ml / l ) : 3 . 043 - 3 . 043 phosphate ( umol / l ) : 1 . 235 - 1 . 235 silicate ( umol / l ) : 5 . 700 - 5 . 700 note : this information has not been validated . check this * note * . your feedback is most welcome .

stocks , k . 2009 . seamounts online : an online information system for seamount biology . version 2009 - 1 . world wide web electronic publication .

the distribution of this genus is worldwide , found mainly on hard substrata , although japanese species have been found on sandy bottoms . these snails occur from shallow waters to bathyal depths .

the rather thin , acute , coeloconoid ( = approaching conical shape but with concave sides ) shell is imperforate or rarely umbilicate . the whorls are smooth , often polished and spirally ridged or granular . the

perron , frank e . ; turner r . d . ( 1978 ) .

dall w . h . 1889 . reports on the results of dredging , under the supervision of alexander agassiz , in the gulf of mexico ( 1877 - 78 ) and in the caribbean sea ( 1879 - 80 ) , by the u . s . coast survey steamer " blake " , lieut . - commander c . d . sigsbee , u . s . n . , and commander j . r . bartlett , u . s . n . , commanding . xxix . report on the mollusca . part 2 , gastropoda and scaphopoda . bulletin of the museum of comparative zoölogy at harvard college 18 : 1 - 492 , pls . 10 - 40

vilvens c . ( 2012 ) new species and new records of seguenzioidea and trochoidea ( gastropoda ) from french polynesia . novapex 13 ( 1 ) : 1 - 23 . [ 10 march 2012 ] page ( s ) : 18

williams , s . t . ; k . m . donald , h . g . spencer and t . nakano ( march 2010 ) .

vilvens c . ( 2009 ) . new species and new records of calliostomatidae ( gastropoda : trochoidea ) from new caledonia and solomon islands . novapex 10 ( 4 ) : 125 - 163

note : many of our articles have direct quotes from sources you can cite , within the wikipedia article ! this article doesn ' t yet , but we ' re working on it ! see more info or our list of citable articles .

its distribution is world - wide . the name of this genus is derived from the greek words kallos ( beautiful ) and stoma ( mouth ) , referring to the pearly aperture .

according to the latest taxonomy of bouchet & rocroi , this genus belongs in the family calliostomatidae in the clade vetigastropoda . earlier malacologists placed this genus within the trochidae .

, a deep - water gastropod , dredged in the atlantic ocean at a depth of from 100 m to 1170 m .

malacolog 4 . 1 . 0 : : a database of western atlantic marine mollusca - malacolog 4 . 1 . 0 : western atlantic mollusk species database at the academy of natural sciences