Differentiation in a greenhouse world 2

1 Differentiation of high-latitude and polar marine faunas in a greenhouse world J Alistair Crame1, Alistair J McGowan2, Mark A Bell3 41British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK 52BioGeoD, Edinburgh, EH16 6DR, UK E mail: biogeod@gmail.com 63Department of Earth Sciences, University College London, Gower Street, WC1E 6BT, UK E mail: 7mark.bell521@gmail.com 9Keywords: faunal differentiation, greenhouse world, Neogastropoda, dominance in polar faunas, 10trophic generalists, seasonality in primary productivity, relative diversity distributions, rank 11abundance models 12 13Short running title: Early Cenozoic faunal differentiation 14*Correspondence: J Alistair Crame, British Antarctic Survey, High Cross, Madingley Road, Cambridge 15CB3 0ET, UK E mail: jacr@bas.ac.uk 16Number of words in Abstract: 299 17Number of words in main body of paper: 5714 (excluding in-paper Appendix) 18Number of references: 69 19Number of figures: 20ABSTRACT 21Aim To investigate those factors that influenced the differentiation of high-latitude and polar marine 22faunas on both ecological and evolutionary timescales Can a focus on a greenhouse world provide 23some important clues? 24Location World-wide, but with particular emphasis on the evolution of Antarctic marine faunas 25Time period Early Cenozoic era and present day 26Major taxa studied Mollusca, especially Neogastropoda 27Methods The Early Cenozoic global radiation of one of the largest extant marine clades, 28Neogastropoda, was examined and detailed comparisons made between two tropical localities and 29Antarctica High – low latitude faunal differentiation was assessed using Sørensen’s dissimilarity 30index, and component species in each of the three faunas were assigned to 29 families and family 31groups Relative diversity distributions were fitted to these three faunas as well as two modern ones 32to assess the contrast in evenness between high- and low-latitude assemblages 33Results By the Middle Eocene a distinct high-latitude neogastropod fauna had evolved in Antarctica 34In addition, the distribution of species within families in this fauna is statistically significantly less 35even than that in the tropics Indeed, there is no detectable difference in the scale of this separation 36from that seen today Just as in the modern fauna, Middle Eocene Antarctic neogastropods are 37dominated by a small number of trophic generalist groups 38Main Conclusion As the hyperdiverse Neogastropoda clade radiated globally through the Early 39Cenozoic it differentiated into distinct high- and low-latitude components The fact that it did so in a 40greenhouse world strongly suggests that something else besides temperature was involved in this 41process The predominance of generalist feeding types in the Antarctic fossil faunas is linked to the 42phenomenon of a seasonally pulsed food supply, just as it is today Seasonality in primary 43productivity may act as a fundamental control on the evolution of large-scale biodiversity patterns 44INTRODUCTION 45There is a widespread impression that modern high-latitude and polar biotas first became firmly 46established at approximately the Eocene – Oligocene (E – O) boundary, some 34 Myr ago (Thomas & 47Gooday, 1996; Hawkins et al., 2006; Mittelbach et al., 2007; Archibald et al., 2010) At this time we 48know that there was either a marked dip in global mean annual temperatures, increase in the 49volume of the East Antarctic ice sheet, or, very probably, a combination of the two (Eldrett et al., 502009; Petersen & Schrag, 2015) The equatorial - polar temperature gradients almost certainly 51steepened considerably at this time and this in turn intensified the essentially latitude-parallel 52zonation patterns that are so characteristic of both marine and terrestrial biotas at the present day 53(Lomolino et al., 2010) 54Nevertheless, as our investigations into the biogeography and palaeobiogeography of the high55latitude and polar regions continue it is becoming apparent that, at least in the marine realm, 56distinctive polar assemblages with strikingly modern affinities can be detected over 20 Myr prior to 57the E – O boundary in the fossil record of the Early – Middle Eocene epochs This is particularly so in 58Antarctica where intensive investigation of the prolific La Meseta Formation of Seymour Island, 59Antarctic Peninsula (c 65°S palaeolatitude) has revealed that approximately 32% of the Middle 60Eocene molluscan fauna (147 species) can be assigned to modern Antarctic and sub-Antarctic genera 61(Beu, 2009; Crame et al., 2014) Furthermore, analysis of one of the principal taxonomic groups 62within this fauna, the Neogastropoda, has revealed that, not only are 37% of the species present 63assignable to modern genera, but the vast majority of these belong to a single family, Buccinidae, s.l 64(Beu, 2009; Crame et al., 2014) In this respect the overall taxonomic structure of the Middle Eocene 65neogastropod fauna is very similar to that of the extant fauna A recent investigation established 66that, whereas both the Arctic and Antarctic modern neogastropod faunas were characterised by 67patterns of high dominance/low evenness, tropical faunas typically showed the reverse (i.e low 68dominance/high evenness) (Crame, 2013) In all probability this is a pattern that is present in a 69number of other widespread taxonomic groups at the present day (Brown, 2014; see also, below) 70Could it be that polar marine faunas were in fact differentiating well before the E – O boundary 71under essentially greenhouse world conditions? In this study we make quantitative tropical – polar 72comparisons of neogastropod assemblages and demonstrate that the degree of high – low latitude 73faunal differentiation in the Early Cenozoic (c 40 – 60 Myr ago) is very similar to that seen at the 74present day This in turn strongly suggests that temperature alone is not sufficient to generate the 75differentiation of high-latitude and polar marine faunas 76MATERIALS AND METHODS 77Neogastropoda (sensu Bouchet & Rocroi, 2005) is estimated to contain at least 26,000 living species 78and constitutes one of the most diverse extant marine clades (Crame, 2013) Although a 79comprehensive global overview of modern neogastropod latitudinal diversity gradients (LDGs) is 80currently lacking, there is evidence to indicate that they must be extremely steep An estimate of 81tropical diversity was obtained from the six regions used by Crame (2013) to investigate global 82variation in the spatial structure of living neogastropod faunas: Philippines, New Caledonia, Guam, 83French Polynesia, Panamic Province, Caribbean This gave a grand total of 4518 species, compared to 84just 183 and 166 for the Arctic and Antarctic oceans, respectively In making this comparison it 85should be noted that the combined shelf area of the six tropical regions is < 33% of the continental 86shelf in either polar ocean (Crame, 2013) It should be stressed that such comparisons represent 87latitudinal contrasts rather than gradients, but the pattern is a striking one and reflects what is 88known in general about latitudinal trends in marine gastropods (Roy et al., 2004; Rivadeneira et al., 892015) As a previous estimate has indicated that >70% of neogastropod species were removed by the 90K – Pg mass extinction (Stanley, 2008), the rise to the present day richness of 26,000 species and 91concentration within the tropics must be very largely a Cenozoic phenomenon (Sepkoski, 2002; Alroy, 922010a) 93To investigate the global radiation of the Neogastropoda more closely we downloaded the total 94number of taxa as recorded in the Paleobiology Database (http://fossilsworks.org) These taxa were 95then split into 10 Myr time bins from the latest Jurassic onwards and a curve through time produced 96in two different ways The first of these was simply the raw number of neogastropod genera through 97time, and the second a sample-standardised version using the Shareholder Quorum Subsampling 98(SQS) technique (Alroy 2010b), and a quorum ranging between 0.3 – 0.6, in steps of 0.1 99Three regional localities were then used to make detailed polar – equatorial comparisons through 100the Early Cenozoic era The polar locality is that of Seymour Island, and the two tropical ones are the 101US Gulf Coast (c 30°N palaeolatitude) and Paris Basin (c 40°N), respectively (Appendix – Data 102sources) It should be emphasised that both the latter localities were well within the tropical belt 103which was much more extensive than that of the present day through the greater part of the Early 104Cenozoic (Adams et al., 1990; Morley, 2007) Key criteria in making these locality selections were: as 105complete a stratigraphical record as possible between approximately the K – Pg boundary and Late 106Eocene; and a proven history of comprehensive investigations Other global localities have partial 107records of this critical Early Cenozoic interval but were considered to be either too incomplete 108stratigraphically, or to have substandard palaeontological records Full details of the stratigraphical 109and palaeontological procedures employed at each of the three main localities to generate 110comprehensive faunal lists are contained in Appendix 1, together with taxonomic notes on the 111Neogastropoda 112For both the tropical localities, neogastropod faunas were divided into three stratigraphical horizons, 113Paleocene, Early Eocene and Middle Eocene, and for Antarctica just the Paleocene and Middle 114Eocene (the Early Eocene fauna for this locality being incomplete – Appendix 1) At each of these 10 115horizons the fauna was split into a common set of 29 neogastropod families and family groups and 116the results displayed as a histogram with number of species on the y axis 117Taxonomic composition was compared between the three localities at the generic level using 118Sørensen’s dissimilarity index, which is dependent upon the proportion of shared taxa between two 119or more assemblages (Magurran, 2004; Baselga, 2010) Baselga (2010) extended the use of various 120measures of beta diversity to partition the relative contributions of spatial turnover and nestedness 121The former of these categories relates to the replacement of some taxa by others, and the latter to a 122non-random process of species loss; assemblages with smaller numbers of taxa are simply subsets of 123those from richer sites (Baselga, 2010; Stuart et al., 2016) To allow calculation of these values we 124used the package ‘betapart’ developed by Baselga & Orme (2012) in R (R Development Core 125Team, 2016) Pairwise comparisons were made between each of the three localities in both the 126Paleocene and Middle Eocene, together with a multiple site analysis that included all three localities 127The main statistical method used to further compare the taxonomic structure of the three Middle 128Eocene neogastropod faunas, both with each other and with their modern counterparts, was the use 129of dominance - diversity plots In these the x-axis of each fauna is re-ordered from most to least 130speciose family and then plotted against the log% of that family in the fauna on the y-axis It should 131be stressed that these are not rank – abundance plots in the strict sense as numbers of individuals 132are not involved They are closer in concept to the relative diversity distributions (RDDs) of Harnik et 133al (2010) where taxonomic structure within regional bivalve faunas was investigated by fitting 134various models to the shapes of species: genus ratios Essentially the same principle is adopted here 135but in this case using the number of species within each neogastropod family 136Rank - abundance distributions, and thus by extension RDDs, are based on the principle that the 137abundance of a particular species reflects the size of its realized niche, which in turn is shaped by 138ecological interactions within a community or assemblage (Magurran, 2004) A great many different 139types have now been recognised, but in essence they range from steep, straight lines, such as the log 11 12 140series, to flatter, more sigmoidal curves, such as the ubiquitous log normal (Matthews & Whittaker, 1412014) And it is this gradation in form, as much as precise fits to any one particular model, that is of 142real value in both ecological and evolutionary studies Whereas distribution patterns showing strong 143dominance/low evenness are traditionally linked to “harsh” environments, such as the earliest stages 144of ecological succession, much more even ones are characteristic of mature environments where 145there has been time for significant ecological interactions (Magurran, 2004; McGill et al., 2007) In 146this study the fit of five distribution models (Zipf, Zipf-Mandelbrot, log normal, niche pre-emption 147and broken stick) was assessed using the radfit function of the R ‘vegan’ package (Oksanen, 2016) 148Goodness of fit is reported as AIC values which in turn were used to calculate evidence ratios (Table 149S1, Supporting Information, where further information on this procedure is provided) 150As the utility of a number of these models is still open to debate (McGill et al., 2007; Alroy, 2015), we 151also fitted linear regressions through the RDDs and compared slopes and intercepts using an 152ANCOVA procedure and Tukey simultaneous tests (an extension of the application of such techniques 153to rank-abundance plots by Magurran (2004) and McGregor-Fors et al., (2010)) Finally, the 154robustness of this regression technique was tested using rank-based regression and a re-sampling 155protocol within the ‘Rfit’ package of Kolke & McKean (2012) 156RESULTS 157Evolutionary dynamics of the Neogastropoda 158The curve of raw numbers of neogastropod genera over the last 150 Myr shows a steep rise through 159the Early Cenozoic punctuated by a Late Eocene – mid-Oligocene plateau (Fig 1A), and this is in 160agreement with the generally perceived view of how this very large clade has evolved (Taylor et al., 1611980; Stanley, 2008) Nevertheless, when this curve is sample-standardised, the numbers peak in the 162mid-Oligocene and then fall away steeply into the Pliocene (Fig 1B) The latter feature probably 163reflects both a significant under-sampling in the tropics, especially in the Indo-West Pacific (Valentine 13 14 164et al., 2013), and over-correction in the sample-standardisation procedure by exclusion of certain 165temporally restricted preservational modes (Bush & Bambach, 2015) 166Following a period of intensive re-investigation of the sequence exposed at Seymour Island it is now 167possible to plot the stratigraphic ranges of all neogastropod taxa on a composite, 1500 m-thick 168stratigraphic section spanning the uppermost Cretaceous (i.e Maastrichtian) to Upper Eocene 169(Stilwell & Zinsmeister, 1992; Beu, 2009; Crame et al., 2014, fig 3; Appendix 1) None of the eight 170Late Maastrichtian species can be referred to extant genera, and only one of them crosses the K – Pg 171boundary Higher in the Antarctic section, a second distinctive neogastropod fauna occurs in the Early 172Paleocene (i.e Danian) at the 48 – 120 m level within the Sobral Formation (Crame et al., 2014, fig 1733) This fauna is quite different from the Maastrichtian one and, of the 16 species identified, at least 174five (31%) show strong affinities to extant genera The Early Eocene is not well-defined on Seymour 175Island but an extensive Middle Eocene sequence has yielded 57 neogastropod species, 21 of which 176(37%) can be assigned to living genera Both the increases in numbers of species and the proportion 177of modern genera up section are statistically significant (Crame et al., 2014) Furthermore, by the 178Middle Eocene the distribution of observed neogastropod species amongst families is beginning to 179resemble that of the present day (Fig S1, Supporting Information) In addition it should be 180emphasised that some of the modern genera in the Middle Eocene fauna are represented by several 181species For example the buccinid (s.l.) genus Prosipho has at least seven species, and Chlanidota 182five These are two of the most speciose neogastropod genera in the Southern Ocean at the present 183day and their adaptive radiation can now be traced back to at least the Middle Eocene 184At the composite US Gulf Coast locality some 84 Maastrichtian neogastropod species (50 genera) 185have been identified but only six (7%) are assignable to extant genera From this Maastrichtian fauna 186only three genera and no species cross the K – Pg boundary, where the Paleocene (Danian) fauna 187comprises 62 species/45 genera (Appendix 1; Fig S2) However, it is noticeable that 27 of these 62 188species (44%) are now assignable to extant genera The Early Eocene fauna of the Gulf Coast 15 16 189comprises 103 species/53 genera and the Middle Eocene, 437 species/123 genera (Fig S2); the 190proportions assignable to extant genera are 49% and 44%, respectively 191Even though the Maastrichtian gastropod fauna of the Paris Basin, and indeed NW Europe as a 192whole, remains imperfectly known, there is good evidence for a moderately rich assemblage that 193contains a suite of neogastropod taxa (Appendix 1) In a preliminary re-investigation, Pacaud et al 194(2000) identified five gastropod species that cross the K – Pg boundary, but only one of these is a 195neogastropod The same authors recognise a “notable radiation” of neogastropods in the Early 196Paleocene (Danian) and in the compilation used in this study there were 61 species/42 genera 197(Appendix 1; Fig S3) with 48% of these species assignable to extant genera These figures increase to 198149 species/77 genera in the Early Eocene and 433 species/126 genera in the Middle Eocene (Fig 199S3), with respectively 48% and 51% being assignable to extant genera 200A quantitative comparison of tropical and polar faunas 201The Antarctic and two tropical localities all show clear indications that richness of Early Cenozoic 202neogastropods peaked during the Middle Eocene (Dockery & Lozouet, 2003; Huyghe et al., 2015; 203Crame et al., 2014; Figs S1 – S3) Nevertheless, levels of dissimilarity between all three localities in 204the Paleocene are already extremely high as there are no genera in common between the Paris Basin 205(42 genera) and Antarctica (19 genera), and only one between the Gulf Coast (45 genera) and 206Antarctica (Table 1; Appendix 1) Even though there are ten genera in common between the two 207tropical localities the level of dissimilarity is still high, as indeed it is in the three-way (multi-site) 208comparison (Table 1) A very similar pattern is maintained into the Middle Eocene where three 209genera are shared between Antarctica (30 genera) and both the Paris Basin (126 genera) and Gulf 210Coast (123 genera), and 33 genera between the two tropical localities (Table 1) When Sørensen’s 211dissimilarity index (S) is broken down into its component parts, turnover (S sim) makes a much larger 212contribution than nestedness (Snes) between all localities in both time periods This result indicates 213that the differences very largely arise from the replacement of some species by others, rather than 17 18 214non-random species loss The Antarctic neogastropod fauna is characterised by high levels of 215endemism throughout the Early Cenozoic (Beu, 2009; Crame et al., 2014) 216The Antarctic Middle Eocene neogastropod fauna is also quite distinct from either of the two tropical 217localities when comparisons are made using the proportion of species in each of 29 families and 218family groups (Fig 2) A single family, the Buccinidae s.l., dominates the Antarctic fauna, with twelve 219other families only containing a very small number of species, in marked contrast to the two tropical 220faunas where species are distributed more evenly among several prominent families (Fig 2, where 221the Middle Eocene tropics is represented by the US Gulf Coast) The high – low latitude contrast in 222the structure of neogastropod faunas closely resembles the present day situation (Fig 2; Crame, 2232013, fig 1) Neogastropoda is a particularly good group for this type of analysis as it is 224phylogenetically distinct and overwhelmingly belongs to one main trophic guild (i.e 225predatory/scavenging; Appendix 1) 226The most striking feature to emerge from the model fits using the radfit function of the R ‘vegan’ 227package (Oksanen, 2016) is that both the Recent and Middle Eocene tropical faunas agree best with 228the classical broken stick model (Fig 3; Table S1, Supporting Information) Usually labelled as a 229biological model (as opposed to a purely statistical one), the broken stick is expected when a major 230resource is apportioned approximately evenly between a community’s constituent species (May, 2311975) It is one of the most even distributions known and has been noted on somewhat smaller 232scales in a range of terrestrial and marine taxa (May, 1975) Fine-scale resource partitioning within 233various neogastropod taxa has been widely demonstrated in modern coral reef environments (Kohn, 2341997), and in all probability underpins the patterns shown here at both the present day and in the 235Middle Eocene In marked contrast, both the Recent and Antarctic faunas agree best with the Zipf 236distribution, which is markedly less even (Fig 3; Table S1, Supporting Information) Less is known 237about the occurrence of Zipf distributions in nature but it is interesting note that the modern 238Antarctic marine bivalve fauna is also best fitted by the Zipf model (Harnik et al., 2010) 19 20 10 1081Strepsiduridae: Strepsidura Volutidae: Athleta, Eopsephea, Harpella, Harpula, Leptoscapha, Lyria, 1082Mitreola, Neoathleta, Plejona, Pseudolyria, Volutocorbis, Volutospina Olividae: Amalda, Ancilla, 1083Ancillarina, Baryspira, Gracilispira, Olivancillaria, Pseudolivella, Turrancilla Pseudolividae: 1084Pseudoliva Ptychactridae: Ptychactrus Conidae: Conus, Conilithes, Hemiconus, Leptoconus, 1085Lithoconus, Stephanoconus Terebridae: Mirula Clavatulidae: Catenotoma, Crenaturricula, Nihonia, 1086Turricula.Drilliidae: Elaeocyma Pseudomelatomidae: Anacithara, Crassispira, Tripia Turridae: 1087Eopleurotoma, Epalxis, Gemmula, Oxyacrum Cochlespiridae: Apiotoma, Cochlespira, Knefastia 1088Clathurellidae: Acamptogenotia, Domenginella, Drillola, Scobinella Borsoniidae: Asthenotoma, 1089Borsonia, Cordieria Conorbidae: Conorbis, Cryptoconus Raphitomidae: Amblyacrum, Anomalotella, 1090Pleurotomella, Raphitoma, Systenope Mangeliidae: Bela, Buchozia, Mangelia, Mangeliella, 1091Oenopotidae: Buchozia Oenopota Siphopsinae: Amplosipho, Andoniopsis, Coptosipho, 1092Pseudoandonia, Siphonaliopsis, Syphopsis Cancellariidae: Admetula, Coptostoma, Plesiotriton, 1093Sveltella, Unitas 1094 1095 1096 Seymour Island, Antarctica 1097Paleocene 1098Taiomidae: Taioma Buccinidae: Austrosphaeara, “Colus”, cf.Germonea, Microfulgur, Probuccinum?, 1099Pseudofax?, Pseudotylostoma? Fasciolariidae: Paleosephea? Turbinellidae: Heteroterma?, Pyropsis? 1100Volutidae: Miomelon, Palaeomelon Volutomitridae: Volutomitra “Turridae”: Cosmasyrinx, 1101Marshallaria, Tholitoma 1102 1103Early Eocene 1104(interval incomplete so faunal list not included in the study) 1105 1106Middle Eocene 1107Taiomidae: Taioma Buccinidae: Austroficopsis, Chlanidota, Pareuthria, Penion, Probuccinum, 1108Prosipho, Fasciolariidae: “Fusinus”, Microfulgur? Muricidae: Eupleura, Trophon Turbinellidae: 1109“Turbinellidae” indet., Fulgurofusus Volutidae: Adelomelon, Miomelon, Tractolira, Odontocymbiola 1110Volutomitridae: Volutomitra? Clavatulidae: Makiyamaia? Drilliidae: Agladrillia?, Spirotropis?, 1111Splendrillia? Turridae: Gemmula, Marshallaria? Cochlespiridae: Cochlespira? Borsoniidae: 1112Typhlomangelia?, Zemacies Raphitomidae: Austrosullivania?, Austrotoma.”Turridae” indet.: Aforia?, 1113Cancellariidae: Coptostomella?, Pristimercia 1114 83 84 42 11153 Neogastropod taxonomy 1116The division of gastropods into nine major taxonomic groups used in this study follows that of Crame 1117(2013, appendix S1) The monophyletic status of the largest of these groups, the Neogastropoda, has 1118been a subject of much debate, with morphological studies on the whole providing broad support 1119(Ponder et al., 2008) but molecular phylogenetic ones proving equivocal (Riedel, 2000; Colgan et 1120al.,2000, 2007; Cunha et al., 2009) Nevertheless, two recent molecular investigations support 1121monophyly (Oliverio & Modica, 2010; Zou et al., 2011), with the latter of these including a 1122significantly improved sample base and the first use of the critical 18S rRNA gene in such a study 1123The classification of neogastropod superfamilies and families used here very largely follows that of 1124Bouchet & Rocroi (2005) and Bouchet et al (2011), with the important proviso that some doubt still 1125surrounds taxonomic subdivision within the Buccinoidea And this is particularly so with the very 1126large family Buccinidae, which is truly global in its distribution and contains in excess of 200 genera 1127and subgenera (Dell, 1990; Harasewych, 1998; Hayashi, 2005) Historically, southern, high-latitude 1128whelks have been classified in both Buccinidae Rafinesque, 1815 and Buccinulidae Finlay, 1928, with 1129evidence for the latter being provided by the influential study by Powell (1951) In this work three 1130subfamilies, Buccinulinae, Prosiphiinae and Cominellinae, were established based on radula 1131characteristics, and the Buccinidae was restricted to the northern genera Buccinum Linné, 1758 and 1132Burnupena Iredale, 1918; Powell (1951) believed the Buccinulidae to be more closely related to the 1133Neptuneidae than Buccinidae In a later review of Antarctic buccinoideans, Harasewych & Kantor 1134(2004) proposed that use of Buccinulidae and its subdivisions as defined by Powell (1951) might still 1135be a useful way forward, but without necessarily assigning these categories to any particular 1136taxonomic rank 1137Although Harasewych & Kantor’s (2004) suggestion seems eminently sensible, it has to be borne in 1138mind that buccinulid whelks are not necessarily strictly confined to the southern high latitudes They 1139appear to be well represented in the tropical deep sea, as well as shallower waters of the North 1140Pacific (Bouchet & Warén, 1986; Vermeij, 1991) Ponder (1973) was unable to find any major 1141anatomical differences between the southern Penion Fischer, 1884 and northern Kelletia Bayle in 1142Fischer, 1884, and in a subsequent molecular analysis of some 35 taxa using 16S rRNA, Hayashi 1143(2005) found these two genera to be sister taxa There is some palaeontological evidence to suggest 1144that the lineage comprising these taxa spread northwards from New Zealand to North America 1145between the Early Paleocene and Early Miocene (Hayashi, 2005) In addition, a morphological study 1146of the genus Buccinulum Deshayes, 1830 suggested that there was no justification for the subfamilial 1147separation of buccinulids from the Buccinidae (Ponder, 1971) 1148The northern Pacific genus Lirabuccinum Vermeij, 1991 has a radula dentition very similar to 1149southern taxa such as Notoficula Thiele, 1917, Falsimohnia Powell, 1951, Pareuthria Strebel, 1905 1150and Tromina Dall, 1918, and Powell (1951) considered it (as Searlesia Harmer, 1914) to be part of his 1151Cominellinae The only other cool-water northern buccinid with a lirate outer lip is Barbitona Dall, 11521916 This genus had traditionally been linked with Neptunea Röding, 1798, but Nelson (1978), 1153largely on the basis of shell structure, linked it to Powell’s (1951) Buccinulinae (Vermeij, 1991) 1154Finally, it should be noted that Kantor (2003) was unable to differentiate between the Buccinidae and 1155Buccinulidae on the basis of stomach anatomy Whereas nearly all of the component families of the 1156Buccinoidea had a set of distinctive stomach characters, Kantor (2003) found at least one stomach 85 43 86 1157type that was present in both northern Colus Röding, 1798 and Siphonorbis Mörch, 1869, and 1158southern Chlanidota Martens, 1878, and ‘Tromina’ 1159A close phylogenetic relationship between northern Buccinidae and southern Buccinulidae is a 1160reasonable conclusion Partial molecular analyses undertaken to date of this relationship are at best 1161ambiguous (Oliverio & Modica, 2010; Zou et al., 2011; Hayashi, 2005) and full resolution of this 1162critical neogastropod taxonomic problem will not be achieved until a more wide-ranging molecular 1163study has been undertaken The position taken by previous Southern Hemisphere taxonomic 1164authorities, such as Dell (1990) and Beu (2009), of using ‘Buccinidae’, but in its widest possible sense, 1165is a reasonable one and adopted here 1166When global comparisons of modern neogastropod faunas are made it is clear that there are some 1167inconsistencies in both the assignment of species to genera and genera to families; this is particularly 1168so in tropical faunas, and with some of the smaller families in the Muricoidea Nevertheless, it is 1169believed that the majority of taxonomic assignments above species level are essentially correct and 1170sufficient to generate the broad taxonomic patterns between families and superfamilies 1171demonstrated in this study Caution also has to be exercised with supra-specific taxonomic 1172assignments in the fossil record In particular attention has been drawn to nomenclatorial 1173inconsistencies in Late Cretaceous – Early Paleogene Buccinidae (Allmon, 1990; Squires, 1997), 1174Fasciolariidae (Haasl, 2000) and Muricidae (Bandel, 1993) 1175 1176References for Appendix – Data sources 1177N.B References given in the main text are not repeated here 1178Allmon, W.D (1989) Paleontological completeness of the record of Lower Tertiary mollusks, U.S 1179 Gulf and Atlantic Coastal plains: Implications for phylogenetic studies Historical Biology, 3, 1180 141-158 1181Allmon, W.D (1990) Revision of the Bullia group (Gastropoda: Nassariidae) with comments on its 1182 evolution, biogeography and phylogeny Bulletins of American Paleontology, 99, 1-179 1183Bandel, K (1993) Caenogastropoda during Mesozoic times Scripta Geologica Special Issue, 2, 7-56 1184Binkhorst, J.T (1861) Monographie des Gastéropodes et des Céphalopodes de la craie supérieur du 1185 Limbourg, suivie d’une description de quelques espèces de crustacés dumême dépôt crétacé 1186 Bruxelles (Muquardt), Maastricht (Müller Fréres), 83pp 1187Bouchet, P & Warén, A (1986) Taxonomical notes on tropical deep water Buccinidae with 1188 1189 87 88 description of new taxa Résultats des Campagnes MUSORSTOM, Tome Mémoires Museum national d’Histoire naturelle (A), 133, 457-499 44 1190Bouchet, P., Kantor, Yu.I., Sysoev, A & Puillandre, N (2011) A new operational classification of the 1191 Conoidea (Gastropoda) Journal of Molluscan Studies, 77, 273-308 1192CoBabe, E.A & Allmon, W.D (1994) Effects of sampling on paleoecologic and taphonomic 1193 1194 analyses in high-diversity fossil accumulations: an example from the Eocene Gosport Sand, Alabama Lethaia, 27, 167-178 1195Colgan, D.J., Ponder, W.F & Eggler, P.E (2000) Gastropod evolutionary rates and phylogenetic 1196 relationships assessed using partial 28S rDNA and histone H3 sequences Zoologica Scripta, 1197 29, 29-63 1198Colgan, D.J., Ponder, W.F., Beacham, E & Macaranas, J.M (2007) Molecular phylogenetics of 1199 1200 Caenogastropoda (Gastropoda: Mollusca) Molecular Phylogenetics and Evolution, 42, 717737 1201Cope, K.H., Utgaard, J.E., Master, J.M & Feldmann, R.M (2005) The fauna of the Clayton Formation 1202 (Paleocene, Danian) of southern Illinois: a case of K/P survivorship and Danian recovery 1203 Bulletin of the Mizunami Fossil Museum, 32, 97-108 1204Cossmann, M & Pissarro, G (1910-13) Monographie complete de coquilles fossils de l’Éocène des 1205 environs de Paris Paris, vols 1206Cunha, R.L., Grande, C & Zardoya, R (2009) Neogastropod phylogenetic relationships based on 1207 entire mitochondrial genomes BMC Evolutionary Biology, 9, 210 doi:10.1186/1471-2148-9- 1208 210 1209Dell, R.K (1990) Antarctic Mollusca: with special reference to the fauna of the Ross Sea Bulletin of 1210 the Royal Society of New Zealand, 27, 1-311 1211De Geyter, G., de Man, E., Herman, J., Jacobs, P., Moorkens, T., Steurbaut, E & Vandenberghe, N 1212 (2006) Disused Paleogene regional stages from Belgium: Montian, Heersian, Landenian, 1213 Paniselian, Bruxellian, Laekenian, Ledian, Wemmellian and Tongian Geologica 1214 Belgica, 9, 203 -213 1215De Wever, P & Cornée, A (2008) Le cadre géographique et géologique Stratotype Lutétien Merle, 1216 D (coord) (Museum National d’Histoire naturelle Paris; Biotope Mèze; BRGM, Orléans), pp 1217 57-58 89 90 45 1218Dockery, D.T., III (1984) Crisis events for Paleogene molluscan faunas in the southeastern United 1219 States Mississippi Geology, 5, 1-7 1220Dockery, D.T., III (1986) Punctuated succession of Paleogene mollusks in the northern Gulf Coastal 1221 Plain Palaios 1, 582-589 1222Dockery, D.T., III (1998) Molluscan faunas across the Paleocene/Eocene series boundary in the North 1223 American Gulf Coastal Plain Late Paleocene – Early Eocene climatic and biotic events in the 1224 marine and terrestrial records (ed M.-P Aubry, S Lucas & W.A Berggren), pp 296-322 1225 Columbia University Press, New York 1226Dutton, A.L., Lohmann, K.C & Zinsmeister, W.J (2002) Stable isotope and minor element proxies for 1227 Eocene climate of Seymour Island, Antarctica Paleoceanography, 17, 1016, 1228 0.1029/2000PA000593 1229Eargle, D.H (1968) Nomenclature of formations of Claiborne Group Middle Eocene Coastal Plain of 1230 Texas U.S Geological Survey Bulletin, 1251-D, 1- 25 1231Francis, J.E., Ashworth, A., Cantrill, D.J., Crame, J.A., Howe, J., Stephens, R., Tosolini, A.-M 1232 & Thorn, V (2008) 100 million years of Antarctic climate evolution: evidence from fossil 1233 plants Antarctica: A keystone in a changing world (ed A.K.Cooper et al.) Proceedings 10th 1234 International Symposium Antarctic Earth Sciences, pp 19-27 National Academies Press, 1235 Washington, DC 1236Garvie, C L (1996) The molluscan macrofauna of the Reklaw Formation, Marquez Member 1237 1238 (Eocene: Lower Claibornian) in Texas Bulletins of American Paleontology, 111, 1- 177 1239Gély, J.-P (2008) La stratigraphie et al paléogeographie du Lutétien en France Stratotype Lutétien 1240 Merle, D (coord) (Museum National d’Histoire naturelle Paris; Biotope Mèze; BRGM, 1241 Orléans), pp 76-104 1242Glibert, M (1973) Revision des Gastropoda du Danien et du Montien de la Belgique Mémoire 1243 Institute Royal Sciences Naturelle Belgique, 173, 1- 116 1244Haasl, D.M (2000) Phylogenetic relationships among nassariid gastropods Journal of Paleontology 1245 91 92 74, 839-852 46 1246Haasl, D M & Hansen, T A (1996) Timing of latest Eocene molluscan extinction patterns in 1247 Mississippi Palaios, 11, 487-494 1248Hansen, T.A (1987) Extinction of Late Eocene to Oligocene molluscs: Relationship to shelf area, 1249 temperature changes, and impact events Palaios, 2, 69-75 1250Hansen, T.A (1988) Early Tertiary radiation of marine molluscs and the long-term effects of the 1251 Cretaceous – Tertiary extinction Paleobiology, 14, 37-51 1252Hansen, T.A (1993) Patterns of molluscan extinction and recovery across the Cretaceous – Tertiary 1253 boundary in east Texas; report on new outcrops Cretaceous Research, 14, 685-706 1254Hansen, T.A., Farrell, B.R & Upshaw, B., III (1993) The first two million years after the Cretaceous – 1255 Tertiary boundary in east Texas: rate and paleoecology of the molluscan recovery 1256 Paleobiology, 19, 251-265 1257Harasewych, M.G (1998) Family Buccinidae Mollusca The Southern Synthesis Part B (ed P.L 1258 Beesley et al.), pp 825-827 CSIRO, Canberra 1259Harasewych, M.G & Kantor Yu.I (2004) The deep-sea Buccinoidea (Gastropoda, Neogastropoda) of 1260 the Scotia Sea and adjacent abyssal plains and trenches The Nautilus, 118, 1-42 1261Harris, W.B., Zullo, V.A & Laws, R.A (1993) Sequence stratigraphy of the onshore Palaeogene, 1262 southeastern Atlantic Coastal Plain Sequence stratigraphy and facies associations (ed H.W 1263 Posamentier, C.P Summerhayes, B.U Haq & G.P Allen), pp 537-561 Wiley, New York 1264Harwood, D.M & Levy, R.H (2000) The McMurdo erratics: Introduction and overview Antarctic 1265 Research Series, 76, 1-18 1266Hayashi, S (2005) The molecular phylogeny of the Buccinidae (Caenogastropoda: Neogastropoda) as 1267 inferred from the complete mitochondrial 16S rRNA gene sequences of selected 1268 representatives Molluscan Research, 25, 85-98 1269Horton, J.W & Zullo, V.A (ed.) (1991) The geology of the Carolinas, 424pp.University of Tennessee 1270 Press, Knoxville 1271Huyghe, D., Merle, D., Lartaud, F., Cheype, E & Emmanuel, L (2012) Middle Lutetian climate in the 1272 93 94 Paris Basin: implications for a marine hotspot of paleodiversity Facies, 58, 587-604 47 1273Ivany, L.C., Wilkinson, B.H., Lohmann, K.C., Johnson, E.R., McElroy, B.J & Cohen, G.J (2004) Intra1274 annual variation in Venericardia bivalves: Implications for Early Eocene temperature, 1275 seasonality, and salinity in the U.S.Gulf Coast Journal of Sedimentary Research, 74, 7-19 1276Kantor, Yu.I (2003) Comparative anatomy of the stomach of Buccinoidea (Neogastropoda) Journal 1277 of Molluscan Studies, 69, 203-220 1278Kaunhowen, F (1898) Die Gastropoden der Maestrichter Kreide Paläontologisches Abhandlung, NF, 1279 Bd IV, Heft 51pp 1280Koch, C.F (1996) Latest Cretaceous mollusc species ‘fabric’ of the US Atlantic and Gulf Coastal Plain: 1281 a baseline for measuring biotic recovery Geological Society of London Special Publication, 1282 102, 309-317 1283Kosnik, M.A (2005) Changes in Late Cretaceous – early Tertiary benthic marine assemblages: 1284 analyses from the North American coastal plain shallow shelf Paleobiology, 31, 459-479 1285Le Renard, J (1994) Révision des Mollusques paléogènes du basin de Paris I – Rectification de 1286 nomenclature d’espèces Cossmanniana, 3, 35-40 1287Le Renard, J (1995a) Révision des Mollusques paléogènes du basin de Paris III – Chronologie des 1288 créateurs de références primaires Cossmanniana, 3, 33-150 1289Le Renard, J (1995b) Sur la position systématique des Gastropoda éocènes du bassin de Paris classés 1290 Parvisipho et Siphonalia Cossmanniana, 3, 57-64 1291Le Renard, J (1998) Révision des Mollusques paléogènes du basin de Paris VI – Liste des Genres 1292 typifies par des espèces de cette provenance Cossmanniana, 5, 29-56 1293Le Renard, J & Pacaud, J.-M (1995) Révision des Mollusques paléogènes du basin de Paris II 1294 Liste de références primaires des espèces Cossmanniana, 3, 65-132 1295Lockwood, R (2003) Abundance not linked to survival across the end-Cretaceous mass extinction: 1296 Patterns in North American bivalves Proceedings of the National Academy of Sciences USA, 1297 100, 2478-2482 1298Mancini, E.A & Tew, B.H (1990) Tertiary sequence stratigraphy and biostratigraphy of 1299 95 96 Southwestern Alabama Geological Survey of Alabama Field Trip Guidebook, 51p 48 1300Marenssi, S.A (2006) Eustatically controlled sedimentation recorded by Eocene strata of the James 1301 Ross Basin, Antarctica Cretaceous – Tertiary high-latitude palaeoenvironments, James Ross 1302 Basin, Antarctica (ed J.E Francis, D Pirrie & J.A Crame) Geological Society of London 1303 Special Publication, 258, 125-133 1304Marenssi, S.A., Santillana, S.N & Rinaldi, C.A (1998) Stratigraphy of the La Meseta Formation 1305 (Eocene), Marambio (Seymour Island), Antarctica Publicación Especial de la Asociación 1306 Paleontológica Argentina, 5, 137-146 1307Marenssi, S.A., Net, LI & Santillana, S.N (2002) Provenance, environmental and paleogeographic 1308 controls on sandstone composition in an incised-valley system: the Eocene La Meseta 1309 Formation, Seymour Island, Antarctica Sedimentary Geology, 150, 301-321 1310Merle, D (2008a) Les sites stratotypiques Stratotype Lutétien Merle, D (coord) (Museum Naturelle 1311 d’Histoire naturelle Paris; Biotope Mèze; BRGM, Orléans), pp 59-63 1312Merle, D (2008b) Le Lutétien du basin de Paris: un example de point-chaud de la paléobiodiversité 1313 Stratotype Lutétien Merle, D (coord) (Museum Naturelle d’Histoire naturelle Paris; Biotope 1314 Mèze; BRGM, Orléans), pp 174-181 1315Montes, M., Nozal, F., Santillana, S., Marenssi, S & Olivero, E (2010) Mapa geológico de la Isla 1316 Marambio (Seymour) Escala 1:20,000 (Instituto Antárctico Argentina & Instituto Geológico 1317 y Minera Espa) 1318Nelson, C.M (1978) Neptunea (Gastropoda: Buccinacea) in the Neogene of the north Pacific and 1319 adjacent Bering Sea The Veliger, 21, 203-215 1320Oliverio, M & Modica, M.V (2010) Relationships of the haematophagous marine snail 1321 Colubraria (Rachiglossa: Colubrariidae), within the neogastropod phylogenetic framework 1322 Zoological Journal of the Linnean Society, 158, 779-800 1323Pacaud, J.-M (1998) Nouvelles données sur le genre Popenoeum (Mollusca, Pseudolividae) 1324 1325 Remarques taxinomiques sur une espèce ubiquiste du Paléocène inférieur, Popenoeum anbiguum (Binkhorst, 1861) nov comb Cossmanniana, 5, 1-28 1326Pacaud, J.-M (2004) Révision des mollusques du Danien (Paléocène inférieur) du Bassin de Paris 1327 97 98 Gastropoda: Patellogastropoda et Vetigastropoda (pro parte) Geodiversitas, 26, 577-629 49 1328Pacaud, J.-M (2007) Nouveautés nomenclaturales et taxonomiques introduites par Alcide d’Orbigny 1329 1330 dans le Prodrome (1850, 1852) pour les espèces du Paléocène et de l’Éocène Geodiversitas, 29, 17-85 1331Pacaud, J.-M (2008) Le contenu paléontologique du Lutétien du basin de Paris: Classe Gastropoda 1332 Stratotype Lutétien Merle D (coord) (Museum National d’Histoire naturelle Paris; Biotope 1333 Mèze; BRGM, Orléans; cd rom) 1334Pacaud, J.-M (2009) Révision des mollusques du Danien (Paléocène inférieur) du Basin de Paris 1335 Gastropoda: Neritomorpha Revue de Paléobiologie Genève, 28, 349-369 1336Pacaud, J.M & Le Renard, J (1995) Révision des Mollusques paléogènes du basin de Paris IV Liste 1337 systématique actualisée Cossmanniana 3: 151-187 1338Pacaud J-M, Merle D (2002) Alcide d’Orbigny, un précurseur dans l’étude de la faune du Danien du 1339 basin de Paris Comptes Rendus de l’ Academie des Sciences Palevol, 1, 587-598 1340Pacaud, J.-M., Schnetler, K.I (1999) Revision of the gastropod family Pseudolividae from the 1341 1342 Paleocene of West Greenland and Denmark Bulletin of the Geological Society of Denmark, 46, 53-67 1343Pacaud, J.-M., Merle, D & Meyer, J.-C (2000) La faune danienne de Vigny (Val-d’Oise, France): 1344 importance pour l’étude de la diversification des mollusques au début du Tertiaire Comptes 1345 Rendus de l’ Academie des Sciences de la Terre et des planetes, 330, 867-873 1346Palmer, K.V.W & Brann, D.C (1965) Catalogue of the Paleocene and Eocene Mollusca of the 1347 southern and eastern Unites States Part I Pelecypoda, Amphineura, Pteropoda, 1348 Scaphopoda, and Cephalopoda Bulletins of American Paleontology, 48, 1-466 1349Palmer, K.V.W & Brann, D.C (1966) Catalogue of the Paleocene and Eocene Mollusca of the 1350 southern and eastern Unites States Part II Gastropoda Bulletins of American Paleontology, 1351 48, 1- 1057 1352Petit, R.E & Harasewych, M.G (2005) Catalogue of the superfamily Cancellarioidea Forbes and 1353 Hanley, 1851 (Gastropoda: Prosobranchia) 2nd edition Zootaxa, 1102, 1-161 1354Ponder, W.F (1971) A review of New Zealand Recent and fossil species of Buccinulum Deshayes 1355 99 100 (Mollusca: Neogastropoda: Buccinidae) Journal of the Royal Society of New Zealand, 1, 23150 1356 283 1357Ponder, W.F (1973) The origin and evolution of the Neogastropoda Malacologia, 12, 2951358 338 1359Ponder, W.F., Colgan, D.J., Healy, J.M., Nützel, A, Simone, L.R.L & Strong, E.E (2008) 1360 Caenogstropoda Phylogeny and evolution of the Mollusca (ed W.F Ponder & D.R 1361 Lindberg), pp 331-383 University of California Press, London 1362Porębski, S.J (2000) Shelf-valley compound fill produced by fault subsidence and eustatic sea-level 1363 changes Eocene La Meseta Formation, Seymour Island, Antarctica Geology, 28, 147-150 1364Powell, A.W.B (1951) Antarctic and Subantarctic Mollusca: Pelecypoda and Gastropoda Discovery 1365 Reports, 26, 47-196 1366Powell, R.J & Baum, G.R (1982) Eocene biostratigraphy of South Carolina and its relationship to Gulf 1367 Coastal Plain zonations and global changes of coastal onlap Bulletin of the Geological Society 1368 of America, 93, 1099 –1108 1369Riedel, F (2000) Ursprung und Evolution der “höheren” Caenogastropoda Berliner 1370 Geowissenschaftliche Abhandlungen, E32, 1-240 1371Sadler, P.M (1988) Geometry and stratification of uppermost Cretaceous and Paleogene units on 1372 Seymour Island, northern Antarctic Peninsula Geological Society of America Memoir, 169, 1373 303-320 1374Siesser, W.G (1984) Paleogene sea levels and climates: U.S.A eastern Gulf Coastal Plain 1375 Palaeogeography, Palaeoclimatology, Palaeoecology, 4, 61-275 1376Snyder, M.A (2000) Nomenclatural issues concerning the Eocene mollusks Fusinus porrectus 1377 1378 1379 (Solander in Brander, 1766), Fusinus acuminatus (J Sowerby, 1821), Fusinus aciculatus (Lamarck, 1803) and Clavilithes rugosus (Lamarck, 1803) Cossmanniana, 7, 23-28 1380Sohl, N.F (1977) Utility of gastropods in biostratigraphy Concepts and methods of biostratigraphy 1381 (ed E.G.Kauffman & J.E Hazel), pp 519-539 Dowden, Hutchinson & Ross, Stroudsburg, PA 1382Sohl, N.F & Koch, C.F (1983) Upper Cretaceous (Maastrichtian) Mollusca from the Haustator bilira 1383 101 102 assemblage zone in the East Gulf Coastal Plain US geological Survey Open File Report, 8351 1384 451, 1-239 1385Sohl, N.F & Koch, C.F (1984) Upper Cretaceous (Maastrichtian) larger invertebrate fossils from the 1386 Haustator bilira assemblage zone in the West Gulf Coastal Plain US geological Survey Open 1387 File Report, 83-687, 1-282 1388Sohl, N.F & Koch, C.F (1987) Upper Cretaceous (Maastrichtian) larger invertebrate fossils from the 1389 Haustator bilira assemblage zone in the Atlantic Coastal Plain with further data for the East 1390 Gulf US geological Survey Open File Report, 87-194, 1-172 1391Squires, R.L (1997) Taxonomy and distribution of the buccinid gastropod Brachysphingus from 1392 uppermost Cretaceous and Lower Cenozoic marine strata of the Pacific slope of North 1393 America Journal of Paleontology, 71, 847-861 1394Stilwell, J.D (2000) Eocene Mollusca (Bivalvia, Gastropoda and Scaphopoda) from McMurdo Sound: 1395 Systematics and paleoecologic significance Antarctic Research Series, 76, 261-320 1396Stilwell, J.D (2002) Geological exploration of Cockburn Island, Antarctic Peninsula Polish Polar 1397 Research, 23, 47-73 1398Stilwell, J.D (2005) A new species of Calliotropis (Mollusca: Gastropoda: Vetigastropoda: Trochidae: 1399 Eucyclinae) from the Eocene of Antarctica Molluscan Research, 25, 9-13 1400Toulmin, L.D (1977) Stratigraphic distribution of Paleocene and Eocene fossils in the Eastern Gulf 1401 Coast region Geological Survey of Alabama Monograph, 13, 1-602 1402Tucker, J.K & Le Renard, J (1993) Liste bibliographique des Turridae (Gastropoda, Conacea) du 1403 Paléogène de l’Angleterre, de la Belgique et de la France Cossmanniana, 2, 1-66 1404Vermeij, G.J (1991) Generic identity and relationships of the northern Pacific buccinid gastropod 1405 Searlesia dira (Reeve, 1846) The Veliger, 34, 264-271 1406Wilckens, O (1911) Die mollusken der antarktischen Tertiarformation Wissenschaftliche Ergebnisse 1407 der Schwedischen Südpolar Expedition 1901-1903, 3, 1-62 1408Willis, P.M.A & Stilwell, J.D (2000) A probable piscivorous crocodile from Eocene deposits of 1409 McMurdo Sound, East Antarctica Antarctic Research Series, 76, 355-358 1410Zinsmeister, W.J (1976) A new genus and species of the family Struthiolariidae, Antarctodarwinella 103 104 52 1411 ellioti, from Seymour Island, Antarctica Ohio Journal of Science, 76, 111-114 1412Zinsmeister, W.J & Camacho, H.H (1980) Late Eocene Struthiolariidae (Mollusca: Gastropoda) from 1413 Seymour Island, Antarctic Peninsula and their significance to the biogeography of Early 1414 Tertiary shallow-water faunas of the Southern Hemisphere Journal of Paleontology, 54, 1- 1415 14 1416Zou, S., Li Q & Kong, L (2011) Additional gene data and increased sampling give new insights into 1417 the phylogenetic relationships of Neogastropoda, within the caenogastropod 1418 1419 phylogenetic framework Molecular Phylogenetics and Evolution, 61, 425-435 1420 105 106 53 ... Persicula Harpidae: Cryptochorda, Eocithara 1079Marginellidae: Dentimargo, Eburnospira, Gibberula, Glabella, Marginella, Microvulina, Nudifaba, 1080Stazzania, Volvarina, Volvarinella Mitridae: Conomitra,... 817Vetigastropoda, and these strongly suggest very shallow water, peri-reefal habitats (Pacaud, 20 04, 69 35 70 81 820 07, 20 09; Pacaud & Merle, 20 02; Pacaud et al., 20 00) In a total fauna of approximately 122 .. .20 ABSTRACT 21 Aim To investigate those factors that influenced the differentiation of high-latitude and polar marine 22 faunas on both ecological and evolutionary timescales Can a focus on a greenhouse