The central muscle scar field of the beyrichioidean palaeocopid ostracodes includes an adductor muscle scar composed of many polygonal scars, a long mandibular scar composed of eight individual scars, and an oval frontal muscle scar. Probably, as in the extant ostracodes, the muscle scars served as attachment points for the closing muscles as well as for the muscles and chitinous supporting structures from the appendages. the fulcral depression, on which the dorsal apex of the mandible pivots in recent ostracodes, has also been recognized in the Early Carboniferous beyrichiids and paraparchitids.

The pore systems of the beyrichioideans are more advanced than assumed so far, and they include, documented for the first time, the secretory (‘exocrine’) pores and ‘marginal’ pores in Paleozoic beyrichioideans. It seems likely that the development of these pores, was related to the transition of beyrichioideans from shallow marine into unstable, possibly brackish, water paleoenvironments.

The partially calcified inner lamella and the ‘marginal’ pore canals are apomorphies of some Early Carboniferous beyrichioideans. Internal features of the paraparchitids confirm their beyrichioidean affinity. the adductor and mandibular scars are plesiomorphic in the Beyrichiidae and Paraparchitidae. the presence of mandibular scars and fulcral depressions may indicate that these ostracodes were actively feeding bottom crawlers.

Multivariate morphometric analysis was applied for differentiation of closely related species and evaluation of intra- and interspecific variation in Manipora from the Selkirk Member, Red River Formation, in southern Manitoba. Seven morphological characters were quantified in transverse thin sections of 46 coralla and statistically tested for selecting effective characters in discriminating species. Cluster analysis was performed on a raw data matrix coordinated with 46 coralla by three selected characters. Two major clusters on the resulting dendrogram were regarded as morphospecies, following comparative examination of the coralla using serial sections. Cluster analyses were also conducted on principal component score matrices obtained from the raw data set coordinated with 46 coralla by all seven characters, and from an experimental data set including the 46 coralla plus two replicates of each and six of the characters. the results agree closely with the first cluster analysis, but discrimination of morphospecies was slightly degraded. the validity of two morphospecies recognized in the first cluster analysis was verified by discriminant analyses, descriptive statistics, and bivariate plots. the results show that tabularium area is the most meaningful character for distinguishing these morphospecies; ranges of variations of the other six characters overlap between morphospecies.

Another cluster analysis like the first was performed, but with the addition of 11 type specimens and reference coralla of Manipora species from the Upper Ordovician of southern and northern Manitoba and Texas. Based on this analysis, together with comparative examination of thin sections, the two morphospecies are identified as valid species: M. amicarum Sinclair, 1955 and M. manitoba (Sokolov, 1955). Manipora magna Flower, 1961 is considered to be a synonym of M. amicarum, while M. trapezoidalis Flower, 1961 and M. garsonensis Caramanica, 1992 are considered to be synonyms of M. manitoba, and the hypotypes of M. amicarum of Nelson (1963) are assigned to M. manitoba.

The uppermost 5–15 m of the Douling Formation in the southern Hunan area, South China, yields a diverse fauna comprised of ammonoids, bivalves, and brachiopods. The brachiopods reported in this paper consist of 51 species in 34 genera and are dominated by the Lopingian (Late Permian) species associated with a few species persisting from the underlying Maokouan (Late Guadalupian). This fauna is of earliest Wuchiapingian in age as precisely constrained by the associated conodont Clarkina postbitteri postbitteri and the Guadalupian-type ammonoid fauna of the Roadoceras-Doulingoceras Zone in the brachiopod horizon. The discovery of the Lopingian species-dominated brachiopod fauna in the earliest Wuchiapingian in southern Hunan suggests a much less pronounced effect of the pre-Lopingian crisis (end-Guadalupian mass extinction) than the end-Changhsingian mass extinction in terms of brachiopods, a contemporaneous onset of the Lopingian recovery/radiation during the pre-Lopingian crisis period, and taxonomic selectivity of the pre-Lopingian crisis in terms of different fossil groups. New taxa are Echinauris doulingensis n. sp., Pararigbyella quadrilobata n. gen. and n. sp. and P. doulingensis n. gen. and n. sp.

Black shales of the Coroico Formation are part of a thick succession of Lower and Middle Ordovician strata that were deposited in the Cordillera Oriental foreland basin along the margin of West Gondwana. The basin was inhabited primarily by a cool-water, Atlantic-type graptolite fauna. Newly discovered material from rocks that crop out near the town of Consata in NW Bolivia include unexpected warm-water or Pacific-type elements such as Parisograptus caduceus and Pseudotrigonograptus within an assemblage dominated by abundant pendent Didymograptus specimens, Cryptograptus schaeferi, and diplograptaceans such as Oelandograptus oelandicus and Hustedograptus bulmani n. sp. Parisograptus caduceus has generally been considered to be restricted to oceanic depths below those of the epipalagic realm that occupied continental shelves, whereas the remainder of the assemblage is more characteristic of relatively shallow water, epicratonic sites. We interpret this mixed assemblage to be the Atlantic Province, West Gondwanan equivalent of the off-shore isograptid biofacies that is much more widely known from low latitude sites around the globe. These results suggest that in this region of West Gondwana, the properties of local water masses (productivity and physical features such as temperature, salinity, or oxygenation) strongly influenced graptolite species distribution and led to biofacies differentiation among coeval assemblages. It also suggests that some isograptids inhabited the epipelagic biotope in mid to high latitude regions. The new species Hustedograptus bulmani is described herein.

Adhesive meniscate burrows (AMB) are common in alluvial paleosols of the Paleogene Willwood Formation, Bighorn Basin, Wyoming. AMB are sinuous, variably oriented burrows composed of a nested series of distinct, ellipsoidal packets containing thin, tightly spaced menisci subparallel to the bounding packet. Menisci are non-pelleted and texturally homogeneous with each other and the surrounding matrix. AMB were constructed most likely by burrower bugs (Hemiptera: Cydnidae), cicada nymphs (Hemiptera: Cicadae), and less likely by scarabaeid (Coleoptera: Scarabaeidae) or carabid beetles (Coleoptera: Carabidae), based on burrow morphology and comparison to similar structures produced by these organisms in modern soils. Extant burrowing insects excavate backfilled burrows in well-rooted A and upper B horizons of soils generally below field capacity depending on soil type. This study demonstrates that AMB are distinct morphologically from such previously described ichnofossils as Beaconites, Laminites, Scoyenia, Taenidium, and Ancorichnus. Naktodemasis bowni, a new ichnogenus and ichnospecies, represents burrows composed of nested ellipsoidal packets backfilled with thin, tightly spaced, menisci subparallel to the bounding packet. The presence of N. bowni indicate periods of subaerial exposure associated with pedogenic modification under moderately to well-drained soil conditions, or during periods of better drainage in imperfectly drained soils. N. bowni, therefore, can differentiate alluvial paleoenvironments from marine and lacustrine paleoenvironments, as well as periods of subaerial exposure of sediments deposited in aquatic settings.

Late Mississippian and earliest Pennsylvanian trilobite faunas of North America are dominated by the Paladin and Kaskia clades. Phylogenetic analysis of middle Carboniferous species of these clades demonstrates the close ancestral relationship between these groups. The Kaskia clade consists of eight species: K. chesterensis Weller, 1936, K. osagensis (Cisne, 1967), K. longispina (Strong, 1872), K. wilsoni (Walter, 1924), K. genevievensis (Walter, 1924), K. rosei (Cisne, 1967), K. gersnai n. sp., and K. rollinsi n. sp. Kaskia Weller, 1936 ranges from late Osagean to middle Chesterian (early Visean-early Serpukhovian) and is restricted to cyclothemic shelf and nearshore deposits. Species of Kaskia appear to have evolved in areas of shallow water and high environmental stress. The Paladin clade consists of 12 species including previously named species P. morrowensis (Mather, 1915), P. girtyianus Hahn and Hahn, 1970, P. rarus Whittington, 1954, P. helmsensis Whittington, 1954, and P. moorei (Branson, 1937). New species belonging to this clade are Paladin moorefieldensis n. sp., P. pleisiomorphus n. sp., P. imoensis n. sp., P. mangeri n. sp., and P. wapanukaensis n. sp. This group ranges from the early Chesterian to early Morrowan (late Viseanlate Bashkirian). Species of Paladin appear to be confined to outer shelf shelf-edge and off-shelf facies where presumably deeper water environments existed. This is manifested in their paleogeographic distribution, which is paleoenvironmentally controlled.

Seemingly consistent proportional differences in several palatal structures have been noted between Permian and Triassic anomodont therapsids for nearly a century. These patterns have been cited as evidence in support of a decline in atmospheric oxygen concentrations that may have contributed to end-Permian terrestrial extinctions. However, it is not known whether the observed differences are significant, or whether they stem from continued directional selection. If they are not significant, or if their timing does not match that proposed for the oxygen decline, support for the hypoxia-based extinction scenario would be weakened. We tested whether the internal nares and bony secondary palate, two palatal features proposed to be related to respiratory efficiency, are significantly larger in Triassic anomodonts, and whether the variation can be attributed to a long-term tendency for increase. Results based on raw data indicate that Triassic anomodonts have significantly larger secondary palates than Permian anomodonts. They also have significantly larger internal nares, but only when primitive, morphologically-divergent specimens are not considered. Although nares and palate size are correlated with stratigraphic occurrence, available data reject the hypothesis that the observed differences were the result of a long-term trend. Most of these findings are consistent with the predictions of the hypoxia scenario. However, removing the effects of body size and phylogeny causes some of the differences to break down, indicating that if selection for increased respiratory efficiency affected these characters, it was most likely not the only factor to do so. Therefore, the characters provide only weak evidence in support of the hypoxia scenario, and we recommend against their use for this purpose. Our results emphasize the need for caution when invoking presumed differences between Permian and Triassic vertebrates as support for hypoxia, or other extinction scenarios, without a rigorous study of the character(s) in question.

A bone bed in the middle part of the Javelina Formation (Maastrichtian) in Texas yielded parts of about 37 identifiable ceratopsid dinosaur bones, mostly appendicular and limb girdle elements belonging to one juvenile and two adult individuals of Torosaurus cf. utahensis. The bone bed is a lag assemblage comprising large immobile parts of the skeletons accumulated in an abandoned stream channel. In general form and proportions the postcranial bones are similar to those in Pentaceratops sternbergi and are not as robust as those in Torosaurus latus or Triceratops horridus. A few cranial elements are preserved, including parts of a parietal, squamosal, maxilla, and two dentaries. The form of the parietal fragment is comparable to that of a more nearly complete specimen of Torosaurus cf. utahensis collected nearby at about the same stratigraphic level. The bone bed material provides a basis for the first skeletal reconstruction of this enigmatic horned dinosaur. Most characters used in diagnoses of T. utahensis and T. latus are inadequate. Only the raised bar along the squamosal/parietal suture, present in T. latus; and the midline epiparietal, absent in T. latus, may discriminate the two species.

Twenty-seven graptolite species are reported from the lowermost Silurian (Rhuddanian) ascensus-acuminatus and vesiculosus biozones of Montagne Noire in southwestern France. Four species are left in open nomenclature, four are new: Normalograptus crassus, Neodiplograptus lautus, Dimorphograptus compactus and Huttagraptus solidus. The joint occurrence of Akidograptus ascensus, Parakidograptus acuminatus and Cystograptus ancestralis, recorded in the Gabian-1 section, suggests correlation of the whole succession at this site with the middle part of a combined ascensus-acuminatus Biozone. Revision of museum collections revealed that other elements that are characteristic of the ascensus-acuminatus Biozone assemblage in peri-Gondwanan Europe, such as Normalograptus trifilis, N. longifilis and Neodiplograptus lanceolatus, have been recovered from several other localities in Montagne Noire that are no longer accessible. The graptolite assemblage of the Gabian-2 section, with common Cystograptus vesiculosus, Dimorphograptus extenuatus, D. elongatus and Atavograptus atavus, belongs to the lower part of the vesiculosus Biozone, whilst the appearance of D. swanstoni and D.? physophora in the upper part of the section represents a higher, although not the uppermost, part of the biozone. This is the first record of a diverse dimorphograptid fauna within the vesiculosus Biozone in the Gondwanan part of Europe.

Echinoderm skeletal debris from the Early-Middle Cambrian boundary Micmacca Breccia of Morocco includes the oldest known holomeric columnals. the original calcite of these ossicles is coated and replaced by iron oxides, occasionally overlain by a late coating of silica, and preserves with high fidelity fine details of their three-dimensional microstructure. Irrespective of their external morphology, columnals can be divided into three groups based on the distribution of stereom microfabrics, which we suggest indicates the presence of at least three different holomeric stemmed taxa. One of these columnal types has well-developed galleried stereom perpendicular to its articulation facets, a sure sign that long, penetrative collagen bundles bound columnals together, as in modern stemmed crinoids. This columnal morphology also shows a primitive type of interlocking articulation, which we term parasymplexy and which may have helped to counter torsional stresses. the two other columnals either lacked fibrous connective tissue or had shallow, non-penetrative fibers between columnals.

We used up to 30 morphological characters to discriminate and describe species of the genus Discoporella based on complete colony specimens collected from both coasts of the Isthmus of Panama. The characters included zooidal characters and colony-level characters such as colony size and basal granule density. Species were classified by a series of multivariate cluster and linear discriminant analyses until the majority of specimens were assigned to their putative species with high confidence. In the first phase of the analyses, the colonies were grouped by ocean (Caribbean versus eastern Pacific), discriminated predominantly by colony size and basal granule density, characters that might reflect ecophenotypic responses to different conditions in primary productivity and predation between the two oceans. Further analyses of these two groups separately resulted in the discrimination of seven species. Five new species from the Caribbean (D. scutella, D. peltifera, D. bocasdeltoroensis, D. terminata and D. triangula), and two from the eastern Pacific (D. marcusorum and D. cookae). Of these, D. cookae had been identified previously as D. umbellata, a species once considered cosmopolitan, with a range spanning the Caribbean and eastern Pacific coasts of America. With the exception of one genetically defined clade represented by only two specimens, the correspondence of classification between groups discriminated morphometrically by separate step-wise multivariate analyses and those detected by a previous genetic analysis, ranged from 91% to 100%. In analyses of all specimens combined or separated by ocean, but using the total number of characters, 20% to 30% of the specimens could not be distinguished morphometrically from extremely similar sympatric species or cognate (“geminate”) species from the opposite ocean. Diversity was higher in the Caribbean compared to the eastern Pacific, which reflects a similar pattern recently described for the genus Cupuladria from the same region.

A small faunule of hypercalcified agelasiid demosponges has been recovered from outcrops of the Silurian Heceta Formation on Prince of Wales Island in southeastern Alaska. Included are abundant Girtyocoeliana epiporata (Rigby and Potter, 1986), of the Girtyocoeliidae Finks and Rigby, 2004; fragments of Alaskaspongiella laminosa n. gen. and sp., Polyplacospongia nodosa n. gen. and sp., and Monolaminospongia gigantia n. gen. and sp., of the Auriculospongiidae Termier and Termier, 1977, and Cladospongia alaskensis n. gen. and sp., Virgulaspongia uniforma n. gen. and sp., and Stipespongia laminata n. gen. and sp. of the Preperonidellidae Finks and Rigby, 2004. Also included are a few fossils of uncertain taxonomic placement, including Turbospongia biperforata n. gen. and sp., along with a small, chambered, tubular fragment and several porous tubular stems that may be additional poriferans. Some isolated octactine-based heteractinid spicules were also recovered from the etched residues.

The Amphoracrinidae Bather, 1899 is redefined, and all genera of this family are diagnosed with objective characters. Dilatocrinus Webster and Lane, 1987 and Pimlicocrinus Wright, 1943 are transferred into the Amphoracrinidae. Type specimens that define Displodocrinus Webster and Lane, 1987 and Dilatocrinus Webster and Lane, 1987 are clarified. The emphasis here is on genus definition, and comprehensive species-level systematics is not attempted. However, Amphoracrinus blairi Miller and Gurley, 1896a and Amphoracrinus jessieae Miller and Gurley, 1896b are designated nomina dubia; Sampsonocrinus sp. Webster and Lane, 1987 is reassigned to Amphoracrinus rupinus Webster and Lane, 1987; Amphoracrinus divergens var. multiramosus (Meek and Worthen, 1866) is reassigned to Dilatocrinus multiramosus (Meek and Worthen, 1866); and Sunwaptacrinus nevadensis Webster and Lane, 1987 is reassigned to Displodocrinus nevadensis (Webster and Lane, 1987).

Microscopic teeth isolated from the early Cambrian Mahto Formation, Alberta, Canada, are identified as components of a molluscan radula, the oldest on record. Tooth-rows are polystichous and lack a medial rachidian tooth-column. Anterior-posterior differences in tooth-row morphology are interpreted as ontogenetic and correspond broadly to the diversity of isolated teeth, some of which correspond closely with those of extant aplacophoran molluscs. Associated pock-marked cuticular fragments are interpreted as having supported multiple biomineralized sclerites/spines in the manner of a modern chiton girdle. On the assumption that the cuticle and radula derive from the same species, there is a strong case for identifying this fossil as an aculiferan (aplacophoran + polyplacophora) mollusc, possibly a stem-group chiton. Similarities between the Mahto radula and the feeding apparatus of Wiwaxia and Odontogriphus are shown to be superficial. Terminal wear on some of the Mahto teeth indicate that they were used to scrape hard-substrates.

The Middle and Upper Ordovician sequence of the Langkawi Islands, northwestern peninsular Malaysia, contains 20 species of conodonts belonging to 15 genera and four unidentified species, which are described and illustrated. The following four biostratigraphic zones are established for the study area: the Scolopodus striatus assemblage zone, the Periodon sp. A range zone, the Baltoniodus alobatus range zone, and the Hamarodus europaeus range zone, in ascending order. The Middle Ordovician fauna belongs to the low-latitude, warm-water Australian Province. Conodonts of the H. europaeus zone represent the HDS (Hamarodus europaeus-Dapsilodus mutatus-Scabbardella altipes) biofacies, which has been reported from the cool-water North Atlantic Faunal Region. The middle Arenigian limestones in the study area were deposited on a shallow-water shelf, whereas the late Arenigian to middle Darriwilian limestones formed in hemipelagic deeper-water conditions on an outer shelf or slope.

We describe Numbigilga ernielundeliusi new genus and species, a highly unusual marsupial represented by a partial right mandible with p2-m4 and a left upper molar from early Pliocene deposits at Bluff Downs, Queensland, northeastern Australia. Numbigilga n. gen. is characterized by a bunodont dentition with a number of striking specializations, and we refer it to Numbigilgidae new family. This taxon shares a range of dental apomorphies with various bunodont marsupial groups from the Late Cretaceous of North America and Paleogene of Gondwana. However, many of these features are most likely highly homoplastic within marsupials, reflecting convergent adaptations to a frugivorous-omnivorous diet. Other dental characters suggest possible affinities to the Australian order Peramelemorphia (bandicoots). Alternatively, Numbigilga may be a representative of an entirely new order of Australian marsupials. in the absence of more nearly complete specimens that might clarify its relationships, we refer Numbigilga to Marsupialia incertae sedis. We consider the distributions of a number of dental characters in bunodont marsupials and argue that no North American Late Cretaceous taxa can be convincingly referred to the order Polydolopimorphia. Thus, polydolopimorphians continue to be known only from the Cenozoic of Gondwana, with no fossil evidence that their initial divergences occurred in North America.

The whip scorpions (Arachnida: Uropygi) from the Pennsylvanian Coal Measures of Mazon Creek, Illinois, USA are restudied. Four Mazon Creek uropygid specimens have previously been described and a fifth is added here. Contrary to earlier reports, none of the specimens lack eyes and the sternum is similarly shaped in all the specimens. Consequently, the two younger names, Geralinura similis Petrunkevitch, 1913 and G. gigantea Petrunkevitch, 1913 are here treated as junior synonyms of G. carbonaria Scudder, 1884. The morphology of the pedipalps is more like those of some modern amblypygids, being spiniferous and non-chelate, suggesting the subchelate palps found in all Recent whip scorpions is an apomorphy not yet incorporated into the bodyplan of G. carbonaria. Indeed, subchelate palps also seem to be absent in other species of this age. For completeness, we summarise here the six Pennsylvanian whip scorpions currently recognised—including sketch reconstructions—with comments on further differences between the Paleozoic and living taxa. Geralinura Scudder, 1884 is reserved for G. carbonaria and the British species G. britannica Pocock, 1911. Prothelyphonus Friĉ, 1904 is reinstated for the Czech species P. bohemicus (Kuŝta, 1884). Parageralinura gen. nov. is proposed for the widely overlooked Dutch species P. neerlandica (Laurentiaux-Vieria and Laurentiaux, 1961) and the German species P. naufraga (Brauckmann and Koch, 1983). All the Coal Measures whip scorpion genera are treated here as plesion taxa, basal to the Thelyphonidae, which can be defined as whip scorpions with a fully subchelate pedipalp, the chelae formed from large and distinct patellar and tibial apophyses.

The specimens of Gastrochaena cuneiformis Spengler, 1783, with Spengler-written labels at the Zoologisk Museum, Copenhagen, did not come from Spengler's type locality in the Nicobar Islands, and may instead be syntypes of Chemnitz's (1788) West Indies “Pholas hians”. the identity of Gastrochaena cuneiformis as a senior synonym of Gastrochaena gigantea (Deshayes, 1830) is established on the basis of Spengler's original descriptions and illustrations, and by examination of specimens from the type locality. A neotype for G. cuneiformis is designated and illustrated, and its genus is revised to exclude Rocellaria Blainville, 1829, and Lamychaena Freneix in Freneix and Roman, 1979. Gastrochaena Spengler, 1783 is the most plesiomorphic of these three genera, as shown by its simple boring, short siphons, and diffuse, poorly differentiated anterior pedal muscles. Rocellaria evolved from a close common ancestor with Gastrochaena, and is characterized by a ventral shift and fusion of the posteroventral pallial sinus with the posteroventral pallial band, low, irregular posterior commarginal lamellae, and well defined anterior pedal retractor muscles generally supported by myophores. Lamychaena evolved from Rocellaria during the Oligocene, extending its ctenidia far posterior into the siphonal part of the boring, and, in some species, uniting its anterior pedal retractor and protractor muscles as they approach the byssus apparatus.

The Mysidiellidae are morphologically isolated among Triassic bivalves but share important characters with Late Paleozoic Ambonychioidea. Apart from a great similarity in the general shape of the shell, the most primitive mysidiellid genus Promysidiella resembles ambonychioids in the presence of a duplivincular-opisthodetic ligament system. Within the Mysidiellidae, this ligament type evolved into the transitional ligament system that characterizes Late Triassic Mysidiella. The phyletic polarity indicates that this evolution probably took place by paedomorphosis. New examinations of the shell microstructure of Mysidiella demonstrate the presence of simple prismatic and possibly foliated structures in the calcitic outer shell layer, which further supports an ambonychioid affinity. Therefore, the Mysidiellidae are removed from the Mytiloidea and assigned to the Ambonychioidea. The poorly known genus Protopis, which was originally included in the Mysidiellidae, probably had a parivincular ligament system and was hence a member of the Heteroconchia. Joannina, which was previously considered a junior synonym of Protopis, is re-established. The hinge margin of Joannina carries a well developed nymph but lacks teeth. These characters as well as its modioliform shape, anterior shell lobe, and pronounced diagonal carina link Joannina with the Late Triassic genus Healeya (Modiomorphoidea). Both taxa are herein placed in the new family Healeyidae, which differs from the morphologically similar Kalenteridae in the absence of elaborated hinge teeth. Protopis, as well as the recently described genera Leidapoconcha, Waijiaoella, and Qingyaniola, are tentatively assigned to the Healeyidae.

Five new species of the highly successful reef-building coral genus Acropora are described from Eocene locations in England and France (Acropora britannica, A. alvarezi, A. wilsonae, A. bartonensis, and A. proteacea) and additional records are given for six fossil species (A. deformis, A. anglica, A. solanderi, A. roemeri, A. lavandulina, and A. ornata), based on re-examination of material in the collections of the Natural History Museum, London. Specimens came from the Lutetian (49.0 to 41.3 Ma) of France, Bartonian (41.4 to 37.0 Ma) of England and France and Priabonian (36.0-34.2 Ma) of England. Included are the earliest record of a species with tabular or plate-like colonies similar to those in the modern “hyacinthus” species group (A. proteacea n. sp.) and the earliest records of simple hispidose forms (A. bartonensis n. sp. and A. roemeri), similar to those in the modern “florida” species group. The Priabonian material from southern England (A. brittanica n. sp. and A. anglica) shows the earliest occurrence of two sturdy species groups, the “humilis II” and “robusta” groups respectively, which now occur together on reef fronts throughout the modern Indo-Pacific. The new descriptions and records contribute to evidence that the genus diversified rapidly after its appearance in the fossil record. This diversification may have contributed to the rapid speciation and dispersal, observed in this genus during the Neogene, culminating in its extraordinary dominance of modern Indo-Pacific reefs.