Several french oceanographie expeditions have permitted to explore the bathyals lope, off the New Caledonia Island (South Western Pacifie), between 300 and 2 900 metres depth. During these recent cruises (Biocal, Biogeocal, Musorstom IV-VI, Smib, Calsub),many stalked Crinoids of different families were sampled, or observed and took in pictures with the help of the IFREMER submarine "Cyana". The New Caledonian Crinoid fauna is relatively abundant but less diversified that the fauna which was collected off the Philippines Islands (Western Pacifie). A first list of this stalked Crinoid fauna (13 taxa identified) is established in this paper with a description of three new species (Metacrinus l evii n. sp., Caledonicrinus vaubani n. sp., Proeudesicrinus lifouensis n. sp.) belonging to two new genera (Caledonicrinus n. gen., Proeudesicrinus n. gen.). Further descriptions are supplied for some taxa (Naumachocrinus hawaiiensis, Gymnocrinus, Guillecrinus).Nevertheless, New Caledonian stalked Crinoid fauna appears to be the most archaic in there cent oceans with close relationship with the fossil fauna of the Mesozoic Mesogean Sea. Many taxa have inneed very ancient affinities. Guillecrinus sp. Is the only living representative of the Paleozoic subclass Inadunata. Proisocrinus ruberrimus, Gymnocrinus richeri, Proeudesicrinus lifouensis have relationships with Jurassic adaptative radiation. Caledonicrinus vaubani is the most archaic (late Cretaceous affinities) and the shallower species of the deep-sea family Bathycrinidae. Consequently, historical biogeography and phylogeny of the Indo-Pacific stalked Crinoids through Post-Paleozoic times are discussed with regard to the origin of New Caledonia fauna.

BIOCAL, BIOGEOCAL, CALSUB, CHALCAL 2, MUSORSTOM 4, MUSORSTOM 5, MUSORSTOM 6, SMIB 3

Les calcaires à entroques correspondent à des accumulations d'ossicules d'échinodermes. Ce sont principalement des calcaires crinoïdiques, mais occasionnellement les débris d'astérides peuvent dominer. Le bon niveau d'organisation des ossicules de crinoïdes permet leur reconnaissance et leur interprétation écologique à partir de l'analyse de lames minces, ce qui étend leur intérêt à l'étude des forages. Pendant longtemps, ces animaux ont été pris pour des "fossiles vivants" réfugiés dans les profondeurs océaniques. Cela faisait obstacle à toute interprétation actualiste des calcaires à entroques. En fait, les faunes fossiles habitaient le plus fréquemment les plate-formes externes et les talus continentaux, donc des milieux similaires à ceux des faunes actuelles, mis à')part quelques périodes particulières (Roux, 1979). Ce changement d'optique ouvre la voie à l'analyse des modèles fournis par l'océan actuel en tant que références utiles à l'interprétation paléoécologique des faunes fossiles de crinoïdes (Roux, 1982 et 1987). Celles-ci enregistrent avec précision des points cruciaux de l'histoire des marges continentales. La bonne connaissance des faunes actuelles va favoriser une lecture correcte des annales paléontologiques. Elle fournira un remarquable outil pour apprécier les paléobathymétries, pour reconstituer l'évolution morphologique des marges et pour comprendre la géométrie et la localisation des réservoirs potentiels d'hydrocarbures que peuvent être les calcaires à entroques.

CALSUB

The stalk morphology of the deep-sea stalked crinoid Guillecrinus changes a lot from juvenile to adult. As a result of its unusual morphology among the extant crinoids, its taxonomic and phylogenetic affinities remain unsettled. Distinctive morphological changes characterize the various growth stages in stalked crinoids. We conduct and discuss a detailed ontogenetic analysis of the stalk of the two species (Guillecrinus neocaledonicus and G. reunionensis) of this Indo-Pacific genus, which was observed in its environment during submersible dives off New Caledonia. Analyses examined (1) morphological changes, (2) the degree of change in morphology, (3) architectural constraints, and (4) the functional constraints related to environmental factors. The relations between three levels of integration were examined: the ossicle (columnal), the stalk, and the complete individual. The changes in level of organization were estimated. The analysis reveals that the external stalk morphology of Guillecrinus goes from a pronounced xenomorphic type in juveniles, characterized by diversified columnal articulations, which provide the proximal and distal part of the stalk with a considerable degree of flexibility, to a dominant homeomorphic type in adults, characterized by columnal articulations which allow little or no movement. This ontogenetic change through a mosaic of heterochronic developments corresponds with a change in the hydrodynamic environment, from a turbulent to a laminar water flow, and from nutritional contraints. The extensive development of deep ligament fossae in adults and in the distal stalk of juveniles corresponds to a relatively low allocation of energy to the skeleton, rather than a functional necessity. Proximal columnals in juvenile Guillecrinus display characteristics of adult Hyocrinidae. Distal columnals exhibit the typical morphology observed in Bourgueticrinina. Juveniles stages of both proximal and distal columnals show a high degree of specialization (derived characters). Well-supported classifications have typically placed the Bourgueticrinina and the Hyocrinidae in two very dissimilar groups. Specific characteristics from the three very different families Bathycrinidae, Guillecrinidae and Hyocrinidae appear to be expressed either separately (Hyocrinus or Bathycrinus) or together (Guillecrinus). Their expression appears to depend on functional and environmental constraints. The transformation of columnals from juvenile to adult shows the important role of hypermorphic processes. However, no evidence of phylogenetic recapitulation was observed. Does the evidence presented here support or disprove current taxonomic interrelationships? How does morphology relate to ontogeny? Is heterochrony involved?

BIOCAL, BIOGEOCAL, CALSUB, HALIPRO 1, MD32 (REUNION)

Ontogeny of non-muscular brachial articulations in extant species of Balanocrininae, i.e., Neocrinus decorus, Neocrinus blakei and Hypalocrinus naresianus (Crinoidea, Isocrinida), is described using SEM observations. All three species share embayed synarthries and symplexies (previously only known in crinoid stalks) showing a radiating crenularium pattern in their proximal arms but differ in several important ways. Neocrinus decorus has a shallow simple symmorphy affecting symplexies, and embayed synarthries. During the latest ontogeny of embayed synarthries, irregular syzygial ridges appear on the aboral segment of the fulcral ridge. Neocrinus blakei and H. naresianus share a peculiar sharp deep symmorphy superimposed on symplexies, and synarthries with a more complete single fulcral ridge that only appears late in ontogeny. Comparison with other crinoid taxa that have more advanced arm axial synarthries shows that this ontogenetic trajectory is restricted to paedomorphic stages in extant balanocrinins. An embayed synarthry seems to be derived from the earliest developmental stage of the radiating symplexial crenularium via hypermorphosis of a single crenula. An embayed synarthry is, therefore, a symplesiomorphy based on paedomorphic stage of development; it thus lacks phylogenetic significance, and should be abandoned as a major character in the classification of Isocrinida. The most advanced brachial synarthries shared by distant crinoid taxa mainly represent a homoplasy under morphofunctional constraints. However, they could result from different ontogenetic trajectories, which have only rarely been investigated. Another distinctive articulation feature, the peculiar sharp deep symmorphy observed in extant balanocrinins is a derived character known in a few fossil isocrinids beginning in the Middle Jurassic. We question its phylogenetic significance and suggest that it has developed repeatedly via iterative evolution in Isocrinida. Therefore, because these three extant balanocrinin species share the same ontogenetic trajectories of arm and stalk ligamentary articulations, and differ only in various states of heterochronic development of a few characters, we treat them as belonging to the same genus. We, therefore, consider Hypalocrinus as a junior synonym of the genus Neocrinus.

Restreint, BIOCAL, KARUBENTHOS 2, MUSORSTOM 1, MUSORSTOM 2, VAUBAN 1978-1979

Previous molecular phylogenetic reconstructions have highlighted frequent convergences and iterations of external morphological characters during the evolution of crinoids. Classifications of extant and fossil crinoids based on these characters need to be thoroughly revised. This is particularly the case for the Isocrinida. We propose a new classification of this order based on molecular data and ontogenetic analysis of the derived characters displayed on ossicles and their articulations. The argument is strengthened by the discovery and description of a species belonging to a new genus (Panglaocrinus isseliformis gen. nov., sp. nov.) closely related to the genus Isselicrinus, which was abundant and widespread during the Late Cretaceous and Eocene. Extant Isocrinida appear to be divided into two major lineages that we interpret as two distinct families: Isocrinidae and Balanocrinidae. Isocrinidae are represented by the subfamily Metacrininae (genera Metacrinus and Saracrinus), while Balanocrinidae comprise four subfamilies: Balanocrininae (Neocrinus), Diplocrininae (Endoxocrinus and Teliocrinus), Isselicrininae (Panglaocrinus), and Proisocrininae (Proisocrinus). In the absence of molecular data, the genus Cenocrinus has not been attributed to any subfamily, but its close relationship to Balanocrinidae is suggested. Possible relationships between Mesozoic and modern taxa are discussed, although descriptions of arms in the palaeontological record are often important details.

KANADEEP, KARUBENTHOS 2, MIRIKY, NORFOLK 1, PANGLAO 2005, SALOMONBOA 3

The stalked crinoid fauna off New Caledonia (S.W. Pacific): a bathyal relic from the Mesogean Sea. During 1985, MUSORSTOM V and BIOCAL cruises were conducted on the bathyal slope off New Caledonia. They revealed a benthic fauna abunding in stalked crinoids. The following living species are listed : Saracrinus nobilis, Metacrinus aff. Serratus, Diplocrinus alternicirrus, Proisocrinus ruberrimus, Guillecrinus sp., Bathycrinus sp. And Zeuctocrinus sp. One additional species is only known from many brachials which are well-preserved into a bioclatic carbonate sediment: Gymnocrinus sp. Four taxa have very ancient affinities. Guillecrinus sp. is the only living representative of the paleozoic subclass Inadunata. P. ruberrinmus and Gymnocrinus have relationships with jurassic adaptative radiation. Zeuctocrinus sp. is the most archaic (late Cretaceous affinities) and the shallower species of the deep-sea family Bathycrinidae. The stalked crinoid fauna of New Caledonia appears to be the most archaic in recent oceans with close relationships with the fossil fauna of the mesozoic Mesogean Sea. Consequently, historical biogeography of the Indo-Pacific stalked crinoids through Post-Paleozoic times is discussed with regard to the origin of New Caledonia fauna.

BIOCAL, MUSORSTOM 5

A recent representative (Echinodermata) of the jurassic family Hemicrinidae: Gymnocrinusricheri nov. sp. from the bathyal slope, off the New Caledonia Island (South Western Pacific) Gymnocrinus richeri nov. sp. is a new stalked crinoid (Crinoidea) with a short stem and a very asymmetrical crown, a feature which was not yet observed in the recent fauna. The peculiar morphology of the brachials suggests an attribution to the jurassic genus Gymnocrinus which was only known from a few disassociated ossicles. The complete specimens permit to confirm the close affinities between Cyrtocrinus, Gymnocrinus and Hemicrinus, three genera which may be gathered into the family Hemicrinidae (Jurassic-Lower Cretaceous). That strange crinoid was discovered from the epibathyal slope, off New Caledonia at a depth of 470m.

BIOCAL, BIOGEOCAL, CHALCAL 2, SMIB 3

Echinodermata : Pentacrinidae crinoids procured by the MUSORSTOM 2 and CORINDON 2 expeditions. During MUSORSTOM 2 and CORINDON 2 expeditions (West Philippines for the former, Makassar channel for the latter) many stalked crinoids of the family Pentacrinidae were sampled. They are more diversified and comparatively more abundant than the fauna which was collected during the MUSORSTOM 1 expedition. The samplings come from depths between 170 and 970 meters. Four genera are represented : Diplocrinus, Hypalocrinus, Metacrinus and Saracrinus. Detailed descriptions of the ten following species are given : D. alternicirrus, D. sibogae, H. naresianus, M. interruptus, M. musorstomae, M. nodosus, M. serratus, M. wyvillii, S. angulatus and S. superbus. For each specimen, data on morphological features, biometry, arm branching and ossicle articulations are given. Stalk and arm joints were observed under, scanning electron microscope, especially stem synostosis with regard to their importance for taxonorny. Sometimes, some peculiar growth patterns appear to be a consequence of fast regeneration. Such features are illustrated by the proximal part of the stalk of a few specimens belonging to S. angulatus and M. wyvillii. As numerous individuals of each species were collected, it was possible to study the variation of crown and stem characters. The morphological features and their variability seem to be depth related. The bathymetrical distribution of Pentacrinidae in the Western Pacific province is examined and discussed. Intraspecific polymorphism with regard to external stem morphology and arm organization is suggested for a few species of this biogeographical province. The number of recognized species might be reduced because sorne of them might be interpreted as a consequence of ecophenotypic or geographical variations. So, in the subfamily Metacrininae, S. acutus, S. cingulatus, S. batheri and S. suluensis might be synonyms of S. angulatus. It is also suggested that S. nobilis (S. varians and S. superbus included) shows intraspecific polymorphism or large morphological variations through a wide depth range. For the genus Metacrinus, simplification of the species number is more difficult to effect because each phenotype frequently seems to be clearly distinguished. Nevertheless, M. interruptus and M. musorstomae are very similar and the latter might be an ecophenotype of the former. M. costatus and M. serratus are also two species with large morphological affinities; the first species seems to be a morph living in deeper environment. M. rotundus might include M. multisegmentatus and M. cyaneus. Stem and arm morphological variations linked to bathymetry are also interpreted in terms of adaptative strategy (r and K selection). For pentacrinids, two unstability limits are suggested from their depth repartition : the upper boundary (about 100 meters) couId correspond to hydrodynamic vulnerability threshold, the lower (about 1500-2500 meters) to the trophic vulnerability limit, the food becoming too scarce. In one genus, species living close to these two unstability limits have a very important morphological variability (for example : M. rotundus, M. wyvillii). In the Western Pacifie, the most stable depth range for these crinoids could be situated between 300 and 600 meters with development of K strategy (M. serratus). Biogeographical repartition of these species is analysed from such a point ofview. Typical r strategy species (M. rotundus, M. wyvillii, S. nobilis, H. naresianus) have the largest geographical repartition. S. nobilis seems to be the species with the most eurybathic pattern with polymorphie characters. Taxonomy, paleoecology and biostratigraphy of fossil stalked crinoids must be reconsidered and discussed as a consequence of these results.

CORINDON 2, MUSORSTOM 1, MUSORSTOM 2

Several French oceanographic expeditions have enhanced the exploration of the bathyal slope, off New Caledonia (South Western Pacific). During these recent cruises (BIOCAL, BIOGEOCAL, MUSORSTOM 4-6, CHALCAL 2, SMIB 3-4, CALSUB), many stalked Crinoids of different orders and suborders (Isocrinida Pentacrinidae, Millericrinina, Bourgueticrinina, Cyrtocrinida and incertae sedis) have been sampled, or observed and photographed with the help of the IFREMER submersible « Cyana ». The samples come from depths between 230 and 3700 meters but the most numerous faunas have been gathered in the 200-600 meters bathymetrical interval. Fourteen genera are represented in the crinoid fauna of New Caledonia which have never been inventoried or illustrated : Metacrinus, Saracrinus, Diplocrinus, Proisocrinus, Caledonicrinus, Porphyrocrinus, Naumachocrinus, Bathycrinus, Gymnocrinus, Holopus, Proeudesicrinus, Thalassocrinus, Hyocrinus, Guillecrinus. Some of these are only known from the New Caledonian bathyal slope ( Caledonicrinus, Proeudesicrinus). Until now the genus Holopus was known only from the Tropical Western Atlantic Ocean and the genus Guillecrinus was known only from the bathyal slope of the Indian Ocean. Detailed descriptions of sixteen species are given. Three taxa are illustrated for the first time : Holopus alidis sp. Nov., Guillecrinus neocaledonicus sp. Nov. And Hyocrinus cyanae sp. Nov. Further descriptions are supplied for some species (Naumachocrinus hawaiiensis, Gymnocrinus richeri) and for three recently described new taxa from New Caledonia off shore (Metacrinus levii, Caledonicrinus vauhani, Proeudesicrinus lifouensis). The New Caledonian Pentacrinid fauna is abundant but ess diverse than the rich fauna which has been collected off the Philippines (Western Pacific). Only four species are known from New Caledonia : Metacrinus levii. Metacrinus musorstomae, Saracrinus nohilis, Diplocrinus allernicirrus. Cyrtocrinida are very numerous between 300-500 meters, especially Gymnocrinus richeri and Holopus alidis. This bathymetrical interval is also occupied by Caledonicrinus vauhani. The shallower species of the deep-sea family Bathycrinidae and by Porphyrocrinus. Proisocrinus ruberrimus. Naumachocrinus hawaiiensis. Bathycrinus. Hyocrinidac with Hyocrinus, Thalassocrinus and the incertae sedis Guillecrinus neocaledonicus are living in the deep sea (below 1000 meters). Nevertheless, the New Caledonian stalked Crinoid fauna appears to be the most archaic in the recent oceans showing a close relationship with the fossil fauna of the Mesozoic Mesogean Sea. Many taxa have indeed very ancient affinities : Guillecrinus is the only living representative of the Paleozoic subclass Inadunata. Proisocrinus ruberrimus. Gymnocrinus richeri and Proeudesicrinus lifouensis have relationships with Jurassic adaptative radiation, Caledonicrinus vauhani is the most archaic (late Cretaceous affinities) species of the deep-sea family Bathycrinidae. Consequently, historical biogeography and phylogeny of the Indo-Pacific stalked Crinoids, through Post-Paleozoic times, are discussed with regard on the origin of New Caledonia fauna.

BIOCAL, BIOGEOCAL, CALSUB, CHALCAL 2, CORAIL 2, Restreint, MUSORSTOM 1, MUSORSTOM 2, MUSORSTOM 3, MUSORSTOM 4, MUSORSTOM 5, MUSORSTOM 6, SMIB 3, SMIB 4, VAUBAN 1978-1979, VOLSMAR

ATIMO VATAE, BIOPAPUA, BORDAU 2, MIRIKY, NORFOLK 1, PANGLAO 2005, SALOMON 1, SALOMON 2, SALOMONBOA 3

CALSUB

Holopodidae is one of the three families in the order Cyrtocrinida that have extant representatives. Two genera have been described, Holopus and Cyathidium, both with extant species and fossil representatives dating back to the Cenomanian (Late Cretaceous). Eocene (Lutetian) holopodid material from the Chiampo Valley (north-eastern Italy) has recently been attributed to H. spileccense, the type-stratum and locality of which is the Ypresian of the nearby Spilecco Hill, and to C. gastaldii known from the Miocene of Turin. Here we describe new holopodid material from both Chiampo and Spilecco, comprising cups and numerous brachials. Using qualitative and quantitative characters, the Chiampo holopodids are deemed to be assignable to two new species: Holopus fabianii sp. nov. and Cyathidium chiampoensis sp. nov. The Chiampo material includes the first records of keystone plates and distal brachials for an extinct species of Holopus. New proximal brachials are described for H. spileccense but no keystone plate was found for this species. Access to the holotype of Cyathidium gastaldii has enabled a description of the specimen and a first diagnosis for the species. Formerly described cups, as well as a newly collected one, are attributed to Cyathidium sp. due to the lack of diagnostic characters. The affinities between H. spileccense, H. fabianii sp. nov. and the extant Indo-Pacific H. alidis suggest that these three species might share a common Gondwanan origin.

BORDAU 2, KARUBENTHOS 2, MUSORSTOM 6

L'observation directe, à l'aide de la soucoupe plongeante CYANA, des pentes bathyales néocalédoniennes révèle l'ampleur des phénomènes d'érosion (cf. Vanney, ce volume) qui entaillent le substratum géologique. Pour la première fois nous avons eu accès aux affleurements. Bien que l'échantillonnage de roches soit très réduit, une description même sommaire des unités géologiques rencontrées et de leurs relations est utile compte tenu de l'état actuel des connaissances. Les produits de l'érosion vont s'accumuler dans le bassin des Loyauté. Ils s'ajoutent aux apports planctoniques, aux éléments biogènes autochtones ou subautochtones, et aux sédiments issus de la plateforme pour constituer un mélange de matériaux de nature, d'origine et d'âge variés (cf. Lambert et al., ce volume, Fig. 1). Nous tenterons ici de cerner ces différences d'origine et d'apprécier leur importance. Nous décrirons aussi quelques modes de transport vers le bassin.

BIOCAL, BIOGEOCAL, CALSUB

The MUSORSTOM Expedition has gathered stalked Crinoids (family: Isocrinidae) belonging to the two genera Metacrinus and Saracrinus. Four species are described here, M. musorstomae is a new one. The validity of the genus Saracrinus is confirmed. The organization of the skeleton is analysed. It shows some aspects of the evolution of the Isocrinidae. Metacrinus and Saracrinus present several primitive characteristics. The study of the MUSORSTOM specimens permits a review of our knowledge about recent and fossil Isocrinidae. The recent representatives of this family are more hightly diversified than the fossil one. It becomes apparent that Metacrinus and Saracrinus are two young taxa at the outset of their adaptative radiation.

MUSORSTOM 1

During the CALSUB cruise, bathyal environments were explored off the New Caledonia corallian platfdrms (southwestern Pacific). Green algae were observed down to a depth of 1 IO m, and red algae down to 145 m. Algal blocks, pebbles and sands contribute to sedimentation to a depth of 400 m and beyond, and are mixed with autochthonous fossils and bioclasts produced by bathyal benthos. Epibathyal fauna suggests similarities with Jurassic and Cretaceous fauna of Tethyan margins (Nautilus, pleurotomarian gastropods, sponges, brachiopods and crinoids…). Richness and abundance of the benthos are the highest in areas where currents are frequent between 300 m and 700 m (sometimes 10 to 20 terebratulid brachiopods per m2 or dense populations of echinoderms entirely covering the substrate). Such currents induce erosion of' substrate or bioclastic accumulations. Biocorrosion seems to be very active in erosion processes, especially on hard grounds. Burrows and traces show the importance of sediment bioturbation on slopes. The occurrence on bathyal slope of some taphonomic processes previously known from geological series and generally considered as closely related lo shallow-water environments should be emphasized.

CALSUB

L'exploration de la faune profonde de NouvelleCalédonie a débuté par des campagnes d'essai de 1977 à 1979 sur des fonds de 200 m à 1000 m au large de la Grande Terre, de l'île des Pins et des îles Loyauté (Intès, 1978). A partir de 1985, elle s'est élargie et intensifiée avec les campagnes MUSORSTOM 4 à 6 et CHALCAL (Richer de Forges, 1990), BIOCAL, BIOGEOCAL et SMIB, complétées par des observations directes à l'aide de la soucoupe plongeante Cyana lors de la campagne CALSUB. Nous ne donnerons ici que les grands traits de l'étagement de la macrofaune et de la mégafaune benthique en insistant sur les observations directes insitu lors de la campagne CALSUB et sur la liaison avec les caractères du milieu.

CALSUB

La Nouvelle-Calédonie s'étend entre 20 et 23° S selon une orientation NW-SE (Fig. 1 et 2). Elle correspond à la partie émergée du segment nord de la ride de Norfolk et appartient à la plaque australienne qui, vers l'Est, plonge sous la plaque pacifique au niveau de la fosse des Nouvelles-Hébrides en induisant un bombement de la lithosphère à l'origine de l'émersion des Iles Loyauté. La Grande Terre, prolongée au SE par l'Ile des Pins, est bordée au SW par le bassin de Nouvelle-Calédonie, d'une profondeur comprise entre 3000 et 3500 m, et au NE par le bassin des Loyauté dont la profondeur, d'environ 2000 m au SE, s’accroît jusqu'à plus de 3000 m au NW . Sa plateforme externe est limitée par un récif barrière isolant un lagon de largeur variable. Les trois principales îles de l'archipel des Loyauté sont alignées parallèlement à la Grande Terre : au SE Maré, puis Lifou et au NW Uvéa.

BIOCAL, BIOGEOCAL, CALSUB

The CALSUB cruise took place in 1989 off the coast of New Caledonia. The diving saucer Cyana enabled the exploration of the bathyal environment from the edge of the coral platform down to a depth of 3000 m. In this paper an account is given of how the study was carried out, along with the material gathered during the course of the study which may be consulted (in particular the photographs and the videos). The various sectors explored, and the principal observations made are discussed. Apart from the wide diversity of ecological niches observed, what makes this sector of the Pacific Ocean original, is the existence of bathyal benthic communities rich in "living fossils", giving us an idea of the fauna which populated the Tethys Ocean during the Mesozoic. The use of the Cyana diving saucer allowed direct observation of the nature of the sea beds and the associated fauna, in particular of rocky slabs, and environments affected by deep currents, where fields of hydraulic bioclastic dunes develop along fault scarps covered with dense populations dominated by Echinoderms. We were able to establish the bathymetrical distribution of the bathyal populations.

CALSUB

Two new species of hyocrinid stalked crinoids from deep waters of the Pacific Ocean are described. Thalassocrinus alvinae n. sp. was collected on the Gorda Ridge and represents the first record of the genus from the Eastern Pacific. Thalassocrinus mironovi n. sp. was found on the bathyal slope off New Caledonia (southwester Pacific). A short revision of the genus Thalassocrinus is given and affinities between the four known species are discussed.

CALSUB

CALSUB

The extant crinoid fauna results from more than 485 Myr of evolution (from Early Ordovician). Detailed morphological studies on extant crinoids document large intraspecific variations, strong changes through ontogeny with various mosaics of heterochronic development, and adaptive characters which depend on environment, mainly hydrodynamics and food supply. The importance of paedomorphy and morphological convergences (homoplasies) in crinoid evolution is confirmed by studies using DNA markers, and makes difficult the use of cladistic methods of phylogenetic reconstructions. Many clades of extant crinoids based on external skeleton morphology are polyphyletic. Using the hyocrinids and a recent extensive molecular phylogeny of the extant crinoids, we show that the molecular approach, when coupled with detailed ontogenetic analyses on a large sample of specimens and taxa, may help understand the evolutionnary trends within a given group of organisms. Purely molecular or phenotypic analyses produce contrasting results because these analyses work at scales that are separated by a strong gap. We propose a deep reappraisal of the relationships between extant and fossil taxa using the concept of onto phylogeny which rejects the classical separation between ontogeny and phylogeny and argues that natural selection acts at every level of integration of the organism from DNA, cells, tissues, to the individuals and populations.

ATIMO VATAE, BIOPAPUA, BORDAU 2, MIRIKY, NORFOLK 1, PANGLAO 2005, SALOMON 1, SALOMON 2, SALOMONBOA 3

Tormocrinus, have yielded arguments for a revision of the taxonomy and interrelationships of extant and fossil taxa in the family Bourgueticrinidae. Conocrinus (= Tormocrinus), as here interpreted, includes six Eocene species: C. thorenti, C. archiaci, C. cahuzaci n. sp., C. duperrieri, C. cf. suessi and C. veronensis. Numerous extinct species previously attributed to Conocrinus or Democrinus are here transferred to two new genera which first occur in the lower Paleocene: Paraconocrinus n. gen. (type species: P. pyriformis) and Pseudoconocrinus n. gen. (type species: P. doncieuxi). Aboral cups from the “Rocher du Goulet” (Biarritz) are here assigned to Paraconocrinus pellati n. gen., n. sp., while the Danian species Democrinus maximus is transferred to Pseudoconocrinus n. gen. A new genus, Cherbonniericrinus, is created to accommodate a single extant species, Ch. cherbonnieri, previously attributed to Conocrinus, while the extant genus Rhizocrinus, closely related to Democrinus, is resurrected. Conocrinus and closely related genera are derived from a bourgueticrinine lineage the first record of which is from the lower Campanian, with the new genus Carstenicrinus. These are all attributed to the family Rhizocrinidae which is here considered distinct from the family Bourgueticrinidae. Rhizocrinids rapidly diversified immediately after the Cretaceous-Paleogene (K/Pg) event. Cretaceous taxa previously placed within the family Bourgueticrinidae now appear to be polyphyletic. Some of them do not belong to Bourgueticrinina, such as those of the Dunnicrinus lineage. Interrelationships of Rhizocrinidae and other post-Palaeozoic families having a xenomorphic stalk are discussed.

CALSUB, SALOMON 1

CALSUB

Une morphologie de fonds sous-marins bathyaux comportant des indurations liées à des dépôts ferro-manganésifères inclus dans des sédiments hémipélagiques peu ou pas cimentés a été découverte sur une ride volcanique tertiaire au large de la Nouvelle-Calédonie (SW Pacifique). Elle semble être en relation avec des circulations hydrothermales au travers de la couverture sédimentaire pendant l'activité volcanique miocène de la ride des Loyauté. (Résumé d'auteur)

CALSUB