KARUBAR

Numerous recent oceanographic expeditions have provided much new data on the morphology and ecology of stalked crinoids. Of the many taxa that have been sampled, the order Cyrtocrinida represents one of the most peculiar, as a majority of its species are archaic, with Mesozoic afffinities. In this study, we examine in detail the morphology of several members of the cyrtocrinid family Holopodidae, provide biometric analyses, and amend the diagnoses of the family and one of its constituent genera, Cyathidium. The family Holopodidae consists of only two genera, Cyathidium and Holopus. As the latter genus has been previously studied in some detail, here we present only an abbreviated description of this taxon; the study focuses primarily on Cyathidium. Of the four Cyathidium species examined, one, C. pourtalesi, is a newly described extant species, while another, C. senessei, is a fossil species. All specimens were examined using optical and scanning electron microscopy; because of their taxonomic importance, special attention was given to the morphology and biometry of the dorsal cup, and the arm and pinnular joints. Availability of Cyathidium specimens in different ontogenic stages, has allowed us to conclude that heterochronic processes played an important role in the evolution of this genus. Data on ontogenic stages of Cyathidium made it possible to make a comparison between different species within this genus, between Cyathidium and Holopus and between the Holopodidae and the remaining Cyrtocrinids.

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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.

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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

We describe the first molecular and morphological analysis of extant crinoid high-level inter-relationships. Nuclear and mitochondrial gene sequences and a cladistically coded matrix of 30 morphological characters are presented, and analysed by phylogenetic methods. The molecular data were compiled from concatenated nuclear-encoded 18S rDNA, internal transcribed spacer 1, 5.8S rDNA, and internal transcribed spacer 2, together with part of mitochondrial 16S rDNA, and comprised 3,593 sites, of which 313 were parsimony-informative. The molecular and morphological analyses include data from the bourgueticrinid Bathycrinus; the antedonid comatulids Dorometra and Florometra; the cyrtocrinids Cyathidium, Gymnocrinus, and Holopus; the isocrinids Endoxocrinus, and two species of Metacrinus; as well as from Guillecrinus and Caledonicrinus, whose ordinal relationships are uncertain, together with morphological data from Proisocrinus. Because the molecular data include indel-rich regions, special attention was given to alignment procedure, and it was found that relatively low, gene-specific, gap penalties gave alignments from which congruent phylogenetic information was obtained from both well-aligned, indel-poor and potentially misaligned, indel-rich regions. The different sequence data partitions also gave essentially congruent results. The overall direction of evolution in the gene trees remains uncertain: an asteroid outgroup places the root on the branch adjacent to the slowly evolving isocrinids (consistent with palaeontological order of first appearances), but maximum likelihood analysis with a molecular clock places it elsewhere. Despite lineage-specific rate differences, the clock model was not excluded by a likelihood ratio test. Morphological analyses were unrooted. All analyses identified three clades, two of them generally well-supported. One well-supported clade (BCG) unites Bathycrinus and Guillecrinus with the representative (chimaeric) comatulid in a derived position, suggesting that comatulids originated from a sessile, stalked ancestor. In this connection it is noted that because the comatulid centrodorsal ossicle originates ontogenetically from the column, it is not strictly correct to describe comatulids as "unstalked" crinoids. A second, uniformly well-supported clade contains members of the Isocrinida, while the third clade contains Gymnocrinus, a well-established member of the Cyrtocrinida, together with the problematic taxon Caledonicrinus, currently classified as a bourgueticrinid. Another cyrtocrinid, Holopus, joins this clade with only weak molecular, but strong morphological support. In one morphological analysis Proisocrinus is weakly attached to the isocrinid clade. Only an unusual, divergent 18S rDNA sequence was obtained from the morphologically strange cyrtocrinid Cyathidium. Although not analysed in detail, features of this sequence suggested that it may be a PCR artefact, so that the apparently basal position of this taxon requires confirmation. If not an artefact, Cyathidium either diverged from the crinoid stem much earlier than has been recognised hitherto (i.e., it may be a Palaeozoic relic), or it has an atypically high rate of molecular evolution.

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TAIWAN 2000

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

Sibogacrinus anomalus is a feather star species of which only one specimen was known until recently. It has been historically attributed to Atelecrinidae from which it was excluded and later reintroduced by C. Messing. A second specimen has recently been collected off Papua New Guinea. Here, we compare observations based on X-ray tomography for S. anomalus and eight specimens sampled from the genera Atelecrinus, Paratelecrinus and Adelatelecrinus. In addition to the external morphological characters from the literature, we describe the articulations between basals, radials and the centrodorsal, as well as characters of the axillary brachials. Another difference concerns the canals for the aboral nervous system within the radial. Comparison of these characters between Sibogacrinus anomalus and representatives of the genera Atelecrinus, Adelatelecrinus and Paratelecrinus suggests that Sibogacrinus does not belong to the family Atelecrinidae.

BIOPAPUA, BORDAU 2, KARUBENTHOS 2, MIRIKY, SALOMON 1, SALOMON 2

Fifteen species of comatulid crinoids in eleven genera and four families collected in 180-800 m by the joint French-Indonesian KARUBAR Expedition to the Kai and Tanimbar Islands, Indonesia (October 1991), are described in detail. The specimens represent the most important collection of bathyal comatulids from the East Indies in the second half of the twentieth century. The material described herein comprises four species of Comasteridae, one Asterometridae, two Calometridae and eight Thalassometridae. One species of calometrid (Neometra xenocladia sp. nov.) is described as new. FiveTpecies are recorded for the first dme since they were originally collected. Four thalassometrids (Aglaometra valida, Oceanometra annandalei, Cosmiometra philippinensis and Stenometra cristata) together account for 75% of identified specimens, reflecting this family's importance to the outer shelf-upper bathyal comatulid fauna of the tropical Indo-Western Pacific. The substantial amount of material of several species, notably A. valida and O. annandalei, permits a better understanding of morphological variability than previously. Statistical analyses of several sipposedly diagnostic characteristics including aspects of calyx form and number of cirri, reveal substantial variation. We place several taxa in sinonymy as a result. SIM studies of different ossicles have been made for the first time for A. valida and O. annandalei. The preliminary results show that great morphological differences exist within the family. Three species (Stiremetra breviradia, Palaeocomatella hiwia and Cosmonuetra iole) are recorded from Indonesian waters for the first time. Moreover, most of the KARUBAR comatulids represent geographical and bathymetrical range extensions.

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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