Various cnidarians, sponges, and other fossils / 21st December 2016

CORONADO I., FERNANDEZ-MARTINEZ E., RODRIGUEZ S., TOURNEUR F. 2015. Reconstructing a Carboniferous inferred coral-alcyonarian association using a biomineralogical aproach. Geobiology. DOI: 10.1111/gbi.12133, 1-17.
The taxonomic assignation and ecological implications of the genus Syringoalcyon Termier & Termier, 1945 have been a palaeontological problem for a long time. Carboniferous material from Morocco and Spain has been studied using a biomineralogical approach by means of petrographic microscopy, SEM, AFM, EMPA and CIP microscopy analysis. Detailed morphological, structural, chemical composition and crystallographic data enable a deeper understanding of the nature of Syringoalcyon. The coral walls and the so-called epithecal scales exhibit conspicuous differences in microstructure (lamellae and holacanthine fibres in the coral vs. single crystal in scales), nanostructure (pill-shaped vs. granule-shaped nanocrystals), composition (LMC vs. HMC) and crystallographic orientation. The results of these analyses imply that Syringoalcyon is an association between the tabulate coral Syringopora and an epibiont. They also suggest that the epibiont was an alcyonarian (a rare occurrence in the fossil record) that was attached to the syringoporoid. This work highlights the utility of the biomineralizational approaches for solving palaeontological problems, such as systematic affinities, and for advancing knowledge of the evolution of biocrystallization processes. [original abstract; Rodriguez]

CORONADO I., PEREZ-HUERTA A., RODRIGUEZ S. 2016. Analogous biomineralization processes between the fossil coral Calceola sandalina (Rugosa, Devonian) and other Recent and fossil cnidarians. Journal of structural Biology 196: 173-186. http://dx.doi.org/10.1016/j.jsb.2016.06.013
The current work represents a distinctive study about the biomineral properties of exceptionally good preserved skeletons of Calceola sandalina from the Middle Devonian of Couvin (Belgium), Smara (Morocco) and (Algeria) and their relation in the evolution of biomineralization of cnidarians. Structural and crystallographic analyses of the skeletons have been done by petrographic microscopy, electron scanning microscopy (SEM), atomic force microscopy (AFM), electron backscatter diffraction (EBSD), computer-integrated polarization microscopy (CIP) and electron microprobe analysis (EMPA). Calceola skeletons have many similarities with other cnidarians, mainly with other Palaeozoic corals as Syringoporicae: The microcrystals are composed of co-oriented nanocrystals that remind to mesocrystals, suggesting a biocrystallization process by particle attachment (CPA). The relationship between the nanocrystals and microcrystals suggest a growth mode similar to mineral bridges. A similar model was described for Syringoporicae corals (Tabulata) and it is similar to the coordinated-growth mode described in scleractinians and molluscs. Calceola skeletons show also a convergent structure with scleractinian forming Rapid Accretion Deposits (RAD), which share some structural and chemical properties. These evidences suggest analogous processes of biomineralization derived from a stem group of cnidarians. The results of this paper highlight the value of biomineralization studies in fossil organisms to understand the evolution of biomineralization mechanism through Phanerozoic. [original abstract; Rodriguez]

DONG Xi-ping, VARGAS K., CUNNINGHAM J. A., ZHANG Huaqiao, LIU Teng, CHEN Fang, LIU Jianbo, BENGTSON S., DONOGHUE P. C. J. 2016. Developmental biology of the early Cambrian cnidarian Olivooides. Palaeontology 59, 3: 387-407.
[keywords: development; embryo; Cnidaria; Scyphozoa; Kuanchuanpu; Cambrian]
Fossilized embryos afford direct insight into the pattern of development in extinct organisms, providing unique tests of hypotheses of developmental evolution based in comparative embryology. However, these fossils can only be effective in this role if their embryology and phylogenetic affinities are well constrained. We elucidate and interpret the development of Olivooides from embryonic and adult stages and use these data to discriminate among competing interpretations of their anatomy and affinity. The embryology of Olivooides is principally characterized by the development of an ornamented periderm that initially forms externally and is subsequently formed internally, released at the aperture, facilitating the direct development of the embryo into an adult theca. Internal anatomy is known only from embryonic stages, revealing two internal tissue layers, the innermost of which is developed into three transversally arranged walls that partly divide the lumen into an abapertural region, interpreted as the gut of a polyp, and an adapertural region that includes structures that resemble the peridermal teeth of coronate scyphozoans. The anatomy and pattern of development exhibited by Olivooides appears common to the other known genus of olivooid, Quadrapyrgites, which differs in its tetraradial, as opposed to pentaradial symmetry. We reject previous interpretations of the olivooids as cycloneuralians, principally on the grounds that they lack a through gut and introvert, in embryo and adult. Instead we consider the affinities of the olivooids among medusozoan cnidarians; our phylogenetic analysis supports their classification as total-group Coronata, within crown-Scyphozoa. Olivooides and Quadrapyrgites evidence a broader range of life history strategies and bodyplan symmetry than is otherwise commonly represented in extant Scyphozoa specifically, and Cnidaria more generally. [original abstract; Wrzolek]

FORD R. C., Van ITEN H., CLARK G. R. 2016. Microstructure and composition of the periderm of conulariids. Journal of paleontology 90, 3: 389-399.
Transmitted light and scanning electron imaging of sectioned specimens of Conularia and Paraconularia, prepared using HCl etching and critical point drying, revealed that their periderm is composed of extremely thin (approximately 0.5-3 µm), variably distinct microlamellae that are alternately organic poor and organic rich. Organic-rich microlamellae are cross-connected by slender strands of organic matter originally embedded in calcium phosphate, which in etched specimens has been dissolved. Microlamellae may be organized in thicker (approximately 5-75 µm) layers, or macrolamellae, that vary in color and organic matter content, possibly owing to changes in the ambient paleoenvironment. Thickening of the periderm to form transverse ribs and internal carinae was achieved through gradual thickening of individual microlamellae. In the core of the transverse ribs and internal carinae the distinction between organic-rich and organic-poor microlamellae may be reduced, owing to organic material becoming dominant over (former) mineral matter or vice versa. Combined with observations of plicated aperture closure in thin-walled conulariids, including Archaeoconularia slateri (Reed, 1933) (Upper Ordovician, Scotland) showing smooth folding of midline carinae through angles greater than 90°, these results suggest a structure and original flexibility in the organic-rich biocomposite forming the conulariid periderm that supports its homology to the chitinous lamellar periderm of coronate scyphozoans. [original abstract; Wrzolek]

HAN Jian, HU Shixue, CARTWRIGHT P., ZHAO Fangchen, OU Qiang, KUBOTA Shin, WANG Xing, YANG Xiaoguang 2016. The earliest pelagic jellyfish with rhopalia from Cambrian Chengjiang Lagerstatte. Palaeogeography, Palaeoclimatology, Palaeoecology 449: 166-173 (1 May 2016).
[keywords: Pelagic; Medusozoa; Cambrian; Chengjiang; Medusa; Rhopalium]
Modern cnidarian medusae generally show a triphasic life cycle with the succession of a larva, a sessile polyp and a pelagic medusa stage. The debate around the metagenesis of sessile polyps into pelagic medusae has lasted for more than 100 years. When pelagic forms originated is not clear. Hitherto, the earliest crown-group medusae have been found at Cambrian Stage 5 (traditional Middle Cambrian, 509 Ma) in Utah, while diverse stem-group medusozoans were found in the basal Cambrian Fortunian Stage. No reliable medusae have been found from Cambrian Series 2 Stage 3 (ca. 521 Ma), although the marine benthic community teemed with many phyla of bilaterians, sponges and ctenophores. Here, we reinterpret Yunnanoascus haikouensis Hu et al. (2007), originally described as a ctenophore, as a pelagic, predatory, crown-group medusozoan, based on the presence of rhopalia, possible radial canals and marginal tentacles. The medusae were a predatory member of the pelagic food web at the middle level of the ocean at Cambrian Stage 3. [original abstract; Wrzolek]

HAN Jian, HU Shixue, CARTWRIGHT P., ZHAO Fangchen, OU Qiang, KUBOTA Shin, WANG Xing, YANG Xiaoguang 2016. Erratum to "The earliest pelagic jellyfish with rhopalia from Cambrian Chengjiang Lagerstätte" [Palaeogeography, Palaeoclimatology, Palaeoecology 449 (2016) 166-173]. Palaeogeography, Palaeoclimatology, Palaeoecology 451, 1 June 2016, p. 227. http://dx.doi.org/10.1016/j.palaeo.2016.04.001
[corrected affiliations of the authors]

KOLODZIEJ B. 2015. Corals of the Stramberg-type limestone from Poland: Taxonomic and palaeoecological aspects. Neues Jahrbuch fur Geologie und Palaontologie, Abhandlungen 276, 2: 181-199.
The paper provides new data and the summary of the previous studies on the taxonomy and palaeoecology of corals from the Stramberk-type limestones, occurring as pebbles to boulders (so-called exotics) in the flysch sucessions of the Polish Outer Carpathians. At least 80 species (53 genera) are known from these limestones. Less abundant and less diversified than corals of the Stramberk Limestone from Moravia, but they still represent one of the most species-rich assemblage of the latest Jurassic - earliest Cretaceous age (mostly Tithonian). Uniqueness of these coral faunas, especially in Czech Republic, is an unusual proliferation of the suborder Pachythecaliina (order Hexanthiniaria). 22 species and 14 genera, occur in the Stramberk-type limestones in Poland. Corals, many with phaceloid growth form, are commonly associated with microbialites and microencrusters, which are important reef framework contributors. Macrobiota and microencrusters (some typical for the Tethyan realm) suggest oligotrophic or mildly mesotrophic environments. Four scleractinian species, representing poorly known genera Bilaterocoenia, Thecomeandra and Misistella are described. [original abstract; Löser]

KOSEVICH I. A. 2015. Basis of ontogenetic and evolutionary transformations of thecate hydroids. Paleontological Journal 49, 14: 1561-1571.
[keywords: Thecate hydroids; ontogenetic and evolutionary changes]
The high diversity of spatial organization of shoots in colonies of thecate hydroids (Cnidaria, Hydroidomedusa, Leptomedusae) is determined by their modular organization, which is characterized by the cyclic morphogenesis in the colony. It is attempted to show that evolutionary and ontogenetic changes in the spatial organization of hydroids of this group are based on the allometric growth of modules of colony shoots. An increase in size of a developing module provides prerequisites for earlier initiation of the growing tips of succeeding moduls (heterochrony). In some cases, heterochronies determined transition from cyclic to acyclic morphogenesis. The earlier emergence of new growing tips allowed integration of several primary modules into secondary modules, resulting among other things in changes in relative positions of primary modules (heterotopy). In complex colonies, these changes are traced in the ontogeny of a single colony. [original abstract; Wrzolek]

LOESER H. 2015. Les coraux. In: Morel N. (coord.): Stratotype Cenomanien. Museum national d'Histoire naturelle, Paris: 280-282. [Löser]

LOESER H. 2015. Die Gattung Moltkia (Gorgonacea, Cnidaria) in der Sachsischen Oberkreide (Deutschland). Geologica Saxonica 60, 3: 427-434.
The calcified internodes of the gorgonid genus Moltkia are typical faunal elements in the Cenomanian sediments of Saxony (Germany). Depending on their position in the living animal, the internodes measure between five to 15mm in length and one to three millimetres in width. They are ornamented with fine striae or - in younger stages - with slightly depressed calicular pits. Moltkia is known from the Cenomanian to the Early Eocene and reached its highest morphological differentiation during the Danian. In the present publication, the authorship of the type species of the genus, Moltkia isis, is discussed and assigned to Steinmann & Doderlein (1890). Synonyms of the genus and known species are stated. The material from the Saxon Upper Cretaceous is presented. [original abstract; Löser]

LOESER H. 2016. Systematic part. Catalogue of Cretaceous Corals 4: 1-710, 1763 figs.
The fourth volume of the Catalogue of Cretaceous Corals is a taxonomic revision of all Cretaceous coral genera (Hexacorallia and Octocorallia), with an emphasis on the order Scleractinia, which constitutes 96% of the included genera. The revision concentrates on the genus level, but it encompasses as well a critical consideration of the higher taxonomic levels such as order, superfamily, and family. A new classification system and evolutionary model for the order Scleractinia is proposed. [initial part of an abstract; for full version see "announcements" at the present page]

MIENIS F., DUINEVELD G., LAVALEYE M., Van WEERING T. (eds) 2014. Biology and Geology of Deep-Sea Coral Ecosystems: Proceedings of the Fifth International Symposium on Deep Sea Corals. Deep Sea Research Part II: Topical Studies in Oceanography 99, pp 1-326 (January 2014); http://www.sciencedirect.com/science/journal/09670645/99
[contains 30 papers on various aspects of extant deep-see corals and also sponges;
* is there anybody who would like to review this volume for the readers of our Page and our Newsletter - as I can see from titles and keywords it seems to be of special intereset to us;
** the price of an individual paper is fixed for 39.95$; I could not find info on price of the whole volume - I hope this is more acceptable than 1 158.55$ = price of 29 restricted access papers; the only open access paper in this volume is HENNIGE S. J., WICKS L. C., KAMENOS N. A. et al. 2014;
*** the papers are listed in "Announcements" section of the present page]

MUSCENTE A. D., ALLMON W. D., XIAO S. 2016. The hydroid fossil record and analytical techniques for assessing the affinities of putative hydrozoans and possible hemichordates. Palaeontology 59, 1: 71-87. doi: 10.1111/pala.12209
[keywords: backscattered electron scanning electron microscopy; cnidarian; fossil record; graptolite; hemichordate; hydroid; hydrozoan]
Hydrozoan cnidarians are widespread in modern environments, but their polyps or hydroids, when not biomineralized, are generally rare in the fossil record. To assess the affinities of four hydrozoan taxa previously described on the basis of supposed fossils of non-biomineralized hydroids, we re-analysed the type specimens of these taxa using a combination of light and electron microscopic tools, including backscattered electron (BSE) scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). New morphological, ultrastructural and taphonomic data were generated for Archaeoantennularia byersi from the Devonian of Michigan, Archaeocryptolaria compacta from the Ordovician of Virginia, and Mazohydra megabertha and Drevotella proteana from the Carboniferous Mazon Creek Lagerstatte of Illinois, which are preserved as carbonaceous fossils, aluminosilicate films and iron carbonate minerals in siderite concretions, respectively. In the context of these results, we provide a review of the fossil record of non-biomineralized hydroids, describe possible biases and changes through time in their occurrence and preservation, and evaluate the criteria commonly used to identify and interpret their fossils. Although hydroids have been reported from Phanerozoic (particularly lower Palaeozoic) rocks around the world, many putative hydroids from the Palaeozoic are poorly substantiated and may actually be hemichordates. Indeed, none of the type specimens in this study represent unequivocal hydrozoans. As shown in BSE images, metatype specimens of A. byersi possess autothecae, fusellae, stolons, stolothecae and bithecae, which decisively indicate that they are dendroid graptolites rather than hydroids. The analyses yielded no evidence that A. compacta, Mazohydra and Drevotella are hydrozoans, as their holotypes lack the diagnostic morphological, taphonomic and ecological features characteristic of purported hydroid analogues. Consequently, our results suggest that many Palaeozoic hydroids may be hemichordates and that interpretations of hydroid fossils should be tested and refined using data collected via in situ analytical techniques like BSE-SEM and EDS. [original abstract; Wrzolek]

OGAR V., KLEVTSOVSKIY A. 2015. Carboniferous corals and Chaetetids from exotic limestone block of the Crimea. Rivista Italiana di Paleontologia e Stratigrafia 121, 2: 123-124.
[keywords: Carboniferous; Crimea; exotic block; Tabulate corals; Rugose corals; Chaetetid sponge]
A chaetetid sponge and coral fauna from a Carboniferous exotic limestone block in the Lower Jurassic Esciorda olistostrome on the Bodrak River (Crimean Mountains) are described for the first time. The Bodrak exotic block is composed of massive limestone. It contains the chaetetid Chaetetes (Boswellia) sp., the tabulate coral Multithecopora sp., and poorly preserved rugose corals, including Dibunophyllum? sp., Cordibia? sp. and gen. et sp. indet. Only the fasciculate colonies of the rugose coral Lytvophyllum askynensis (Kossovaya, 2009) are confidently identified. The studied association of fossils is similar to that of the Donets Basin and the Urals and confirms the Lower Bashkirian age of the Bodrak limestone block.

RODRIGUEZ S., SAID I., SOMERVILLE I. D., COZAR P., CORONADO I. 2016. Description of the Serpukhovian rugose and tabulate corals from Idmarrach and Tirhela Formations (Adarouch, Morocco). Boletín de la Real Sociedad Espanola de Historia Natural, Sección Geológica 109: 71-101.
The Serpukhovian coral assemblages from the Idmarrach and Tirhela formations in Central Morocco are described. 32 rugose species belonging to 19 genera and 1 tabulate species have been identified. The Serpukhovian assemblages are composed mostly of species that have their greater abundance in the upper Viséan. However, most recorded taxa in Adarouch have been already mentioned in Serpukhovian rocks from other regions in the Palaeotethys and in North African epicontinental basins. The coral assemblage is dominated by colonial corals belonging to the family Lithostrotionidae and solitary corals belonging to the family Aulophyllidae. In addition, representatives of the families Axophyllidae, Cyathaxoniidae, Cyathopsidae, Palaeosmiliidae, Stereophrentidae and Zaphrentoididae are also present in the assemblages. The environment where the corals lived was mostly an inner to middle carbonate platform with a minor but significant input of terrigenous sediments. [original abstract; Rodriguez]

RODRIGUEZ S., SOMERVILLE I. D., COZAR P., CORONADO I., SAID I. 2016. Inventory and analysis of the distribution of Viséan corals from the Guadiato Area (Córdoba, SW Spain). Spanish Journal of Palaeontology 31, 1: 181-220.
The coral content of the Viséan rocks from the Guadiato Area (SW Spain) have been studied during the last 25 years. Part of the coral assemblages have been previously described, but never as whole. The 69 recorded coral species belonging to Rugosa, Tabulata and Heterocorallia are illustrated. The family Antiphyllidae is represented by two genera and three species; the family Laccophyllidae is represented by one species; the family Cyathaxoniidae is represented by one genus and two species; the family Amplexidae is represented by one species; the family Zaphrentoididae is represented by one species; the family Plerophyllidae is represented by one species; the family Polycoeliidae is represented by one species; the family Pentaphyllidae is represented by one species; the family Cyathopsidae is represented by four genera and five species; the family Bothrophyllidae is represented by one species, the family Aulophyllidae is represented by nine genera and ten species; the family Palaeosmiliidae is represented by four genera and four species; the family Lithostrotionidae is represented by five genera and sixteen species; the family Axophyllidae is represented by three genera and thirteen species; the family Geyerophyllidae is represented by one species; the family Heterophyllidae is represented by two genera and two species; the family Syringoporidae is represented by one species; the family Multithecoporidae is represented by one genus and three species; the family Syringolitidae is represented by one species; the family Pyrgiidae is represented by one species. The degree of abundance and diversity is regarded as moderate and the degree of endemism is low. The significance of the coral assemblages for biostratigraphy, palaeobiogeography and environmental palaeontology is analysed. [original abstract; Rodriguez]

Van ITEN H., MUIR L., SIMOES M. G., LEME J. M., MARQUES A. C., YODER N. 2016. Palaeobiogeography, palaeoecology and evolution of Lower Ordovician conulariids and Sphenothallus (Medusozoa, Cnidaria), with emphasis on the Fezouata Shale of southeastern Morocco. Palaeogeography, Palaeoclimatology, Palaeoecology 460, 15 October 2016, pp 170-178; http://dx.doi.org/10.1016/j.palaeo.2016.03.008
[keywords: Conulariids; Sphenothallus; Medusozoa; Lower Ordovician; Gondwana; Fezouata]

The fossil record of conulariids (Cnidaria, Scyphozoa) extends downward into the topmost part of the Ediacaran System, but the first appearance of diverse, widespread conulariids is in siliciclastic rock units of Early Ordovician age, which collectively host at least six conulariid genera. Some of these same units also contain Sphenothallus, a probable medusozoan that frequently co-occurs with conulariids in Ordovician and younger deposits. Lower Ordovician conulariid localities are distributed among five (originally) Southern Hemisphere terranes, namely Core Gondwana (Archaeoconularia, Eoconularia and Teresconularia), Armorica (Conularia azaisi), Avalonia (Archaeoconularia, Eoconularia and Exoconularia), Perunica (Archaeoconularia, Conularia and Conulariella) and South China (Conulariella). C. azaisi, currently known from the Southern Montagne Noire (France), probably represents a new genus. Sphenothallus occurs in South China, North China (Korea), Armorica (Southern Montagne Noire) and Core Gondwana (Morocco). In southeastern Morocco, Burgess Shale-type Konservat-Lagerstätten in the Fezouata Shale (Tremadocian–Floian) yield Archaeoconularia sp., Eoconularia sp. and at least one species of Sphenothallus. This low-diversity conulariid assemblage is most similar to the Tremadocian assemblage of Wales (Avalonia), which likewise consists of a single species each of Archaeoconularia and Eoconularia. In the Fezouata Shale, Archaeoconularia sp. and Eoconularia sp. frequently occur in monospecific mass associations. Such associations probably represent an original clumped distribution on the seafloor. Additionally, some Eoconularia sp. occur in V-like pairs or radial clusters, and also some specimens were attached at the apical end to a phosphatic brachiopod or to a corner sulcus of a larger specimen of Eoconularia sp. Similar conulariid/brachiopod associations, consisting of Conularia trentonensis and Onniella sp., occur in the Upper Ordovician (Katian) Collingwood Shale of southern Ontario, Canada. [original abstract; Wrzolek]

VINN O., TOOM U. 2016. Early symbiotic rugosan endobionts in stromatoporoids from the Rhuddanian of Estonia (Baltica). Lethaia, DOI: 10.1111/let.12190 (online since 14 October 2016).
The earliest known symbiotic rugosan endobionts occur in stromatoporoids from the early Rhuddanian of Estonia. The stromatoporoid Ecclimadictyon nikitini from the Tamsalu Formation contains the rugosan Donacophyllum middendorffii endobiont. A stromatoporoid Clathrodictyon boreale from the Varbola Formation contains Streptelasma estonica and Bodophyllum sp. endobionts. There are up to three endobiotic rugosans per stromatoporoid host. Stromatoporoid hosts were beneficial for symbiotic rugosans as elevated substrates on a seafloor that offered a higher tier for feeding; they also offered enhanced substrate stability. Stromatoporoids of the end-Ordovician mass-extinction recovery fauna hosted a diverse fauna of symbiotic endobionts. There were few if any negative effects of this mass extinction on the symbiotic endobionts. [original abstract; Wrzolek]