Yves Plusquellec

Automobility in Tabulata, Rugosa, and extant scleractinian analogues: Stratigraphic and paleogeographic distribution of Paleozoic mobile corals

Freeliving corals capable of automobility (e.g., lateral migration) were rare during Paleozoic time, but some species within the tabulate genera Procterodictyum, Procteria (Granulidictyum), P. (Pachyprocteria), Palaeacis and Smythina, and the rugose genera Combophyllum, and Baryphyllum, have morphologic characters that suggest they were capable of such self-directed movement. The rugose corals Gymnophyllum and Hadrophyllum sensu stricto may have exhumed and righted themselves. No single morphological character is diagnostic for an automobile habit, but the following characters appear to be important indicators: 1) lack of an external attachment surface; 2) concentric skeletal accretion; 3) discoid corallum shape; 4) concavo-convex, piano-convex, and, less commonly, biconvex corallum profile; and 5) small, lightweight corallum. Additionally, the occurrence of corallites on the base of the corallum (hypocorallites) is a good indicator of automobility in freeliving corals, but the character is so far known only in Procterodictyum. All known fossil automobile taxa appear to have inhabited relatively quiet environments on muddy or silty, soft substrates. The earliest known automobile corals were early Emsian (Devonian) Procterodictyum. Paleozoic automobile corals were most abundant during Devonian time, with Procterodictyum, Procteria (Granulidictyum), and Combophyllum distributed in a narrow longitudinal band in the southern hemisphere on both sides of the Rheic Ocean. Carboniferous and Permian automobile taxa (Palaeacis partim, Smythina and Baryphyllum) were less diverse, but more cosmopolitan. Throughout Paleozoic time, the vast majority of automobile corals was confined to within 40 degrees of the paleoequator. However, additional research will be required before coral automobility can be used to constrain paleolatitude independently.

Attribution de «Michelinia compressa Michelin, 1847 au genre Yavorskia Fomitchev (Tabulé, Tournaisien)

Resume Une coupe longitudinale effectuee dans le type de Michelinia compressa Michelin montre que cette espece appartient au genre Yavorskia Fomitchev .

The microstructure of Michelinia meekana Girty, 1910

The wall of Michelinia meekana Girty is composed predominantly of lamellae that are approximately parallel to the median dark line, confirming its placement in the genus Michelinia s.s. The presence of a Praemichelinia -type microstructure in some parts of the wall is a recurrence of primitive architecture that suggests derivation of Michelinia from Praemichelinia .

Revision of Parastriatopora gigantea (KNOD, 1908) (Anthozoa, Tabulata) from the Devonian of Bolivia

Abstract The revision and detailed description of the original material and several topotypic specimens of Parastriatopora gigantea ( Knod , 1908) from the Lower Devonian of Yaco (Bolivia) allow the selection of a lectotype and its diagnosis. A more precise geographic and stratigraphic location of the type locality is provided, together with a reassessment of its most probable age (Pragian-Emsian). Present knowledge of South American Devonian tabulate corals has important implications on their paleobiogeography. Data from Bolivia and Argentina suggest an earlier age for the extinction of Malvinokaffric taxa and reveal a greater abundance and specific diversity.

Lower Devonian faunas and palynomorphs from the Dornes Syncline (Central Iberian Zone, Portugal): stratigraphical and paleogeographical implications

In the Dornes syncline, southern Central Iberian Zone, Portugal, the uppermost levels of the Serra do Luacao Formation up to now have been considered to be of Pridoli-Lochkovian? age because they lie immediately under the Dornes Formation, which is of Pragian age and is well defined stratigraphically. New paleontological elements including benthic faunas and palynomorphs allow us to confirm that the top of the Serra do Luacao Formation is securely Lochkovian, for upper Lochkovian strata are present although relatively thin. The transition from the Serra do Luacao to the Dornes formations and their lithostratigraphical relationship are now clear: the terrigenous succession belongs to the Serra do Luacao Formation and the limestones represent the Dornes Formation. The benthic faunas clearly have North-Gondwanan affinities.

Persistance de Favositides microlamellaires (Cnidaria, Tabulata) dans le Dévonien

Abstract The structural and microstructural study of some devonian ‘Favosites’ shows the persistence of the microlamellar species related to Paleofavosites until the lower Eifelian. The evolution of the wall is characterized by an increase of the size of the microlamellae and the substitution of the granules of the median dark line by fiber-like units.

Revision of the Early Devonian tabulate coral Pleurodictyum bifidum from New South Wales

Plusquellec, Y. & Wright, A.J., October 2017. Revision of the Early Devonian tabulate coral Pleurodictyum bifidum from New South Wales. Alcheringa 41, xxx–xxx. ISSN 0311-5518. The tabulate coral Pleurodictyum bifidum Jones, 1944, from the Early Devonian (Pragian or lower Emsian) Garra Formation of central New South Wales, Australia is revised on the basis of the holotype and three other specimens. It is selected as the type species of the new monotypic genus Bifidomeria (Family Roemeriidae), which differs from Roemeria in its strictly cerioid corallum, its bifid septal spines and aspects of its microstructure. Study of the detailed microstructure of two other tabulate corals from the Devonian of New South Wales has led to the following revised generic assignments: Michelinia progenitor Chapman, 1921, previously assigned to Roemeripora, is assigned to Roemeria, and Holacanthopora clarkei Wright & Flory, 1980 is assigned to Michelinia. Yves Plusquellec [yves.plusquellec@univ-brest.fr], Université de Bretagne Occidentale, CNRS-UMR 6538 ‘Domaines océaniques’, Laboratoire de Paléontologie, UFR Sciences et Techniques, 6 avenue Le Gorgeu, CS 98837, F-29283 Brest, France; Anthony Wright [tony.wright@optusnet.com.au], GeoQuEST Research Centre, School of Earth & Environmental Sciences, University of Wollongong, Wollongong NSW 2522, Australia.

Devonian operculate corals (Calceolidae, Cnidaria) from the Massif Armoricain, France

Wright, A.J., Plusquellec, Y. & Gourvennec, R., February 2016. Devonian operculate corals (Calceolidae, Cnidaria) from the Massif Armoricain, France. Alcheringa 40, xxx–xxx. ISSN 0311-5518 The operculate coral Calceola gervillei Bayle, 1878 is described for the first time on the basis of the type material from the Cotentin region of Normandy (North Armorican Domain), from Early Devonian (likely upper Lochkovian to lower Pragian) strata, and is chosen as the type species of the monotypic new genus Gerviphyllum. The new genus is also present in the l’Armorique Formation (lower Pragian) of the Plougastel Peninsula (Central Armorican Domain) as Gerviphyllum sp. cf. G. gervillei. One locality in the upper Emsian (Polygnathus serotinus Conodont Zone) Le Fret Formation, on the northern coast of the Crozon Peninsula, has yielded operculate coral specimens described here as ?Chakeola sp., the first (tentative) record of the genus outside eastern Australia, south China and Vietnam. The operculate coral Calceola collini sp. nov. is described from six localities in the early Middle Devonian (Eifelian: Polygnathus costatus Conodont Zone) Saint-Fiacre Formation of the Plougastel and Crozon Peninsulas (Central Armorican Domain), despite the fact that knowledge of the internal characters, especially of the operculum, of the type species Calceola sandalina is very limited. From an extensive review of published references to Calceola from France, we conclude that only the record of Collin (1929) is valid. Anthony Wright (tony.wright@optusnet.com.au), GeoQuEST Research Centre, School of Earth & Environmental Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia; Yves Plusquellec (yves.plusquellec@univ-brest.fr) and Rémy Gourvennec (remy.gourvennec@univ-brest.fr), Université de Bretagne Occidentale, CNRS-UMR 6538 ‘Domaines océaniques’, Laboratoire de Paléontologie, UFR Sciences et Techniques, 6 avenue Le Gorgeu, CS 98837, F-29283, Brest, France. Received 1.10.2015; revised 8.12.2015; accepted 14.12.2015.

Frasnian rugose and tabulate corals from the eastern Taurus (Kozan region, Turkey)

A section near the Kilgen Lake (Adana Province) has yielded a fauna of rugose and tabulate corals including Disphyllum cf. rugosum (Wedekind, 1922), D. cf. curtum Hill, 1954, Wapitiphyllum sp., Thamnopora sp., and Alveolites sp. This coral assemblage is consistent with the previous Frasnian age assigned to the limestones of the Gümüşali Formation. The rather well-preserved material provides new data on the structure and microstructure of Disphyllum and allows to describe in Thamnopora unusual calicinal morphology (septal ridges, median teeth, and pseudopercula) as well as new structures linked to the lateral increase (basal low wall, apical cul-de-sac).