Aretz et al_2011.pdf - ORBi - Université de Liège

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Kölner Forum Geol. Paläont., 19 (2011)
M. ARETZ, S. DELCULÉE, J. DENAYER & E. POTY (Eds.)
Abstracts, 11th Symposium on Fossil Cnidaria and Sponges, Liège, August 19-29, 2011
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A comparison of Mississippian colonial rugose corals from Western
Europe and South China
Edouard POTY 1 , Markus ARETZ 2 & XU Shaochun 3
1 Service de Paléontologie animale et humaine, Département de Géologie, Université de Liège, Bat. B18,
Allée du Six-Août, Sart Tilman, B-4000 Liège, Belgium; e.poty@ulg.ac.be
2 Université de Touloluse (UPS), GET (OMP), 14, Avenue Edouard Belin, 31400 Toulouse, France;
markus.aretz@get.obs-mip.fr
3 Algoma University College, Ontario, Canada
Sections in Hunan, Guanxhi and Guiyang were investigated or revised during the last years and their
biostratigraphy (foraminifers and rugose corals) and sequence stratigraphy were precised (POTY et al. 2006;
HANCE et al. in press). They provide a composite section from the uppermost Famennian to the lowermost
Serpukhovian which was correlated with Western Europe. The systematics and the stratigraphy of the
South-Chinese colonial rugose corals of this interval were revised and allow to do comparisons with those
present in Western Europe and to precise their relationships and their palaeogeography.
From the lower Tournaisian to the lowermost Namurian (Serpukhovian), 14 genera of colonial rugose
corals were recognized in Western Europe (WE) and 11 in South China (SC), that is a total of 17, 8 being
common to both regions. But these latters have not the same stratigraphic distributions, none of them
appearing at the same level in the two regions (Fig. 1).
The oldest Tournaisian colonial rugose coral is Parastelechophyllum which appeared only in China. It is
closely related to Stelechophyllum (POTY & XU 1996) which is known in the North-American realm and in
Central Asia. Its stratigraphic distribution is limited to the Uralinia tangpakouensis Coral Zone (MFZ3).
Heterostrotion and its closely related Solenodendron (POTY & XU 1997) are the oldest European Tournaisian
colonial genera, the first being previously known in the Uppermost Famennian of Poland. Both appeared in
the RC3α Coral Subzone (base of MFZ5) in the lower part of the Ivorian (Upper Tournaisian). Heterostrotion
is known only from one locality in North France and limited to only one level, but the second extends up to
the uppermost Viséan. Both can be considered as migrants from an outside area. In SC, Solenodendron was
not recorded, but Heterostrotion got into a little later than in WE (upper MFZ5). It became very common and
extended up to the top of the Livian (Middle Viséan). It gave rise to a cerioid form (possibly corresponding
to the not well defined Lithostrotionella YABE & HAYASAKA 1915) at the base of the Keyserlingophyllum-
Dorlodotia interval Coral Zone (base of MFZ7) and to Stylostrotion possibly in the upper part of the same
Coral Zone (base of MFZ10). That evolution can be considered as parallel to the evolution of
Lithostrotionids in WE and its surrounding regions. Dorlodotia is known from the RC4β1 Coral Zone
(MFZ7) in WE and from the base of the Dorlodotia Zone (MFZ11) in SC. It extends up to the top of the
Moliniacian (RC5 – MFZ11 Zones) in WE, but up to the top of the Livian (top of MFZ12) in SC.
Siphonodendron introduced in WE from the base of the RC5 Zone (upper MFZ11) was common until the
Namurian. It gave rise to Lithostrotion during the earliest Livian, and to Diphyphyllum, Nemistium and
Orionastrea during the Warnantian. Siphonodendron, Lithostrotion and Diphyphyllum got into China later,
during the late Warnantian (MFZ15). Aulina is the only genus recorded earlier in SC (late Warnantian,
MFZ15) than in WE (Namurian, RC9-MFZ16).
Therefore, most recorded colonial genera in SC are late migrants from outside regions, regional
radiation being traced only for heterostrotionids. Note that some solitary genera known in WE got also
later into SC, for example Axophyllum and Palaeosmilia. Migrants got usually earlier into WE, giving rise to
lineages into the lithostrotionids, whereas originations can determined for Lonsdaleia, Palastraea and
possibly Corwenia.
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