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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In section, these different types of auriculae are cut in various orientations and levels and then produce
different shapes at the inner edge of septa. The rhopaloid or claviform sections of the auriculae represent
potentially the section of many different inner edges including in corals devoid of auriculae. Nevertheless it
is a common feature in corals that bear koutaliform or flabelliform auriculae.
The podoid section of the auricula is like a man’s foot with a swollen and terminal asymmetric
elongation. The interpretation of the section is similar to rhopaloid/claviform sections (Fig. 3).
The T-form section of the auriculae is not very common and not clearly specific of a special kind of
auricula (Fig. 3).
The forked section is typical for koutaliform auriculae and appears like a “Y” both in transverse and
longitudinal sections (Fig. 3).
Rhopaloid or claviform
Podoid
T-form
Forked
Lanceolate
Lozenge
Flabelloid
Fig. 3. Different types of transverse sections of auriculae
The lanceolate section could be interpreted as the section of a hastiform auricular, but it can also result
from special sections of koutaliform or flabelliform auriculae (Fig. 3).
The lozenge and flabelloid sections are typical for flabelliform auriculae. We cannot exclude that
exceptionally, koutaliform auriculae produce this type of section (Fig. 3).
As the sections are not always significant in terms of 3D microarchitecture, it is necessary to use a
complete set of sections to get the best idea of the nature of auriculae.
The function (s) of auriculae is (are) still unknown. It is suggested that auriculae support some soft
tissue(s) of the body, for instance mesenterial filaments.
As proposed by GILL (1977) auriculae can be used as tools to distinguish suprageneric systematic
groups. Koutaliform auriculae are distinctive of a group in which we place Heliocoenia, Stylina (sensu
Etallon) Stylosmilia, Enallhelia… Flabelliform auriculae could be a synapomorphic character of a number of
genera such as Ironella, presently included in the family Rhipidogyridae. Hastiform auriculae occur in some
Pseudocoenia but their systematic value still need to be explored.
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leurs septes. - Mémoire B.R.GM., 89: 283-295.
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