Complexastrea
Orbigny, 1849, p. 10
In 1849, d'Orbigny created Complexastrea based on Astrea burgundiae Leymerie 1846 non Defrance. In 1850 (p. 35-36,n°565) d'Orbigny abandoned Complexastrea and Astrea burgundiae Leymerie was attributed to Confusastrea subburgundiae . But the genus is presently considered available and valid.
Type Species
Astrea burgundiae Leymerie 1846 p. 252, pl. 10 fig. 13 non Defrance,; Monotypy
Type Specimen: Lectotype; MNHN M00051; Not Traced; Dry Preserved
Type Locality: Upper Oxfordian (Upper Jurassic) of Tonnerre (Yonne; France)
Astrea burgundiae Leymerie 1846 p. 252, pl. 10 fig. 13 non Defrance, = Confusastrea subburgundiaeD'Orbigny 1850, p. 35; The type material was redescribed and figured in Morsch, 1994, p. 10, pl. 1,2,3.
Classification
Synonyms
Description
Massive astroid, plocoid to subcerioid corallum with rounded corallites. Increase through intracalicular budding with lamellar linkages between centers, which interrupt at later stage. Peritheca very narrow when present. Radial elements are exsert, compact, free, attenuated to bicuneiform, costo-septa with a small costal part. Radial elements differentiated size orders. Distal edge with rhomboidal equal regular teeth, inner edge rhopaloid, lateral faces with subvertical carinae, no palis. Microarchitecture montlivaltid with one fan system of trabecules corresponding to carinae. Hexameral symmetry generally not deciphered, bilateral symmetry marked by torsion of septa. Endotheca made of vesicular, cellular or tabuloid dissepiments which pass from one corallite to another , columella absent or weak parietal, synapticulae absent, wall absent to paraseptothecal. In case of an absent wall, a narrow depression occurs (astraeoid situation)
Comparisons
The main differences with Isastrea consist in size of trabecules and corallites (bigger in Complexastrea), the higher divergence of trabecules in the septal plan that produce a costal part, more exsert septa, and locally a peritheca in Complexastrea. Complexastrea is close of other montlivaltid genera with large corallites like Complexastreopsis, Thecomeandra, Fromentellia, Phyllogyra but these genera show tendencies more or less developed toward the meandroid structure.
Remarks
See Geyer 1954, Roniewicz 1960 , Morsch 1994, Lathuilière 1996a, b In the Bajocian, Lathuilière 1996 documented development of a morphogenetic series from solitary Montlivaltia morphotype to colonial, ploco-cerioid Complexastrea morphotype. In the Late Oxfordian – Tithonian an expansion of the astreoid Complexastrea morphotype is observed. Possibly in this morphogenetic trend emerged the evoked meandroid genera.
Distribution
- Western Europe, Southern Europe, Central Europe, Eastern Europe, North Africa, Central Asia, South Asia, North America, South America; Middle Jurassic - Early Cretaceous
This page has been in preparation since 07-May-2009 10:42
This version was contributed by Bernard Lathuilière on 27-May-2017 09:46.
Page authors are: Bernard Lathuilière Ewa Roniewicz. Please contact the editor if you would like to contribute to the diagnosis of this taxon.
The editor is: Bernard Lathuilière
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