Milne Edwards, 1848, p. 467
Caryophyllia extinctorium Michelin 1841, p. 9 pl. 2 fig. 3b; Monotypy
Type Specimen: Lectotype; MNHN M00053; Verified; Dry Preserved
Type Locality: Croisilles (near Bayeux, Calvados France), Middle Jurassic (Bajocian).
4 paralectotypes are available. see Beauvais, 1967
Solitary corallum, attachment area absent or very small. Calicular platform generally infundibuliform, occasionally flat and more rarely a little convex. Calice elliptical. "Epitheca" or external coating folded, Costae short, unequal, unornamented, corresponding to septa. Radial elements are compact bicuneiform costosepta, generally free and straight, sometimes curved according to the bilateral plan. They are very regularly arranged in cyles according to their length and their thickness with shorter S1 placed in the dorso-ventral plan. A first cycle septum can be linked to the columella according to the bilateral plan. Some of the last cycle septa may also anastomose to major septa Lateral faces display unequal granules, randomly arranged. Thick septa smoother. Distal margin weakly ornamentated mainly characterised by a zigzag pattern in thinner septa. On transverse sections, the internal margin displays no denticulation. Microstructure characterised by a zigzag mid-septal line which gives birth to a microarchitecture marked by zigzag shaped young septa and by randomly arranged granules in older septa. Original microarchitecture progressively smoothed during growth by addition of laminar layers, firstly in the wall region and secondarily nearby the internal edge. Columella essential, lamellar and continuous with a microarchitecture similar to septa. It is surrounded by a small groove. In depth it is connected with a S1 and then to other septa in the deepest part of the corallite. Endotheca made of few large vesiculous dissepiments distally convex in the outer part and of dissepiments (or tabulae ?) perhaps more distally concave nearby the columella. Wall made up by the enlargement of costae, itself induced by the development of laminar layers of the stereome which are in continuity with thickened dissepiments. The place of the wall does not coincide with the largest thickness of costo-septa. No palus; no synapticule.
The lectotype of the type-species is rather badly preserved and the species is rare in the type area and generally in the Bajocian. So the name of Axosmilia is kept only because C. extinctorium is compatible with better preserved Upper Jurassic or Cretaceous specimens classified as Axosmilia or Pleurosmilia. Several tens of nominal Jurassic (Lathuilière 1989) and Cretaceous (Loeser 2000) species initially attributed to various genera are in need of a revision.
This page has been in preparation since 07-May-2009 07:31
This version was contributed by Bernard Lathuilière on 22-Jan-2011 10:08.
Page authors are: Bernard Lathuilière. Please contact the editor if you would like to contribute to the diagnosis of this taxon.
The editor is: Bernard Lathuilière