Dimorphoseris
Duncan, 1872, p. 22
Type Species
Dimorphoseris oolitica Duncan 1872, p. 22, pl. 4 fig. 1-4; Monotypy
Type Specimen: Syntype; NHMUK R 778; Verified; Dry Preserved
Type Locality: Inferior Oolite (Bajocian , Middle Jurassic) East Coker (Great Britain)
A single syntype and its plaster mould are available.
Classification
Description
Massive dimorphastreoid massive corallum. Lower surface without holotheca (or holotheca incomplete and badly preserved), subequal costae. Radial elements are compact or subcompact (?) free or anastomosed, subequal, straight to curved, rather constant in thickness. The ornamentation is typically pennular with pennular edge toothed and turned distally and with a good alternation in level of pennulae and discontinuous menianae. Distal edge moniliform with regular elliptical teeth, inner edge attenuated No pali. Hexameral symmetry hypothetically deciphered in the mother corallite, bilateral symmetry characterised by the curvature of septa in daughter corallites. Abundant endotheca made of dissepiments Axial zone with a small fossa, synapticulae probably present, No wall.
Comparisons
Like Periseris but without columella and with a poorly developed holotheca. Like Dimorpharaea but without pores. Like Protoseris but with a distinct fossa.
Remarks
Five nominal species in Jurassic
Distribution
- Western Europe; Middle Jurassic - Late Jurassic
This page has been in preparation since 18-Aug-2009 16:42
This version was contributed by Bernard Lathuilière on 04-Feb-2010 17:08.
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
|