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Neocoenia

Hackemesser, 1936, p. 24

Type Species

Neocoenia renzi Hackemesser, 1936, p. 24, pl. 3, figs. 4-6; Subsequent Designation Alloiteau, 1952, p. 634

Type Specimen: Holotype; ; Not Traced; Unknown

Type Locality: Cretaceous of Greece (Kiona massive, Nomo Fokida).

The holotype of the type species is housed at NMB (Basel) under D 6127.

Classification

Diagnosis

Colonial, massive, plocoid. Budding extracalicular. Corallites are circular to irregularly oval or subpolygonal in outline. Costosepta compact; their lateral flanks are covered by granulae, varying in shape (such as spiniform, rounded, carina-like) and size (20-100 µm, but generally 40-70 µm high). Costae confluent or non-confluent, peripherally dissociating into granular structures or not. Columella rather dense and large (occupying around 30% of corallite lumen) spongy-papillose to irregularly parietal, or lamellar. Pali present or absent; often indistinguishably intermingled with columella. Endothecal and exothecal dissepiments vesicular to subtabular, moderately developed. Wall septothecal, septoparathecal, parathecal. Microstructure not preserved but, based on arrangement of granulae, polyaxial development of perithecal wall present.

Remarks

The taxonomic position of the genus Neocoenia has long been discussed. Alloiteau (1952, p. 633-634) grouped it with the family Smilotrochidae but did not mention it in his 1957 work. Wells (1956, p. 405) considered Neocoenia to be a junior synonym of the genus Montastraea. Turnšek and Polšak (1978, p. 25) and Baron-Szabo (1997, p. 64) placed it in the Heliastraeidae. Later, Neocoenia was frequently grouped with the Placocoeniidae (e.g., Baron-Szabo, 2002, p. 39; Morycowa and Marcopoulou-Diacantoni, 2002, p. 48). Recently, Neocoenia was transferred to the family Columastreidae (Loeser, 2011, p. 8). Study of the holotype of the type species of Neocoenia (N. renzi Hackemesser, 1936) in 2015 by Baron-Szabo revealed, however, that in its thecal and axial developments, it closely corresponds to the Heliastraea-group (s.l.). Furthermore, in having carina-like granulation, polyaxial (peri-)thecal developments, and a moderately developed endotheca, it shows close affinities to the merulinids and is, therefore, transferred to the family Merulinidae. The columastreids differ from Neocoenia in 1) a less and very finely developed type of septal granulation with granules that are only around half the height of the ones seen in Neocoenia; 2) the lack of carina-like granulae types; 3) the presence of thecal pores (sensu lacunes as in the actinastreids); and 4) a less developed endotheca which more closely corresponds to the kind seen in the actinastreids.

Distribution

  • Southern Europe; Early Cretaceous - Late Cretaceous
  • Central Europe; Late Cretaceous
  • Eastern Europe; Late Cretaceous
  • South Asia; Late Cretaceous

Contains

This page has been in preparation since 31-Aug-2010 18:35

This version was contributed by Rosemarie Baron-Szabo on 27-Oct-2016 17:22.

Page authors are: Rosemarie Baron-Szabo. Please contact the editor if you would like to contribute to the diagnosis of this taxon.

The editor is: Rosemarie Baron-Szabo


Neocoenia renze Hackemesser, 1936, holotype
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Heliocoenia renzi Hackemesser, 1936, holotype
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