The Palaeozoic corals, I: origins and relationships

Abstract

SUMMARY The status, origins and relationships of the various groups of Palaeozoic corals are reviewed. Five orders are currently recognized: Rugosa, Tabulata, Heterocorallia, Cothoniida and Kilbuchophyllida, to which I add the Tabulaconida and Numidiaphyllida. The Rugosa and Tabulata are considered to be broadly monophyletic clades, and the Tabulata are confirmed as zoantharian corals. Morphological features, particularly aspects of septal insertion in both groups, are discussed as clues to their likely origins and relationships. They are not considered to have had a skeletonized common ancestor, but they may have arisen as separate skeletonization events from the same broad group of anemones, represented by the living Zoanthiniaria. The Rugosa are not considered to be ancestral to the Scleractinia. The latter, together with the Permian Numidiaphyllida, are considered to have evolved through skeletonization events among a group of anemones derived from the Actiniaria/Corallimorpharia, a member of which also gave rise to the Kilbuchophyllida in the Ordovician. The pattern of septal insertion in the Heterocorallia is controversial and the relationship of these corals to contemporary coral groups remains uncertain. The increasingly important record of Cambrian coralomorphs is assessed, and considered to include several genera of zoantharian corals. However, although similarities are apparent, none is regarded as directly ancestral to the post-Cambrian coral clades. The history of diversification and extinction of corals through the Palaeozoic is briefly reviewed.

Treatise Online, no. 20, Part E, Revised, Volume 4, Chapter 2A: Introduction to the fossil hypercalcified chaetetid-type Porifera (Demospongiae).

“…3A-F). reitner, 1992;Gautret, reitner, & marin, 1996;WörHeiDe, reitner, & Gautret, 1996, 1997reitner & others, 1997;WörHeiDe & others, 1997;WörHeiDe, 1998 St u d i e s b y H a r t m a n a n d G o r e a u (1975); reitner and enGeser (1987); c u i f a n d G a u t r e t ( 1 9 9 1 ) ; r e i t n e r (1991,1992); WooD (1991); Gautret, reitner, and marin (1996); reitner and ; WörHeiDe, reitner, and These are, from the exterior inward: (1) the dermal area; (2) the internal dermal area; (3) the central part of tubules; (4) the tabulae within the tubules; (5) the space(s) between tabulae; and (6) the nonliving calcareous skeleton. reitner and others (2001, p. 230), in referring to zone 1, reported that, "The uppermost portion is formed by a thick crust of spiraster microscleres (dermal area, zone 1) and tylostyle megascleres arranged in clearly plumose bundles…" Some spicules may be entrapped in the calcareous skeleton, resulting in what would be termed a rigid aspicular skeleton ( Fig.…”

Eumetazoan fossils in terminal Proterozoic phosphorites?

“…Bischoff (39) interpreted S. siluricum as an anthozoan, despite significant differences from extant members of this group. Some Paleozoic coralomorphs (40), such as Moorowipora and Flindersipora, also share certain features (e.g., axial budding and transverse walls) with the Doushantuo tubes, despite obvious differences from them. Paleozoic conularids and Stephanothallus, interpreted as fossil scyphozoans (41)(42)(43), have one or more transverse walls (''schotts''; refs.…”

A lowermost Ordovician tabulate-like coralomorph from the Precordillera of western Argentina: a main component of a reef-framework consortium

“…"Coralomorpha" (Jell, 1984;Scrutton, 1997) Remarks.-The calcified modular skeletons of several organisms have similarities with coralline organization. Most of these forms were recorded in the Cambrian (e.g., Rosellatana Kobluk, 1984;Flindersipora Lafuste et al, 1991;Moorowipora Fuller and Jenkins, 1994;Tabulaconus Handfield, 1969;Harklessia Hicks, 2006).…”

“…Although many of these generally coralline forms (e.g., the Coralomorpha of Jell, 1984) are of uncertain affinities, among them are undoubted corals (Scrutton, 1997(Scrutton, , 1999. The oldest definite tabulate coral, Lichenaria Winchell and Schuchert, 1895, occurs in the Early Ordovician (Scrutton 1979(Scrutton , 1999Webby et al, 2004).…”