Microstructure and taxonomy of Amphiastraeina (Scleractinia)

Abstract

Mikrostruktura i taksonomia Amphiastraeina (Scleractinia) A new classification o f the suborder Amphiastraeina Alloiteau, 1952 is proposed based on microstructure. It is supposed, that the distinguishing of the suborder Heterocoeniina Morycowa, 1964 (not Beauvais, 1977) is not justified in consideration of microstructural and morphological features. Two superfamilies: Amphiastraeoidea and Heterocoenioidea which display differences in the microstructure of radial elements are introduced into the suborder Amphiastraeina. The development of skeletal elements in both groups is characterized by the wall developed prior to the septa. The wail is composed o f medium-sized and thick, compound (branching) polyaxial main trabeculae giving secondary trabeculae. Septa are formed by minitra- beculae which are in microstructural continuity with trabeculae of the wall.The distinctive development of secondary septal trabeculae in taxa o f the superfamily Heterocoenioidea is reflected by the spiniform septal ornamentation. The occurrence of intracalicular budding (Taschenknospung, septal division) is noted in some heterocoeniids. Three species: Confusaforma carpathica sp.n., Preverastraea tenuiseptata sp.n., and Thecidiosmilia morycowae sp.n. (family Heterocoeniidae) are described from the Upper Jurassic and Lower Cretaceous of the Polish and Romanian Carpathians.