ALBERT

Description: In the Cantabrian Mountains stromatoporoids only have been found up to now in Devonian formations. They occur together with tabulate and rugose corals and brachiopods. Together with these organisms they form biostromes or just biogenetic layers of brecciated and overturned colonies. Four primary microstructures could be distinguished: compact, microlaminate, ordinicellular, and cellular. Alteration seems to begin before fossilization in many cases: the microtissue becomes flocculent by migration and/or destruction of specks. After fossilization the microstructure is altered mainly by migration of specks along slip planes and by rearrangement of the calcite crystals. In this paper the original microstructure is used as the main character for the determination of genera. The form of the coenosteum and features of the gross structure such as superposition of pillars, absence or presence of ring pillars, spacing of laminae and pillars, and others, are strongly influenced by ecological factors. Therefore they cannot be used as characters for the definition of genera and often not even for species. Four genera can be distinguished in the Spanish material: Actinostroma (compact with continuous pillars), Stromatoporella? (microlaminate), Stromatoporella? (ordinicellular) and Stromatopora (cellular). The genera Geronostroma and Atelodictyon are considered to be synonyms of Actinostroma. The genus Stromatoporella should be divided into two genera: one genus with microlaminate and one genus with ordinicellular microstructure. In the microlaminate genus the genera Clathrocoilona, Trupetostroma and Stictostroma (partly) should also be included and perhaps Idiostroma (partly). The ordinicellular genus can be combined with part of the genus Stictostroma and some species of Anostylostroma. The genera Parallelopora and Ferestromatopora are considered to be synonyms of Stromatopora. For the determination of species an attempt is made to establish the variability of the gross structure for each species. As this variability seems to be rather wide, species determinations are only given when sufficient material was available. The following species are described: Actinostroma papillosum (= A. clathratum), Actinostroma verrucosum?, Actinostroma stellulatum, Stromatoporella? granulata? (microlaminate), Stromatoporella? selwyni (ordinicellular), and Stromatopora huepschi?. Stromatopora concentrica

Description: In the abundant material of the species described in this paper great variation occurs in the form of the coenosteum, the structure of laminae and pillars and the microstructure. The shape of the coenosteum is dependent on environmental factors such as the form of the substrate, wave action, currents and sedimentation. These factors influence the ratio between the vertical and horizontal growth rates and the formation of mamelons, astrorhizae and latilaminae. The same ecological conditions also greatly influence the superposition of pillars and the formation of repair tissue and cyst plates. The number of laminae per mm is rather constant, it only varies between certain limits. Ring pillars are not considered as a generic character for they are associated with very different types of microstructures. Microstructures can be changed very strongly by alterations before, during and after sedimentation. Laminae are originally composed of two or more compact layers with a clear layer or vacuoles between them. They can become transversely fibrous, flocculent and pseudocellular by recrystallization. For these reasons great variations in the fossil material occur and are the cause that many new genera and species were created adding to the great confusion in the classification of stromatoporoids. The following genera are probably synonyms: Stromatoporella, Clathrocoilona, Stictostroma, Trupetostroma and Taleastroma. Many species have also erroneously been described as helonging to other genera, principally Stromatopora, Syringostroma and Parallelopora.

Description: In the Cantabrian Mountains stromatoporoids only have been found up to now in Devonian formations. They occur together with tabulate and rugose corals and brachiopods. Together with these organisms they form biostromes or just biogenetic layers of brecciated and overturned colonies.\nFour primary microstructures could be distinguished: compact, microlaminate, ordinicellular, and cellular. Alteration seems to begin before fossilization in many cases: the microtissue becomes flocculent by migration and/or destruction of specks. After fossilization the microstructure is altered mainly by migration of specks along slip planes and by rearrangement of the calcite crystals.\nIn this paper the original microstructure is used as the main character for the determination of genera. The form of the coenosteum and features of the gross structure such as superposition of pillars, absence or presence of ring pillars, spacing of laminae and pillars, and others, are strongly influenced by ecological factors. Therefore they cannot be used as characters for the definition of genera and often not even for species.\nFour genera can be distinguished in the Spanish material: Actinostroma (compact with continuous pillars), Stromatoporella? (microlaminate), Stromatoporella? (ordinicellular) and Stromatopora (cellular). The genera Geronostroma and Atelodictyon are considered to be synonyms of Actinostroma. The genus Stromatoporella should be divided into two genera: one genus with microlaminate and one genus with ordinicellular microstructure. In the microlaminate genus the genera Clathrocoilona, Trupetostroma and Stictostroma (partly) should also be included and perhaps Idiostroma (partly). The ordinicellular genus can be combined with part of the genus Stictostroma and some species of Anostylostroma. The genera Parallelopora and Ferestromatopora are considered to be synonyms of Stromatopora.\nFor the determination of species an attempt is made to establish the variability of the gross structure for each species. As this variability seems to be rather wide, species determinations are only given when sufficient material was available. The following species are described: Actinostroma papillosum (= A. clathratum), Actinostroma verrucosum?, Actinostroma stellulatum, Stromatoporella? granulata? (microlaminate), Stromatoporella? selwyni (ordinicellular), and Stromatopora huepschi?. Stromatopora concentrica

Description: In the abundant material of the species described in this paper great variation occurs in the form of the coenosteum, the structure of laminae and pillars and the microstructure.\nThe shape of the coenosteum is dependent on environmental factors such as the form of the substrate, wave action, currents and sedimentation. These factors influence the ratio between the vertical and horizontal growth rates and the formation of mamelons, astrorhizae and latilaminae.\nThe same ecological conditions also greatly influence the superposition of pillars and the formation of repair tissue and cyst plates. The number of laminae per mm is rather constant, it only varies between certain limits. Ring pillars are not considered as a generic character for they are associated with very different types of microstructures.\nMicrostructures can be changed very strongly by alterations before, during and after sedimentation. Laminae are originally composed of two or more compact layers with a clear layer or vacuoles between them. They can become transversely fibrous, flocculent and pseudocellular by recrystallization.\nFor these reasons great variations in the fossil material occur and are the cause that many new genera and species were created adding to the great confusion in the classification of stromatoporoids.\nThe following genera are probably synonyms: Stromatoporella, Clathrocoilona, Stictostroma, Trupetostroma and Taleastroma. Many species have also erroneously been described as helonging to other genera, principally Stromatopora, Syringostroma and Parallelopora.