摘要
本文描述了广西隆林祥播中二叠世茅口期生物礁中的钙藻化石17属18种,其中新属5个:Paralithoporella gen. nov., Guangxilamina gen. nov., Favoporella gen. nov., Sinophyllum gen. nov.,和Monostysisyrinx gen. nov.; 新种9个:Solenopora guangxien sis sp. nov., Paralithoporella sincrisis gen. et sp. nov., Guangxilamina incompta gen. et sp. nov., Favoporella hexagona gen. et sp. nov., Ivanovia permica sp. nov., Anchicodium expressum sp. nov., Sinophyllum hexagonum gen. et sp. nov., Sphaeroporella minima gen. et sp. nov., Monostysisyrinx circula ris gen. et sp. nov.。本文还建立一新科——Monostysi sy rinaceae。在当前生物礁中,钙藻是重要的造礁生物,可以起造架、粘结、障积等作用。
Rich calcareous algae has been collected from the Middle Permian reefs of Xiangbo, a small village 35 km NW of Longlin County, Guangxi. Ba ed on fusulinids such as Newschwagerina and Verbeekina, the reefs belong to the Maokouan stare of Middle Permian in age.
The calcareous algae are the reef-formers accessary of calcisponges in importance, performing the functions of (1) framers (such as Monostysisyrinx), (2) binders (such as Archaeolithoporella), (3) dwellers (such as Solenoporaceae and some Codia eae), and (4) bafflers (such as some phylloid Co- diaceae). Besides, they also could form algal bands (such as Anthracoporella), or served as sediments producers.
DESCRIPTION OF NEW GENERA AND SPECIES
Order Rhodophyceae
Family Solenoporaceae
Genus Solenopora Dybowski, 1878
Solenopora guangxiensis sp. nov.
(Pl. Ⅰ, fig. 1)
Thallus nodular. Radiating walls between fi'aments conspicuous. Partitions between cells within filaments irregularly spaced, 0.02—0.04 mm apart. Cells rounded to polygonal in cross section, 0.015—0.02 mm wide.
Solenopora guangxiensis sinuosa sp. et subsp, nov.
(Pl. Ⅰ, fig. 2)
Thallus hemispherical. Radiating filaments slightly sinuous, 0.015—0.02 mm wide. Partitions between cells within the filaments absent.
Family Corallinaceae Harvey, 1849
Paralithoporella gen. nov.
Type species Paralithoporella sinensis gen. et sp. nov.
Diagnosis Thallus laminar (often encrusting other organisms), consisting of a layer of cells.
Discussion This genus resembles Lithoporella Fosilis in growth form and inner construction.
Paralithoporella sinensis gen. et sp, nov.
(Pl. Ⅳ, fig. 4)
Thallus consisting of squat cells, which are 0.03—0.08 mm high and 0.06—0.08 mm wide in vertical section.
Problematical Rhodophyta
Guangxilamina gen. nov.
Type species Guangxilamina incompta gen. et. sp. nov.
Diagnosis Thallus laminar, inconstant in thickness, showing no cell structure.
Discussion The growth habit of entrusting other organisms suggests that the genus may be a rhodophyte.
Guangxilamina incompta gen. et sp. nov.
(Pl. Ⅰ, fig. 4)
Thallus wavy, inconstant in thickness generally 0.02—0.07 mm (at most 0.12 mm) thick, and several centimetre wide. Order Chlorophyceae
Family Dasycladaceae Kutzing, 1843
Favoporella gen. nov.
Type species Favoporella hexagona gen. et sp. nov.
Diagnosis Thallus and stem swollen, cylindrical, not segmented. Only one class of side branches normal to and irreglalarly arranged on the stem.
Favoporella hexagona gen. et sp. nov.
(Pl. Ⅱ, fig. 2; Pl. Ⅲ, fig. 7; Pl. Ⅳ, fig. 6)
Thallus 7 mm wide; stem 2.5 mm wide. Side branches hexagonal in cross section, 0.05 mm in diameter.
Family Codiaceae Zanardini, 1843
Genus Ivanovia Khvorova, 1946
Ivanovia permica sp. nov.
(Pl. Ⅱ, fig. 8; Pl. Ⅲ, fig. 1)
Thallus 0.25 mm thick. Cortical region 0.075—0.12 mm wide, containing tubes 0.03—0.05 mm wide and 0.015—0.02 mm apart.
Genus Anchicodium Johnson, 1946
Anchicodium expressum sp. nov.
(Pl. Ⅱ, fig. 7; Pl. Ⅲ, fig. 2)
Thallus 0.67—1.00 mm thick. Medulla containing filaments which are 0.025 mm wide, sinuous and irregularly branched. Cortex 0.25 mm thick, containing filaments 0.01 mm wide.
Problematical Chlorophyta
Sinophyllum gen. nov.
Type species Sinophyllum hexagonum gen. et sp. nov.
Diagnosis Thallus sheetlike, consisting of small tubes normal to surface of thallus.
Sinophyllum hexagonum gen. et sp. nov.
(Pl. Ⅲ, fig. 1)
Thallus 0.25—0.50 mm thick. Tubes polygonal in cross section, 0.05 mm in diameter. Walls. between tubes 0.015 mm thick.
Sphaeroporella gen. nov.
Type species Sphaeroporella minima gen. et sp. nov.
Diagnosis Thallus spherical or hemispherical, cryptocrystalline in microstructure, consisting of a spherical or hemispherical stem cavitv and closely arranged fine branches (?) radiating from the wall of the stem cavity. Discussion This genus resembles Dasycladaceae in construction, but differs in its unique microstructure.
Sphaeroporella minima gen. et sp. nov. (Pl. Ⅳ, fig. 7)
Thallus 0.28mm and stem cavity 0.22—0 23 mm in diameter. Radiating tubes 0.005—0.007mm wide, and 0.025—0.03 mm long. Walls between tubes below 0.04 mm in thickness.
Monostysisyrinaceae fam. nov.
Type genus Monostysisyrinx gen. nov.
Definition Algae included in this family are characterized by small, erect, and unbranched tubular thalluses.
Monostysisyrinx gen. nov.
Type species Monostysisyrinx circularis gen. et sp. nov.
Diagnosis Thallus erect, unbranched, tubular, circular in cross section.
Discussion This genus is possibly a chlorophyte, as suggested by its growth form, living habit and preservation mode.
Monostysisyrinx eireularis gen. et sp. nov. (Pl. Ⅱ, fig. 3; Pl. Ⅲ, fig. 4; Pl. Ⅳ, figs. 3, 9)
Thallus over 10 cm high, circular in cross section, 0.1—0.5 mm in diameter. Walls of the tubes 0.005mm thick, cryptocrystalline in microstructure.
Paleoeeology This genus tended to grow into an 'algal forest', and was always encrusted by Archaeolithoporella, indicating a typical reef framer.
出处
《古生物学报》
CAS
CSCD
北大核心
1991年第6期750-767,811-814,共18页
Acta Palaeontologica Sinica
基金
国家自然科学基金
关键词
钙藻
生物礁
古生态
二叠世
calcareous algae, reefs, Permian, palaeoecology
