Dasycladales from the upper Maastrichtian of Salento peninsula (Puglia, Southern Italy)

被引:19
|
作者
Parente, M [1 ]
机构
[1] UNIV NAPLES,DIPARTIMENTO PALEONTOL,I-80138 NAPLES,ITALY
关键词
stratigraphy; facies; dasycladales; ciolo limestone; Salento peninsula (southern Italy); upper Cretaceous (Maastrichtian);
D O I
10.1007/BF02536879
中图分类号
P5 [地质学];
学科分类号
0709 ; 081803 ;
摘要
A rich dasycladalean assemblage, mainly consisting of new taxa, has been discovered in upper Maastrichtian coarse bioclastic limestones of shelf margin facies cropping out along the southeastern coast of Salento peninsula (Puglia, Southern Italy). It consists of 8 species grouped into 6 genera: Cymopolia decastroi PARENTE, 1994; C. barattoloi PARENTE, 1994; Zittelina fluegeli n. sp; Jodotella koradae (DIENI, MASSARI & RADOICIC, 1983) nov. comb.; Barattoloporella salentina n. gen. n. sp.; Morelletpora dienii n. sp.; Neomeris spp. (two different species). Zittelina fluegeli n. sp. is characterized by an ovoid thallus with calcification made by a calcareous wall enveloping only the proximal part of the branches (except in basal whorls) and by closely packed, and partly coalescent, calcified ampullae arranged all around the median and distal portion of branches. The transferral of Neomeris (Larvaria) koradae DIENI, MASSARI & RADOICIC, 1983 into the genus Jodotella, with the new combination Jodotella koradae, is proposed on the basis of new observations on the number and arrangement of fertile ampullae. The new genus Barattoloporella, type-species Barattoloporella salentina n. gen. n. sp., is erected for dasycladalean algae characterized by a segmented thallus. Each segment consists of: a) basal and apical sterile whorls made by primary branches only, b) central fertile whorls made by primary branches bearing in terminal position one fertile ampulla and one or two secondary branches. Morelletpora dienii n. sp. is characterized by a segmented thallus with barrel shaped to pear shaped repetitive elements, consisting of simple whorls of first order branches only. Shape of the branches varies from regularly phloiphorous to more or less differentiated in a stalk and a swollen portion, with or without a subterminal constriction. This is by far the most diverse dasycladalean assemblage ever found in the Maastrichtian. Its diversity supports the conclusion that, within the Late Cretaceous, the Maastrichtian represents a maximum in dasycladalean diversity. Its taxonomic composition strenghtens the hypothesis that dasycladaleans were hardly affected by K/T mass extinction.
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页码:91 / 122
页数:32
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