Abstract A lower and upper Barremian 690 m-thick succession composed of freshwater and brackish limestones, marls and clays was measured and sampled in the Maestrat Basin, Eastern Iberian Chain (Castello, Spain). Thirty-three taxa were identified from charophyte fructifications and thalli, belonging to the three families that coexisted during the Early Cretaceous, i.e. Porocharaceae, Characeae and Clavatoraceae. Up to 25 different Clavatoraceae utricles were identified. This high species richness of clavatoraceans has not been observed elsewhere and sheds light on the role of Iberia, and particularly the Maestrat Basin, as a diversity hotspot for this family during the Barremian. Several of them have been taxonomically revisited, as regards both utricles and thalli. The Echinochara lazarii utricle is reinterpreted as showing bilateral rather than triradial symmetry. Anagenetic evolution within Clavator calcitrapus has been documented and has enabled us to distinguish between two varieties linked by intermediate morphotypes of biostratigraphic and palaeobiogeographic interest. The taxon Clavator grovesii var. jiuquanensis is reported for the first time in the Iberian Chain and in Spain. The structure of Charaxis spicatus is revisited and a new type of cortication is defined, called the double triplostichous cortication, which is unknown in either fossil or extant charophytes. This thallus is found in anatomical connection with Echinochara lazarii utricles, enabling a whole-plant reconstruction of the Echinochara plant. Lastly, new characters were found in Munieria grambastii thalli that confirm the membership of genus Munieria to the clavatoracean charophytes, particularly the calcification pattern of the internodal cell, which recalls that of clavatoroid utricles.

中文翻译：

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来自 Maestrat 盆地的 Barremian 轮藻（伊比利亚链）

摘要 在东伊比利亚链（西班牙卡斯特洛）的 Maestrat 盆地测量并采样了一个由淡水和微咸石灰岩、泥灰岩和粘土组成的下巴雷米亚和上巴雷米亚 690 米厚的层序。从轮藻结实和菌体中鉴定出33个分类群，属于早白垩世共存的三个科，即孔木科、木兰科和棒状科。鉴定了多达 25 种不同的 Clavatoraceae 椭圆囊。克拉托科动物的这种高物种丰富度在其他地方尚未观察到，这揭示了伊比利亚，特别是马埃斯特拉特盆地在巴雷米亚时期作为该科物种多样性热点的作用。其中一些已经在分类学上重新审视，关于胞囊和菌体。Echinochara lazarii 椭圆囊被重新解释为显示双边而不是三径向对称。Clavator calcitrapus 内的后生进化已被记录在案，使我们能够区分通过生物地层学和古生物地理兴趣的中间形态类型相关联的两个变种。分类群 Clavator grovesii var. 酒泉种首次在伊比利亚链和西班牙被报道。Charaxis spicatus 的结构被重新审视，并定义了一种新的皮质，称为双三叶皮质，这在化石或现存的轮藻中都是未知的。这种叶状体在解剖学上与 Echinochara lazarii 胞囊相连，从而能够重建 Echinocara 植物的全株。最后，