The specimen-rich and diverse bryozoan fauna encrusting oyster shells from the Maastrichtian and Danian Jagüel and Roca formations in the Neuquén Basin (Patagonia, Argentina) is described. Thirteen cyclostome species are recorded, along with 18 cheilostomes. We introduce two new species: Akatopora kaufmanni sp. nov. and Eoporella lunata gen. et sp. nov. The latter is a homeomorph of the common Miocene–Recent genus Microporella. Ten of the cyclostomes and ten of the cheilostomes could not be identified at species-level because of preservational limitations or lack of diagnostic characters in the available specimens. The most common bryozoans present are sheet-like colonies, among which the ascophoran cheilostome Balantiostoma is particularly well represented. Results show that in northern Patagonia the diversity of encrusting bryozoans associated with oyster shells exhibits no major changes across the K/Pg boundary. However, an important increase in the diversity is recorded during the upper Danian.

描述了内乌肯盆地（阿根廷巴塔哥尼亚）Maastrichtian和DanianJagüel和Roca地层的牡蛎壳中富含牡蛎壳的富含标本的动物，种类繁多。记录了13种气孔菌物种以及18种化学stostostomes。我们引入了两个新物种：Akatopora kaufmanni sp.。十一月 和月见草（Eoporella lunata gen）。等 十一月 后者是常见的中新世近来微孔菌属的同胚异形体。由于现有样本的保存限制或缺乏诊断性，无法在物种一级鉴定出十个气旋成虫和十个化学成虫菌。存在的最常见的苔藓动物是片状菌落，其中的以虫为主要成分的蛇足石龟科Balantiostoma代表得特别好。结果表明，在巴塔哥尼亚北部，包裹牡蛎壳的苔藓虫的多样性在整个K / Pg边界上没有显着变化。但是，在上大年纪期间记录到了多样性的重要增加。