Herein we provide the first report of the rare cardiid bivalve Schedocardia from Cuba. The single, partial, valve external mold was derived from the Madruga Formation which is characterized by a richly diverse marine fauna including echinoderms, brachiopods, benthic and planktonic foraminiferans, but from which bivalves were not previously reported. The unit is considered late Paleocene in age (Thanetian), but the presence of Schedocardia supports a possible age extension of the formation into the early Eocene (Ypresian). Moreover, we provide a reconsideration of the historical factors that affected the accepted type locality of the outcrop, which allows for an alternative interpretation of the shallow water fauna found therein.

中文翻译：

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来自古巴的始新世双壳类Schedocardia（软体动物，心脏科）的首次报道

在此，我们提供了来自古巴的罕见心律性双壳类Schedocardia报告。单一的，部分瓣膜的外部霉菌来源于马德古拉组，其特征是海洋生物种类丰富，包括棘皮动物，腕足动物，底栖生物和浮游有孔虫，但以前从未报道过双壳类动物。该单元被认为是年龄较新世晚期（Thanetian），但Schedocardia的存在支持了该地层向新世早期（Ypresian）的年龄扩展。此外，我们重新考虑了影响露头公认类型局部性的历史因素，这为在其中发现的浅水动物区系提供了另一种解释。