Abstract New Aptian (Lower Cretaceous) bakevelliid bivalves are described for the Romualdo Formation, Santana Group, Araripe Basin, northeastern Brazil. Together with the other known member of the family Bakevelliidae, already recorded from the unit (i.e., Aguileria dissita), the new bivalves (Araripevellia musculosa gen. et sp. nov., Aguileria romualdoensis sp. nov., and Gen. et sp. indet.) indicate that the Romualdo bakevelliid fauna was more diverse than previously realized. Bakevelliid-rich carbonates, some with specimens preserved in situ, are restricted to the upper third of this unit, a stratigraphic interval yielding also echinoderm-, gastropod- and stromatolite-bearing limestones. These pteriomorphian bivalves were widely distributed in the Romualdo Formation and are a testimony of the short-lived Bakevelliid-Sea that flooded the whole Araripe Basin during the Aptian. Notably, Aguileria romualdoensis sp. nov. closely resembles Aguileria renauxiana from the Cenomanian Woodbine Formation, Texas, US. In addition, Aguileria dissita is also recorded in the upper Aptian–Albian Riachuelo Formation of the Sergipe-Alagoas Basin. Together with other macroinvertebrates (i.e., gastropods, echinoderms, bivalves) the bakevelliid fauna of the Romualdo Formation can be tightly correlated with that of the Riachuelo Formation, supporting a paleogeographic scenario with a marine ingression flooding the Araripe Basin from the southeast, probably via the seaway developed in the Reconcavo-Tucano basin area. Finally, sedimentologic, stratigraphic and paleontological data indicates that the fate of the bakevelliids in the Romualdo Formation was linked to the onset of continentalization of the Araripe Basin.

中文翻译：

---

巴西东北部 ARARIPE 盆地 APTIAN ROMUALDO 地层中的短寿命“BAKEVELLIID-SEA”

摘要 巴西东北部阿拉里佩盆地桑塔纳群的 Romualdo 组描述了新的 Aptian（下白垩纪）bakevelliid 双壳类动物。连同已从该单位记录的 Bakevelliidae 科的其他已知成员（即 Aguileria dissita），新的双壳类动物（Araripevellia musculosa gen. et sp. nov.、Aguileria romualdoensis sp. nov. 和 Gen. et sp.。 indet.) 表明 Romualdo bakevelliid 动物群比以前意识到的更加多样化。富含 Bakevelliid 的碳酸盐，其中一些带有原位保存的标本，仅限于该单元的上三分之一，这个地层间隔也产生了含有棘皮动物、腹足动物和叠层石的石灰岩。这些翼形双壳类动物广泛分布在 Romualdo 组中，是阿普蒂安期淹没整个阿拉里佩盆地的短命 Bakevelliid 海的见证。值得注意的是，Aguileria romualdoensis sp。十一月 与来自美国德克萨斯州 Cenomanian Woodbine Formation 的 Aguileria renauxiana 非常相似。此外，Sergipe-Alagoas 盆地上部 Aptian-Albian Riachuelo 组也记录了 Aguileria dissita。与其他大型无脊椎动物（即腹足动物、棘皮动物、双壳类动物）一起，Romualdo 组的贝氏动物群可以与 Riachuelo 组的动物群密切相关，支持古地理情景，海侵从东南部淹没阿拉里佩盆地，可能通过在 Reconcavo-Tucano 盆地地区开发了海道。最后，沉积学，