Paläontologisches Institut und Museum, Universität Zürich, Karl-Schmid-Strasse 4, 8006 Zürich, Switzerland.
Center for Tropical Paleoecology and Archeology, Smithsonian Tropical Research Institute, Balboa, Ancón 0843-03092, Panama.
Biol Lett. 2023 Jun;19(6):20230124. doi: 10.1098/rsbl.2023.0124. Epub 2023 Jun 21.
Fossil cetaceans are often found in Miocene marine outcrops across the globe. However, because this record is not homogeneous, the dissimilar increase in occurrences, along with the sampling bias has created regions with extensive records and others with great scarcity. Among these, the Caribbean has remained enigmatic due to the lack of well-preserved cetacean fossils. Here, we report new Caribbean fossil cetaceans from the Upper Miocene Chagres Formation exposed along Piña beach, Eastern Panama, including a scaphokogiine kogiid, an -like physeteroid and the phocoenid . Along with previous records of the iniid and the kogiine , the Chagres cetacean fauna shows some similarities with other Late Miocene cetacean communities such as the Californias in the North Pacific, although their closest affinities lie with the eastern South Pacific Pisco Formation, Peru. Such findings indicate that though deep and intermediate Caribbean-Pacific water interchange was reduced by the Middle Miocene due to the shallowing of the Central American Seaway, shallow waters marine connection that persisted until the Pliocene might have facilitated the dispersal of coastal species across both sides of the Isthmus.
古鲸类动物常被发现在世界各地中新世的海洋露头中。然而，由于这个记录并不均匀，不同的出现率增加，以及采样偏差，导致一些地区有广泛的记录，而另一些地区则非常稀缺。在这些地区中，加勒比地区由于缺乏保存完好的鲸类化石而一直是个谜。在这里，我们报告了来自巴拿马东部皮纳海滩上新世 Chagres 组的新的加勒比古鲸类动物，包括一个 scaphokogiine kogiid、一个 -like physeteroid 和一个 phocoenid 。加上之前记录的 iniid 和 kogiine，Chagres 鲸类动物群与其他中新世晚期鲸类动物群（如北太平洋的加利福尼亚州）有一些相似之处，尽管它们最接近的亲缘关系是秘鲁东部的南太平洋皮斯科组。这些发现表明，尽管由于中美洲海道的变浅，中中新世期间深层和中层加勒比-太平洋水交换减少，但一直持续到上新世的浅水海洋连接可能促进了沿海物种在地峡两侧的扩散。
