The fossil record offers glimpses into ancient worlds, and a new study on Clypeaster echinoids from Cuba’s Damují Formation provides valuable insights into the Caribbean’s past. These fossils, dating from the Late Eocene to Early Oligocene, represent some of the earliest known occurrences of this genus in the region.
The research, conducted in Rodas, south-central Cuba, extends the known temporal and geographical range of Clypeaster, a genus of sand dollars that still thrives in tropical and subtropical oceans today. While previous studies focused on Oligocene and Miocene specimens, these newly examined fossils fill a gap in our understanding of how echinoids evolved and dispersed during a critical period of climatic transition—the Eocene-Oligocene boundary.
The geological context of the Damují Formation suggests that Clypeaster lived in a diverse marine environment, alongside large foraminifera, corals, and small fish. The presence of these fossils indicates that warm, shallow-water reef systems persisted in the Caribbean despite global cooling trends at the time. This challenges previous assumptions that echinoid diversification in the region occurred later, during the Miocene.
The study also raises intriguing questions about the role of the Caribbean as a migration corridor for marine life during the Paleogene. Were these Clypeaster populations early colonizers, or did they represent a more ancient lineage persisting through climatic shifts? Future research, including detailed morphological analyses and comparisons with other fossil sites, may help unravel the evolutionary pathways of these echinoids.
By documenting these fossils, this study contributes to our understanding of past ecosystems and the biogeographical history of echinoids. It also underscores the importance of Cuba’s fossil record in reconstructing ancient marine environments and refining our models of species distribution during critical periods of Earth’s history.
This work was made possible through the contributions of coauthors Carlos Rafael Borges-Sellén, Alberto F. Arano-Ruiz, Johanset Orihuela, and Yasmani Ceballos-Izquierdo, whose efforts in fieldwork, analysis, and writing were fundamental to this research. The full paper is available for download here.
The study is published in POEYANA, a peer-reviewed open-access journal (ISSN: 2410-7492, RNPS: 2403) that has been a cornerstone of zoological research in Cuba, the Caribbean, and the Neotropics since its founding in 1964. Originally established at the former Institute of Zoology of the Cuban Academy of Sciences, POEYANA is now edited by the Institute of Ecology and Systematics under the Ministry of Science, Technology, and Environment (CITMA). With over 500 published articles spanning more than five decades, the journal continues to serve as a platform for scientific contributions from Cuban and international researchers in the field of natural sciences.