The San Sebastián Formation is a geologic formation in Puerto Rico. It preserves fossils dating back to the Oligocene period.[1]
| San Sebastián Formation | |
|---|---|
| Stratigraphic range: Early to Late Oligocene, | |
| Type | Formation |
| Unit of | Rio Guatemala Group |
| Lithology | |
| Primary | Limestone |
| Other | Sandstone, mudstone |
| Location | |
| Coordinates | 18°24′N 67°00′W / 18.4°N 67.0°W |
| Approximate paleocoordinates | 17°36′N 66°00′W / 17.6°N 66.0°W |
| Region |  Puerto Rico |
| Country |  United States |
| Type section | |
| Named for | San Sebastián, Puerto Rico |
It was primarily deposited as limestone in a marine environment, but some localities with a significant amount of terrestrial fauna appear to have been deposited in a deltaic environment. It contains some of the earliest fossils of terrestrial Caribbean vertebrates, including chinchilloid rodents and Eleutherodactylus frogs.[2][3] In addition, taxa that are no longer known from the Caribbean, such as gavialid crocodilians and geomyoid rodents, have also been recovered from the formation.[4]
Vertebrate paleofauna
editBased on the Paleobiology Database:[1]
Cartilaginous fish
edit| Genus | Species | Location | Notes | Images |
|---|---|---|---|---|
| Ginglymostomatidae indet. | A nurse shark of uncertain affinities. |
Amphibians
edit| Genus | Species | Material | Notes | Images |
|---|---|---|---|---|
| Eleutherodactylus | E. sp. | Distal humerus | A coquí frog.[3] | 
|
Reptiles
edit| Genus | Species | Material | Notes | Images |
|---|---|---|---|---|
| Aktiogavialis | A. puertoricensis | Incomplete braincase, cranial elements | A gavialid crocodilian. Type locality of genus and species. | 
|
| Pelomedusidae indet. | A pelomedusid side-necked turtle. |
Mammals
edit| Genus | Species | Material | Notes | Images |
|---|---|---|---|---|
| Borikenomys | B. praecursor | Teeth | A chinchilloid rodent. Type locality of genus and species.[2] | |
| Caribeomys | C. merzeraudi | Teeth | A geomyoid rodent. Type locality of genus and species, first evidence of geomyoids from the Caribbean.[4] | |
| Caribosiren | C. turneri | A dugongid sirenian. | ||
| Priscosiren | P. atlantica | A dugongid sirenian. |
See also
edit
References
edit- ^ a b "PBDB Strata Results". Paleobiology Database. Retrieved 2024-11-16.
- ^ a b Marivaux, Laurent; Vélez-Juarbe, Jorge; Merzeraud, Gilles; Pujos, François; Viñola López, Lázaro W.; Boivin, Myriam; Santos-Mercado, Hernán; Cruz, Eduardo J.; Grajales, Alexandra; Padilla, James; Vélez-Rosado, Kevin I.; Philippon, Mélody; Léticée, Jean-Len; Münch, Philippe; Antoine, Pierre-Olivier (2020-02-12). "Early Oligocene chinchilloid caviomorphs from Puerto Rico and the initial rodent colonization of the West Indies". Proceedings of the Royal Society B: Biological Sciences. 287 (1920): 20192806. doi:10.1098/rspb.2019.2806. ISSN 0962-8452. PMC 7031660. PMID 32075529.
- ^ a b Blackburn, David C.; Keeffe, Rachel M.; Vallejo-Pareja, María C.; Vélez-Juarbe, Jorge (2020). "The earliest record of Caribbean frogs: a fossil coquí from Puerto Rico". Biology Letters. 16 (4): 20190947. doi:10.1098/rsbl.2019.0947. ISSN 1744-9561. PMC 7211465. PMID 32264782.
- ^ a b Marivaux, Laurent; Vélez-Juarbe, Jorge; Viñola López, Lázaro W.; Fabre, Pierre-Henri; Pujos, François; Santos-Mercado, Hernán; Cruz, Eduardo J.; Grajales Pérez, Alexandra M.; Padilla, James; Vélez-Rosado, Kevin I.; Cornée, Jean-Jacques; Philippon, Mélody; Münch, Philippe; Antoine, Pierre-Olivier (2021). Lautenschlager, Stephan (ed.). "An unpredicted ancient colonization of the West Indies by North American rodents: dental evidence of a geomorph from the early Oligocene of Puerto Rico". Papers in Palaeontology. 7 (4): 2021–2039. doi:10.1002/spp2.1388. hdl:2027.42/170885. ISSN 2056-2799.
External links
edit- Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 17 December 2021.
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