Chilcatay Formation
| Chilcatay Formation | |
|---|---|
| Stratigraphic range: Early Miocene (Burdigalian)[1] ~ | |
| Type | Geological formation |
| Unit of | Pisco Basin |
| Underlies | Pisco Formation |
| Overlies | Otuma Formation |
| Lithology | |
| Primary | Sandstone, siltstone |
| Location | |
| Country |  Peru |
The Chilcatay Formation is a geologic formation located in Peru. The formation was deposited in the Pisco Basin, during the Early Miocene, roughly from 19.2 to 18.0 Ma. Fossil remains of baleen whales, sharks, and rays have been found in the formation.[2][3]
Paleobiota of the Chilcatay Formation
[edit]Mammals
[edit]Dolphins
[edit]| Taxa | Species | Material | Description | Images | Notes |
|---|---|---|---|---|---|
| Huaridelphis | H. raimondii | A squalodelphinid river dolphin | |||
| Incacetus | I. broggii | A kentriodontid dolphin | |||
| cf. Kentriodon | cf. K. sp. | A kentriodontid dolphin | |||
| Macrosqualodelphis | M. ukupachai | A squalodelphinid river dolphin | |||
| Notocetus | N. vanbenedeni | A squalodelphinid river dolphin | |||
| Squalodelphinidae | Gen. et. sp. indet. | A river dolphin |
Whales
[edit]| Taxa | Species | Material | Description | Images | Notes |
|---|---|---|---|---|---|
| Cetotheriidae | Gen. et. sp. indet. | ||||
| Chaeomysticeti | Gen. et. sp. indet. | A partial skull (CTZ 02) | A baleen whale; either a late-diverging stem mysticete or an early-branching crown mysticete | ||
| A badly damaged dentary (ZM 98) | A baleen whale; crownward of Eomysticetidae | ||||
| A skull (ZM 152) | A crown-group baleen whale, possibly a basal plicogulan | ||||
| Chilcacetus | C. cavirhinus | A toothed whale | |||
| Eurhinodelphinidae | Gen. et. sp. indet. | A toothed whale | |||
| Inticetus | I. vertizi | A toothed whale | |||
| Mysticeti | Gen. et. sp. indet. | A baleen whale | |||
| Odontoceti | Gen. et. sp. indet. | A toothed whale | |||
| Physeteroidea | Gen. et. sp. indet. | A sperm whale |
Seals
[edit]| Taxa | Species | Material | Description | Images | Notes |
|---|---|---|---|---|---|
| Pinnipedia | Gen. et. sp. indet. | A seal |
Birds
[edit]Penguins
[edit]| Taxa | Species | Material | Description | Images | Notes |
|---|---|---|---|---|---|
| Palaeospheniscus | P. sp. | A early penguin |
Reptiles
[edit]Turtles
[edit]| Taxa | Species | Material | Description | Images | Notes |
|---|---|---|---|---|---|
| Testudines | Gen. et. sp. indet. | A turtle |
Crocodilians
[edit]| Taxa | Species | Material | Description | Images | Notes |
|---|---|---|---|---|---|
| Sacacosuchus | S. cordovai | A gavialid crocodilian |
Cartilaginous fish
[edit]Rays
[edit]| Taxa | Species | Material | Description | Images | Notes |
|---|---|---|---|---|---|
| cf. Anoxypristis | cf. A. sp. | A rostral spine | A sawfish | ||
| Dasyatidae | Gen. et. sp. indet. | Dermal denticles | A whiptail stingray | ||
| Myliobatoidea | Gen. et. sp. indet. | Teeth | A stingray; several of the teeth compare favorably with Myliobatis eagle rays |
Sharks
[edit]| Taxa | Species | Material | Description | Images | Notes |
|---|---|---|---|---|---|
| Alopias | A. superciliosus | Teeth | The bigeye thresher | ||
| A. cf. vulpinus | Teeth | Tentatively assigned to the common thresher | |||
| Anotodus | A. agassizii | Teeth | A thresher shark | ||
| Carcharhinus | C. brachyurus | Teeth | The copper shark | ||
| C. cf. leucas | A tooth | Tentatively assigned to the bull shark | |||
| Carcharias | C. sp. | Teeth | A sand tiger shark | ||
| Carcharodon | C. subauriculatus | A white shark | |||
| Cosmopolitodus | C. hastalis | Teeth | White sharks | ||
| C. plicatilis | Teeth | ||||
| Galeocerdo | G. aduncus | Teeth | A tiger shark | ||
| Hemipristis | H. serra | Teeth | A weasel shark | ||
| Isurus | I. oxyrinchus | Teeth | The shortfin mako shark | ||
| Megalolamna | M. paradoxodon | A tooth | A megatoothed shark | ||
| Megachasma | M. cf. applegatei | Teeth | A megamouth shark | ||
| Negaprion | N. brevirostris | Teeth | The lemon shark | ||
| Otodus | O. chubutensis | Teeth | A megatoothed shark; sometimes placed in separate genus Carcharocles | ||
| Parotodus | P. benedenii | Teeth | A possible megatoothed shark | ||
| Physogaleus | P. contortus | Teeth | A ground shark | ||
| Sphyrna | S. zygaena | Teeth | The smooth hammerhead | ||
| Squatina | S. sp. | Teeth | An angel shark |
References
[edit]- ^ Bosio, Giulia; Malinverno, Elisa; Villa, Igor Maria; Di Celma, Claudio; Gariboldi, Karen; Gioncada, Anna; Barberini, Valentina; Urbina, Mario; Bianucci, Giovanni (2020-03-25). "Tephrochronology and chronostratigraphy of the Miocene Chilcatay and Pisco formations (East Pisco Basin, Peru)". Newsletters on Stratigraphy. 53 (2): 213–247. Bibcode:2020NewSt..53..213B. doi:10.1127/nos/2019/0525. ISSN 0078-0421.
- ^ Nobile, Francesco; Lambert, Olivier; Bianucci, Giovanni; Amson, Eli; Bosselaers, Mark; Bosio, Giulia; Pellegrino, Luca; Malinverno, Elisa; Di Celma, Claudio; Urbina, Mario; Collareta, Alberto (2025-03-13). "Surviving a Dark Age: The Oldest Baleen-Bearing Whales (Cetacea: Chaeomysticeti) of Pacific South America (Lower Miocene, Peru)". Life. 15 (3): 452. doi:10.3390/life15030452. ISSN 2075-1729. PMC 11944254. PMID 40141799.
- ^ Landini, Walter; Collareta, Alberto; Di Celma, Claudio; Malinverno, Elisa; Urbina, Mario; Bianucci, Giovanni (2019-04-01). "The early Miocene elasmobranch assemblage from Zamaca (Chilcatay Formation, Peru)". Journal of South American Earth Sciences. 91: 352–371. Bibcode:2019JSAES..91..352L. doi:10.1016/j.jsames.2018.08.004. ISSN 0895-9811.