Cerro Lisandro Formation
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The Cerro Lisandro Formation is a geologic formation with outcrops in the Neuquén province of Argentina. It is the youngest formation within the Río Limay Subgroup, the lowest section of the Neuquén Group.
The type locality of the Cerro Lisandro Formation is the hill known as Cerro Lisandro in Neuquén province (Fossa Mancini et al. 1938). This formation conformably overlies the Huincul Formation, and it is in turn overlain by the Portezuelo Formation, which is a part of the Río Neuquén Subgroup.
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[edit] Age
Era: Mesozoic
Period: Late Cretaceous
Faunal stage: early Turonian
Absolute Age: ~94 to ~91 mya
[edit] Composition
The Candeleros Formation varies between 35 and 75 meters thick, the smallest of the three formations in its subgroup. It is made up of siltstones and claystones, red in color, which have been interpreted as a swampy environment (Leanza et al. 2004.
[edit] Paleontology
Not many dinosaurs are represented in the Cerro Lisandro Formation, although other types of animals are frequently found, including:
- freshwater bivalve molluscs
- fish
- turtles
- crocodilians
- an abelisauroid theropod
- at least one bird
- ornithopods (including Anabisetia)
The swampy terrain may have limited the numbers of larger dinosaurs such as sauropods and carcharodontosaurids, which are found in earlier formations in the region but have not yet been found in the Cerro Lisandro.
[edit] References
- Fossa Mancini, E., Feruglio, E., Yussen de Campana, J.C.. 1938. Una reunión de geólogos de YPF y el problema de la terminología estratigráfica. Boletín de Informaciones Petroleras 15: 1-67.
- Leanza, H.A,, Apesteguia, S., Novas, F.E. & de la Fuente, M.S. 2004. Cretaceous terrestrial beds from the Neuquén Basin (Argentina) and their tetrapod assemblages. Cretaceous Research 25(1): 61-87.
