Abstract
ABSTRACT We report 130 vertebrate fossils preserved as bony elements and the co-occurring assemblage of fish teeth and spines from the lower strata of the Pisco Formation exposed along the western side of the lower Ica Valley (East Pisco Basin, Peru). Geological mapping at 1:10,000 scale reveals that all these fossils originate from the Langhian–Serravallian P0 allomember. In the study area, P0 is up to ∼40 m thick and features a sandy lower portion, reflecting shoreface deposition, that fines upwards into a package of offshore silts. Marine vertebrates only occur in the lower sandy layers and include whales, dolphins, reptiles, birds, and bony and cartilaginous fishes. The reconstructed paleoenvironment is consistent with a warm-water, marginal-marine setting with a strong connection to the open ocean. This work helps to elucidate the rich yet still poorly understood middle Miocene portions of the Pisco Formation, and highlights the need to conserve this outstanding Fossil-Lagerstätte.
Highlights
The middle Miocene to Pliocene Pisco Formation of southern Peru is a shallow-marine sedimentary unit consisting of diatomaceous mudstones, siliciclastic sandstones, and siltstones, nodular dolomite layers, tephra beds, and minor conglomeratic and phosphatic intervals (Brand et al, 2011; de Muizon & DeVries, 1985; Di Celma, Malinverno, Cantalamessa, et al, 2016; Di Celma, Malinverno, Gariboldi, et al, 2016; Dunbar et al, 1990)
The Pisco Formation is known to paleontologists worldwide for the richness, abundance and quality of its vertebrate fossils
In the surroundings of the Ocucaje village (Ica desert), integrated studies aimed at elucidating the spatial and stratigraphic distribution of the fossil vertebrates from the Pisco Formation have been recently performed at the localities of Cerro Colorado, Cerro Los Quesos, Cerro Queso Grande and Cerro Ballena (Bianucci, Di Celma, Collareta, et al, 2016; Bianucci, Di Celma, Landini, et al, 2016; Esperante et al, 2015), resulting in the construction of a rather comprehensive overview of the late Miocene vertebrate assemblages from the Pisco Lagerstätte (Di Celma et al, 2017)
Summary
The middle Miocene to Pliocene Pisco Formation of southern Peru is a shallow-marine sedimentary unit consisting of diatomaceous mudstones, siliciclastic sandstones, and siltstones, nodular dolomite layers, tephra beds, and minor conglomeratic and phosphatic intervals (Brand et al, 2011; de Muizon & DeVries, 1985; Di Celma, Malinverno, Cantalamessa, et al, 2016; Di Celma, Malinverno, Gariboldi, et al, 2016; Dunbar et al, 1990). The Pisco Formation is known to paleontologists worldwide for the richness, abundance and quality of its vertebrate fossils. The latter include sharks and rays, bony fishes, marine turtles and crocodiles, seabirds, cetaceans (featuring both baleen-bearing and echolocating toothed whales), pinnipeds (seals) and sloths, which collectively provide one of the best record of Neogene marine vertebrates anywhere in the world Examples of exceptional preservation range from phosphatized whale baleen plates to stomach contents, regurgitations and even skeletons of cartilaginous fishes like sharks, characterizing the Pisco Formation as a true Konservat-Lagerstätte (Bianucci, Di Celma, Urbina, et al, 2016; Bosio et al, in press; Collareta et al, 2015, Collareta, Landini, et al, 2017; Gariboldi et al, 2015; Gioncada et al, 2016; Gioncada, Gariboldi, et al, 2018; Gioncada, Petrini, et al, 2018; Lambert et al, 2015; Marx, Collareta, et al, 2017). The middle Miocene basal strata of the Pisco Formation and their fossil vertebrate content have been only cursorily investigated (Bosio, Malinverno, Collareta, et al, 2020; Di Celma et al, 2017), the lower Pisco strata are thought to be home to important fossils such as the holotypes of the basal delphinidan Incacetus broggi
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
