When paleontology meets technology: 3D reconstructions of fossil vertebrates from the Pisco Formation (Ica, Peru)

Abstract

In the last years different 3D reconstruction methods have been increasingly used in paleontological studies, especially in vertebrate paleontology. Recently we supported our taphonomic studies on the marine vertebrate assemblage from the Pisco Formation (Peru) by using a 3D rendering technique. We chose the Agisoft PhotoScan Software which elaborates 3D images from just a photo shooting in series around the fossil. For the successful completion of the 3D reconstruction we factored 50% overlap between a photo and the next one. The main challenge during image capture was the different lighting of exposed bones and the low contrast between the fossil and the background; for example, sometimes the color contrast between bones and the surrounding sediment was poorly defined. The fossils from Pisco Formation are particularly indicated for this technique due to their exceptional preservation permitting to get spectacular and very informative 3D images. A significant fossil from a taphonomic point of view is a portion of a partially articulated skeleton of Messapicetus gregarius (Cetacea, Ziphiidae) discovered in Cerro Colorado, the type locality of the giant stem sperm whale Livyatan melvillei. The 3D image evidences the peculiar preservation of this fossil with the skull and articulated mandibles far from the thoracic portion of the skeleton (ribs, vertebrae and sternum partially articulated). Another interesting specimen consists of a large skeleton of a balaenopteroid cetacean from Cerro los Quesos locality. Its 3D image shows the skull lying dorsally and partially destroyed by the Recent erosion, the mandibles a few centimeters displaced from their original position, the incomplete vertebral column with several fragmented ribs and a scapula. A third examined specimen is now kept in the Museum de Historia Natural de la Universitad Nacional Mayor de San Marco. This fossil is still partially inside the sediment. The bones are exceptionally well preserved: the skull and the mandibles are articulated whereas the postcranial skeleton (vertebrae, ribs and scapulae) are disarticulated but still associated. The specimen belongs to Brachydelphis mazeasi (Cetacea, Pontoporiidae) and was collected in Corriviento locality. The three-dimensional reconstructions of the specimens above described represent the first application of 3D technology to the paleontological studies conducted in the areas of the Pisco Formation. Acknowledgements. This research was supported by a grant of the Italian Ministero dell’Istruzione, dell’Università e della Ricerca (PRIN Project 2012YJSBMK) and by a National Geographic Society Committee on Research Exploration grant (9410-13)