IPCH 3D Scans Cycadeoidea Fossil

In the late 1800s, amid the hubbub of the Black Hills Gold Rush and the lawlessness of Deadwood, a great scientific discovery was made in Dakota Territory. A specimen dealer unearthed a treasure-trove of beautifully preserved petrified tree trunks. The stout tree trunks, with diamond shaped cavities from which leaves once sprouted, were unlike any contemporary tree trunks in the area. They harkened back to an older time and were subtropical in appearance. These fossils were classified as Cycadeoidea.

Cycadeoidea were very common during the Jurassic and Cretaceous, when dinosaurs last roamed the Earth. They date to a time when the global climate was comparatively warm and as a result sea levels were considerably higher. It is projected that during this period, North America was oriented about a 45 degree rotation toward the Prime Meridian and was situated closer to the equator than today. This gave present-day South Dakota a warm climate, which fostered conditions quite hospitable to Cycadeoidea.

In 1898, George Reber Wieland, a paleontologist from the Peabody Museum, who was on assignment collecting vertebrate fossils in Dakota Territory on behalf of O.C Marsh, learned about the rich cretaceous Cycadeoidea trunks in Black Hills. George Reber Wieland was intrigued by the fossilized plants found here and shifted his focus to collecting and studying the 120 million year old Cycadeoidea specimens.  Wieland is credited with amassing a collection of around one thousand specimens.

A view of a Cycadeoidea fossil locality in South Dakota in 2012. Photograph taken by Shusheng Hu.

A view of a Cycadeoidea fossil locality in South Dakota in 2012. Image taken by Shusheng Hu.

This collection, still the largest Cycadeoidea collection in the world, is housed here at Yale and currently cared for by the Collections Manager of Paleobotany, Shusheng Hu. Shusheng approached the Digitization Lab in October of 2014 with the idea of digitizing the well-preserved structures of a Cycadeoidea trunk as a part of a greater conservation and research project.  This project, lead by the curator of Paleobotany, Dr. Peter Crane, focuses on the origin of early angiosperms, or flowering plants. The Cycadeoidea specimens are viewed as crucial to this project as they may provide new information about the origin of angiosperms. Since these specimens are quite heavy and precarious to move, creating 3D models has the capacity to greatly aid research, teaching and exhibition!

Scanning the Cycadeoidea trunk on location at the Yale Peabody Museum. Photograph taken by Shusheng Hu.

Scanning the Cycadeoidea trunk on location at the Yale Peabody Museum. Image taken by Shusheng Hu.

The Cycadeoidea trunk was acquired via ShapeGrabber triangulation laser scanner on location at the Peabody Museum.  The fossil was rotated between scans taken from different angles and objects were placed in the foreground to aid in alignment. Once the acquisition was complete, much time was invested in post-processing. Individual scans were cleaned, aligned and refined in order to yield the final geometry of the model.

Visualizing geometry of the 3D model in MeshLab. Snapshots taken with the Lambertian Lit Sphere radiance scaling shader applied.

Visualizing geometry of the 3D model in MeshLab. Snapshots taken with the Lambertian Lit Sphere radiance scaling shader applied.

This geometry has the potential to be interacted with and analyzed remotely by paleobotanists and enthusiasts alike. The 3D model has been incorporated into visualizations for education and outreach.

Cycad_02HardLightEffect

The 3D model, visualizations and print of this fossil were created with contributions and assistance from Chelsea Graham of the Yale IPCH Digitization Lab, Shusheng Hu of the Yale Peabody Museum, Holly Rushmeier of the Department of Computer Science and Ngoc Doan of the Yale CEID. Special thanks must also be given to Tim White and Annette Van Aken of the Yale Peabody Museum for coordinating and providing transportation of the equipment.

 

Leave a Reply

Your email address will not be published.