Expeditions

AP3: Antarctica Peninsula Paleontology Project

February 29–March 6, 2016

Project G-182-N (PI Matt Lamanna)

The team completed several of its research objectives and continued to make progress towards others during week three. At the Sandwich Bluff locality on Vega Island, scientists discovered four new fossil plant sites, found additional Cretaceous fish and bird material, and prepared a plesiosaur (long-necked marine reptile) shoulder girdle for extraction.

All of these specimens were recovered from the Upper Cretaceous Sandwich Bluff Member of the López de Bertodano Formation. At approximately 70 million years in age, this rock unit dates to only a few million years prior to the infamous mass extinction that ended the Mesozoic era, or Age of Dinosaurs.

Geologists Eric Roberts and Zubair Jinnah completed their stratigraphic and sedimentological study of the sections of the Snow Hill Island and López de Bertodano formations exposed on the southwestern flank of Sandwich Bluff, an area that, due to its steepness, elevation, and snow cover, has been nicknamed ‘K2’ after that well-known Himalayan peak. They sampled the middle and upper levels of the Sandwich Bluff Member for aragonitic fossil invertebrate shells to be used in strontium isotope geochronological analyses.

Scientists also continued to conduct helicopter-supported reconnaissance visits to other areas of the James Ross Basin, identifying two previously undocumented Cretaceous exposures that were targeted for future investigation.

Inclement weather forced many members of the team to return to their ship, the RVIB Nathaniel B. Palmer, for two days during week three. They spent the time refining strategies for the remainder of the field season, updating the project’s blog and social media pages, and studying fossils that had already been collected.

1) G-182-N paleontologists Abby West (left) and Steve Salisbury (center) collect a plesiosaur shoulder girdle co-discovered by Salisbury with ASC Marine Technician Julia Carlton (right). Photo by Matt Lamanna.

2) G-182-N geologists Zubair Jinnah (foreground) and Eric Roberts study the stratigraphy and sedimentology of the ‘K2’ section on Vega Island. Photo by Pat O’Connor.

3.) G-182-N paleontologist Kerin Claeson searches for fossils in the ‘Fish Horizon’ near the K–Pg boundary on Seymour Island. Claeson and other G-182-N personnel have collected dozens of partial to nearly complete fish skeletons from the ‘Fish Horizon’ to date, the analysis of which promises to inform understanding of the K–Pg mass extinction in the southern high latitudes. Photo by Meng Jin.

Matt Lamanna is a paleontologist and the principal dinosaur researcher at Carnegie Museum of Natural History in Pittsburgh. Matt and his team of researchers blog frequently from Antarctica while on expedition at antarticdinos.org.

AP3: Antarctica Peninsula Paleontology Project

February 21–28, 2016

Project G-182-N (PI Matt Lamanna)

Work at the main basecamp on the western shore of Vega Island continued in week two and resulted in the discovery of a wealth of fossils.

Senior project geologist Eric Roberts located a partial plesiosaur. The specimen, which preserves numerous vertebrae, ribs, paddle bones, and gastroliths (stomach stones), appears to be the most complete marine reptile discovered by the project to date. Many of its bones remain articulated (preserved in life position) and are beautifully preserved within sandstone concretions. With time and effort in the laboratory, much of the postcranial skeleton will likely be reassembled and will likely be significant both for scientific study and possible display.

The project made significant progress towards its geological aims as well. Roberts and fellow geologist Zubair Jinnah continued their efforts to decipher the age and depositional environments of the sediments exposed on the uppermost levels of Sandwich Bluff. They collected rock and fossil samples from the uppermost Sandwich Bluff Member and basal Sobral Formation for geochemical and palynological analyses and strontium isotopic dating. They also began to subdivide the Sobral Formation into discrete units, as Roberts and colleagues did for the Sandwich Bluff Member in a 2014 paper.

Helicopter reconnaissance efforts continued with additional trips to Seymour and eastern Vega Island. Considerable effort was expended during week two towards installing a field camp near the Cretaceous–Paleogene boundary horizon in the central area of Seymour Island. Those at the camp are having success in recovering fossils of fishes, putative turtles, and other Cretaceous vertebrates.

Lastly, filmmaker Matt Koshmrl continues to skillfully document all aspects of the project through video and still photography.

Also discovered during week two

– A second plesiosaur partial skeleton. Several partial-to-complete fossil leaves and a conifer branch. Partial skeletons of Cretaceous fishes that may be the most completely-preserved fishes yet found from Cretaceous sediments on Vega Island.

– A partial dorsal rib of a very large-bodied tetrapod, possibly a sauropod (long-necked plant-eating dinosaur)

– Multiple isolated Cretaceous bird bones were also collected, as was a possible avian skull

– An abundance of exceptionally-preserved Eocene penguin bones, including a partial skull of a giant species (possibly Anthropornis nordenskjoeldi or Palaeeudyptes antarcticus). This is exciting as only a handful of cranial elements of fossil penguins have ever been described from Seymour Island.

Matt Lamanna is a paleontologist and the principal dinosaur researcher at Carnegie Museum of Natural History in Pittsburgh. Matt and his team of researchers blog frequently from Antarctica while on expedition at antarticdinos.org.

“It’s not just dino bones we’re seeking. Here’s some fossilized wood found on Cape Lamb.”

Matt Lamanna is a paleontologist and the principal dinosaur researcher at Carnegie Museum of Natural History in Pittsburgh. Matt and his team of researchers blog frequently from Antarctica while on expedition at antarticdinos.org.