Research: Whale fossil provides key to unlock date of East Africa’s mysterious uplift

Michael Polcyn

Research: Whale fossil provides key to unlock date of East Africa’s mysterious uplift

A 17 million-year-old Turkana ziphiid beaked whale fossil from the Great Rift Valley, East AfricaPaleontologists have used a fossil from the most precisely dated beaked whale in the world to pinpoint for the first time a date when East Africa’s mysterious elevation began.

The 17 million-year-old fossil is from the Ziphiidae family. It was discovered 740 kilometers inland at a elevation of 620 meters in modern Kenya’s harsh desert region and is the only stranded whale ever found so far inland on the African continent, said SMU vertebrate paleontologist Louis Jacobs.

Uplift associated with the Great Rift Valley of East Africa and the environmental changes it produced have puzzled scientists for decades because the timing and starting elevation have been poorly constrained. Determining ancient land elevation is very difficult, but the whale provides one near sea level.

“It’s rare to get a paleo-elevation,” Jacobs said, noting only one other in East Africa, determined from a lava flow.

At the time the whale was alive, it would have been swimming far inland up a river with a low gradient ranging from 24 to 37 meters over more than 600 to 900 kilometers, said Jacobs. He is co-author of a study, published in the Proceedings of the National Academy of Sciences, that provides the first constraint on the start of uplift of East African terrain from near sea level.

“The whale was stranded up river at a time when east Africa was at sea level and was covered with forest and jungle,” Jacobs said. “As that part of the continent rose up, that caused the climate to become drier and drier. So over millions of years, forest gave way to grasslands. Primates evolved to adapt to grasslands and dry country. And that’s when – in human evolution – the primates started to walk upright.”

Identified as a Turkana ziphiid, the whale would have lived in the open ocean, like its modern beaked cousins. Ziphiids, still one of the ocean’s top predators, are the deepest diving air-breathing mammals alive, plunging to nearly 10,000 feet to feed, primarily on squid.

In contrast to most whale fossils, which have been discovered in marine rocks, Kenya’s beached whale was found in river deposits, known as fluvial sediments, said Jacobs, a professor in the Roy M. Huffington Department of Earth Sciences of SMU’s Dedman College of Humanities and Sciences.

The whale, probably disoriented, swam into the river and could not change its course, continuing well inland.

“You don’t usually find whales so far inland,” Jacobs said. “Many of the known beaked whale fossils are dredged by fishermen from the bottom of the sea.”

The beaked whale fossil was discovered in 1964 by J.G. Mead in what is now the Turkana region of northwest Kenya. Mead, an undergraduate student at Yale University at the time, made a career at the Smithsonian Institution, from which he recently retired. Over the years, the Kenya whale fossil went missing in storage.

Jacobs, who was at one time head of the Division of Paleontology for the National Museums of Kenya, spent 30 years trying to locate the fossil. His effort paid off in 2011, when he rediscovered it at Harvard University and returned it to the National Museums of Kenya.

The fossil is only a small portion of the whale, which Mead originally estimated was 7 meters long during its life. Mead unearthed the beak portion of the skull, 2.6 feet long and 1.8 feet wide, specifically the maxillae and premaxillae, the bones that form the upper jaw and palate.

The researchers reported their findings in “A 17-My-old whale constrains onset of uplift and climate change in east Africa” online at the PNAS web site. Besides Jacobs, other authors from SMU are Andrew Lin, Michael Polcyn, Dale Winkler and Matthew Clemens.

From other institutions, authors are Henry Wichura and Manfred R. Strecker, University of Potsdam, and Fredrick K. Manthi, National Museums of Kenya.

Funding for the research came from SMU’s Institute for the Study of Earth and Man and the SMU Engaged Learning program.

Written by Margaret Allen

> Read the full story from the SMU Research blog

March 19, 2015|For the Record, News, Research|

Research Spotlight: Digital dino track a roadmap for saving at-risk natural history resources

Portable laser scanning technology allows researchers to tote their latest fossil discovery from the field to the lab in the form of lightweight digital data stored on a laptop. But sharing that data as a 3D model with others requires standard formats that are currently lacking, say SMU paleontologists.

University researchers used portable laser scanning technology to capture field data of a huge 110 million-year-old Texas dinosaur track and then create to scale an exact 3D facsimile. They share their protocol and findings with the public – as well as their downloadable 145-megabyte model – in the online scientific journal Palaeontologia Electronica.

The model duplicates an actual dinosaur footprint fossil that is slowly being destroyed by weathering because it’s on permanent outdoor display, says SMU paleontologist Thomas L. Adams, lead author of the scientific article. The researchers describe in the paper how they created the digital model and discuss the implications for digital archiving and preservation. Click here for the download link.

“This paper demonstrates the feasibility of using portable 3D laser scanners to capture field data and create high-resolution, interactive 3D models of at-risk natural history resources,” write the authors.

“3D digitizing technology provides a high-fidelity, low-cost means of producing facsimiles that can be used in a variety of ways,” they say, adding that the data can be stored in online museums for distribution to researchers, educators and the public.

SMU paleontologist Louis L. Jacobs is one of the coauthors on the article. “The protocol for distance scanning presented in this paper is a roadmap for establishing a virtual museum of fossil specimens from inaccessible corners across the globe,” Jacobs said.

The full-resolution, three-dimensional digital model of the 24-by-16-inch Texas footprint is one of the first to archive an at-risk fossil, the SMU paleontologists say. They propose the term “digitype” for such facsimiles, writing in their article “High Resolution Three-Dimensional Laser-scanning of the type specimen of Eubrontes (?) Glenrosensis Shuler, 1935, from the Comanchean (Lower Cretaeous) of Texas: Implications for digital archiving and preservation.”

Laser scanning is superior to other methods commonly used to create a model because the procedure is noninvasive and doesn’t harm the original fossil, the authors say. Traditional molding and casting procedures, such as rubber or silicon molds, can damage specimens.

But the paleontologists call for development of standard formats to help ensure data accessibility. “Currently there is no single 3D format that is universally portable and accepted by all software manufacturers and researchers,” the authors write.

SMU’s digital model archives a fossil that is significant within the scientific world as a type specimen – one in which the original fossil description is used to identify future specimens. The fossil also has cultural importance in Texas. The track is a favorite from well-known, fossil-rich Dinosaur Valley State Park, where the iconic footprint draws tourists.

The footprint was left by a large three-toed, bipedal, meat-eating dinosaur, most likely the theropod Acrocanthosaurus. The dinosaur probably left the footprint as it walked the shoreline of an ancient shallow sea that once immersed Texas, Adams said. The track was described and named in 1935 as Eubrontes (?) glenrosensis. Tracks are named separately from the dinosaur thought to have made them, he explained.

“Since we can’t say with absolute certainty they were made by a specific dinosaur, footprints are considered unique fossils and given their own scientific name,” Adams said.

The fossilized footprint, preserved in limestone, was dug up in the 1930s from the bed of the Paluxy River in north central Texas about an hour’s drive southwest of Dallas. In 1933 it was put on prominent permanent display in Glen Rose, Texas, embedded in the stone base of a community bandstand on the courthouse square.

The footprint already shows visible damage from erosion, and eventually it will be destroyed by gravity and exposure to the elements, Adams said. The 3D model provides a baseline from which to measure future deterioration, he said.

Besides Adams and Jacobs, other co-authors on the article are paleontologists Christopher Strganac and Michael J. Polcyn in the Roy M. Huffington Department of Earth Sciences at SMU.

The research was funded by the Institute for the Study of Earth and Man at SMU. – Margaret Allen

> Find more information, photos and links at the SMU Research blog

February 15, 2011|Research|

Faculty in the News: Sept. 22, 2009

Mosasaur skeletonWilliam Lawrence, Dean, Perkins School of Theology, discussed the importance of truth and discovering what it is in an essay for KERA Public Radio, originally broadcast on Sept. 14, 2009. audio

Michael Polcyn, Huffington Department of Earth Sciences, Dedman College, appears as an expert source in “Mega Beasts: T-Rex of the Deep.” The science documentary debuted Sept. 13, 2009, on the Discovery Channel. Read more from the SMU Research blog. video

David Chard, Dean, Annette Caldwell Simmons School of Education and Human Development; and Reid Lyon, the Simmons School’s Distinguished Professor of Educational Policy and Leadership, were interviewed by Krys Boyd of KERA Public Radio’s “Think” on Sept. 10, 2009. They talked about the importance of educational leadership at students’ schools and districts and how such leadership affects the quality of their education. audio

September 22, 2009|Faculty in the News|
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