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

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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|

SMU fossils, expertise to be an ongoing part of new Perot Museum

Malawisaurus in the Perot Museum

A 35-foot skeletal cast of the Early Cretaceous sauropod dinosaur Malawisaurus stands sentry in the spacious glass lobby of the new Perot Museum of Nature and Science in Dallas. SMU paleontologist Louis Jacobs, who discovered the dinosaur in Africa, provided the cast to the museum. (Image: Dallas Morning News)

SMU faculty and students, the University’s Shuler Museum of Paleontology, and the SMU Innovation Gymnasium have teamed with the nation’s new premier museum of nature and science to provide everything from dinosaurs and sea turtles to technical assistance and advice.

Fossils on loan by SMU to Dallas’s new Perot Museum of Nature and Science include those of animals from an ancient sea that once covered Dallas.

The fossils represent a slice of SMU’s scientific collaboration with the Perot Museum and its predecessor, the Dallas Museum of Natural History.

Items from SMU’s scientists include a 35-foot skeletal cast of the African dinosaur Malawisaurus (pictured above) standing sentry in the spacious glass lobby of the Perot, which opened Dec. 1 near downtown Dallas.

“The new museum building itself is an icon, but it’s also a statement by the city about taking the advances of science to the public,” said vertebrate paleontologist Louis Jacobs, an SMU earth sciences professor, who serves on the Perot Museum’s advisory board and Collections Committee.

Jacobs, who was ad interim director of the Dallas Museum of Natural History in 1999, led the team that discovered Malawisaurus in Africa. He provided the cast to the museum.

“Here at SMU we train students and create new knowledge. The museum’s mission is to take the stories of science out to the general public so they can be used,” said Jacobs. “Anthony Fiorillo, Perot Museum Curator of Earth Sciences, is a world-class scientist with whom we work. We have a junction between the mission, training and knowledge we have here, infused into and enhanced by what the museum does. That’s why the museum is important to SMU and that’s why SMU is important to the museum.”

Fossils on loan are from the Shuler Museum collection in the Roy M. Huffington Department of Earth Sciences. SMU scientists provided technical expertise for exhibits and serve on the Perot Museum’s advisory committees.

Also on exhibit from SMU is a miniature unmanned autonomous helicopter designed for fighting fires that was built by students in SMU’s Lyle School of Engineering.

Shuler Museum fossils can be viewed in the T. Boone Pickens Life Then and Now Hall. They include an unnamed 113 million-year-old herbivorous dinosaur discovered in 1985 at Proctor Lake southwest of Stephenville, Texas.

For perspective on that exhibit’s paleoenvironment in Texas at the time, SMU paleobotanist Bonnie Jacobs provided fossil wood, fossil cones, fossil leaves and images of microscopic pollen grains from the Shuler Museum. The fossils provided information used to create a model of an extinct tree to accompany the exhibit.

> Read the full story from the SMU Research blog

December 6, 2012|News, Research|

Research: SMU paleontologist identifies new Texas fossil species

A new species of coelacanth fish has been discovered in Texas. Pieces of tiny fossil skull found in Fort Worth have been identified as 100 million-year-old coelacanth bones, according to SMU paleontologist John Graf.

The coelacanth has one of the longest lineages — 400 million years — of any animal. It is the fish most closely related to vertebrates, including humans.

The SMU specimen is the first coelacanth in Texas from the Cretaceous, said Graf, who identified the fossil. The Cretaceous geologic period extended from 146 million years ago to 66 million years ago.

Graf named the new coelacanth species Reidus hilli. It is now the youngest coelacanth identified in the Lone Star State, a distinction previously belonging to a 200 million-year-old coelacanth from the TriassicReidus hilli is also the first coelacanth ever identified from the Dallas-Fort Worth area.

Coelacanth fossils have been found on every continent except Antarctica. Few have been found in Texas, said Graf, a paleontology graduate student in the Huffington Department of Earth Sciences of SMU’s Dedman College.

The coelacanth has eluded extinction for 400 million years. Scientists estimate it reached its maximum diversity during the Triassic. The fish was thought to have gone extinct about 70 million years ago. However, the fish rose to fame in 1938 after live specimens were caught off the coast of Africa. Today coelacanths can be found swimming in the depths of the Indian Ocean.

“These animals have one of the longest lineages of any vertebrates that we know,” Graf said.

The SMU specimen demonstrates there was greater diversity among coelacanths during the Cretaceous than previously known.

“What makes the coelacanth interesting is that they are literally the closest living fish to all the vertebrates that are living on land,” he said. “They share the most recent common ancestor with all of terrestrial vertebrates.”

Coelacanths have boney support in their fins, which is the predecessor to true limbs. “Boney support in the fins allows a marine vertebrate to lift itself upright off the sea floor,” Graf said, “which would eventually lead to animals being able to come up on land.”

Written by Margaret Allen

> Read the full story at the SMU Research blog

October 31, 2012|Research|

Research Spotlight: SMU researcher names rare ‘flying lizard’

Aetodactylus_halli%5Bkc%5D-lorez.jpgA 95 million-year-old fossilized jaw discovered in Texas has been identified as a new genus and species of flying reptile, Aetodactylus halli.

Aetodactylus halli is a pterosaur, a group of flying reptiles commonly referred to as pterodactyls. The rare pterosaur – literally a winged lizard – is also one of the youngest members in the world of the pterosaur family Ornithocheiridae, according to paleontologist Timothy Myers, who identified and named the creature.

The newly identified reptile is only the second ornithocheirid ever documented in North America, Myers says. He is a postdoctoral fellow in the Roy M. Huffington Department of Earth Sciences in SMU’s Dedman College.

Aetodactylus halli would have soared over what is now the Dallas-Fort Worth area during the Cretaceous Period when much of the Lone Star state was under water, covered by a vast ancient sea.

Jawbone of Aetodactylus halliWhile rare in North America, toothed pterosaurs belonging to the Ornithocheiridae are a major component of Cretaceous pterosaur faunas elsewhere in the world, Myers says. The Texas specimen (right) – a nearly complete mandible with most of its 54 teeth missing – is definitively younger than most other ornithocheirid specimens from Brazil, England and China, he says. It is five million years younger than the only other known North American ornithocheirid.

Myers describes the new species in the latest issue of the Journal of Vertebrate Paleontology. He named the pterosaur Aetodactylus halli after Lance Hall, a member of the Dallas Paleontological Society who hunts fossils for a hobby. Hall found the specimen in 2006, embedded in a soft, powdery shale exposed by excavation of a hillside next to a highway near Mansfield. He donated the specimen to SMU.

Myers’ article in the Journal of Vertebrate Paleontology is titled “A new ornithocheirid pterosaur from the Upper Cretaceous (Cenomanian-Turonian) Eagle Ford Group of Texas.”

The research was funded by SMU’s Huffington Department of Earth Sciences and Institute for the Study of Earth and Man.

Written by Margaret Allen

> Read more at the SMU Research blog

May 4, 2010|Research|
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