Tag: Louis L. Jacobs

17 million-year-old whale fossil provides 1st exact date for East Africa’s puzzling uplift

Post author By Margaret Allen
Post date March 16, 2015

Uplift and aridification of East Africa causing changes in vegetation has been considered a driver of human evolution. Now a fossil whale stranded far inland in Kenya marks the first time scientists can pinpoint how many millions of years ago the uplift began.

Uplift associated with the Great Rift Valley of East Africa and the environmental changes it produced have puzzled scientists for decades. Timing and starting elevation have been poorly understood.

Now paleontologists have tapped 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 stranded whale is the only one ever found so far inland on the African continent.

The 17 million-year-old fossil is from the beaked Ziphiidae whale family. It was discovered 740 kilometers inland at a elevation of 620 meters in modern Kenya’s harsh desert region, said vertebrate paleontologist Louis L. Jacobs, Southern Methodist University, Dallas.

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, a co-author of the study.

A map of Africa and Kenya showing where a 17-million-year-old whale fossil was found far inland . (Wichura/PNAS)

The study, published in the Proceedings of the National Academy of Sciences, 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 fossil bones were originally thought to be those of a turtle specimen, as was recorded in the fossil catalogue for the Harvard Loperot Expedition in 1964. (Museum of Comparative Zoology, Harvard University.)

The ancient large Anza River flowed in a southeastward direction to the Indian Ocean.

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.”

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.

Beaked whale fossil surfaced after going missing for more than 30 years
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.

Modern cases of stranded whales have been recorded in the Thames River in London, swimming up a gradient of 2 meters over 70 kilometers; the Columbia River in Washington state, a gradient of 6 meters over 161 kilometers; the Sacramento River in California, a gradient of 4 meters over 133 kilometers; and the Amazon River in Brazil, a gradient of 1 meter over 1,000 kilometers.

Besides Jacobs, other authors from SMU are Andrew Lin, Michael J. Polcyn, Dale A. 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. — Margaret Allen

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Tags Andrew Lin, Dale A. Winkler, Dedman College, Featurette, Louis L. Jacobs, Matthew Clemens, Michael J. Polcyn, Roy M. Huffington Department of Earth Sciences

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International Business Times: Angola — Ancient Mystery Mammal Tracks Found in Angolan Diamond Mine

Post author By Margaret Allen
Post date November 5, 2014

Tracks of an unknown mammal dating to the Early Cretaceous are discovered along with tracks of a crocodile and a dinosaur

The creature was about the size of a raccoon, researchers said. (Photo: Marco Marzola)

The research of an international team co-led by SMU paleontologist Louis L. Jacobs is receiving worldwide coverage for discovery of the first dinosaur tracks discovered in Angola, including those of a mysterious mammal from 118 million years ago.

Reporter Hannah Osborne wrote about the discovery Nov. 5 for The International Business Times in the article “Angola: Huge Mystery Mammal Tracks from Early Cretaceous Period Discovered in Catoca Diamond Mine.”

The Society of Vertebrate Paleontology announced the discovery in a press release Nov. 5, “African diamond mine reveals dinosaur and large mammal tracks.”

The discovery was made by a Octávio Mateus, a member of Projecto PaleoAngola.

Jacobs, a professor of earth sciences at SMU, is a former president of the Society of Vertebrate Paleontology. His research focus is the interrelationships of biotic and abiotic events through time.

His fieldwork is currently focused through Projecto PaleoAngola on the iconic, puzzle-like fit of Africa and South America, as viewed through the rocks and fossils of coastal Angola.

SMU paleontologist Michael J. Polcyn is also a member of the Projecto PaleoAngola team.

The PaleoAngola researchers have described Angola as a “museum in the ground” for the abundance of fossils there.

A professor in Dedman College’s Roy M. Huffington Department of Earth Sciences, Jacobs joined SMU’s faculty in 1983.

In the laboratory, Jacobs’ research utilizes advanced imaging and stable isotope techniques to investigate paleoenvironmental, biogeographic and phylogenetic issues of the Mesozoic and Cenozoic eras.

Polcyn is director of the Visualization Laboratory in SMU’s Department of Earth Sciences and an SMU research associate.

A world-recognized expert on the extinct marine reptile named Mosasaur, Polcyn’s research interests include the early evolution of Mosasauroidea and adaptations in secondarily aquatic tetrapods. Polcyn’s research also includes application of technology to problems in paleontology.

Read the full story.

EXCERPT:

By Hannah Osborne
International Business Times
The tracks of a huge mysterious mammal dating to the Early Cretaceous period have been discovered in the world’s fourth-biggest diamond mine in Africa.

Dating to 118 million years ago, researchers discovered the tracks of a crocodile, a dinosaur and a large unknown mammal inside the Catoca Diamond Mine in Angola.

Over 70 tracks were uncovered by researcher from the PaleoAngola Project, a programme that researches vertebrate palaeontology in Angola.

The dinosaur tracks – the first to be found in the African nation – were from a sauropod and were discovered with a preserved skin impression. The crocodile, a crocodilomorph trackmaker, was from a group that includes all modern species.

However, the most important find was that of the large mammal. Researchers believe it was about the size of a raccoon – huge compared to all other mammals at the time, which were mostly no larger than a rat.

Marco Marzola, one of the study authors, told IBTimes UK there is no way of telling to what species the mystery mammal belongs as you cannot identify animals by their tracks – “the most you can say is that the track resembles the anatomy of that animal,” he explained.

“We cannot narrow down to a species but we can say they do belong to – they were made by an exceptionally large mammal – that we can say for sure.”

Read the full story.

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Tags Dedman College, Louis L. Jacobs, Michael J. Polcyn, Roy M. Huffington Department of Earth Sciences

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Richest marine reptile fossil bed along Africa’s South Atlantic coast is dated at 71.5 mya

Post author By Margaret Allen
Post date May 14, 2014

A new study uses carbon isotope dating to determine the first precise age for this bed, and ties the western coast of Africa to 30 million years of global geologic records

Paleontologists at Southern Methodist University have measured the carbon isotopes in marine fossils to precisely date for the first time 30 million years of sediments along Africa’s South Atlantic shoreline.

The researchers matched the pattern of ratios of carbon-13 and carbon-12 isotopes in marine fossils from Africa’s South Atlantic shoreline to known patterns of carbon ratios in fossils found elsewhere in the world. From that they determined the age of the coastal sediments at a fossil locality near the southern Angolan village of Bentiaba, said paleontologist Christopher Strganac, lead author on the study.

The analysis focused on a sequence of shoreline sediments totaling 140 meters thick. Their age spans a timeline of nearly 30 million years, from 95 million years ago to 68 million years ago. That period was about 40 million years after Africa and South America split, allowing the South Atlantic Ocean to slowly emerge.

Chemostratigraphy and magnetostratigraphy of Bentiaba section. (Credit: Strganac)

The analysis revealed that the richest marine reptile fossil bed on Africa’s South Atlantic dated to 71.5 million years ago, he said. This new date at the Bentiaba locality is more than 2 million years older than the estimated date of about 69 million years previously assigned to those marine beds by earlier researchers.

Africa’s South Atlantic coast is remarkable in plate tectonics as the place where part of the prehistoric supercontinent Gondwana split 130 million years ago into what we now call Africa and South America.

“The precise age for these rocks allows better understanding of the ancient life and environments at Bentiaba by placing them accurately within the history of the ancient South Atlantic,” said Strganac, a doctoral student in SMU’s Roy M. Huffington Department of Earth Sciences. “It’s a benchmark now from the Southern Hemisphere with which we can better understand ancient life at that time.”

The precise dating was made possible by new scientific dating techniques. The age of the rocks hadn’t previously been assessed because Africa’s South Atlantic shore — noted for its puzzle-like fit with South America — has few localities with well-exposed rocks of this age. Also, it has been essentially unexplored by scientific expeditions since the 1960s largely because war and unrest prevented exploration in the previous century.

The new measurements stem from the work of Projecto PaleoAngola, an international team of scientists who in recent years have explored Angola and discovered an abundance of fossils. Their discoveries include the bones of dinosaurs, whales, mosasaurs and other ancient life from what is the richest marine reptile fossil bed along the South Atlantic coast.

Strganac and his co-authors report their findings in the Journal of African Earth Sciences. The article, “Carbon isotope stratigraphy, magnetostratigraphy, and 40Ar/39AR age of the Cretaceous South Atlantic coast, Namibe Basin, Angola,” is available online through open access at http://bit.ly/1v4r8xi.

“This improvement in understanding the ages of the rocks along the shore is a great first step in trying to understand the climatic and evolutionary events that accompanied the growth of this ocean,” said vertebrate paleontologist Louis L. Jacobs, also a co-author on the study and co-leader of Projecto PaleoAngola. Jacobs describes Angola as “an untapped frontier” for fossil hunters.

Aids in new knowledge of climate, temperature and vegetation
Scientists have recognized since the 1960s that ancient supercontinents split apart and their remnants drifted to the current positions of today’s continents over the course of millions of years. One of the results was the creation of vast new oceans. Little is known of the vertebrate life that lived during that time along the eastern and western margins of the emerging South Atlantic Ocean.

Fossils being discovered now by Projecto PaleoAngola hold the key to understanding the South Atlantic Ocean’s ancient past. Analysis of the fossils sheds light on the paleoenvironment, including changes in climate, temperature, vegetation and ecology.

The geologic time period covered by the 30-million-year sequence represents the Late Cretaceous. Studies have shown it was a period of dramatic change in climate, beginning with one of the warmest periods on Earth, then starting to transition to cooler climates, Strganac said.

Determining carbon ratios allowed comparison with global geologic events
To discover the age of the sediments, Strganac tested 55 fossil shells of ancient oysters and clams from 40 different rock layers on the coast. Testing determined the ratio of stable carbon isotopes, carbon-13 and carbon-12, in each shell. Because these isotopes do not decay with time, the relative abundance of each relates to the ocean when the shells formed. These isotope ratios can be compiled as a sequence with the rock layers, producing a pattern of carbon isotope change in the ancient oceans through millions of years. To accurately date the rocks, Strganac matched the pattern in isotope ratios in the shell record at Angola with the pattern known from ancient geologic events that occurred elsewhere in the world.

Specifically, the red rift-valley layers at Bentiaba were deposited as Africa and South America began to split. Also observed in the layers are a reversal in the Earth’s magnetic polarity at 71.4 million to 71.64 million years to delimit the age of marine fossils; rocks deposited in the South Atlantic Ocean 93.9 million years ago during an oceanic anoxic event; and rocks south of Bentiaba that bracket the mass extinction of dinosaurs at 66 million years.

Besides comparing the stable carbon isotopes, other measuring techniques included: magnetostratigraphy, which measures the ancient polarity of the Earth’s magnetic field when various sedimentary layers were deposited; and argon-argon radiometric dating of a volcanic basalt layer at the site, which measures the radioactive decay of potassium to argon and dates the cooling of the volcanic lava to 85 million years ago.

“Adding a new ocean to the globe, in this case the South Atlantic, has many long-lasting effects,” said SMU’s Jacobs. “One obvious example is the formation of energy resources found along the coasts of Brazil and Angola.”

The research was funded in part by the National Geographic Society and the Petroleum Research Fund of the American Chemical Society. — Margaret Allen

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SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.[/fusion_builder_column][/fusion_builder_row][/fusion_builder_container]

Tags Christopher Strganac, Dedman College, Louis L. Jacobs, Roy M. Huffington Department of Earth Sciences

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Bloomberg: Ancient Angola Crocodile Ate Fish as Oil Fields Formed

Post author By Margaret Allen
Post date August 12, 2013

Angola%20006a.jpg The research of an international paleontological team working in Angola and co-led by SMU paleontologist Louis L. Jacobs has been covered by Bloomberg news service.

Fossils in the rock outcrops of the coast of Angola in Africa are a “museum in the ground,” says SMU vertebrate paleontologist Jacobs. Reporters Colin McClelland and Manuel Soque with Bloomberg interviewed Jacobs for Ancient Angola Crocodile Ate Fish as Oil Fields Formed. Business Week also published the story “Ancient Angola Crocodile Feasted on Fish as Oil Fields Formed.”

“Angola is the final frontier for palaeontology,” Jacobs has told reporters about the PaleoAngola project. “Due to the war, there has been little research carried out… but now we are getting in finally and there is so much to find. In some areas there are literally fossils sticking out of the rocks, it is like a museum in the ground.”

SMU paleontologist Michael J. Polcyn is also a member of the Projecto PaleoAngola team.

Read the full story.

EXCERPT:

By Colin McClelland
and Manuel Soque
Bloomberg
Scientists have found a new type of crocodile that trundled across Angola millions of years ago while the crude oil that it now pumps as Africa’s second-largest producer was forming.

PaleoAngola, a team of fossil-hunters from the U.S., Portugal, Angola and the Netherlands, found the reptile’s 30 million-year-old remains this year on a beach within sight of oil rigs drilling into the same rocks offshore Cabinda province north of the Congo River.

“The croc is certainly new to the age in which it was found,” Louis Jacobs, geology and paleontology professor at Southern Methodist University in Dallas, said in an e-mailed response to queries yesterday. “It would have been the size of a large modern croc, but two-thirds of the head would have been a narrow snout adapted for fish eating.”

Some of the 1.78 million barrels-a-day Angola pumped in July was formed around the same time as the crocodile fossil, after Africa and South America broke apart through plate tectonics. Oil explorers such as ConocoPhillips (COP) and BP Plc (BP/) are betting on the industry’s Atlantic mirror theory which says there may be huge deposits of oil deep beneath the sea off West Africa, similar to those across the ocean in Brazil.

Resembles Gharial
The crocodile, which is yet to be named, may be related to a fossil found in the province almost 100 years ago and a more recent find in Kenya, Jacobs said. The beast was probably coastal and isn’t directly related to modern African crocodiles, he said. It resembled a gharial, but wasn’t one, he said. Gharials are a type of crocodile found in Asia.

The team also found a well-preserved skull of a 70 million-year-old mosasaur, sometimes called a marine monster, north of Luanda, the capital, and another in southern Namibe province with three smaller ones in its stomach.
“Quite a last meal,” Jacobs said.

Other finds this year include a tooth from an arsinoitherium, a rhino-like animal with two large horns forming a V off its nose that is known from digs in Egypt, and skulls of 18 million-year-old relatives of the pygmy right whale, which swims off Angola’s southern coast today, Jacobs said. They’re the continent’s only fossils of the oldest filter-feeding whales known from Africa, he said. One skull has two fish fossils in its blow hole.

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SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

Tags Dedman College, Louis L. Jacobs, Roy M. Huffington Department of Earth Sciences

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Dallas Morning News: Fort Worth coelacanth fossil is missing link among world’s oldest animal lineages

Post author By Margaret Allen
Post date February 5, 2013

The coelacanth research of SMU paleontology doctoral student John Graf was covered by Dallas Morning News journalist Marc Ramirez.

Graf identified a new species of coelacanth from fossil fish bones discovered in Texas. Ramirez described the discovery and identification in a Feb. 1 article, “Fort Worth coelacanth fossil proves to be a missing link in one of the world’s oldest animal lineages.”

Graf discusses the fossil in this video: “100 million-year-old coelacanth discovered in Texas is new fish species from Cretaceous.”

Read the full story.

EXCERPT:

By Marc Ramirez
Dallas Morning News
Never mind that it took more than 20 years to give the celebrity critter its due, because out here in Dino Land, things tend to move s-l-o-w-l-y.

And let’s be honest — when you’ve been waiting a million centuries to be identified, what’s another couple of decades, really?

Last year, Reidus hilli officially earned its stripes as a new species of coelacanth, quite the feat for a fish whose path to reality began as a Fort Worth fossil the size of a Girl Scout cookie.

For those who spend their time rebuilding prehistory’s narrative, the find was — as earth science professor Louis Jacobs of Southern Methodist University puts it — “tremendously fascinating.”

“Every place in the world is unique, so every place is a single piece of a puzzle that fits into the whole story of the world,” Jacobs said.

“Our piece is here. This coelacanth provides a piece of our puzzle that we didn’t have before of what life was like and what was here.”

The area known as the Albian Duck Creek Formation stretches over southwest Tarrant County, a one-time marine environment rich in Cretaceous-era fossils between 90 million and 100 million years old, any present company excluded.

Before it was largely developed, a plucky amateur geologist could regularly turn up evidence of ancient sea life, especially after rains that would free clay earth from its moorings.

Around 1990, Fort Worth design artist Robert Reid and a fossil-hunting friend were trolling the soggy wash, seeing what they could find. Typically that would be bits of turtle, shark vertebrae or ammonites, spiral-shelled cephalopods that once filled the seas.
The piece of rock that caught Reid’s eye was small, barely a couple of inches in length.

“I could tell it was some kind of bone material,” he said. “I didn’t know it was fish.”

He could just as easily have left it behind. Instead, he packed it into a Baggie, took it home and washed it off.

And thus the fragment eventually ended up in Reid’s geology cabinet, a millennia-old fossil stored in a cushioned box alongside dozens of other millennia-old fossils stored in cushioned boxes.

And there it would sit for years.

Long assumed extinct
The coelacanth is so old that for a long time people figured it was dead.

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Tags Dedman, John F. Graf, Louis L. Jacobs, Roy M. Huffington Department of Earth Sciences, Shuler Museum of Paleontology

Uplift and aridification of East Africa causing changes in vegetation has been considered a driver of human evolution. Now a fossil whale stranded far inland in Kenya marks the first time scientists can pinpoint how many millions of years ago the uplift began.

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Tracks of an unknown mammal dating to the Early Cretaceous are discovered along with tracks of a crocodile and a dinosaur

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A new study uses carbon isotope dating to determine the first precise age for this bed, and ties the western coast of Africa to 30 million years of global geologic records

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