Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Two dinosaurs from Africa give clues to continents’ split

02.06.2004


Fossils support idea of lingering bridges between landmasses



The fossil skull of a wrinkle-faced, meat-eating dinosaur whose cousins lived as far away as South America and India has emerged from the African Sahara, discovered by a team led by University of Chicago paleontologist Paul Sereno. The find provides fresh information about how and when the ancient southern continents of Africa, South America and India separated.

The new species, which is 95 million years old, and a second new meat-eating species Sereno found on a separate expedition, help fill in critical gaps in the evolution of carnivorous dinosaurs on Africa. The species are described in a paper published online June 2 in the Proceedings of the Royal Society of London, Biological Sciences. The July issue of National Geographic magazine also will include an article on one of the dinosaurs. Sereno’s research was funded by National Geographic, the David and Lucile Packard Foundation, the Pritzker Foundation and Nathan Myhrvold.


Sereno, a National Geogrpahic Explorer-in-Residence, has named the ancient skull Rugops primus, meaning "first wrinkle face." Measuring about 30 feet long in life, the animal had a short, round snout and small, delicate teeth, he said. It belongs to a group of southern carnivorous dinosaurs called abelisaurids.

The head of Rugops had a tough covering of scales or surface armor and was riddled with arteries and veins, leaving a crisscross of grooves on the skull. "It’s not the kind of head designed for fighting or bone-crushing," Sereno said. Instead, he believes Rugops was a scavenger, using its head to pick at carrion rather than fighting other animals for food.

Sereno is puzzled by the presence of two neat rows of seven holes along the dinosaur’s snout. He speculates that the holes anchored something ornamental, used by the animal for display. "This may have been a scavenger with head gear," he said. "It’s really a beautiful intermediate species of the group that later evolved into the first horned predators."

The authors of the scientific paper describing the two new dinosaur finds are Sereno, Jeffrey Wilson of the University of Michigan and Jack Conrad of the University of Chicago. The second new dinosaur species, named Spinostropheus gautieri, was found in Niger in the same 135-million-year-old rocks where Sereno’s expeditions excavated the dinosaurs Jobaria and Afrovenator. The fossil is an articulated, or connected, spine of a dinosaur and represents an ancient relative of Rugops and other abelisaurids.

These finds provide fresh evidence about when Africa, Madagascar, South America and India finally split from each other as a result of continental drift. Before these discoveries, abelisaurids were virtually unknown on Africa, leading some to suggest that Africa had split off first from the southern landmass Gondwana, perhaps as early as 120 million years ago. The new fossils indicate that Africa and other southern continents that formed Gondwana separated and drifted apart over a narrow interval of time, about 100 million years ago.

Coauthor and team member Jeffrey Wilson, assistant professor at the University of Michigan, said, "Until the continents fully separated, dinosaurs like Rugops and other animals used narrow land bridges to colonize adjacent continents and roam within a few degrees of the South Pole."

The fossils were discovered on two separate expeditions that Sereno led to Niger, one in 1997 and the other in 2000, which have brought to light many new dinosaurs and the 40-foot-long crocodilian Sarcosuchus, also known as "SuperCroc."

Sereno recalls the day in 2000 when team member Hans Larsson, now an assistant professor at McGill University in Montreal, spotted a jawbone -- and then, about two feet away, the rest of the skull. "It was hard to see which end was the front, but we quickly realized we were looking at a brain case, and that it was probably an abelisaur -- a huge find," Sereno said.

Both Rugops and Spinostropheus came from the Cretaceous Period, when this area of Africa featured broad rivers and lush plains. Today it is located in the southern Sahara Desert, part of the Republic of Niger. Expeditions to the Sahara led by Sereno in 1993, 1995, 1997 and 2000 unearthed a gallery of new dinosaurs, including the first from Africa’s Cretaceous Period; they include Afrovenator, Jobaria, Deltadromeus, Carcharodontosaurus and Suchomimus.

A National Geographic Explorer-in-Residence since 2000, Sereno has received 11 research grants from the Society’s Committee for Research and Exploration as well as two grants from the Society’s Expeditions Council.


For PHOTOGRAPHS, contact Chris Pollock, 202-857-7760; cpollock@ngs.org.

Steve Koppes | EurekAlert!
Further information:
http://www.projectexploration.org
http://www.nationalgeographic.com/news

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Researchers devise microreactor to study formation of methane hydrate

23.08.2017 | Materials Sciences

ShAPEing the future of magnesium car parts

23.08.2017 | Automotive Engineering

New insights into the world of trypanosomes

23.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>