Wednesday, February 24, 2010

Ancient Man-eating Crocodiles

Researcher: horned, man-eating crocodiles once roamed Africa

A University of Iowa researcher and his colleagues have found evidence in existing fossil collections that horned crocodiles lived in the Olduvai Gorge region of Tanzania, Africa, about two million years ago.

"Olduvai Gorge is the location of many key discoveries of early human ancestors, and these crocodiles appear to have dined on them," said Chris Brochu, associate professor of geoscience in the UI College of Liberal Arts and Sciences. Brochu is the co-author of an article published in the Feb. 24 issue of the journal PLoS ONE (Public Library of Science) that describes a new species of crocodile.

"So, what I've got is a horned, man-eating crocodile," said Brochu. "In fact, its name is Crocodylus anthropophagus, and 'anthropophagus' literally means 'eater of people.'"

Crocodylus anthropophagus would have been about as large as its living cousin, the Nile crocodile, which can reach lengths of almost 20 feet and weigh up to a ton. The early humans walking along the lake and stream margins that used to exist at Olduvai Gorge were smaller than people of today and would have been in grave danger if they got too close to the water, according to Brochu.

"The bones of early humans have been found in rocks of the same age in Olduvai Gorge showing bite marks made by crocodiles," he said.

A crocodile that ate humans would have been frightening enough, but this variety also had horns.

"Not antlers or anything, but the back of the skull was somewhat fancier than in most living crocs," he said. "Two living crocodiles -- the Cuban and Siamese crocodiles -- also have horns, but those of the Olduvai crocodile were more prominent." Of course, horns probably would have given the crocodile a devilish appearance, as if that were needed on a man-eating crocodile.

Brochu and his colleagues based their conclusions on fossils collected over many decades. Some were collected in 2007 by a team led by Robert Blumenschine of Rutgers University and Jackson Njau, then of the National Natural History Museum of Tanzania. But others were collected as long ago as the 1930's and kept in museums in Kenya and the United Kingdom. Most of these fossils, by themselves, are fragmentary and not very impressive, but together, they reveal a crocodile different from any of its living relatives.

"It would have looked more or less like a Nile crocodile except for a deeper snout and, of course, the horns," Brochu said.

Apart from the very scary image projected by the beast, Brochu said that the discovery of Crocodylus anthropophagus teaches us something new about the variety of crocodiles to be found in pre-historic Africa.

"The fossil evidence is geologically fairly young, at just under two million years. We knew crocodiles were more diverse in the geological past, but we assumed their diversity was much lower as recently as 2 million years ago. Crocodile diversity in Africa remained higher than at present for longer than we had thought," he said.

Brochu's co-authors are Njau, Blumenschine and Llewellyn Densmore of Texas Tech University.

STORY SOURCE: University of Iowa News Services, 300 Plaza Centre One, Iowa City, Iowa 52242-2500

Intact Sauropod Heads Discovered in Utah

Abydosaurus: New dinosaur discovered head-first, for a change

Media Contact: Joe Hadfield
Brigham Young University
Phone: 801 422 9206

A team of paleontologists has discovered a new dinosaur species they’re calling Abydosaurus, which belongs to the group of gigantic, long-necked, long-tailed, four-legged, plant-eating dinosaurs such as Brachiosaurus.

In a rare twist, they recovered four heads – two still fully intact – from a quarry in Dinosaur National Monument in eastern Utah. Complete skulls have been recovered for only eight of more than 120 known varieties of sauropod.
“Their heads are built lighter than mammal skulls because they sit way out at the end of very long necks,” said Brooks Britt, a paleontologist at Brigham Young University. “Instead of thick bones fused together, sauropod skulls are made of thin bones bound together by soft tissue. Usually it falls apart quickly after death and disintegrates.”

Britt is a co-author on the discovery paper scheduled to appear in the journal Naturwissenshaften. The lead author is Daniel Chure, a paleontologist at Dinosaur National Monument, who has no trouble boiling down the significance of the discovery.

“We’ve got skulls!” he shouted with sweeping hand gestures during a recent visit to the site.

BYU geology students and faculty resorted to jackhammers and concrete saws to cut through the hardened 105-million-year-old sandstone containing the bones. At one point the National Park Service called in a crew to blast away the overlying rock with explosives.

The skulls are temporarily on display at BYU’s Museum of Paleontology, where visitors can also watch BYU students prepare other bones from Abydosaurus.

“The hardest bone I personally have worked on is a vertebra that was half-eroded before discovery and is so fragile that it crumbles if you look at it wrong,” said Kimmy Hales, a geology major studying vertebrate paleontology at BYU. “The funnest project I have worked on was a set of five toe bones. Each toe bone was larger than my hand.”

Analysis of the bones indicates that the closest relative of Abydosaurus is Brachiosaurus, which lived 45 million years earlier. The four Abydosaurus specimens were all juveniles.

Most of what scientists know about sauropods is from the neck down, but the skulls from Abydosaurus give a few clues about how the largest land animals to roam the earth ate their food.

“They didn’t chew their food; they just grabbed it and swallowed it,” Britt said. “The skulls are only one two-hundredth of total body volume and don’t have an elaborate chewing system.”

All sauropods ate plants and continually replaced their teeth throughout their lives. In the
Jurassic Period, sauropods exhibited a wide range of tooth shapes. But by the end of the dinosaur age, all sauropods had narrow, pencil-like teeth.

Abydosaurus teeth are somewhere in between, reflecting a trend toward smaller teeth and more rapid tooth replacement.

The fossils were excavated from the Cedar Mountain Formation in Dinosaur National Monument near Vernal, Utah. The site is just a quarter of a mile away from the condemned visitor center that displays thousands of bones that remain in place on an uplifted slab of sandstone.

University of Michigan researchers John Whitlock and Jeffrey Wilson are also co-authors on the study.

What’s in the name Abydosaurus mcintoshi?

The generic name refers to Abydos, the Greek name for the city along the Nile River (now El Araba el Madfuna) that was the burial place of the head and neck of Osiris, Egyptian god of life, death and fertility. Abydos alludes to the type specimen, which is a skull and neck found in a quarry overlooking the Green River. Sauros is the Greek word for lizard.

The specific name mcintoshi honors the American paleontologist Jack McIntosh for his contributions to the study of sauropod dinosaurs. In 1975 McIntosh debunked the myth of Brontosaurus, exposing it as a mixed-up skeleton with an Apatosaurus body and a Camarasaurus skull.

Thursday, February 18, 2010

Birds/Dinosaurs Have Super Vision According to Chicken Study

ScienceDaily (Feb. 17, 2010) — Researchers at Washington University School of Medicine in St. Louis have peered deep into the eye of the chicken and found a masterpiece of biological design.

Scientists mapped five types of light receptors in the chicken's eye. They discovered the receptors were laid out in interwoven mosaics that maximized the chicken's ability to see many colors in any given part of the retina, the light-sensing structure at the back of the eye.

"Based on this analysis, birds have clearly one-upped us in several ways in terms of color vision," says Joseph C. Corbo, M.D., Ph.D., senior author and assistant professor of pathology and immunology and of genetics. "Color receptor organization in the chicken retina greatly exceeds that seen in most other retinas and certainly that in most mammalian retinas."

Corbo plans follow-up studies of how this organization is established. He says such insights could eventually help scientists seeking to use stem cells and other new techniques to treat the nearly 200 genetic disorders that can cause various forms of blindness.

Scientists published their results in the journal PLoS One.

Birds likely owe their superior color vision to not having spent a period of evolutionary history in the dark, according to Corbo. Birds, reptiles and mammals are all descended from a common ancestor, but during the age of the dinosaurs, most mammals became nocturnal for millions of years.

Vision comes from light-sensitive photoreceptor cells in the retina. Night-vision relies on receptors called rods, which flourished in the mammalian eye during the time of the dinosaurs. Daytime vision relies on different receptors, known as cones, that are less advantageous when an organism is most active at night.

Birds, now widely believed to be descendants of dinosaurs, never spent a similar period living mostly in darkness. As a result, birds have more types of cones than mammals.

"The human retina has cones sensitive to red, blue and green wavelengths," Corbo explains. "Avian retinas also have a cone that can detect violet wavelengths, including some ultraviolet, and a specialized receptor called a double cone that we believe helps them detect motion."

In addition, most avian cones have a specialized structure that Corbo compares to "cellular sunglasses": a lens-like drop of oil within the cone that is pigmented to filter out all but a particular range of light. Researchers used these drops to map the location of the different types of cones on the chicken retina. They found that the different types of cones were evenly distributed throughout the retina, but two cones of the same type were never located next to each other.

"This is the ideal way to uniformly sample the color space of your field of vision," Corbo says. "It appears to be a global pattern created from a simple localized rule: you can be next to other cones, but not next to the same kind of cone."

Corbo speculates that extra sensitivity to color may help birds in finding mates, which often involves colorful plumage, or when feeding on berries or other colorful fruit.

"Many of the inherited conditions that cause blindness in humans affect cones and rods, and it will be interesting to see if what we learn of the organization of the chicken's retina will help us better understand and repair such problems in the human eye," Corbo says.

Funding from the National Eye Institute supported this research.

Tuesday, February 16, 2010

New Dinosaur Mulit-Media Experience Coming in 2011

29 October 2009: FremantleMedia Enterprises (FME), Atlantic Productions, ZOO and Geffen-Medavoy Pictures have announced today a major collaboration to create a groundbreaking new CGI franchise, Dinosaurs Resurrected [working title], which will be a global entertainment concept based on the latest, and most credible, science available. By combining state-of-the-art computer animation and visual effects with the latest research and insights from dramatic new paleontological finds, Dinosaurs Resurrected rewrites what we thought we knew about dinosaurs and reinvents them with stunning visuals in HD and 3D for a 21st century audience.

Dinosaurs Resurrected will be a genuinely 360° brand encompassing a prime-time television series (based on a returning format) for delivery in 2011 and a feature-length narrative 3D movie for theatrical release. The movie will be the first major dinosaur experience using the latest immersive 3D technology in the world, for both cinemas and IMAX. The project will include accompanying books, DVD, tie-in consumer products and educational resources as well as gaming spin-offs and live events.

Dinosaurs Resurrected brings together the specialist expertise of four companies. FME is one of the world’s leading licensing, distribution and home entertainment companies responsible for launching some of the best-known entertainment brands including recent global phenomenon The Adventures of Merlin, a Shine Production for the BBC. Selling to over 180 countries, FME has co-invested in the series, with the programme featuring spectacular CGI from Oscar-winning effects house The Mill. Additional entertainment franchises include Idols, now entering its ninth season, with brand extensions including The American Idol Experience at Walt Disney World Resort. FME has had tremendous success with other prestigious television projects such as the CGI family series Prehistoric Park produced by Impossible Pictures which has sold to over 150 countries, and will be distributing the CGI 90-minute special, March of The Dinosaurs which will be produced by Wide-Eyed Entertainment.

Atlantic Productions has a seventeen-year track record in producing high-end, award-winning and acclaimed programming for global audiences such as recent hits The Link, Predator X and Egypt Unwrapped, the latter of which is distributed internationally by FME. All titles feature high-end CGI in their story-telling which further underscores the strong partnership between companies in bringing this next dinosaur experience to a global audience.

Rounding out the producing partners, ZOO brings their talent as a specialist digital effects company, previously working with the best visual effects artists and animators from the around the world - members of the ZOO team have worked on award-winning features including Harry Potter, The Chronicles of Narnia, Lord of the Rings, King Kong and 10,000 BC. And Geffen-Medavoy Pictures bring their established gravitas in creating feature documentaries for theatrical release, chaired by Mike Medavoy, the Hollywood producer who has been behind seven Best Picture Academy Award winning movies.

Announcing the collaboration, David Ellender, Global CEO of FME, said, "This group of partners has at our collective fingertips the fantastic combination of the most up to date production technology and the latest from the science community which means we can create a groundbreaking and completely up to date dinosaur franchise across numerous platforms. It is a big undertaking for FME and one we wouldn't have taken on without the calibre of partners we'll be working with."

Anthony Geffen, CEO of Atlantic Productions, added, “We are delighted to be working with Fremantle on this exciting venture. In the same way that Jurassic Park and Walking With Dinosaurs revolutionised our experience of dinosaurs at the end of the 20th century, this project will bring dinosaurs into the 21st century – on HD and in 3D. We are looking forward to combining the very best of traditional storytelling techniques with all the opportunities new technologies and platforms offer.”

Mike Medavoy, chairman of Geffen-Medavoy Pictures, said “Ever since they were first discovered, dinosaurs have captured our imagination. This project is a fantastic opportunity to bring them back to life for movie audiences around the world in the most realistic, most complex and most terrifying way we’ve ever seen.”

-Ends-

Monday, February 15, 2010

"Devil Frog" Unveiled

EXHIBITION HIGHLIGHTS RESEARCH AND DISCOVERY OF RENOWNED STONY BROOK UNIVERSITY PALEONTOLOGIST, DR. DAVID KRAUSE

STONY BROOK, N.Y., February 10, 2010 – A life-sized reconstruction of the “devil frog,” the largest frog known to ever exist; a cast of the complete skeleton of a small meat-eating dinosaur named after Mark Knopfler, the lead singer from the rock band Dire Straits; a skeleton and life-sized reconstruction of a rare, 2.5 foot long pug-nosed vegetarian crocodile; and a pristinely preserved skull of a large dinosaur predator still partially entombed in sandstone are among the 65 million year old fossils from Madagascar that were publicly unveiled for the first time at Stony Brook University on Tuesday, February 9, 2010.

Funded by the Stony Brook University Medical Center Development Council, the exhibition highlights the research and discovery of world-renowned paleontologist and lead discoverer of the fossils, Dr. David Krause, Distinguished Service Professor in the Department of Anatomical Sciences at Stony Brook University. A ceremony marking the unveiling of the permanent exhibition took place at Stony Brook University Medical Center. Leading the cermony was Dr. Steven L. Strongwater, CEO of Stony Brook University Hospital, was joined by Professor Krause, who presented his science, discoveries, and social initiatives in Madagascar; Dr. Richard N. Fine, Dean of the Stony Brook University School of Medicine, Dr. Ray Williams, Dean of the School of Dental Medicine, as well as many others, including more than 125 students from area school districts.

In addition to bringing a healthy, humanistic and interesting form of distraction to visitors and patients at the hospital, the exhibit also serves to heighten awareness of the Madagascar Ankizy Fund (MAF) - an organization founded by Dr. Krause that finances the construction of schools, water sources and health clinics in remote areas of that African island. The addition of health clinics and schools in more remote parts of the island is imperative; currently, Madagascar is one of the poorest countries in the world, with over half of its population surviving on less than $1 a day. The children in most rural areas cannot read or write and have never been seen by a doctor or dentist; the island nation’s rural populations have among the highest death rates for children under five in the world.Exhibit pieces include:

Beelzebufo ampinga: One of the most exciting specimens on display will be a reconstruction of the largest frog ever know to exist. The mammoth-sized ancient frog, scientifically named Beelzebufo was over 16-inches long (not including the legs) and weighed an astounding 10-pounds. The massive size, girth, appearance, and predatory nature of the frog prompted its discoverers to call it the “frog from hell.” They derived the genus name from the Greek word for devil (Beelzebub) and the Latin word for toad (bufo). The species name, dubbed “ampinga,” means “shield.” The discovery of Beelzebufo was hailed by National Geographic as the second most significant fossil discovery of 2008.

Simosuchus clarki (three pieces): Simosuchus clarki is one of the most bizarre crocodiles to have ever lived. In contrast to most crocodiles, this small 2.5 foot, pug-nosed crocodile had a tall, rounded skull, eyes that faced toward the side, an extremely blunt snout, and leaf-shaped, multi-cusped teeth, suggesting it may have been a plant-eater – an attribute very unique for a crocodile. Simosuchus clarki was built like a tank; complete with armor for protection against its many predators: dinosaurs and larger species of crocodiles. Its tank-like construction, the positioning of its legs, as well as its eyes (facing to the side rather than toward the sky), and its very short tail indicate that it lived on land rather than in water.

Masiakasaurus knopfleri: Masiakasaurus knopfleri is named after Mark Knofler, the lead singer of the band Dire Straits because it seemed that, when his music was played, more bones of Masiakasaurus were uncovered. This fossil, measuring about six feet in length, was a small predatory theropod dinosaur. With its compact body, long neck, and long arms, Masiakasaurus resembled the well-known dinosaurian carnivore Velociraptor, of Jurassic Park fame. Strangely, the skull of Masiakasaurus had teeth in the front of its jaws that project directly forward, an adaptation for stabbing prey.

Majungasaurus crenatissimus (two pieces): At roughly 21 feet long, this dinosaur was the top predator on the island of Madagascar 65 million years ago. Skulls found in 1996 and 2005 by Stony Brook paleontologists are among the best preserved and most complete dinosaur skulls ever found. Majungasaurus was a very unusual theropod. It had a short snout, a thick skull roof, and a horn-like bump protruding from the top of its skull. The jaws were equipped with sharp, knife-like teeth designed to slice through flesh. The body of Majungasaurus was also unusual in that it had very short, powerful hind legs but extremely reduced front legs.

Wednesday, February 10, 2010

PHYLOGENETIC RELATIONSHIPS OF THE EXTINCT CAROLINA PARAKEET

PHYLOGENETIC RELATIONSHIPS OF THE EXTINCT CAROLINA PARAKEET (CONUROPSIS CAROLINENSIS) INFERRED FROM ANCIENT-DNA SEQUENCES

Kirchman, J. J., New York State Museum, Albany, USA,
Schirtzinger, E. E., New Mexico State University, Las Cruces, USA,
Wright, T. F., New Mexico State University, Las Cruces, USA,

ABSTRACT: We obtained the first DNA sequences from the extinct Carolina Parakeet (Conuropsis carolinensis) and used these data to infer the phylogenetic relationships of this iconic North American parrot. We compared our sequences of the mitochondrial CO1 gene obtained from two C. carolinensis museum specimens to homologous sequences from individuals representing 44 species in 25 genera of Neotropical parrots (Tribe Arini), and four outgroups from Old World tribes of Psittacines. Maximum likelihood and Bayesian analyses place C. conuropsis on a long branch, sister to a wellsupported clade of Aratinga parakeets that includes the most northern extant species of Neotropical parrots and species endemic to Cuba, Hispaniola, and Socorro Island. Our data do not support a close relationship with the Monk Parakeet (Myiopsistta monachus) with which C. conuropsis shares fully feathered ceres, a putative adaptation for cold tolerance. Based on the high level of sequence divergence from all sampled species (uncorrected P > 5.6%), we recommend continued recognition of the monotypic genus Conuropsis. Taxonomic revision of the highly polyphyletic genus Aratinga is needed.


2010 Joint Meeting of the AOU/Cooper Ornithological Society/Society of Canadian Ornithologists

Thursday, February 4, 2010

More Dinosaur Colors

New Haven, Conn. — Deciphering microscopic clues hidden within fossils, scientists have uncovered the vibrant colors that adorned a feathered dinosaur extinct for 150 million years, a Yale University-led research team reports online Feb. 4 in the journal Science.

Unlike recently published work from China that inferred the existence of two types of melanin pigments in various species of feathered dinosaurs, the Science study analyzed color-imparting structures called melanosomes from an entire fossil of a single animal, a feat which enabled researchers to reveal rich color patterns of the entire animal.

In fact, the analysis of melanosomes conducted by Yale team was so precise that the team was able to assign colors to individual feathers of Anchiornis huxleyi, a four-winged troodontid dinosaur that lived during the late Jurassic period in China. This dinosaur sported a generally gray body, a reddish-brown, Mohawk-like crest and facial speckles, and white feathers on its wings and legs, with bold black-spangled tips.

“This was no crow or sparrow, but a creature with a very notable plumage,” said Richard O. Prum, chair and the William Robertson Coe Professor of Ornithology, Ecology and Evolutionary Biology at Yale and a co-author of the study. “This would be a very striking animal if it was alive today.”

The color patterns of the limbs, which strongly resemble those sported by modern day Spangled Hamburg chickens, probably functioned in communication and may have helped the dinosaur to attract mates, suggested Prum.



The transformation of mankind’s view of dinosaurs from dull to flamboyant was made possible by a discovery by Yale graduate student Jakob Vinther in the Department of Geology and Geophysics. Vinther was studying the ink sac of an ancient squid and realized that microscopic granular-like features within the fossil were actually melanosomes – a cellular organelle that contains melanin, a light-absorbing pigment in animals, including birds.

While some scientists thought these granules were remnants of ancient bacteria, Vinther, Prum and Derek E.G. Briggs, the Frederick William Beinecke Professor of Geology and Geophysics and director of the Yale Peabody Museum of Natural History, disagreed. First, they tested Vinther’s theory on a 112 million year old feather from Brazil and later inferred the colors of an extinct 47 million-year-old bird.

The latest research team — which also included scientists from the University of Texas at Austin, University of Akron, Peking University and the Beijing Museum of Natural History — decided to use the same procedures to closely examine a fossil of Anchiornis huxleyi, recently described in Liaoning Province, People’s Republic of China. The area has been a gold mine for paleontologists and, among other things, provided abundant evidence confirming a once-controversial theory that modern birds are descendants of theropod dinosaurs.

The Yale team and Julia Clarke, an associate professor of paleontology at the University of Texas at Austin’s Jackson School of Geosciences, worked closely with Gao Keqin of Peking University and Li Quanguo and Meng Qingjin of the Beijing Museum of Natural History to select, sample and evaluate the anatomy and feathering of Anchiornis huxleyi, important in its own right as a new feathered dinosaur. The team's effort was funded by a special grant from the National Geographic Society and by the National Science Foundation.

The team closely examined 29 feather samples from the dinosaur and did an exhaustive measurement and location of melanosomes within the feathers. The team then did a statistical analysis of how those melanosomes compared to the types of melanosomes known to create particular colors in living birds, using data compiled by Matt Shawkey and colleagues at the University of Akron. The analysis allowed scientists to discern with 90 percent certainty the colors of individual feathers and, therefore, the colorful patterns of an extinct animal.

The research adds significant weight to the idea that dinosaurs first evolved feathers not for flight but for some other purposes.

"This means a color-patterning function — for example, camouflage or display — must have had a key role in the early evolution of feathers in dinosaurs, and was just as important as evolving flight or improved aerodynamic function,” Clarke said.

The new discoveries provide a wealth of insights into the compelling history of feather evolution in dinosaurs prior to the origin of modern birds. The study documents that color patterning within feathers and among feathers evolved earlier than previously believed. Further, these results indicate dinosaur feathers may have evolved for communication.

"Writing the first scientifically-based ‘field guide’ description of the appearance of an extinct dinosaur was a exciting and unforgettable experience — the ultimate dream of every kid who was ever obsessed with dinosaurs,” Prum said. “Now that dream is really possible."