New dinosaur discovered head first, for a change

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.

Source : Brigham Young University

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DNA sequencing unlocks relationships among flowering plants

The origins of flowering plants from peas to oak trees are now in clearer focus thanks to the efforts of University of Florida researchers.

A study appearing online this week in the Proceedings of the National Academy of Sciences unravels 100 million years of evolution through an extensive analysis of plant genomes. It targets one of the major moments in plant evolution, when the ancestors of most of the world's flowering plants split into two major groups. Together the two groups make up nearly 70 percent of all flowering plants and are part of a larger clade known as Pentapetalae, which means five petals. Understanding how these plants are related is a large undertaking that could help ecologists better understand which species are more vulnerable to environmental factors such as climate change.
Shortly after the two groups split apart, they simultaneously embarked upon a rapid burst of new species that lasted 5 million years. This study shows how those species are related and sheds further light on the emergence of flowering plants, an evolutionary phenomenon described by Charles Darwin as an abominable mystery.
"This paper and others show flowering plants as layer after layer of bursts of evolution," said Doug Soltis, study co-author and UF distinguished professor of biology. "Now it's falling together into two big groups."
Pentapetalae has enormous diversity and contains nearly all flowering plants. Its two major groups, superrosids and superasterids, split apart between 111 million and 98 million years ago and now account for more than 200,000 species. The superrosids include such familiar plants as hibiscus, oaks, cotton and roses. The superasterids include mint, azaleas, dogwoods and sunflowers.
Earlier studies were limited by technology and involved only four or five genes. Those studies hinted at the results found in the new study but lacked statistical support, said study co-author Pam Soltis, distinguished professor and Florida Museum of Natural History curator of molecular systematics and evolutionary genetics.
The new study at UF's Florida Museum of Natural History analyzed 86 complete plastid genome sequences from a wide range of plant species. Plastids are the plant cell component responsible for photosynthesis.
Previous genetic analyses of Pentapetalae failed to untangle the relationships among living species, suggesting that the plants diverged rapidly over 5 million years. Researchers selected genomes to sequence based on their best guess of genetic relationships from the previous sequencing work.
Genome sequencing is more time-consuming for plants than animals because plastid DNA is about 10 times larger than the mitochondrial DNA used in studying animal genomes. But continual improvements in DNA sequencing technology are now allowing researchers to analyze those larger amounts of data more quickly.
The study provides an important framework for further investigating evolutionary relationships by providing a much clearer picture of the deep divergence that led to the split within flowering plants, which then led to speciation in the two separate branches.
Eventually, researchers hope to match these evolutionary bursts with geological and climatic events in the earth's history. "I think we're starting to get to a point with a dated tree where we could start looking at what was happening at some of those time frames," Pam Soltis said.
Source : University of Florida

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An emotion detector for baby

Baby monitors of the future could translate infant cries, so that parents will know for certain whether their child is sleepy, hungry, needing a change, or in pain. Japanese scientists report details of a statistical computer program that can analyze a baby's crying in the International Journal of Biometrics.

As any new parent knows, babies have a very loud method of revealing their emotional state - crying. Unfortunately, the parenting handbook does not offer guidance on how to determine what the crying means. Parents sometimes learn with experience that their child's cries may be slightly different depending on their cause, whether hunger or discomfort. Now, engineers in Japan have turned to an approach to product design, known as kansei engineering, invented in the 1970s by Professor Mitsuo Nagamachi, Dean of Hiroshima International University, which aims to "measure" feelings and emotions.

Tomomasa Nagashima of the Department of Computer Science and Systems Engineering, at Muroran Institute of Technology, in Hokkaido and colleagues explain that the fundamental problem in building an emotion detector for baby's crying is that the baby cannot confirm verbally what its cries mean. Various researchers have tried to classify infant emotions based on an analysis of the crying pattern but with little success so far.

The team has employed sound pattern recognition approach that uses a statistical analysis of the frequency of cries and the power function of the audio spectrum to classify different types of crying. They were then able to correlate the different recorded audio spectra with a baby's emotional state as confirmed by the child's parents. In their tests recordings of crying babies with a painful genetic disorder, were used to make differentiating between the babies' pained cries and other types of crying more obvious. They achieved 100% success rate in a validation to classify pained cries and "normal" cries.

The research has developed a sound theoretical method for classification of infant emotions, although limited to a specific emotion, based on analysis of the audio spectra of the baby's cries. The technique might one day be incorporated into a portable electronic device, or app, to help parents or carers decide on a course of action when their child is crying.

Source : Inderscience Publishers

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