A side-by-side comparison reveals the similarity between the brain of a living onychophoran (L) and that of the anomalocaridid fossil of a Lyrarapax unguispinus Homme Nike Air Max 97 Triple Noir Pas Cher , as seen in an undated handout illustration courtesy of the University of Arizona. REUTERSNicholas StrausfeldUniversity of ArizonaHandout via Reuters An artist's impression of a Lyrarapax unguispinus, one of the species of the world's first predators, the anomalocaridids, chasing primitive fishes that also existed in the Lower Cambrian Period, is seen in this undated handout illustration courtesy of the University of Arizona. Researchers on July 16, 2014 described fossilized remains unearthed in China showing in fine detail the brain structures of a bizarre group of sea creatures that were the top predators more than half a billion years ago.
Researchers on Wednesday described fossilized remains unearthed in China showing in fine detail the brain structures of a bizarre group of sea creatures that were the top predators more than half a billion years ago.
The fossils show an animal called Lyrarapax unguispinus that lived during the Cambrian Period Homme Nike Air Max 270 Premium Noir Pas Cher , a pivotal juncture in the history of life on Earth when many major animal groups first appeared. It was a member of a group known as anomalocaridids - primitive relatives of arthropods, which include crustaceans, insects and spiders - that hunted prey with a pair of claw-like grasping appendages in front of the eyes.
Even though anomalocaridids do not have any direct descendants alive today, the brain structures of Lyrarapax closely resemble those of worm-like animals called velvet worms that crawl along the ground in tropical and semitropical forests in the Southern Hemisphere.
The researchers said the similarities suggest that velvet worms may be very distant cousins of the anomalocaridids, whose best-known example is Anomalocaris, known from a Canadian fossil site called the Burgess Shale.
Velvet worms Homme Nike Air Max 270 Just Do It Blanche Pas Cher , land animals also known as onychophorans, grow to a few inches in length, have two long feelers extending from the head and have numerous pairs of stubby, unjointed tubular legs that each end in a pair of small claws.
Lyrarapax, whose scientific name means spiny-clawed, lyre-shaped predator Homme Nike Air Max 270 Just Do It Sneakers Noir Pas Cher , lived 520 million years ago. Its neuroanatomy resembles that of velvet worms in multiple ways, with a simple brain and a pair of ganglia – a cluster of nerve cells – placed in the front of the optic nerve and the base of the grasping appendages.
The soft parts of any animal's body typically decay after death, meaning that fossils usually preserve only hard parts like bones, teeth and shells. But under exceptional circumstances, soft tissue and anatomical organs can be preserved in fossils.
Lyrarapax was much smaller than some other anomalocaridids. It measured about 6 inches (15 cm) long, roughly the size of a large shrimp. Peiyun Cong Homme Nike Air Max 270 Be True Multi-Color Pas Cher , a paleontologist at Yunnan University in China, said the three specimens of Lyrarapax that were found "may represent immature stages of the animal, so it might be larger."
"Anomalocaridids preserved with the whole body are very rare. None of them have been reported with the brain," Cong said.
The fossils show that anomalocaridids possessed brains that were less complex than those of animals it may have hunted.
University of Arizona neuroscientist Nicholas Strausfeld, another of the researchers, said the threat posed by predators like these creatures may have helped drive brain complexity among animals in the ancient seas.
"Predation may have in part contributed to the evolution of more elaborate brains that could process more complex ecological cues that might have offered camouflage or other protection Homme Nike Air Max 270 Blanche Pas Cher ," Strausfeld said.
The study was published in the journal Nature.
(Agencies)
BEIJING, July 29 (Xinhua) -- "The Continent," a romantic comedy by writer-turned-director Han Han, took 300.8 million yuan (about 48.4 million U.S. dollars) in the week ending July 27 to become the weekly box office champion.
"The House That Never Dies," a horror which tells the story of a haunted mansion in Beijing, was second Homme Nike Air Max 270 Blanche Noir Pas Cher , taking in 172 million yuan, the China Film News reported on Tuesday.
The horror was closely followed by domestic drama "Tiny Times 3," which pulled in 155 million yuan. The movie, which was inspired by author-turned-director Guo Jingming's young adult novel of the same name, topped the box office in the previous week.
"Transformers: Age of Extinction," the fourth installment in the robot movie franchise Homme Nike Air Max 270 Tout Noir Pas Cher , earned 79 million yuan, ranking fourth on the charts, according to the report.
Rounding up the top five list was domestic cartoon "The Magical Brush," which earned 30.1 million yuan.
SYDNEY, Dec. 12 (Xinhua) -- Astronomers have used a powerful array of telescopes across Australia and the rest of the world to examine a black hole 55 million times more massive than the Sun.
The research published Tuesday showed how the International Center for Radio Astronomy Research (ICRAR) used two radio telescopes and several optical telescopes to get a closer look at the intricate workings of a galaxy known as Centaurus A.
"As the closest radio galaxy to Earth, Centaurus A is the perfect cosmic laboratory to study the physical processes responsible for moving material and energy away from the galaxy's core Homme Nike Air Max 270 Flyknit Triple Blanche Pas Cher ," Dr. Ben McKinley from the ICRAR said in a statement.
Although the galaxy is located more than 12 million light-years away from the Earth, astronomically it's considered a mere stone's throw.
"Being so close to Earth and so big actually makes studying this galaxy a real challenge because most of the telescopes capable of resolving the detail we need for this type of work have fields of view that are smaller than the area of sky Centaurus A takes up," McKinley said.
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