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Bizarre ‘Fish Lizard,’ The Oldest Of Its Kind, Unearthed by Paleontologists

November 6, 2014 By Germaine Hicks Leave a Comment

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Recently, the researchers found a 248 million year old fossil of an ancient reptile in China, which is believed to be the oldest known member of a well-known group of marine reptiles, and might have lived both on land and in the sea.

The researchers revealed that the specimen is an ancient type of ichthyopterygian, a group related to ichthyosaurs, which are large marine reptiles that dominated the world’s oceans after the Permian-Triassic extinction. At that time, approximately 252 million years ago, around 96% of marine animals and 70% of land animals went extinct. Researchers said, the recently discovered fossil provides new evidence that ichthyosaurs evolved from creatures that lived on land. The study is published in the Nature journal on 5^th Nov.

The lead-author of the study and a geologist at Peking University in China, Da-yong Jiang said, “This new animal is a link between the terrestrial ancestor and the ichthyosaurs fully adapted to a life in the sea.”

Ichthyosaurs, which is a Greek name for “fish lizard,” lived from about 248 million to 95 million years ago. The group was extremely diverse, with body lengths ranging from less than 3.3 feet (1 meter) to more than 66 feet (20 m).

Jiang told Live Science in an email, “So far, all known ichthyosaur fossils came from animals that lived exclusively in the ocean, and there was a huge gap in the fossil record between them and their ancestors. Scientists didn’t know whether their ancestors were reptiles or amphibians, and if they lived on land or not.”

The recent specimen named “Cartorhynchus lenticarpus” discovered by Jiang and his team is the smallest known ichthyosaur-type creature — only about 1.3 feet (0.4 m) long. “We think the animal is fully grown, but cannot rule out the possibility that the fossil is the remains of an immature form of a larger creature,” researchers say.

In contrast to other ichthyosaurs, the new specimen has oddly large flippers that perhaps limited its ability to get around on land, making it similar to a modern seal. It also has a short muzzle and body trunk, like other land reptiles, the researchers said.

Jiang said, “The animal was probably a suction feeder on the seafloor, and may have eaten worms or eel-like creatures called conodonts. The fossil is quite complete and well-preserved; just part of the animal’s tail is missing.”

The fossil is discovered during an excavation in Chaohu, South China, in 2011. During the dig, researchers found several skeletons of ancient ichthyosaurs and extinct aquatic reptiles called sauropterygians, as well as fishes and other creatures.

Sine 2002, Jiang and his colleagues have been doing excavations in South China, looking for the first ichthyosaur that “jumped into the sea,” he said, so the new discovery “is a milestone after our hard work for more than 10 years.”

Madagascar Fossil: A Hors D’oeuvre Of The Dinosaur Age

November 6, 2014 By Rebecca McGhee Leave a Comment

During the dinosaur age, most of the mammals were frail, usually weighing less than 450g. Recently, a bizarre fossil skull is discovered in Madagascar, which is relatively a giant weighing around 9kg.

David Krause of Stony Brook University in New York said, “It was a monster and looks like a big groundhog.”

The researchers believed that it’s the 2nd heaviest mammal known from the era, and the most massive of that time from the southern hemisphere.

Professor Krause said his best guess was it measured between 50cm and 60cm from nose to rump. It lived between 66 million and 72 million years ago.

In a study published in Nature journal, Professor Krause and colleagues have named it Vintana sertichi, perhaps an agile plant-eater with good eyesight in low light and a good sense of smell, handy to avoid predatory dinosaurs and other beasts that shared its environment.

“It would have been a fine hors d’oeuvre for a dinosaur,” Professor Krause said.

Madagascar Fossil Provides Evidences in Evolution of Mammals

November 6, 2014 By Rebecca McGhee Leave a Comment

While searching for fish fossils in Madagascar four years ago, paleontologists discovered a well-preserved cranium of a mammal. The researchers believed that this mammal lived about 66 million to 70 million years ago, in the closing era of the mighty dinosaurs.

The discovery is known to be rare in the entire Southern Hemisphere and expected to provide new and important insights into early mammalian evolution. The ancient mammals’ fossil record in Madagascar is annoyingly thin. The researchers found just two other mammal skulls from the age of dinosaurs in the entire Southern Hemisphere – and both were from Argentina.

The study is published in Nature journal. The lead researcher of the study and a paleontologist at Stony Brook University on Long Island David W. Krause revealed that the fossil mammal is a distinct new genus and species, Vintana sertichi. Vintana means luck, which was smiling on Joseph Sertich, then a graduate student of Dr. Krause’s and now a curator at the Denver Museum of Nature and Science, in finding the slab of sandstone that held the skull.

Dr. Krause said in a statement, “No paleontologist could have come close to predicting the odd mix of anatomical features that this cranium exhibits.”

The five inches long cranium, which is twice the size of the one from the previous largest known mammal from the age of dinosaurs on the southern super-continent known as Gondwana. At that time, nearly all primitive mammals were no bigger than shrews and mice, cowering in the shadows of hulking reptiles.

Vintana is estimated to have weighed about 20 pounds, twice or even three times the size of an adult groundhog today.

However, the researchers sometimes described the specimen as groundhog-like. Vintana belonged to an ancestry without any known living descendants, Dr. Krause said. “It’s an entirely extinct ancestry, an early experiment in mammals that didn’t make it,” he said in an interview. “And I doubt Vintana was any better at predicting seasonal weather change than Punxsutawney Phil in Pennsylvania.”

Vintana belongs to a group of early mammals known as gondwanatherians, the only previous evidence for which were a few teeth and jaw fragments, researchers claimed.

Consecutively, these mammals were closely related to the multituberculates, which is an evolutionarily successful group of early mammals known almost solely from Northern Hemisphere fossils. All these relationships had been uncertain before now, researchers said.

Anne Weil, an anatomist at the Oklahoma State University Center for Health Sciences said in a commentary accompanying the Nature paper, the new findings offered “a profusion of data not only to solve” the mystery of the mammalian family tree “but also to reveal further amazing morphological diversity among early mammals.”

Other researchers independent of the discovery team endorsed the interpretation of the findings. Guillermo W. Rougier, a specialist in the early evolution of mammals at the University of Louisville, said the study is “a remarkable achievement” and the cranium “is exceptional.”

Zhe-Xi Luo, an anatomist at the University of Chicago who is also an expert in mammalian evolution, called Vintana “the discovery of the decade for understanding the deep history of mammals.”

The study “offers the best case of how plate tectonics and biogeography have impacted the animal evolution — an ancestry of mammals isolated on a part of the ancient Gondwana had evolved some extraordinary features beyond our previous imagination,” he added.

Joe Groenke, a technician working with Dr. Krause was the first person at Stony Brook to see the CT image of the cranium embedded in the sandstone. The specimen had wide eye sockets. Further analysis revealed teeth of a plant eater, and a nasal passage and inner ear of an animal with keen senses of smell and hearing.

Mr. Groenke said, “When we realized what was staring back at us on the computer screen, we were stunned.” He spent the next six months extracting the skull from the surrounding rock matrix, one sand grain at a time.

One Gene Gives Monarch Butterflies the Power to Migrate: Researchers Revealed!

October 1, 2014 By Brian Galloway Leave a Comment

The researcher have sequenced 101 butterfly genes, and discovered that there is only one gene which is responsible for the butterflies to immigrate long distances. The study findings propose that the monarch butterflies are actually evolved with more efficient muscles that help them to fly so far.

A recent genetic analysis published this week in the Nature journal, having some unanticipated twists. First thing, it seems as the intimates of the contemporary monarchs initially dispersed out North America, instead of central or South America, as formerly believed. Secondly, only one gene seems to play a vital role in giving monarchs their prominent coloration.

However, Marcus Kronforst, University of Chicago’s biologist confesses that he along with his fellow colleagues firstly discovered evolutionary proofs hard to accept. He stated in his interview with BBC News, “It really took lots of convincing,” though, the findings portray how genetics could elaborate the origins of a species’ traits on a level far more fundamental than, say, Rudyard Kipling’s “Just So Stories,” said the University of Exeter’s Richard H. ffrench-Constant.

H. ffrench-Constant (not involved in the project), stated in a Nature journal; “Butterflies are leading a revival in our understanding of the molecular basis of natural selection.”

From Where Monarch got its Start?

The different patterns of alteration in genomes are analyzed by researchers to conclude that North American butterflies are nearby to their ancestral roots of evolutionary tree.

The researchers assumed that, the travelling Monarchs originated in Central or South America, and established themselves in North America. But the latest proof indicates that the species got its start in southern United States or Mexico, perhaps 1mn to 2mn years ago said by Kronforst.

The butterflies most likely to followed a short range traveling pattern. The researchers says that, North American population began to expand about 20,000 years ago, at the end of the Last Glacial Maximum, when butterflies could more readily spread on milkweed crowd plants in the American Midwest.

Monarch Spots

The other big inherited finding related to Monarch butterfly is distinctive orange and black spotted wings. But, in Hawaii some monarchs lack that pattern, and they have white wings. When genetic differences are analyzed by researchers, between two varieties, they found a myosin gene called DPOGS206617 which was strongly linked with wing color.

This gene is similar to a myosin gene which plays a key role in the color of a mouse’s furry coat. An alteration in that gene leads to mice with less pigment, and according to latest study the researchers says that, the butterfly’s myosin gene may play a similar role in transporting pigment to the wings. The migrating monarch butterflies are facing a shocking decline, due to factors ranging from deforestation and lack of a severe decline in the Midwest’s milkweed.

This genetic analysis did not put forward any new strategies for saving the monarchs, but it could highlight the importance of protecting an iconic species whose way of life goes back millions of years said by Kronforst.

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