Dinosaur-eating snake discovered


Sanajeh indicus, reconstruction

From British daily The Guardian:

Fossil of dinosaur-eating snake found

Prehistoric snake discovered in India was three metres long and preyed on baby sauropods

* Press Association
* Tuesday 2 March 2010

Even dinosaurs may have been afraid of snakes, a discovery suggests. Scientists have unearthed the almost complete fossil skeleton of a prehistoric snake that preyed on baby dinosaurs. The creature, which was three metres long, was “caught in the act” of pursuing a meal 67m years ago.

Its body was found in a dinosaur nest coiled around a hatched and crushed egg, and next to it was a 50cm fossil hatchling titanosaur – a small version of a plant-eating giant that as an adult weighed up to 100 tonnes. The remains of two other snakes were also found paired with eggs at the same site in Gujarat, western India.

The snake, named Sanajeh indicus, lacked the wide-open jaws of modern snakes such as pythons and boa constrictors and would not have been able to swallow a whole dinosaur egg. But baby dinosaurs would have been just the right size, according to researchers.

Dr Jason Head, from the University of Toronto in Canada, who led a study of the snake reported today in the online journal PLoS One, said: “Living primitive snakes are small animals whose diet is limited by their jaw size, but the evolution of a large body size in Sanajeh would have allowed it to eat a wide range of prey, including dinosaur hatchlings.

“This is the first direct evidence of feeding behaviour in a fossil primitive snake, and shows us that the ecology and early evolutionary history of snakes were much more complex than we would think just by looking at modern snakes today.”

The fossils were uncovered in 1987 by dinosaur egg expert Dr Dhananjay Mohabey, of the Geological Survey of India. At first they were identified as the remains of a hatchling dinosaur. It was not until 2001 that palaeontologist Dr Jeff Wilson, from the University of Michigan, spotted the bone patterns of a snake.

“I saw the characteristic vertebrae of a snake beside the dinosaur eggshell and larger bones, and I knew it was an extraordinary specimen, even if I couldn’t put the whole story together at that point,” said Wilson. More experts were brought in, and years of further research and field trips followed.

The titanosaur eggs were laid in loose sand. Scientists believe the hatchling had just emerged from its egg when the snake struck, attracted by its movements. Predator and prey are believed to have been rapidly buried and preserved in sand and mud, possibly as a result of a storm.

Titanosaurs were among the last surviving members of a group of four-footed, long-necked plant eaters known as sauropods, which included the biggest land animals that ever lived. Like other dinosaurs, they are thought to have grown to a large size quickly after hatching. Until then, they would have been highly vulnerable to predators such as Sanajeh indicus.

“It would have been a smorgasbord,” said Head. “Hundreds or thousands of defenceless baby sauropods could have supported an ecosystem of predators during the hatching season.”

See also here. And here. And here. And here. And here.

November 2010: In a discovery that upends decades of scientific theory on reptile reproduction, researchers at North Carolina State University have discovered that female boa constrictors can squeeze out babies without mating: here.

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4 thoughts on “Dinosaur-eating snake discovered

  1. March 3, 2010 — Paleontologists have discovered a new dinosaur relative that could completely rewrite the history of these animals, according to a new study which appears in tomorrow’s issue of Nature.

    Fossil remains of the new species, Asilisaurus kongwe, date back to about 240 million years ago — around 10 million years before the oldest known dinosaurs first emerged.

    Aside from reshaping the dino timeline, Asilisaurus has shed new light on the evolution of dinosaurs. Researchers believe that dinosaurs and their relatives went from being exclusively meat-eaters to including plants in their diet.

    This new species was about the size of a large dog. Its beak-like jaw and triangular teeth suggest the animal was an omnivore with a diet that consisted mostly of plants.

    Asilisaurus belonged to a group called silesaurs — creatures that shared many dinosaur characteristics but that still lacked key characteristics of all dinosaurs. The relationship is almost analogous to humans and chimps today.

    http://news.discovery.com/dinosaurs/dinosaurs-relative-timeline.html

    See also here.

  2. It’s official: An asteroid wiped out the dinosaurs

    Kate Kelland, Health and Science Correspondent
    LONDON
    Thu Mar 4, 2010 4:16pm EST

    An asteroid slamming into Earth at Chicxulub in what is now Mexico in an undated artist’s rendering. A giant asteroid smashing into Earth is the only plausible explanation for the extinction of the dinosaurs, a global scientific team said on Thursday, hoping to settle a row that has divided experts for decades. REUTERS/NASA

    An asteroid slamming into Earth at Chicxulub in what is now Mexico in an undated artist’s rendering. A giant asteroid smashing into Earth is the only plausible explanation for the extinction of the dinosaurs, a global scientific team said on Thursday, hoping to settle a row that has divided experts for decades.

    Credit: Reuters/NASA

    LONDON (Reuters) – A giant asteroid smashing into Earth is the only plausible explanation for the extinction of the dinosaurs, a global scientific team said on Thursday, hoping to settle a row that has divided experts for decades.

    Science

    A panel of 41 scientists from across the world reviewed 20 years’ worth of research to try to confirm the cause of the so-called Cretaceous-Tertiary (KT) extinction, which created a “hellish environment” around 65 million years ago and wiped out more than half of all species on the planet.

    Scientific opinion was split over whether the extinction was caused by an asteroid or by volcanic activity in the Deccan Traps in what is now India, where there were a series of super volcanic eruptions that lasted around 1.5 million years.

    The new study, conducted by scientists from Europe, the United States, Mexico, Canada and Japan and published in the journal Science, found that a 15-kilometre (9 miles) wide asteroid slamming into Earth at Chicxulub in what is now Mexico was the culprit.

    “We now have great confidence that an asteroid was the cause of the KT extinction. This triggered large-scale fires, earthquakes measuring more than 10 on the Richter scale, and continental landslides, which created tsunamis,” said Joanna Morgan of Imperial College London, a co-author of the review.

    The asteroid is thought to have hit Earth with a force a billion times more powerful than the atomic bomb at Hiroshima.

    Morgan said the “final nail in the coffin for the dinosaurs” came when blasted material flew into the atmosphere, shrouding the planet in darkness, causing a global winter and “killing off many species that couldn’t adapt to this hellish environment.”

    Scientists working on the study analyzed the work of paleontologists, geochemists, climate modelers, geophysicists and sedimentologists who have been collecting evidence about the KT extinction over the last 20 years.

    Geological records show the event that triggered the dinosaurs’ demise rapidly destroyed marine and land ecosystems, they said, and the asteroid hit “is the only plausible explanation for this.”

    Peter Schulte of the University of Erlangen in Germany, a lead author on the study, said fossil records clearly show a mass extinction about 65.5 million years ago — a time now known as the K-Pg boundary.

    Despite evidence of active volcanism in India, marine and land ecosystems only showed minor changes in the 500,000 years before the K-Pg boundary, suggesting the extinction did not come earlier and was not prompted by eruptions.

    The Deccan volcano theory is also thrown into doubt by models of atmospheric chemistry, the team said, which show the asteroid impact would have released much larger amounts of sulphur, dust and soot in a much shorter time than the volcanic eruptions could have, causing extreme darkening and cooling.

    Gareth Collins, another co-author from Imperial College, said the asteroid impact created a “hellish day” that signaled the end of the 160-million-year reign of the dinosaurs, but also turned out to be a great day for mammals.

    “The KT extinction was a pivotal moment in Earth’s history, which ultimately paved the way for humans to become the dominant species on Earth,” he wrote in a commentary on the study.

    (Collins has created a website here which allows readers to see the effects of the asteroid impact.)

    (Editing by Myra MacDonald)

  3. Pingback: Obama lizard became extinct with dinosaurs | Dear Kitty. Some blog

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