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Asteroid that Killed the Dinosaurs also Wiped out the ‘Obamadon’

By Guest PostDecember 11, 2012Nature, Scienceage of dinosaurs, alberta, asteroid collision, asteroid strike, bhart anjan bhullar, boundary, canada, carnivorous lizards, cerberophis, cretaceous, dinosaur species, dinosaurs, diversification, ecosystem, edmontosaurus, evolution, extinct lizard, flood, fossils, gracilis, harvard, jacques a gauthier, kill, lizard, mammals, mass extinction, montana, new mexico, nicholas r longrich, North America, obamadon, obamadon gracilis, odon, palaeosaniwa, paleogene, political significance, polyglyphanodontia, slender, snake, species, survivor, swamps, t rex, taxonomy, tooth, triceratops, united states, us president, yale, yucatan peninsula

The asteroid collision widely thought to have killed the dinosaurs also led to extreme devastation among snake and lizard species, according to new research — including the extinction of a newly identified lizard Yale and Harvard scientists have named Obamadon gracilis.

“The asteroid event is typically thought of as affecting the dinosaurs primarily,” said Nicholas R. Longrich, a postdoctoral associate with Yale’s Department of Geology and Geophysics and lead author of the study. “But it basically cut this broad swath across the entire ecosystem, taking out everything. Snakes and lizards were hit extremely hard.” (more…)

Mass Extinctions Reset the Long-Term Pace of Evolution

By Guest PostJuly 3, 2012Scienceandrew z krug, animal kingdom, birth rate, bivalve, chicago esque, david jablonski, evolution, evolutionary rate, fossil, fossil mollusk, jurassic period, maryland outcrop, mass extinction, oysters, pace of evolution, paleontologist, pleistocene epoch, richard bambach, scallops, species diversification, time boundaries, university of chicago

A new study indicates that mass extinctions affect the pace of evolution, not just in the immediate aftermath of catastrophe, but for millions of years to follow. The study’s authors, University of Chicago’s Andrew Z. Krug and David Jablonski, will publish their findings in the August issue of the journal Geology.

Scientists expected to see an evolutionary explosion immediately following a mass extinction, but Krug and Jablonski’s findings go far beyond that.

“There’s some general sense that the event happens, there’s some aftermath and then things return to normal,” said Krug, a research scientist in geophysical sciences at UChicago. But in reality, Krug said, “Things don’t return to what they were before. They operate at a different pace, sometimes more rapidly, other times more slowly. Evolutionary rates shift, and that shift is permanent until the next mass extinction.” (more…)

Explosive Evolution Need Not Follow Mass Extinctions

By Guest PostFebruary 14, 2012Sciencegraptoloid evolution, mass extinction, ordovician mass extinction, radiation idea, surviving species

In the wake of a mass extinction like the one that occurred 445 million years ago, a common assumption is that surviving species tend to proliferate quickly into new forms, having outlived many of their competitors. (more…)

Global Extinction: Gradual Doom as Bad as Abrupt

By Guest PostFebruary 8, 2012Environment, Sciencebrooks ellwood, canadian arctic, carbon dioxide, charles henderson, coal deposit, dead zone, earth, ellesmere island, extinction, factor, fossil, geologic history, geology, global extinction, greenhouse, greenhouse gas, h richard lane, harry rowe, indian ocean, katherine freeman, marine life, mass extinction, national science foundation, ocean, permian period, permian triassic boundary, sedimentary rock, siberian traps, siberian volcanic activity, south china, steven bates, tethys, the great dying, thomas algeo, timothy lyons, united states, university of calgary, university of cincinnati, volcanic deposit, volcanic rock, volcanism in siberia, warming, west blind fiord

*In “The Great Dying” 250 million years ago, the end came slowly*

The deadliest mass extinction of all took a long time to kill 90 percent of Earth’s marine life–and it killed in stages–according to a newly published report.

It shows that mass extinctions need not be sudden events.

Thomas Algeo, a geologist at the University of Cincinnati, and 13 colleagues have produced a high-resolution look at the geology of a Permian-Triassic boundary section on Ellesmere Island in the Canadian Arctic. (more…)

Last Dinosaur Before Mass Extinction Discovered

By Guest PostJuly 13, 2011Scienceage of dinosaur, fossilized horn, last dinosaur, mass extinction, non avian dinosaurs

A team of scientists has discovered the youngest dinosaur preserved in the fossil record before the catastrophic meteor impact 65 million years ago. The finding indicates that dinosaurs did not go extinct prior to the impact and provides further evidence as to whether the impact was in fact the cause of their extinction. (more…)

Mass Extinction Victim Survives! Snail Long Thought Extinct, isn’t?

By Guest PostJune 9, 2011Natureindustrialization, mass extinction, mass extinction victim

ANN ARBOR, Mich.—Think “mass extinction” and you probably envision dinosaurs dropping dead in the long-ago past or exotic tropical creatures being wiped out when their rainforest habitats are decimated. But a major mass extinction took place right here in North America in the first half of the 20th century, when 47 species of mollusk disappeared after the watershed in which they lived was dammed. (more…)

Earth’s Sixth Mass Extinction: Is It Almost Here?

By Guest PostMarch 4, 2011Environment, Scienceanimal species, anthony barnosky, big five, biodiversity, biodiversity baseline, disease, earth, extinction, extinction rate for mammals, fossil record, global warming, habitat fragmentation, hazard of climate change, human activities, invasive species, mammals, mass extinction, richard lane, road to extinction, species, storm of threats

*Steep decline of many animal species warns that Earth is on the brink*

With the steep decline in populations of many animal species, scientists have warned that Earth is on the brink of a mass extinction like those that have occurred just five times during the past 540 million years.

Each of these “Big Five” saw three-quarters or more of all animal species go extinct.

In results of a study published in this week’s issue of journal Nature, researchers report on an assessment of where mammals and other species stand today in terms of possible extinction compared with the past 540 million years.

They find cause for hope–and alarm. (more…)

What Triggers Mass Extinctions? Study Shows How Invasive Species Stop New Life

By Guest PostJanuary 3, 2011Sciencealycia stigall, amphibians, archaeostraca, biodiversity loss, bivalve, brachiopods, collapse of earth marine life, crinoids, dunkleosteus, ecosystems, environmental crash, floweria, formation of a mountain range, history of life, invasive species, late devonian, late devonian oceans, leiopteria, leptodesma, lisa boush, mass extinction, new river channel, phylogenetic analysis, predatory crustacean, predatory fish, schizophoria, sea levels, sea lilies, trilobites, vicariance

*Collapse of Earth’s marine life 378 to 375 million years ago holds key*

An influx of invasive species can stop the dominant natural process of new species formation and trigger mass extinction events, according to research results published in the journal PLoS ONE.

The study of the collapse of Earth’s marine life 378 to 375 million years ago suggests that the planet’s current ecosystems, which are struggling with biodiversity loss, could meet a similar fate. (more…)

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