Taxonomy term

lucas joel

Origins of plant photosynthesis illuminated

Photosynthesis, the process by which plants harness sunlight to make their food, is a defining feature of plants and an important evolutionary development. But when photosynthesis evolved in ancient plant ancestors is not clear. The Precambrian fossil red alga Bangiomorpha pubescens, discovered in the Canadian Arctic in 1990 by University of Cambridge paleobiologist Nicholas Butterfield, displays evidence of traits that suggest it photosynthesized the way plants do, but the exact age of the fossil was also unknown. In a new study, researchers report an age for the alga of about 1.047 billion years, making it the oldest-known direct ancestor of plants.

25 Apr 2018

Whatever happened to thagomizers and other tail weapons?

Stegosaurus wielded a spiked tail — dubbed a “thagomizer” by cartoonist Gary Larson and informally adopted by paleontologists — which the herbivorous dinosaur likely used for defense against hungry predators. Other extinct animals also sported foe-clobbering tail weapons: Ankylosaurus had a tail club, as did extinct mammals like the glyptodonts, giant armadillo-like animals that once roamed the Americas. Today, though, thagomizers and bony tail clubs are things of the past. In a new study, paleontologists have found that extinct animals with such weapons all shared a now-antiquated set of traits: They were large, herbivorous, and had body armor and a stiff torso.

23 Apr 2018

Coal formation nearly froze Earth

Burning coal releases carbon dioxide, which warms the planet when the gas escapes into the air. On the flip side, coal formation sequesters carbon dioxide removed from the atmosphere by plants, which contributes to global cooling as the planet’s greenhouse gas blanket thins. According to new research, so much carbon was removed from the atmosphere in the Carboniferous Period, when most of Earth’s coal reserves formed, that the planet became almost completely covered in ice.

21 Feb 2018

What drives hot spots of sea-level rise?

As sea levels creep up around the world, scientists have observed hot spots where regional rates of sea-level rise greatly outpace the global average. But what drives the formation of these hot spots, and how long they last, have been mysteries. In a new study, scientists tracking sea levels along the Florida coast suggest that the combined effects of two naturally occurring climate processes, the El Niño-Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO), control sea-level hot spot formation along the U.S. East Coast.

01 Dec 2017

Chemical clues illuminate fossil plant relationships

To reconstruct relationships among extinct plants and animals, paleontologists often compare genetic sequences from distinct organisms or analyze differences in fossil shapes. But both techniques have limitations: DNA does not last more than about a million years in the rock record, so genetic comparisons are typically limited to relatively recent species; and finding fossils intact enough to use for shape comparisons can be difficult. In a recent study, scientists describe a new technique that could help get around these issues — for some plants at least — using molecular remnants that are more robust than DNA and are preserved in fossil leaves.

17 Oct 2017

Volcanism triggered end-Triassic extinction

The end-Triassic mass extinction exterminated up to three-quarters of all species on land and in the oceans 201 million years ago. This die-off opened up ecological niches and allowed for, among other changes, dinosaurs to diversify and spread across terrestrial ecosystems during the rest of the Mesozoic. Volcanism has long been implicated in the extinction, but whether it had a major impact on the planet at the time has remained unclear. In new research, scientists observed elevated mercury concentrations in extinction-aged rocks from around the world. Because volcanism is the main nonanthropogenic source of mercury in the environment, the findings suggest that volcanic activity was likely the main extinction trigger at the end of the Triassic.

21 Sep 2017

Dust influences pollution levels in eastern China

Air pollution often enshrouds cities in eastern China in a thick haze that impairs visibility and causes respiratory health problems. Emissions from human activity are mainly to blame, but climate researchers now report that natural forces — namely, dust kicked into the air by wind — can also exert a strong control over how much pollution persists in the air.

22 Aug 2017

New global volcanic emissions map debuts

Volcanoes may not always be erupting ash or lava, but that doesn’t mean they’re not venting other materials. Many, in fact, continuously spew gases like carbon dioxide and sulfur dioxide into the air. In a new study, volcanologists compiled data tracking such releases, collected by NASA’s Aura satellite, into the first global map of volcanic sulfur dioxide emissions.

13 Jul 2017

Precambrian rumblings of the Cambrian Explosion

The Cambrian Explosion, when the ancestors of most of today’s animal groups began appearing in the fossil record about 542 million years ago, was — as the name suggests — a geologically abrupt event. Paleontologists have long thought of the event as marking a boundary between distinct Precambrian and Cambrian faunas. In new research published in Geology, however, scientists report that small, shelly fossils once thought to occur only in Cambrian rocks have been found in rocks dating to the late Ediacaran, just before the Cambrian, implying an earlier start to the explosion than previously thought.

11 Jul 2017

New cloud types recognized

Familiar clouds like cumulonimbus, cirrocumulus and nimbostratus have some new company. The World Meteorological Organization (WMO) has published a new edition of its International Cloud Atlas, the first revision since 1987. The updated version — released in digital format for the first time — compiles recent observations and introduces about a dozen new terms, such as “asperitas,” which refers to a cloud whose sweeping undulations resemble the surface of a stormy sea, as well as names for clouds induced by wildfires and by human activity. There is even a new cloud species, “volutus,” which describes long, tube-shaped rolling clouds.

27 Jun 2017

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