Fossils

fossil

Massive trove of dinosaur tracks cataloged in Australia

In a remote region of Western Australia, paleontologists have documented the world’s most diverse assemblage of dinosaur tracks. The scientists found preserved in Early Cretaceous rocks thousands of tracks, 150 of which can be assigned to at least 11, and possibly as many as 21, different known track types representing theropods, sauropods, ornithopods and armored thyreophorans.

18 Jul 2017

Hangover echinoderms survived the Great Dying

The end-Permian extinction event was disastrous for a wide range of organisms on land and in the sea, with as many as 70 percent of terrestrial and 81 percent of marine species dying off. One of the hardest hit marine phyla was the echinoderms, which today includes sea urchins and starfish. Echinoderms are thought to have suffered one of the most severe population reductions in evolutionary history, with only a few members surviving to repopulate the oceans in the Triassic. But in a new study, researchers have identified Triassic fossils from a handful of “hangover” species whose ancestors were previously thought to have gone extinct at the end of the Permian, suggesting the extinction wasn’t quite as cataclysmic for echinoderms as paleontologists have suspected.

12 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

Bipedalism left its mark on human skull: Kangaroos and upright rodents show same signs

The transition to bipedal walking in our ancestors changed the hominin skeleton in many ways. New research looking at how upright walking affected the structures at the base of the skull in both early humans and other bipedal mammals, like kangaroos, is shedding light on a once-controversial marker for bipedalism.

04 Jul 2017

Two ichthyosaurs become one

While dinosaurs ruled on land in the Mesozoic, dolphin-like marine reptiles called ichthyosaurs roamed the oceans. Paleontologists first described the genus in 1821 based on remains discovered in England, naming the first species Ichthyosaurus communis. The description of a second species, I. intermedius, followed in 1822. Although these two species were the earliest-known ichthyosaurs, they are also some of the most poorly understood, as their initial descriptions were based on limited remains.

22 Jun 2017

Benchmarks: June 1977: First Excavations at Nebraska's Ashfall Fossil Beds

In the spring of 1971, paleontologist Mike Voorhies was mapping rock exposures on a farm in northeastern Nebraska when he wandered into a small ravine that recent heavy rains had swept clean of debris. High on the gully wall, a change in the color of the rock caught his eye, so he decided to scramble up and take a closer look.

 
31 May 2017

Fossil forest recorded ancient sunspots

The sun’s surface is home to dark, relatively cool blotches of high magnetic activity known as sunspots, which vary in number over a roughly 11-year cycle. In a new study in Geology, scientists found evidence of this solar cycle dating back 290 million years to the Permian Period.

05 May 2017

First trilobite eggs found in fool's gold

Trilobites were one of the most successful groups of animals to ever scurry across the seafloor, thriving for more than 270 million years. But how they reproduced has long been a mystery, since no fossil had ever been found with preserved eggs or genitalia. With the discovery of a cluster of trilobite eggs preserved in pyrite in upstate New York, however, scientists are getting the first glimpse of how these early arthropods reproduced.

01 May 2017

Tiny dinosaur-era marsupial packed a big bite

Newly described fossils from one of the earliest-known marsupials are shedding light on the evolution of mammals during the Mesozoic and revealing an animal with an impressive bite, perhaps strong enough to take down a dinosaur.

19 Apr 2017

Scientists crack the secret of dinosaurs' incubation time

Paleontologists have long thought that the eggs of dinosaurs — like those of their living bird relatives — probably hatched after short incubation times, up to a few weeks at most. But surprising results from a new study suggest that nonavian dinosaurs spent anywhere from three to six months inside an egg, incubation times similar to reptiles like crocodiles and alligators.

18 Apr 2017

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