PALEO

paleo

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

Hot tropics drove out ancient reptiles, but they came back

About 252 million years ago, massive volcanic eruptions in what is now Siberia rapidly warmed Earth, resulting in the end-Permian mass extinction that saw most terrestrial and marine species die off. It’s been thought that surviving reptiles and fish fled the hot tropics and didn’t return for millions of years. But according to new research, the tropical evacuation may not have lasted so long after all.

21 Apr 2018

Travels in Geology: Underground awe in France: The caves of the Causses

The Causses du Quercy region in south-central France has been transformed into a karstic wonderland by the slow dissolution of limestone. The resulting caves, which served as shelters for early humans who left their bones, tools and art for us to ponder, are both geologically and paleoanthropologically fascinating.

06 Apr 2018

Pesky ticks even plagued dinosaurs

Blood-sucking, disease-spreading ticks are one of the most maligned parasites in the world, and new evidence shows they’ve been doing their dirty work for a long time: Fossilized ticks dating to the mid-Cretaceous represent the first direct evidence that the ancestors of today’s pesky critters once plagued dinosaurs.

20 Mar 2018

World's longest sauropod trackway exposed

Excavations at a dinosaur trackway found in 2009 in the French village of Plagne, 200 kilometers east of Lyon, revealed 110 sauropod footprints spanning a distance of 155 meters, making the site the world’s longest sauropod trackway. In a new study published in the journal Geobios, researchers report that the tracks were made roughly 150 million years ago and that the largest tracks measure more than a meter across. Analysis of the trackway suggested the prints were left by an animal at least 35 meters long and weighing more than 35 tons, that traveled about 4 kilometers per hour with an average stride of 2.8 meters. The prints were assigned to a new ichnospecies — a species only known from trace fossils — named Brontopodus plagnensis.

05 Mar 2018

Oldest blood cells found in Early Jurassic ichthyosaur

Since 2005, a steady trickle of reports detailing proteins and other soft tissues preserved in fossils of dinosaurs and other ancient animals has gradually worn down the disbelief that such tissues can last through geologic time. In a new study in Scientific Reports, scientists have now reported the oldest preserved red blood cells, white blood cells and platelets, found in the remains of an ancient marine reptile.

01 Mar 2018

Drought drove early humans from Africa

Genetics studies have dated the largest migrations of early Homo sapiens out of Africa to between 70,000 and 55,000 years ago, although smaller groups may have left earlier. The most widely accepted exodus theory, known as the “green carpet” or “green Sahara” hypothesis, holds that people likely left during wetter periods in the Sahara and Arabia, which would have allowed easier passage into Eurasia via the Middle East. But new research supports the opposite idea: that drier conditions may have triggered at least some of the exodus.

28 Feb 2018

Growing up saber-toothed: Strong from the start

During the Pleistocene, saber-toothed cats were formidable predators, with their massive canines and powerful front legs sporting razor-sharp claws. The bones of saber-toothed cats are thicker and more robust compared to those of other large cats, both modern and extinct. And previous studies of Smilodon have shown that their forelimbs in particular featured several adaptations, including thickened cortical bone, which would have increased strength, presumably useful in subduing ambushed prey.

19 Feb 2018

Did mud volcanoes set the stage for Burgess Shale fossils?

Canada’s Burgess Shale is famous for a wide array of exquisitely preserved 500-million-year-old fossils, which are found in a dozen localities in the Canadian Rockies. Linking all these localities today is a geologic feature called the Cathedral Escarpment, which formed in the Cambrian as a steep line of underwater cliffs where regular mudslides are thought to have gently buried a diversity of organisms, setting the stage for the prolific fossil beds. However, new mineralogical clues found at several of the fossil-rich sites suggest that mud volcanism may have also played a starring role in creating the Burgess Shale.

16 Feb 2018

Fossil sea turtle hatchling reveals its Eocene proteins

study of a 54-million-year-old sea turtle hatchling found in Denmark is adding to a growing body of evidence that certain proteins can remain intact in the fossil record for tens of millions of years.

08 Feb 2018

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