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paleo

Benchmarks: February 17, 2017: Arkansas Gets a State Dinosaur

In 1972, the first dinosaur remains ever found in Arkansas — a fossilized foot — were pulled out of a gravel and sand pit near the Sevier County town of Lockesburg in the southwestern part of the state. Though the foot remained a scientific mystery for decades, it became something of a local celebrity.

17 Feb 2019

Free swimmers came back first after Great Dying

About 252 million years ago, at the boundary between the Permian and Triassic periods, the vast majority of marine and terrestrial life died out in the most devastating extinction event in Earth’s history. Earth’s ecosystems eventually recovered, but not in the way — or as quickly as — scientists thought. In a new study looking at how marine species reemerged in the Triassic, researchers report a surprising trend of recovery from the top of the food chain down.

14 Feb 2019

"Cradle of Humankind" fossils can now be dated

Robyn Pickering was taught as an undergraduate about a collection of limestone caves in northern South Africa known collectively as the Cradle of Humankind for the trove of early hominin fossils discovered there. She learned that, unlike hominin fossils unearthed in East Africa, whose ages have been constrained by dating the surrounding layers of volcanic ash, the fossils in the Cradle — including well-preserved specimens of Australopithecus africanus and the recently discovered Homo naledi, among others — were impossible to date independently. Now, Pickering, an isotope geochemist at the University of Cape Town, and her colleagues have figured out a way to date the South African fossils after all. In a recent study published in Nature, the researchers report ages for flowstones — horizontal deposits of calcium carbonate that form natural cements on cave floors — across eight caves in the Cradle of Humankind. The flowstones sandwich fossil-bearing sediment layers, allowing age ranges for the fossils to be determined.

05 Feb 2019

Mesosaurs may have spent time on land

Mesosaurs are famous for being the earliest-known fully aquatic reptiles. With their whip-like tails, webbed feet and nostrils on top of their heads, the 2-meter-long reptiles appear to have been well adapted for life in the water. But in a new study, scientists have found fossil evidence that mesosaurs may have spent some of their adult lives on land.

21 Jan 2019

Earliest art found in South Africa

Blombos Cave, located along the South African coast about 300 kilometers east of Cape Town, has been excavated since 1991, revealing materials left by Homo sapiens between 100,000 and 70,000 years ago. 

14 Jan 2019

Early mammal reproduced like a reptile

A mother found fossilized alongside 38 of her young is offering a rare glimpse into early mammalian reproductive strategies. Unearthed in northeastern Arizona, the 184-million-year-old fossils are from specimens of Kayentatherium wellesi, an early mammal-like tritylodont that falls between reptiles and true mammals on the evolutionary tree.

09 Jan 2019

Two new species fill gap in dinosaur family tree

Cretaceous rocks in northwestern China have yielded two new dinosaur species that help fill a 70-million-year gap in dinosaur phylogeny. The new species — Xiyunykus pengi and Bannykus wulatensis — are both alvarezsaurians, an odd group of dinosaurs that, by the Late Cretaceous, had evolved many avian characteristics such as birdlike skulls, tiny teeth and light, slender bodies, as well as unique mole-like single-clawed forearms that were likely useful for digging.

17 Dec 2018

Climate cooling a driver of Neanderthals' extinction

Neanderthals disappeared from Europe roughly 40,000 years ago, and scientists are still trying to figure out why. Did disease, climate change or competition with modern humans — or maybe a combination of all three — do them in? In a recent study, researchers offer new evidence from Eastern Europe that climate change was a major player in the Neanderthals’ disappearance.

30 Nov 2018

Spiky new American ankylosaurid originated in Asia

A new genus and species of ankylosaurid discovered in Grand Staircase-Escalante National Monument in southern Utah reveal new information about the spread of armored dinosaurs into North America. Most North American ankylosaurids are known for their smooth skulls, but the new specimen more closely resembles spiky-skulled Asian ankylosaurids.

28 Nov 2018

Marine animals have been migrating for millions of years

Scientists have suspected that ancient animals migrated in response to changing global temperatures, but until now, there was no documentation of this across extensive time periods. In a new study, researchers found that, for millions of years, marine organisms like corals, sponges and snails, have shifted their ranges in response to climate change.

20 Nov 2018

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