PALEO

paleo

Transitional Chilesaurus fills gap between major dinosaur groups

In 2015, a new dinosaur was discovered in southern Chile, but its odd set of characteristics left paleontologists scratching their heads: Was it a carnivore or an herbivore? A closer look at the bones of the dinosaur, named Chile­saurus, is helping scientists determine how it fit into the Late Jurassic landscape.

06 Dec 2017

Dino deaths cleared the way for frogs

Frogs make up almost 90 percent of amphibians, and with 6,775 described species, frogs are considered one of the most diverse groups of vertebrates on the planet. In a new study in Proceedings of the National Academy of Sciences, researchers indicate that frogs’ rapid diversification stems back to the Cretaceous-Paleogene (K-Pg, formerly the K-T) boundary, about 66 million years ago, when nonavian dinosaurs and many other animals went extinct.

30 Nov 2017

Can fossil footprints reveal the weight of a dinosaur?

Body mass is a fundamental factor in determining how much food an animal requires, how it moves and grows, and what role it plays in its ecosystem. Measuring modern animals is often a straightforward matter of putting them on a scale, but it’s no easy feat for paleontologists interested in extinct creatures like dinosaurs, since many of these animals’ weighty parts — their organs, muscles and skin, for example — are long gone. Frequent claims of “the heaviest dinosaur of all time,” for example, as in the case of the recently named Patagotitan, are fraught with uncertainty. Recent research, however, is offering a novel approach to estimating dinosaur body masses by examining the footprints they left behind.

27 Nov 2017

Marine megafaunal extinction discovered

Extinctions of large land animals during the Pleistocene are well documented. In a new study, scientists report that marine megafauna also suffered severe losses several million years ago, around the time that the first hominid ancestors were emerging in Africa.

17 Nov 2017

Humans arrived Down Under earlier than thought

Analysis of sediments surrounding a trove of artifacts discovered in northern Australia suggests the first humans arrived on the continent about 10,000 years earlier than previously thought, a finding that has implications for the hypothesized role of humans in the extinctions of Australian megafauna.

07 Nov 2017

When agriculture went to our heads

The dawn of agriculture left an indelible mark on early human societies, and a new study finds that eating softer, cultivated foods subtly changed the shape of human skulls. Scientists have long suspected that the transition from hunting and foraging to farming and raising livestock would have affected our skulls, specifically the mandible and other anatomy involved in chewing, but quantifying such changes has proven difficult.

01 Nov 2017

Another whiptail dinosaur added to sauropod family tree

With their massive size, long necks and whip-like tails, the sauropods are one of the most recognizable dinosaur groups. They grew as large as 100 metric tons, and it seems their huge frames were an effective adaptation: The sauropods were among the most diverse dinosaur groups, with more than 15 species known from North America alone. That list is now one species longer, with the identification of a new species based on a specimen found in Wyoming in 1995.

25 Oct 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

Cretaceous collagen: Can molecular paleontology glean soft tissue from dinosaurs?

In 2005, a team of molecular paleontologists reported the discovery of soft tissue from a 68-million-year-old Tyrannosaurus rex femur. In the decade since that controversial find, evidence has mounted that dinosaur soft tissue — which could help paleontologists answer long-standing questions about dinosaur physiology — can be recovered.
 

16 Oct 2017

Can preserved proteins reveal paint-by-numbers plumage?

Some of the most compelling dinosaur fossils are those found with clearly defined feathers. Feathers may seem fragile and unlikely to be preserved, but in fact they’re composed of durable keratin, one of the toughest natural proteins. Additionally, some fossil feathers unearthed are speckled with tiny black dots, which, according to different studies, could be remnants of either bacteria or melanosomes. Melanosomes are organelles that produce and store melanin, the main source of pigment in feathers. If melanosomes are indeed preserved in some ancient fossils, they could reveal information about dinosaur coloration and plumage — and represent further evidence of preserved proteins in dinosaurs.
 

16 Oct 2017

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