Science Daily - Fossils

Did the ancient Greeks and Romans experience Alzheimer's? Medical texts from 2,500 years ago rarely mention severe memory loss, suggesting today's widespread dementia stems from modern environments and lifestyles, a new analysis shows.

Evolutionary biologists report they have combined PET scans of modern pigeons along with studies of dinosaur fossils to help answer an enduring question in biology: How did the brains of birds evolve to enable them to fly?

A new study, which centers on evidence from skulls of a 6-million-year-old fossil ape, Lufengpithecus, offers important clues about the origins of bipedal locomotion courtesy of a novel method: analyzing its bony inner ear region using three-dimensional CT-scanning. The inner ear appears to provide a unique record of the evolutionary history of ape locomotion.

DNA from ancient feces can offer archaeologists new clues about the life and health of Japanese people who lived thousands of years ago, according to a new study.

The brown bear is one of the largest living terrestrial carnivores, and is widely distributed across the Northern Hemisphere. Unlike many other large carnivores that went extinct at the end of the last Ice Age (cave bear, sabretoothed cats, cave hyena), the brown bear is one of the lucky survivors that made it through to the present. The question has puzzled biologists for close to a century -- how was this so?

Microorganisms were the first forms of life on our planet. The clues are written in 3.5 billion-year-old rocks by geochemical and morphological traces, such as chemical compounds or structures that these organisms left behind. However, it is still not clear when and where life originated on Earth and when a diversity of species developed in these early microbial communities. Evidence is scarce and often disputed. Now, researchers have uncovered key findings about the earliest forms of life. In rock samples from South Africa, they found evidence dating to around 3.42 billion years ago of an unprecedentedly diverse carbon cycle involving various microorganisms. This research shows that complex microbial communities already existed in the ecosystems during the Palaeoarchaean period.

Of all the organisms that photosynthesize, land plants have the most complex form. How did this morphology emerge? A team of scientists has taken a deep dive into the evolutionary history of morphological complexity in streptophytes, which include land plants and many green algae. Their research allowed them to go back in time to investigate lineages that emerged long before land plants existed.

Gliding winged-reptiles were amongst the ancient crocodile residents of the Mendip Hills in Somerset, England, researchers at the have revealed.

A new study shows the Megalodon, a gigantic shark that went extinct 3.6 million years ago, was more slender than earlier studies suggested. This finding changes scientists' understanding of Megalodon behavior, ancient ocean life, and why the sharks went extinct.

The new theoretical research proposes that animal size over time depends on two key ecological factors.

Researchers have linked the travels of a 14,000-year-old woolly mammoth with the oldest known human settlements in Alaska, providing clues about the relationship between the iconic species and some of the earliest people to travel across the Bering Land Bridge. Isotopic data, along with DNA from other mammoths at the site and archaeological evidence, indicates that early Alaskans likely structured their settlements to overlap with areas where mammoths congregated. Those findings, highlighted in the new issue of the journal Science Advances, provide evidence that mammoths and early hunter-gatherers shared habitat in the region. The long-term predictable presence of woolly mammoths would have attracted humans to the area.

Fossils of kelp along the Pacific Coast are rare. Until now, the oldest fossil dated from 14 million years ago, leading to the view that today's denizens of the kelp forest -- marine mammals, urchins, sea birds -- coevolved with kelp. A recent amateur discovery pushes back the origin of kelp to 32 million years ago, long before these creatures appeared. A new analysis suggests the first kelp grazers were extinct, hippo-like animals called desmostylians.

New research has precisely dated some of the oldest fossils of complex multicellular life in the world, helping to track a pivotal moment in the history of Earth when the seas began teeming with new lifeforms -- after four billion years of containing only single-celled microbes.

The sun has just set on a quiet mudflat in Australia's Northern Territory; it'll set again in another 19 hours. A young moon looms large over the desolate landscape. No animals scurry in the waning light. No leaves rustle in the breeze. No lichens encrust the exposed rock. The only hint of life is some scum in a few puddles and ponds. And among it lives a diverse microbial community of our ancient ancestors.

Researchers have identified a 3D fragment of fossilized skin that is at least 21 million years than previously described skin fossils. The skin, which belonged to an early species of Paleozoic reptile, has a pebbled surface and most closely resembles crocodile skin. It's the oldest example of preserved epidermis, the outermost layer of skin in terrestrial reptiles, birds, and mammals, which was an important evolutionary adaptation in the transition to life on land.

Researchers have developed a new technique to measure the number of chromosomes in ancient genomes more precisely, using it to identify the first prehistoric person with mosaic Turner syndrome (characterized by one X chromosome instead of two [XX]), who lived about 2500 years ago.

Picrodontids -- an extinct family of placental mammals that lived several million years after the extinction of the dinosaurs -- are not primates as previously believed.

The largest ever primate Gigantopithecus blacki went extinct when other Asian great apes were thriving, and its demise has long been a mystery. A massive regional study of 22 caves in southern China explores a species on the brink of extinction between 295,000 and 215,000 years ago. As the environment became more seasonal, forest plant communities changed Primates such as orangutans adapted their eating habits and behaviors in response but G. blacki showed signs of stress, struggled to adapt and their numbers dwindled.

Researchers have identified microstructures in fossil cells that are 1.75 billion years old. These structures, called thylakoid membranes, are the oldest ever discovered. They push back the fossil record of thylakoids by 1.2 billion years and provide new information on the evolution of cyanobacteria which played a crucial role in the accumulation of oxygen on the early Earth.

Fossils of a new group of animal predators have been located in the Early Cambrian Sirius Passet fossil locality in North Greenland. These large worms may be some of the earliest carnivorous animals to have colonized the water column more than 518 million years ago, revealing a past dynasty of predators that scientists didn't know existed.