All posts tagged: Ancient Fossils

500-million-year-old fossil rewrites a missing chapter of Earth’s history

500-million-year-old fossil rewrites a missing chapter of Earth’s history

Published by Jenni Sidey

A remarkable fossil hidden in a museum collection for decades is helping scientists rethink one of the biggest mysteries in early animal evolution. The discovery of a 500-million-year-old arthropod in eastern Canada suggests that a period once thought to be marked by declining biodiversity may have been far richer and more complex than researchers believed. The newly described species, named Magnicornaspis garwoodi, comes from the late Cambrian Period and belongs to a rare group of extinct arthropods known as corcoraniids. These ancient creatures are considered important relatives of the lineage that eventually gave rise to modern chelicerates, a group that includes spiders, scorpions and horseshoe crabs. Researchers say the fossil provides valuable evidence from a poorly understood interval known as the Furongian, a period spanning roughly 497 million to 485 million years ago. For decades, paleontologists have puzzled over why relatively few fossils appeared to come from this time. The new findings suggest the apparent shortage may not reflect a true collapse in life on Earth. Instead, it may reveal gaps in where scientists have …

Ancient fossils suggest complex life got its start on an oxygenated seafloor

Ancient fossils suggest complex life got its start on an oxygenated seafloor

Published by Jenni Sidey

Early eukaryotes, the lineage that later gave rise to animals, plants and fungi, may have depended on oxygen from the start. However, they mostly stayed on the seafloor. That narrow habitat could help explain why complex life took so long to spread widely. The oldest widely accepted eukaryote fossils come from seas that were anything but inviting. Oxygen was scarce, the chemistry of the water shifted from place to place, and much of the ocean floor remained hostile to complex organisms. Yet in that patchwork world, a crucial branch of life appears to have found its footing. A study in Nature argues that some of the earliest known eukaryotes, organisms in the domain that later gave rise to animals, plants and fungi, were already tied to oxygen between about 1.75 billion and 1.4 billion years ago. Moreover, the fossils also point to a more grounded lifestyle than many scientists had assumed. These organisms seem to have lived on or within the seafloor, not drifting freely as plankton in the water above. That picture matters because …

773,000-year-old Moroccan cave fossils reveal human and neandertal evolutionary split

773,000-year-old Moroccan cave fossils reveal human and neandertal evolutionary split

Published by Jenni Sidey

A set of ancient human fossils found on Morocco’s Atlantic coast now sits on one of the tightest timelines in African prehistory. The remains come from Thomas Quarry I, and a new analysis pins them to about 773,000 years ago, give or take 4,000 years. That level of precision is rare for fossils this old, and it pulls you closer to a moment near the split that later led to modern humans, Neandertals, and Denisovans. For anyone trying to picture the human family tree, the hardest part often is timing. Fossils can be stunning, but their age can be blurry. Here, the timeline is the headline. A high-resolution magnetic record captured a major flip in Earth’s magnetic field, and the fossils sit right in that transition. ThI-GH site. (CREDIT: Nature) A Long Dig That Finally Paid Off The discoveries build on more than three decades of fieldwork under the Moroccan-French program “Préhistoire de Casablanca.” You can feel the patience behind that kind of effort. The team did long excavations, careful layer-by-layer mapping, and large geological …

Fossil skull discovery reveals when land animals first learned to eat plants

Fossil skull discovery reveals when land animals first learned to eat plants

Published by Jenni Sidey

Life began in the sea, and it took a long time to move onto land. Plants started creeping ashore about 475 million years ago. Roughly 100 million years later, the first backboned animals followed. For tens of millions of years, those early land animals mainly ate other animals. Now a fossil from Nova Scotia is changing that timeline. Scientists at the Field Museum in Chicago, the University of Toronto, Carleton University and the Smithsonian National Museum of Natural History report a 307-million-year-old skull from one of the earliest known land vertebrates that could handle plants. The study appears in Nature Ecology and Evolution. “This is one of the oldest known four-legged animals to eat its veggies,” says Arjan Mann, assistant curator of fossil fishes and early tetrapods at the Field Museum in Chicago and co-lead author of the study. “It shows that experimentation with herbivory goes all the way back to the earliest terrestrial tetrapods—the ancient relatives of all land vertebrates, including us.” A reconstruction of Tyrannoroter heberti, eating a fern. (CREDIT: Hannah Fredd) “The …

AI helps scientists read dinosaur footprints, offering new clues to ancient life

AI helps scientists read dinosaur footprints, offering new clues to ancient life

Published by Jenni Sidey

Dinosaur skeletons often dominate museum halls, from the towering Tyrannosaurus rex known as Sue in Chicago to Sophie the Stegosaurus in London. These fossils shape how you picture dinosaurs. Yet bones are rare compared with another kind of evidence dinosaurs left behind. Their footprints appear far more often in the fossil record and may tell deeper stories about how these animals lived, moved, and evolved. Recently published results from a project by Helmholtz-Zentrum Berlin physicists Gregor Hartmann and paleontologist Steve Brusatte from the University of Edinburgh demonstrate how artificial intelligence can assist in developing answers to questions about the behaviors and lifestyles of dinosaurs based on their fossilized imprints. The paper uses algorithms to sort through and classify dinosaur foot imprints without the aid of human labels. This approach provides new insights into which organisms created specific tracks and how those tracks reflect potential evolutionary histories of dinosaurs. Dinosaur foot impressions are created when an animal walks over soft, moist soil that later solidifies into hard rock and retains its shape for millions of years …