Ny analys av brasilianska fossil utmanar teorier om tidiga djurs ursprung

12 maj 2026

Rapporterad av AI

Forskare har fastställt att strukturer som tidigare betraktats som spår av små djur i 540 miljoner år gamla brasilianska bergarter i själva verket är fossiliserade kolonier av bakterier och alger. Den förnyade undersökningen använder avancerad avbildningsteknik för att blottlägga bevarade celler och organiskt material.

Forskarna fokuserade på mikrofossil från Tamengo-formationen i Mato Grosso do Sul. Tidigare arbeten hade tolkat märkena som bevis på maskliknande varelser som rört sig genom havsbotten under ediacara-perioden, precis innan den kambriska explosionen av komplext liv. Ny analys med mikrotomografi och Ramanspektroskopi vid partikelacceleratorn Sirius visade cellstrukturer istället för djurspår.

Relaterade artiklar

MIT study links ancient sea sponges to earth's earliest animals

Researchers at MIT have discovered chemical evidence in rocks over 541 million years old suggesting that ancient sea sponges were among Earth's first animals. The findings, published in the Proceedings of the National Academy of Sciences, identify molecular fingerprints matching compounds from modern demosponges. This builds on earlier work and confirms the signals originate from biological sources rather than geological processes.

Jiangchuan Biota fossils in Yunnan reveal complex animals before Cambrian explosion

2 april 2026 Rapporterad av AI

More than 700 fossils from the Jiangchuan Biota in Yunnan Province, southwest China, dating 554-539 million years ago in the late Ediacaran, include early relatives of starfish, acorn worms, deuterostomes, and other bilaterians. Led by Dr. Gaorong Li of Yunnan University, the discovery—after nearly a decade of fieldwork—challenges the suddenness of the Cambrian explosion by showing diverse animal communities predated it. The results, published in Science (DOI: 10.1126/science.adu2291), feature exceptionally preserved carbonaceous films revealing fine details like digestive systems.

Vetenskap

Fossils uncover early evolution of lungfish to land vertebrates

Vetenskap

Scientists identify oxygen-using Asgard archaea as complex life's ancestor

Vetenskap

Ancient microbes may have used oxygen 500 million years early

Fossil confirms mammal ancestors laid eggs after mass extinction

A 250-million-year-old fossil egg containing a Lystrosaurus embryo has provided the first direct evidence that mammal ancestors laid eggs. Discovered in South Africa, the find resolves a decades-old question about early mammalian reproduction following the End-Permian extinction. Researchers used advanced imaging to reveal the embryo's pre-hatching stage inside a soft-shelled egg.

Scientists analyze Darwin's 200-year-old specimen jars without opening them

5 mars 2026 Rapporterad av AI

Researchers have developed a laser technique to examine the contents of Charles Darwin's original specimens from the Galápagos Islands without disturbing the nearly 200-year-old jars. The method, known as Spatially Offset Raman Spectroscopy, reveals the chemical makeup of preservation fluids inside sealed containers. This breakthrough aids museums in preserving delicate collections worldwide.

Symbiotic bacteria in insects have smallest known genomes

Researchers have discovered symbiotic bacteria inside planthopper insects with the smallest genomes recorded for any organism, measuring as little as 50,000 base pairs. These microbes, which have co-evolved with their hosts for about 263 million years, blur the line between independent bacteria and cellular organelles like mitochondria. The findings highlight extreme genome reduction in nutrient-providing symbionts.

New giant virus discovery supports origins of complex life

20 februari 2026 Rapporterad av AI

Scientists in Japan have discovered a giant virus called ushikuvirus that infects amoebae and provides evidence for the theory that viruses contributed to the evolution of complex cells. Isolated from Lake Ushiku, the virus exhibits unique structural and replication traits linking it to other giant DNA viruses. This finding, published in the Journal of Virology, deepens understanding of viral roles in eukaryotic evolution.

12 maj 2026 04:54