FOSSILS
New oviraptor dinosaur from the US Hell Creek Formation lived at the end of the Age of Dinosaurs and weighed about the same as an average woman
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ARTIST’S DEPICTION OF EONEOPHRON INFERNALIS (TOP LEFT), MOR 752 (BOTTOM LEFT), AND ANZU WYLIEI (RIGHT) IN THE HELL CREEK FORMATION. ILLUSTRATION BY ZUBIN ERIK DUTTA.
view moreCREDIT: IMAGE CREDIT: ATKINS-WELTMAN ET AL., 2024, PLOS ONE, CC-BY 4.0 (HTTPS://CREATIVECOMMONS.ORG/LICENSES/BY/4.0/)
New oviraptor dinosaur from the US Hell Creek Formation lived at the end of the Age of Dinosaurs and weighed about the same as an average woman
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Article URL: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0294901
Article Title: A new oviraptorosaur (Dinosauria: Theropoda) from the end-Maastrichtian Hell Creek Formation of North America
Author Countries: USA, Canada
Funding: Funding for histology processing provided to HNW by Oklahoma State University for Health Sciences. Funding to GFF provided by the Royal Society (Grant NIF\R1\191527) and a Banting Fellowship (NSERC). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
JOURNAL
PLoS ONE
ARTICLE TITLE
A new oviraptorosaur (Dinosauria: Theropoda) from the end-Maastrichtian Hell Creek Formation of North America
ARTICLE PUBLICATION DATE
24-Jan-2024
New pieces in the puzzle of first life on Earth
Research team discovers complex microbial communities in ecosystems over 3 billion years ago
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A DRILL CORE SAMPLE FROM THE BARBERTON GREENSTONE BELT USED IN THE STUDY. THE DARK LAYERS CONTAIN PARTICLES OF CARBONACEOUS MATTER, THE ALTERED REMAINS FROM PALAEOARCHAEAN MICROORGANISMS.
view moreCREDIT: MANUEL REINHARDT
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 led by the University of Göttingen and Linnӕus University in Sweden 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. The results were published in the journal Precambrian Research.
The researchers analysed well-preserved particles of carbonaceous matter – the altered remains of living organisms – and the corresponding rock layers from samples of the Barberton greenstone belt, a mountain range in South Africa whose rocks are among the oldest on the Earth's surface. The scientists combined macro and micro analyses to clearly identify original biological traces and distinguish them from later contamination. They identified geochemical "fingerprints" of various microorganisms, including those that must have used sunlight for energy, metabolised sulphate and probably also produced methane. The researchers determined the respective role of the microorganisms in the carbon cycle of the ecosystem at the time by combining geochemical data with findings on the texture of the rocks obtained from thin section analysis with a microscope. "By discovering carbonaceous matter in primary pyrite crystals and analysing carbon and sulphur isotopes in these materials, we were able to distinguish individual microbial metabolic processes," explains the senior author of the study, Dr Henrik Drake from Linnӕus University.
First author Dr Manuel Reinhardt, from Göttingen University’s Geosciences Centre, adds: "We didn't expect to find traces of so many microbial metabolic processes. It was like the proverbial search for a needle in a haystack." The study provides a rare glimpse into the Earth's early ecosystems. "Our findings significantly advance the understanding of ancient microbial ecosystems and open up new avenues for research in the field of palaeobiology."
Original publication: Reinhardt, M. et al. Aspects of the biological carbon cycle in a ca. 3.42-billion-year-old marine ecosystem. Precambrian Research (2024). DOI: 10.1016/j.precamres.2024.107289
Contact:
Dr Manuel Reinhardt
University of Göttingen
Geosciences Centre
Goldschmidtstraße 3, 37077 Göttingen, Germany
Tel: +49 (0)551 39-13756
Email: manuel.reinhardt@uni-goettingen.de
www.uni-goettingen.de/de/646954.html
JOURNAL
Precambrian Research
METHOD OF RESEARCH
Experimental study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Aspects of the biological carbon cycle in a ca. 3.42-billion-year-old marine ecosystem.
ARTICLE PUBLICATION DATE
24-Jan-2024
North China fossils show eukaryotes first acquired multicellularity 1.63 billion years ago
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MULTICELLULAR FOSSILS COME FROM THE LATE PALEOPROTEROZOIC CHUANLINGGOU FORMATION
view moreCREDIT: MIAO LANYUN
In a study published in Science Advances on Jan. 24, researchers led by Prof. ZHU Maoyan from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences reported their recent discovery of 1.63-billion-year-old multicellular fossils from North China.
These exquisitely preserved microfossils are currently considered the oldest record of multicellular eukaryotes. This study is another breakthrough after the researchers’ earlier discovery of decimeter-sized eukaryotic fossils in the Yanshan area of North China, and pushes back the emergence of multicellularity in eukaryotes by about 70 million years.
All complex life on Earth, including diverse animals, land plants, macroscopic fungi, and seaweeds, are multicellular eukaryotes. Multicellularity is key to eukaryotes acquiring organismal complexity and large size, and is often regarded as a major transition in the history of life on Earth. However, scientists have been unsure when eukaryotes evolved this innovation.
Fossil records offering convincing evidence show that eukaryotes with simple multicellularity, such as red and green algae, and putative fungi, appeared as early as 1.05 billion years ago. Older records have claimed to be multicellular eukaryotes, but most of them are controversial because of their simple morphology and lack of cellular structure.
"The newly discovered multicellular fossils come from the late Paleoproterozoic Chuanlinggou Formation that is about 1,635 million years old. They are unbranched, uniseriate filaments composed of two to more than 20 large cylindrical or barrel-shaped cells with diameters of 20–194 μm and incomplete lengths up to 860 μm. These filaments show a certain degree of complexity based on their morphological variation," said MIAO Lanyun, one of the researchers.
The filaments are constant, or tapered throughout their length, or tapered only at one end. Morphometric analyses demonstrate their morphological continuity, suggesting they represent a single biological species rather than discrete species. The fossils have been named Qingshania magnifica, 1989, a form taxon with similar morphology and size, and are described as being from the Chuanlinggou Formation.
A particularly important feature of Qingshania is the round intracellular structure (diameter 15–20 μm) in some cells. These structures are comparable to the asexual spores known in many eukaryotic algae, indicating that Qingshania probably reproduced by spores.
In modern life, uniseriate filaments are common in both prokaryotes (bacteria and archaea) and eukaryotes. The combination of large cell size, wide range of filament diameter, morphological variation, and intracellular spores demonstrate the eukaryotic affinity of Qingshania, as no known prokaryotes are so complex. Filamentous prokaryotes are generally very small, about 1–3 μm in diameter, and are distributed across more than 147 genera of 12 phyla. Some cyanobacteria and sulfur bacteria can reach large sizes, up to 200 μm thick, but these large prokaryotes are very simple in morphology, with disc-shaped cells, and are not reproduced by spores.
The best modern analogues are some green algae, although filaments also occur in other groups of eukaryotic algae (e.g., red algae, brown algae, yellow algae, charophytes, etc.), as well as in fungi and oomycetes.
"This indicates that Qingshania was most likely photosynthetic algae, probably belonging to the extinct stem group of Archaeplastids (a major group consisting of red algae, green algae and land plants, as well as glaucophytes), although its exact affinity is still unclear," said MIAO.
In addition, the researchers conducted Raman spectroscopic investigation to test the eukaryotic affinity of Qingshania from the perspective of chemical composition, using three cyanobacterial taxa for comparison. Raman spectra revealed two broad peaks characteristic of disordered carbonaceous matter. Furthermore, the estimated burial temperatures using Raman parameters ranged from 205–250 °C, indicating a low degree of metamorphism. Principal component analysis of the Raman spectra sorted Qingshania and the cyanobacterial taxa into two distinct clusters, indicating that carbonaceous matter of Qingshania is different from that of cyanobacterial fossils, further supporting the eukaryotic affinity of Qingshania.
Currently, the oldest unambiguous eukaryotic fossils are unicellular forms from late Paleoproterozoic sediments (~1.65 billion years ago) in Northern China and Northern Australia. Qingshania appeared only slightly later than these unicellular forms, indicating that eukaryotes acquired simple multicellularity very early in their evolutionary history.
Since eukaryotic algae (Archaeplastids) arose after the last eukaryotic common ancestor (LECA), the discovery of Qingshania, if truly algal in nature, further supports the early appearance of LECA in the late Paleoproterozoic—which is consistent with many molecular clock studies—rather than in the late Mesoproterozoic of about 1 billion years ago.
This study was funded by the National Key Research and Development Program of China, the National Natural Science Foundation of China, and the Innovation Cross-Team of CAS.
In eukaryotic tree, grey dash lines represent stem group eukaryotes. Solid lines denote crown group eukaryotes (LECA plus its descendants). Grey bars at nodes display the estimated age range of divergence of major branches from a molecular clock study (Parfrey et al., 2011, PNAS). Scale bar in the green algal fossil equals 500 μm; the rest are 50 μm
CREDIT
MIAO Lanyun
JOURNAL
Science Advances
METHOD OF RESEARCH
Meta-analysis
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
1.63-billion-year-old multicellular eukaryotes from the Chuanlinggou Formation in North China
ARTICLE PUBLICATION DATE
24-Jan-2024
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