Platinum metals are depleted in the earth's crust relative to their cosmic abundance; concentrations of these elements in deep-sea sediments may thus indicate influxes of extraterrestrial material. Deep-sea limestones exposed in Italy, Denmark, and New Zealand show iridium increases of about 30, 160, and 20 times, respectively, above the background level at precisely the time of the Cretaceous-Tertiary extinctions, 65 million years ago. Reasons are given to indicate that this iridium is of extraterrestrial origin, but did not come from a nearby supernova. A hypothesis is suggested which accounts for the extinctions and the iridium observations. Impact of a large earth-crossing asteroid would inject about 60 times the object's mass into the atmosphere as pulverized rock; a fraction of this dust would stay in the stratosphere for several years and be distributed worldwide. The resulting darkness would suppress photosynthesis, and the expected biological consequences match quite closely the extinctions observed in the paleontological record. One prediction of this hypothesis has been verified: the chemical composition of the boundary clay, which is thought to come from the stratospheric dust, is markedly different from that of cla...Continue Reading
The synthesis of primitive 'living' forms: definitions, goals, strategies and evolution synthesizers
Multiple factors in the origin of the Cretaceous/Tertiary boundary: the role of environmental stress and Deccan Trap volcanism
Determination of alpha-dialkylamino acids and their enantiomers in geological samples by high-performance liquid chromatography after derivatization with a chiral adduct of o-phthaldialdehyde
Platinum group element enrichments and possible chondritic Ru:Ir across the Frasnian-Famennian boundary, western New York State
Orthopithonella collaris sp. nov., a new calcareous dinoflagellate cyst from the K/T boundary (Fish Clay, Stevns Klint/Denmark)
Phytoplankton growth after a century of dormancy illuminates past resilience to catastrophic darkness
Late Cretaceous restructuring of terrestrial communities facilitated the end-Cretaceous mass extinction in North America
Experimental evidence that an asteroid impact led to the extinction of many species 65 million years ago
Petrographic criteria for recognizing certain types of impact spherules in well-preserved precambrian successions
A search for soot from global wildfires in central Pacific Cretaceous-Tertiary boundary and other extinction and impact horizon sediments
Biosignatures in ancient rocks: a summary of discussions at a field workshop on biosignatures in ancient rocks
Unexpected resilience of species with temperature-dependent sex determination at the Cretaceous-Palaeogene boundary
Cretaceous/Paleogene floral turnover in Patagonia: drop in diversity, low extinction, and a Classopollis spike
Fossil worm burrows reveal very early terrestrial animal activity and shed light on trophic resources after the end-cretaceous mass extinction
Bottom-water conditions in a marine basin after the Cretaceous-Paleogene impact event: timing the recovery of oxygen levels and productivity
Novel insect leaf-mining after the end-Cretaceous extinction and the demise of cretaceous leaf miners, Great Plains, USA
Systematics of the Eucestoda: advances toward a new phylogenetic paradigm, and observations on the early diversification of tapeworms and vertebrates
Time-of-flight mass spectrometry of mineral volatilization: toward direct composition analysis of shocked mineral vapor
Correlated terrestrial and marine evidence for global climate changes before mass extinction at the Cretaceous-Paleogene boundary
Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling
Fluorescence imaging of microbe-containing particles shot from a two-stage Light-gas gun into an aerogel
Rare events in earth history include the LB1 human skeleton from Flores, Indonesia, as a developmental singularity, not a unique taxon
The environmental disaster of Aznalcóllar (southern Spain) as an approach to the Cretaceous-Palaeogene mass extinction event
Persistent ecological shifts in marine molluscan assemblages across the end-Cretaceous mass extinction
Mass extinctions, biodiversity and mitochondrial function: are bats 'special' as reservoirs for emerging viruses?
DNA evidence for a Paleocene origin of the Alcidae (Aves: Charadriiformes) in the Pacific and multiple dispersals across northern oceans
Microbes and mass extinctions: paleoenvironmental distribution of microbialites during times of biotic crisis
Theoretical and experimental considerations linking an environmental stress to expression of endogenous retroviruses in a mammalian tumour
Birth of the eukaryotes by a set of reactive innovations: New insights force us to relinquish gradual models
Platinum stable isotope analysis of geological standard reference materials by double-spike MC-ICPMS
Evolution of body size, vision, and biodiversity of coral-associated organisms: evidence from fossil crustaceans in cold-water coral and tropical coral ecosystems
Replaying Evolution to Test the Cause of Extinction of One Ecotype in an Experimentally Evolved Population
Severest crisis overlooked-Worst disruption of terrestrial environments postdates the Permian-Triassic mass extinction
Severe extinction and rapid recovery of mammals across the Cretaceous-Palaeogene boundary, and the effects of rarity on patterns of extinction and recovery
End-Cretaceous extinction in Antarctica linked to both Deccan volcanism and meteorite impact via climate change
Lower prevalence but similar fitness in a parasitic fungus at higher radiation levels near Chernobyl
Periodic explosive expansion of human retroelements associated with the evolution of the hominoid primate
Site of asteroid impact changed the history of life on Earth: the low probability of mass extinction
The old and the new plankton: ecological replacement of associations of mollusc plankton and giant filter feeders after the Cretaceous?
The last dinosaurs of Brazil: The Bauru Group and its implications for the end-Cretaceous mass extinction
Earth's Impact Events Through Geologic Time: A List of Recommended Ages for Terrestrial Impact Structures and Deposits
New records of theropods from the latest Cretaceous of New Jersey and the Maastrichtian Appalachian fauna
Two-step extinction of Late Cretaceous marine vertebrates in northern Gulf of Mexico prolonged biodiversity loss prior to the Chicxulub impact
Accelerated diversifications in three diverse families of morphologically complex lichen-forming fungi link to major historical events
Holocene vegetation patterns in southern Lithuania indicate astronomical forcing on the millennial and centennial time scales
The extraterrestrial impact evidence at the Palaeocene-Eocene boundary and sequence of environmental change on the continental shelf
Platinum-group elements link the end-Triassic mass extinction and the Central Atlantic Magmatic Province.
Asteroid shower on the Earth-Moon system immediately before the Cryogenian period revealed by KAGUYA
Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.
Chronic Fatigue Syndrome
Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.
Systemic Juvenile Idiopathic Arthritis
Systemic juvenile idiopathic arthritis is a rare rheumatic disease that affects children. Symptoms include joint pain, but also fevers and skin rashes. Here is the latest on this disease.
Chromatin Regulation and Circadian Clocks
The circadian clock plays an important role in regulating transcriptional dynamics through changes in chromatin folding and remodelling. Discover the latest research on Chromatin Regulation and Circadian Clocks here.
Central Pontine Myelinolysis
Central Pontine Myelinolysis is a neurologic disorder caused most frequently by rapid correction of hyponatremia and is characterized by demyelination that affects the central portion of the base of the pons. Here is the latest research on this disease.
Myocardial stunning is a mechanical dysfunction that persists after reperfusion of previously ischemic tissue in the absence of irreversible damage including myocardial necrosis. Here is the latest research.
Pontocerebellar hypoplasias are a group of neurodegenerative autosomal recessive disorders with prenatal onset, atrophy or hypoplasia of the cerebellum, hypoplasia of the ventral pons, microcephaly, variable neocortical atrophy and severe mental and motor impairments. Here is the latest research on pontocerebellar hypoplasia.
Cell Atlas Along the Gut-Brain Axis
Profiling cells along the gut-brain axis at the single cell level will provide unique information for each cell type, a three-dimensional map of how cell types work together to form tissues, and insights into how changes in the map underlie health and disease of the GI system and its crosstalk with the brain. Disocver the latest research on single cell analysis of the gut-brain axis here.
Chronic Traumatic Encephalopathy
Chronic Traumatic Encephalopathy (CTE) is a progressive degenerative disease that occurs in individuals that suffer repetitive brain trauma. Discover the latest research on traumatic encephalopathy here.