Archaeology News Online

Today mammals and birds are the only true warm-blooded animals. They are called endotherms, meaning they produce their body heat internally. The skeleton of a therapsid dicynodont Lystrosaurus [Credit: Flickr] Endotherm animals are the opposite to ectotherms which get their heat from an external factor like the sun. They are considered “cold-blooded”. The origins of warm-bloodedness in mammals has been a very controversial issue for two reasons. One is that several of the anatomical features thought to be linked to warm-bloodedness have also been found in cold-blooded reptiles. The other is that these characteristics are not always preserved in fossils, giving scientists inconsistent signals about the presence of warm-bloodedness. Our research helps shed new light on this controversy. We’ve been able to come up with new insights about how mammals developed a warm-blooded metabolism that may have helped them survive the terrible mass extinction that marked the end of the Permian period

For three years, Tara Djokic, a Ph.D. student at the University of New South Wales Sydney, scoured the forbidding landscape of the Pilbara region of Western Australia looking for clues to how ancient microbes could have produced the abundant stromatolites that were discovered there in the 1970s. Conical stromatolite (view from the top) at the Trendall locality in the Pilbara  [Credit: © Government of Western Australia] Stromatolites are round, multilayered mineral structures that range from the size of golf balls to weather balloons and represent the oldest evidence that there were living organisms on Earth 3.5 billion years ago. Scientists who believed life began in the ocean thought these mineral formations had formed in shallow, salty seawater, just like living stromatolites in the World Heritage-listed area of Shark Bay, which is a two-day drive from the Pilbara. But what Djokic discovered amid the strangling heat and blood-red rocks of the region was evidence that the stromatolite

In the shallow waters of a sea in northern China 500 million years ago, a dazzling new array of creatures was swimming: part of an explosion of animal diversity that would forever change the course of life on Earth. Quietly, in the seabed beneath them, another revolution was underway. Close-up view of fossilized branching burrows preserved in rock formed from an ancient seabed  in what is now northern China [Credit: University of Saskatchewan] For perhaps the first time, tiny creatures were pushing their way through the sediment to create complex mazes of burrows, slowly but profoundly altering the environment around them. Evidence of these early "ecosystem engineers" was published in Scientific Reports by researchers from the University of Saskatchewan (USA) and Henan Polytechnic University in China. The floors of Earth's ancient oceans looked very different than they do today, said Luis Buatois, a professor in the US Department of Geological Sciences and one of the st

Male live-bearing fish are evolving faster than female fish, according to a Kansas State University study, and that's important for understanding big-picture evolutionary patterns. Samples of fish species from the Poeciliidae family show the diversity in color, fin size and body shape.  Kansas State University researchers studied 112 species of these live-bearing fishes and found that  males and females evolve differently [Credit: Kansas State University] Researchers Michael Tobler, associate professor of biology, and Zach Culumber, former university postdoctoral research associate and current postdoctoral researcher at Florida State University, studied 112 species of live-bearing fish and found that males and females evolve differently: Female evolution is influenced more strongly by natural selection and the environment, while male evolution is influenced more strongly by sexual selection, which involves characteristics that females find desirable or that make them superior compe

In a new study, scientists found that aerosol particles released into the atmosphere from the burning of fossil fuels are a primary driver of changes in rainfall patterns across the globe. Top map: Spatial distribution of the annual-mean precipitation averaged from 1979-2008. Bottom: Time series of the  annual mean precipitation anomaly relative to the 1971-2000 climatology over the Sahel region of Africa  [Credit: Top: Global Precipitation Climatology Project (GPCP) data set. Bottom: Global Historical  Climatology Network (GHCN) data set. Background image: Drought - George Safonov] The results of the climate system-model simulations conducted by researchers Brian Soden and Eui-Seok Chung from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science revealed that changes in clouds, as a result of their interaction with these human-made aerosols in the atmosphere, are driving large-scale shifts in rainfall and temperature on Earth. A southward shift of the tropic

A team from the University of Kentucky’s Department of Physics and Astronomy has observed evidence of ancient impacts that are thought to have shaped and structured our Milky Way galaxy. Using observations from the Sloan Digital Sky Survey (SDSS) telescope, the team analyzed the spatial distribution  of 3.6 million stars and found ripples that support evidence of the Milky Way’s ancient impacts  [Credit: University of Kentucky] Deborah Ferguson, a 2016 UK graduate, is the lead author on a paper that published this week in the Astrophysical Journal . Ferguson conducted the research as an undergraduate student with co-authors Susan Gardner, a professor of physics and astronomy in the UK College of Arts and Sciences, and Brian Yanny, a staff scientist and astrophysicist in the Fermilab Center for Particle Astrophysics. Their paper, "Milky Way Tomography with K and M Dwarf Stars: the Vertical Structure of the Galactic Disk," presents observational evidence of asymmetric ripples i

The origin and nature of Mars is mysterious. It has geologically distinct hemispheres, with smooth lowlands in the north and cratered, high-elevation terrain in the south. The red planet also has two small oddly-shaped oblong moons and a composition that sets it apart from that of the Earth. A colossal impact with a large asteroid early in Mars' history may have ripped off a chunk of the northern hemisphere  and left behind a legacy of metallic elements in the planet's interior. The crash also created a ring of rocky  debris around Mars that may have later clumped together to form its moons, Phobos and Deimos  [Credit: University of Colorado at Boulder] New research by University of Colorado Boulder professor Stephen Mojzsis outlines a likely cause for these mysterious features of Mars: a colossal impact with a large asteroid early in the planet's history. This asteroid -- about the size of Ceres, one of the largest asteroids in the Solar System -- smashed into Mars, ripped