Analysis of living vertebrates shows that changes in brain evolution helped drive major shifts in reproduction across dinosaurs and birds. A bird egg can look surprisingly oversized for the body that produced it. That puzzle becomes even stranger when viewed through deep time: the largest known bird eggs exceed the largest eggs found from nonavian [...]
Paleontologists have described a new genus of small, bird-like dinosaur that lived in what is now New Mexico approximately 73 million years ago.
The post New Troodontid Dinosaur Genus Identified from Fossil Bone Found Decades Ago in New Mexico appeared first on Sci.News: Breaking Science News.
Paleontologists studying the La Brea Tar Pits, one of the world’s richest Ice Age fossil sites, have identified a previously unknown species of spadefoot toad that lived in what is now California during the latest Ice Age.
The post La Brea Tar Pits Yield New Species of Ice Age Toad appeared first on Sci.News: Breaking Science News.
Paleontologists working in southern Wyoming have identified a previously unknown species of omomyid primate, adding a new chapter to the story of one of the best-studied fossil lineages in North America.
The post Tiny New Primate Species Emerges from 50-Million-Year-Old Wyoming Sandstone appeared first on Sci.News: Breaking Science News.
Around 70% of the animals were female,
Paleontologists working in southern China have identified a new species of sauropod dinosaur that appears to belong to a group never before documented anywhere in East Asia.
The post Fossil Find in China Reveals Dinosaur Family Never Before Seen in East Asia appeared first on Sci.News: Breaking Science News.
An exquisitely preserved specimen of Austronaga minuta, a small, long-necked marine reptile from the Triassic of China, contains a fossilized stomach, liver and intestines, offering paleontologists their oldest detailed glimpse yet of how early reptiles digested food.
The post 244-Million-Year-Old Fossil Preserves Earliest Reptilian Digestive System appeared first on Sci.News: Breaking Science News.
A 1.4-million-year-old trail of footprints reveals that a powerful human relative grew nearly as large as us and may have traveled in all-male groups. Eight individuals walked across the wet ground beside an ancient Kenyan lake. Within a short time, sediment buried their footprints and preserved a scene that would remain hidden for roughly 1.4 [...]
Almost all of these tiny organisms vanished way back in the early Cretaceous period
The post Microfossils Help Crack Mystery More Than 100 Million Years in the Making appeared first on Nautilus.
Paleontologists have identified the earliest-known cephalopod equipped with a siphuncle -- a tubular extension of the mantle found in shelled cephalopods -- pushing back the fossil record of this key evolutionary feature to the Early Cambrian, roughly 520 million years ago.
The post 520-Million-Year-Old Fossil from China Fills Gap in Evolutionary History of Cephalopods appeared first on Sci.News: Breaking Science News.
The spots on a leopard, the stripes on a zebra, and the mask on a raccoon are all types of coloration in mammal fur, referred to as pelage. Scientists have struggled for a long time to understand how these colorations evolved. A team of researchers recently discovered how to reconstruct the colors of ancient mammal fur using cell structures that contain the chemical pigment melanin, known as melanosomes. They hope to use this understanding of ancient mammal pelage to determine how they lived and what their environments were like.
To decipher the color of ancient mammal fur, the researchers constructed a statistical computer model to predict their fur colors based on the shape of their melanosomes. First, they needed to understand how the shapes of melanosomes control fur color in modern mammals. To measure the length and width of the modern melanosomes, the scientists used a beam of electrons like a flashlight to map them in great detail, a technique called scanning electron microscopy.
They measured the length and width of 2,615 melanosomes from the fur of 116 different living mammal species, including a Red Panda, a German Shepard, and one or more species of most types in the mammalian classification. Then they recorded the wavelengths of light reflected off each melanosome using a microspectrophotometer. These wavelengths represented the exact color of hair from each melanosome they measured. This means they now had a quantitative measurement of the color of each hair to compare with its corresponding melanosome length and width.
When they examined their data, the researchers found that spherical melanosomes produced brighter fur colors, like reds and oranges, while elongated melanosomes produced darker fur colors, like browns and grays. The researchers plotted the microspectrophotometric measurements for each melanosome as a graph showing how much light it absorbed across each possible wavelength, creating reflectance curves. Based on these data, the researchers used computer software to create a statistical model that could predict reflectance curves, and therefore color, from melanosome shape alone.
Once the researchers created a model, they needed to find fossilized mammal melanosomes to predict their fur color. Mammal fossils are rare, and pieces of cells are only preserved in the most immaculate fossil deposits. In fact, these researchers only found 6 fossils of this caliber, from Mesozoic rocks deposited around 250 million years ago, soon after mammals evolved.
The fossils came from 2 world-renowned deposits in Northeastern China, the Yanliao and Jehol biotas. They selected 5 previously studied fossils from these locations, including 1 specimen of Megaconus mammaliaformis, 1 specimen of Vilevolodon diplomylos, 2 specimens from the group Docodonta, and 1 specimen from the group Eutheria. All of these animals were small, rodent-like mammals. The researchers also discovered a new species of tree-dwelling mammal, Arboroharamiya fuscus.
The scientists used scanning electron microscopy to measure a total of 2,159 fossilized melanosomes to refine their color predictions. The fossilized melanosomes were all slightly elongated spheres and had far fewer differences in shape than in modern mammals. The researchers used their model to predict reflectance curves based on the shapes of the fossil melanosomes to determine the ancient mammals’ colors. They found that all the extinct mammals they examined likely had dark brown fur without any color patterns.
Based on these findings, the researchers suggested that most, if not all, early mammals were nocturnal, like many dark-colored mammals today. They suggested that this nocturnal lifestyle probably helped them survive the meteorite impact that wiped out the dinosaurs 100 million years later. While dinosaurs were unable to survive in the post-impact wasteland, these smaller, dark-colored mammals were more resilient and thrived in the aftermath. As mammals filled the ecological roles left by the dinosaurs, they evolved new color patterns, some based solely on camouflage, and others on new factors, like sexual selection and visual communication.
The researchers concluded that their model can predict fossilized mammal colors and help determine how these ancient animals lived. Notably, their data suggest that mammals likely stayed small and nocturnal throughout the Mesozoic until the dinosaurs were gone. Future researchers could use similar methods to uncover exactly how mammals evolved the colors we see today. For example, studying mammals closer to the impact event could reveal if it took a long time to develop diverse fur patterns, or if they began before the dinosaurs’ demise. Ultimately, similar studies could help determine whether the extinction of dinosaurs was necessary for the rise of mammals.
The post What colors were prehistoric mammals? appeared first on Sciworthy.
The Chicxulub impact not only plunged Earth into an impact winter but also produced a dust blanket that later overheated the planet, according to new research from Purdue University and the University of Colorado, Boulder.
The post Dinosaur-Killing Asteroid Didn’t Just Strike Earth, Its Dust Cloud Cooked It appeared first on Sci.News: Breaking Science News.
The tracks suggest Paranthropus boisei grew surprisingly large and traveled in male groups.
New research suggests fine dust trapped heat from falling debris, producing a deadly pulse that could have ignited forests around the world.
An international team of paleontologists has identified a new species of early sauropodomorph dinosaur in Zimbabwe, adding to growing evidence that southern Africa hosted a richer diversity of dinosaurs during the Late Triassic epoch than previously recognized.
The post New Species of Triassic Dinosaur Discovered on Shores of Zimbabwe’s Lake Kariba appeared first on Sci.News: Breaking Science News.
Paleontologists have announced the discovery of a new fossil honeybee species that fills a long-standing gap in the evolutionary record of the genus Apis.
The post Japanese Fossil Bee Fills Two-Million-Year Gap in Honeybee History appeared first on Sci.News: Breaking Science News.
Paleontologists at the University of New South Wales have described a new genus and species of dasyurid marsupial from the Early Miocene of Australia, offering the first solid evidence that the family Dasyuridae -- which today includes quolls, Tasmanian devils and tiny antechinuses -- existed long before scientists had proof of it in the fossil record.
The post Early Miocene Fossil Rewrites Family Tree of Little Carnivorous Marsupials appeared first on Sci.News: Breaking Science News.
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