Triassic Sea Monster Is the Stuff of Nightmares.
Imagine a giant octopus-like sea monster that could crush a bus-sized predator called the ichthyosaur (giant marine reptiles). Mark McMenamin, a paleontologist, was studying the fossilized remains of Triassic-era ichthyosaurs buried in an ancient ocean floor (in Nevada). He noticed that the crushed skeletons of these huge animals were arranged in a somewhat geometric fashion, similar to the way a modern octopus arranges the corpses of its victims. He also noticed that suction-cup shaped markings on the crushed ichthyosaur vertebrae resemble the sucker disks of an octopus-like creature. Based on this evidence, McMenamin proposed that a giant octopus-like predator some 100 feet long, may have existed in the Triassic era. However, other scientists are not convinced and point out a more simple explanation: that the disc-shaped bones also could have been arranged by ocean currents.
Read the full story at National Geographic.
Buried Pre-historic Dog Remains May Contain Signs of Human Ritual.
At a time when mammoths still roamed the landscape, it appears that humans and dogs were already hunting companions. Buried dog remains found in the Czech Republic contain hints that the domestication of dogs was already well under way in the Paleolithic era. The unearthed remains show a canid skull that bears signs of domestication in its features. What appears to be a mammoth bone had been inserted into one dog’s mouth, leading the authors to believe that the dogs may have helped carry mammoth meat for the humans. And, the fact that the dogs’ brains had been removed through an incision in the skull may be indicative of human spiritual ritual.
Read the full story at Discovery.
Jumping Fish May Have Launched Evolutionary Leap.
How aquatic animals eventually made their way onto land to become terrestrial creatures has generated much speculation in evolutionary theory. A new study suggests that this jumping ability is more commonplace than originally thought, and that it may not have required much in the way of anatomical structural change. Apparently, some fish can accomplish the feat by curling their bodies toward their tails and using this energy to launch themselves out of the water. And why do they do it? The authors suggest that avoidance of aquatic predators by jumping onto land may have become a useful tactic that could have led to more permanent land-based behavior.
Read the full story at Red Orbit.
Oh, What A Tangled Web It Weaves!
When a spider becomes the host to the larvae of a parasitic wasp, strange things happen to its web-weaving behavior. Rather than construct the type of web that the spider is hardwired to build, the spider instead begins to spin an odd variant —one that is instead suitable for the parasitic wasp larvae. Exactly what chemical mechanisms are responsible for this behavioral hijacking is unknown. Nor does it end well for the spider, which is in due course consumed by the wasp larvae as a final thank you.
Read the full story at BBC News.
Rocky Mountain Aspens at Center Stage in Cascading Effects of Climate Change.
Earlier this year, reports on the significant drought-related die-off of Aspen trees in the Western United States included a message about human disease. Deer mice, which were advantaged over other small mammals due to the forest decline, were multiplying rapidly and spreading a relatively new viral disease that can be fatal to humans. Now, the plot thickens with additional bad news for the Aspens. It has been recently observed that lower levels of snowfall, also attributable to climate change, have enabled elk to eat young Aspen shoots that are ordinarily buried under a thick snow pack. This in turn has led to marked decreases in Aspen forest density – not a good development for the future of the iconic tree. But help for the Aspens may be on the way, at least in Yellowstone Park, where a burgeoning wolf population is bringing the elk population back to more normal levels.
Genes for Electroreception of Ions Passed Down Through the Eons.
Around half a billion years ago, a fish species that was ancestor to most modern vertebrates had developed the ability to detect electrical charges in the water. This “sixth sense” likely helped with navigation, orientation and finding prey. Over time, the branches of modern animals that evolved from this ancestor into mammals, reptiles and amphibians, lost this sense, except for a few amphibians. However, recently completed research suggests that this additional sense is still present in certain modern fish. For example, sharks, paddlefish and sturgeons still use electroreception to locate food by utilizing thousands of electrical receptors located in the “skin of their heads.” The researchers also compared embryonic development of these sensor cells between fish that had electroreception ability, and those that did not. They conclude that embryonic electroreception cells develop in a way that confirms a very ancient ancestor.
Read the full story at Red Orbit.
Meerkats Can Identify Voices of Family and Friends.
Recognizing the voice of a friend may not be too impressive a skill to humans, but it may not be too impressive to meerkats either. A study of wild meerkats in South Africa found that they can identify and differentiate the voices of different individuals within their communities. Nor are they easily fooled. When researchers played a recording of an individual meerkat voice in a location where that individual could not logically be, the other meerkats showed their confusion.
Read the full story at Daily Mail.
Although its natural host species are still unidentified, scientists have discovered in the water off the coast of Chile the largest virus ever recorded, and have named it Megavirus chilensis. With a DNA of over 1.2 million base pairs, this “megavirus” is larger than some bacteria. The new megavirus is believed to be related to another giant, the mimivirus, which itself has been the source of speculation connecting it to “the emergence of early eukaryotes (complex cells).”
Rats, too, Daydream.
When the human mind “daydreams,” that is, is allowed to wander, scientist say that the brain’s “default mode network” (DMN) is active. Evidence of this active network can be seen using electronic imaging. As soon as a daydreaming person is given a task, or a problem to solve, the DMN tunes down and other neural networks get busy. Perhaps not too surprisingly, monkeys also have a DMN. Now it appears that rats have one also. While no one yet knows what rats think about when they engage their DMN, memory consolidation is a leading candidate hypothesis, according to the researchers.
Read the full story at New Scientist.
Abused Chicks Become Abusing Adults.
It is generally accepted that humans who experience childhood abuse have a greater tendency to become abusers as adults. Surprisingly, a Galapagas Island bird, the Nazca booby, exhibits the same cycle of violence. Because these chicks are left alone for considerable periods of time as nestlings, they encounter adult birds that sometime are physically violent toward them. Researchers identified such abused chicks, combined them with other chicks that had not been abused and, using a blind study, employed a second set of researchers to observe the behavior of the combined group. The second set of researchers, who did not know which birds were from which group, detected higher levels of abusive behavior from the adults that had been abused as chicks.
Read the full story at New York Times.
“The Dirt: This Week in Nature” curated and written by Robert Raciti.