This video from Alaska says about itself:
24 October 2016
Dr. Oakley explains the amazing characteristics of the Bald Eagle.
From Science News:
Ancient armored fish revises early history of jaws
Placoderm fossil had skull bones like those of many modern vertebrates
By Meghan Rosen
2:00pm, October 20, 2016
A freaky fish with a head like a dolphin and a body like a tank may be to thank for human jaws.
The discovery of a 423-million-year-old armored fish from China suggests that the jaws of all modern land vertebrates and bony fish originated in a bizarre group of animals called placoderms, researchers report in the Oct. 21 Science.
Along with a different placoderm fossil from 2013, the new find, named Qilinyu rostrata, is helping rewrite the story of early vertebrate evolution, says paleontologist John Maisey of the American Museum of Natural History in New York City, who was not involved with the work.
“We’ve suddenly realized we had it all wrong,” he says.
The jaws of humans — and dogs, salmon, lizards and all other bony vertebrates — contain three key bones: the maxilla and premaxilla of the upper jaw, and the dentary of the lower jaw.
“Anything from a human being to a cod has recognizably the same set of bones in the head,” says study coauthor Per Ahlberg, a paleontologist at Uppsala University in Sweden. The big question, he says, is “Where did these bony jaws come from?”
More than a hundred million years before dinosaurs walked the Earth, fishes called placoderms thrived under water. Scientists knew that these armored fishes were early jawed animals, but their jaws were unusual: “They look like sheet metal cutters,” Ahlberg says. “They’re these horrible bony blades that slice together.”
The blades, called gnathal plates, looked so peculiar that most scientists thought that the three-part jaw of humans originated in an early bony fish and that placoderms were just a funny little side branch in the vertebrate family tree. “The established view is that placoderms had evolved independently and that our jaw bones must have a separate origin,” Ahlberg says.
In 2013, Ahlberg and colleagues found a new clue in a 419-million-year old fossil that had the body of a placoderm, but the three-part jaw of a bony fish. Such an animal, called Entelognathus primordialis, “could never have been predicted from the fossil record,” says paleontologist Gavin Young of Australian National University in Canberra.
That work bolstered the idea that placoderms weren’t, in fact, their own odd group that dead-ended hundreds of millions of years ago — some were actually the ancestors of bony fish (and thus humans). But it was just one fossil, Ahlberg notes. “You don’t want to draw too big of conclusions from one animal.”
Two animals, though, is a different story. Qilinyu, the new fossil Ahlberg and colleagues describe, had an armored skull and trunk and was probably about the length of a box of tissues. Like Entelognathus, Qilinyu has a three-part, bony fish–like jaw, though the creature looks a bit more like a typical placoderm, Ahlberg says. The two fossils “form almost perfect intermediates” between placoderms and bony fishes, he says. Ahlberg and his colleagues suspect the key jaw elements of bony fish (and all land vertebrates) evolved from those bony blades of placoderms.
“This is part of our own early evolutionary history,” Ahlberg says. “It shows where our own jaws came from.”
Maisey puts it another way: “We are all fundamentally placoderms.”
This video says about itself:
13 October 2016
Clip of capuchin stone on stone percussion and licking of passive hammer associated with capuchin grooming.
Credit: M. Haslam and the Primate Archaeology Group (University of Oxford)
From Science News:
Wild monkeys throw curve at stone-tool making‘s origins
Unlike early hominids, capuchins don’t use sharp-edged rocks to dig or cut
By Bruce Bower
1:00pm, October 19, 2016
A group of South American monkeys has rocked archaeologists’ assumptions about the origins of stone-tool making.
Wild bearded capuchin monkeys in Brazil use handheld stones to whack rocks poking out of cliffs and outcrops. The animals unintentionally break off sharp-edged stones that resemble stone tools made by ancient members of the human evolutionary family, say archaeologist Tomos Proffitt of the University of Oxford and his colleagues. It’s the first observation of this hominid-like rock-fracturing ability in a nonhuman primate.
The new finding indicates that early hominids needed no special mental ability, no fully opposable thumbs and not even any idea of what they were doing to get started as toolmakers, the researchers report October 19 in Nature. All it may have taken was a penchant for skillfully pounding rocks, as displayed by capuchins when cracking open nuts (SN Online: 4/30/15).
Archaeologists have traditionally thought that ancient stone tools appeared as hominid brains enlarged and hand grips became more humanlike.
“Without the intention of making a stone tool, and with the right rock types, capuchins produce objects that are shaped like stone tools,” says University of Oxford primatologist and archaeologist Susana Carvalho, who did not participate in the new study. She suspects the earliest known stone tools were made either by relatively small-brained hominids or, perhaps in some cases, nonhuman primates. “This is not a wild idea anymore.”
The oldest known hominid stone artifacts — a set of pounding rocks and sharp-edged stone flakes — date to 3.3 million years ago in East Africa (SN: 6/13/15, p. 6). Those tools display more elaborate modifications than observed on sharp-edged capuchin creations, Proffitt says. But researchers suspect simpler hominid tools go back 4 million years or more. Those implements might have looked more like what the South American monkeys make, he speculates.
Three capuchins tracked during an episode of rock pounding did not use fractured pieces of sharp stone to cut, scrape or dig up anything. Observations of nearly 100 rounds of rock pounding show that the monkeys sometimes recycled stone flakes as rock-pounding tools. They also often licked or sniffed powdered stone produced as they pounded rocks. Perhaps capuchins want to ingest the trace nutrient silicon, which assists in bone growth, or find lichens for some medicinal purpose, Proffitt suggests.
His team studied 60 stone fragments left behind by capuchins after rock-pounding episodes and another 51 capuchin-modified stones found in two excavations where rock pounding occurred. These artifacts included complete and broken pounding stones, stone flakes and stones that had been struck by rock-wielding monkeys.
Capuchin stone flakes are smaller and contain fewer fractured areas than ancient hominid tools, such as the 3.3-million-year-old East African finds, says archaeologist David Braun of George Washington University in Washington, D.C. But sharp-edged stones produced by the monkeys display “remarkable similarity” to artifacts from a nearby Brazilian site that some researchers think were made by humans more than 20,000 years ago (SN: 10/18/14, p. 14), Braun says. Researchers now must determine whether stone artifacts found at several South American sites dating to more than 14,000 years ago were made by humans or monkeys, he suggests.
Capuchin rock smashers’ inadvertently sharpened debris also raises questions about how hominids started making tools in the first place. Techniques for using one stone to pound away pieces of another stone, creating a rock with smooth faces bordered by razor-sharp edges, “could have been invented independently in different hominid species through [stone-pounding] behaviors we have yet to identify,” Proffitt says.
Those initial tools may have resembled capuchins’ accidentally sharpened stones or even rocks used by chimpanzees to crack nuts, says archaeologist Sonia Harmand of Stony Brook University in New York. But only hominids, and especially humans, went on to make more sophisticated stone tools and, later, everything from smart phones to space stations, says Harmand, who led the team that discovered the 3.3-million-year-old hominid tools.
This video from the USA says about itself:
4 May 2014
Northern, or Yellow shafted Flicker, Colaptes auratus, preening, drinking, bathing, eating berries, showing aggression.
From Science News:
Berries may give yellow woodpeckers a red dye job
by Helen Thompson
3:34pm, October 17, 2016
To the bafflement of birders, yellow-shafted flickers (Colaptes auratus auratus) sometimes sport red or orange wing feathers.
Scientists have suggested that the birds, which inhabit eastern North America, might be products of genetic variation affecting the carotenoid pigments that produce their flight-feather colors. Alternatively, the birds might be hybrids from mixing with a subspecies that lives in the west, red-shafted flickers (Colaptes auratus cafer). Despite decades of study, no clear-cut explanation has emerged.
It turns out that diet may be to blame. Jocelyn Hudon of the Royal Alberta Museum in Canada and her colleagues tested the red flight feathers from two yellow-shafted flickers and found traces of rhodoxanthin, a deep red pigment found in plants, and a potential metabolite. This suggests that the birds’ bodies break down rhodoxanthin — a clue that the pigment enters the body through food. Spectral and biochemical tests of feathers from museum collections also point to rhodoxanthin and suggest that the pigment may mess with yellow carotenoid production as well.
Yellow-shafted flickers probably pick up the red pigment when they eat berries from invasive honeysuckle plants, which contain the ruby pigment and produce similar red hues in other birds, the researchers write October 12 in The Auk. The plants also happen to produce berries just around the time that flickers molt their flight feathers.
This video says about itself:
Reef Life of the Andaman (full marine biology documentary)
31 October 2012
“Reef Life of the Andaman” is a documentary of the marine life of Thailand and Burma (Myanmar).
Scuba diving more than 1000 times from the coral reefs and underwater pinnacles of Thailand‘s Similan Islands, Phuket, Phi Phi Island and Hin Daeng, to Myanmar’s Mergui Archipelago and Burma Banks, I encountered everything from manta rays to seahorses, whale sharks to shipwrecks. The 116-minute film features descriptions of 213 different marine species including more than 100 tropical fish, along with sharks, rays, moray eels, crabs, lobsters, shrimps, sea slugs, cuttlefish, squid, octopus, turtles, sea snakes, starfish, sea cucumbers, corals, worms etc..
This marine biology documentary provides an overview of Indian Ocean aquatic life.
From Science News:
Reef rehab could help threatened corals make a comeback
Solutions for threatened reefs vary by location and damage done
By Amy McDermott
5:30am, October 18, 2016
Coral reefs are bustling cities beneath tropical, sunlit waves. Thousands of colorful creatures click, dash and dart, as loud and fast-paced as citizens of any metropolis.
Built up in tissue-thin layers over millennia, corals are the high-rise apartments of underwater Gotham. Calcium carbonate skeletons represent generations of tiny invertebrate animals, covered in a living layer of colorful coral polyps. Their structures offer shelter, and for about 114 species of fish and 51 species of invertebrates, those coral skyscrapers are lunch.
Important as they are, corals are in jeopardy. Warming oceans are causing more and more corals to bleach white and become vulnerable to destruction. A prolonged spike in temperatures, just 1 to 2 degrees Celsius, is enough to kill the marine animals. Greenhouse gas emissions also acidify the water, dissolving the calcium skeletons. In some countries, fishermen use dynamite to catch fish, leaving behind coral rubble. Today, more than 60 percent of the world’s reefs are at risk of disappearing.
Threats to reefs have “dramatically escalated in the last few decades,” says marine scientist Peter Harrison of Southern Cross University in Lismore, Australia. He has studied corals for three decades. “In my time as a reef researcher,” Harrison says, “I’ve seen it get worse, firsthand.”
Thirty years ago, massive coral bleachings were unheard of. Today, reefs are suffering through a third global bleaching event since 1998. With high ocean temperatures dragging on since 2014, this summer marked the longest and most widespread episode of worldwide coral bleaching on record (SN: 7/23/16, p. 5). Australia has been hit especially hard. More than 80 percent of the northern part of the Great Barrier Reef is bleached and close to half of those corals have died, according to a report in April from Australia’s National Coral Bleaching Taskforce.
As reefs take a nose dive, scientists from Hawaii to the Philippines and the Caribbean are scrambling to save corals. Approaches that were once considered radical are “now seen as necessary in some places,” says coral biologist Ruth Gates of the Hawaii Institute of Marine Biology on Oahu.
In Florida, researchers are restoring reefs with tiny coral fragments. In Hawaii, Gates is scouring the water for stress-tolerant corals and experimenting in the lab to breed the hardiest individuals. At the 13th International Coral Reef Symposium in Honolulu in June, Harrison’s team reported early promising results of its effort to flood damaged reefs in the Philippines with tiny coral larvae.
What works on one reef won’t necessarily save another. So researchers are testing an arsenal of options to rescue a diversity of underwater communities.
The caption of this picture says:
(a) Reproduction from Lascaux cave (France), from the Solutrean or early Magdalenian period (∼20,000 kya—picture adapted from ref. 53). (b) Reproduction from the Pergouset cave (France), from the Magdalenian period (17,000 kya—picture adapted from ref. 54)
From Nature Communications, 18 October 2016:
Julien Soubrier, Graham Gower, Alan Cooper
The two living species of bison (European and American) are among the few terrestrial megafauna to have survived the late Pleistocene extinctions. Despite the extensive bovid fossil record in Eurasia, the evolutionary history of the European bison (or wisent, Bison bonasus) before the Holocene (<11.7 thousand years ago (kya)) remains a mystery.
We use complete ancient mitochondrial genomes and genome-wide nuclear DNA surveys to reveal that the wisent is the product of hybridization between the extinct steppe bison (Bison priscus) and ancestors of modern cattle (aurochs, Bos primigenius) before 120 kya, and contains up to 10% aurochs genomic ancestry. Although undetected within the fossil record, ancestors of the wisent have alternated ecological dominance with steppe bison in association with major environmental shifts since at least 55 kya. Early cave artists recorded distinct morphological forms consistent with these replacement events, around the Last Glacial Maximum (LGM, ∼21–18 kya).
See also here.
This video says about itself:
2 September 2015
“Dryosaurus” is a genus of an ornithopod dinosaur that lived in the Late Jurassic period. It was an iguanodont. Fossils have been found in the western United States, and were first discovered in the late 19th century. “Valdosaurus canaliculatus” and “Dysalotosaurus lettowvorbecki” were both formerly considered to represent species of “Dryosaurus”.
“Dryosaurus” had a long neck, long, slender legs and a long, stiff tail. Its arms, however, with five fingers on each hand, were short. Known specimens were about 8 to 14 feet long and weighed 170 to 200 pounds. However, the adult size is unknown, as no known adult specimens of the genus have been found.
“Dryosaurus” had a horny beak and cheek teeth and, like other ornithopods, was a herbivore. Some scientists suggest that it had cheek-like structures to prevent the loss of food while the animal processed it in the mouth.
A quick and agile runner with strong legs, “Dryosaurus” used its stiff tail as a counterbalance. It probably relied on its speed as a main defense against carnivorous dinosaurs.
The teeth of “Dryosaurus” were, according to museum curator John Foster, characterized by “a strong median ridge on the lateral surface.” “Dryosaurus” subsisted primarily on low growing vegetation in ancient floodplains.
A “Dryosaurus” hatchling found at Dinosaur National Monument in Utah confirmed that “Dryosaurus” followed similar patterns of craniofacial development to other vertebrates; the eyes were proportionally large while young and the muzzle proportionally short. As the animal grew, its eyes became proportionally smaller and its snout proportionally longer.
By Pete Buchholz in Britain:
A specimen of the dryosaurid Valdosaurus has been discovered on the Isle of Wight
The most complete specimen of the poorly known dryosaurid Valdosaurus canaliculatus has been discovered in Lower Cretaceous rocks on the Isle of Wight. This new discovery helps flesh out the anatomy of this dinosaur and is one of the most complete dinosaur specimens known from England.
The Isle of Wight off the south coast of England is a fossil-hunter’s paradise. Rocks of the Wessex Formation, deposited during the Early Cretaceous, approximately 130 million years ago, are exposed in numerous locations across the island. The Wessex Formation preserves numerous fish, turtles, crocodilians, and pterosaurs. It also has a rather famous dinosaur fauna, including the spinosaurid Baryonyx, the early tyrannosaur Eotyrannus, a number of fragmentary sauropods, and the ornithopods Iguanodon, Mantellisaurus, Hypsilophodon, and Valdosaurus.