Fossil dinosaur and fossil wildebeest, discoveries and simillarities


This video says about itself:

Shared noses: Extinct wildebeest relative was remarkably dinosaur-like

5 February 2016

An artist’s interpretation of Rusingoryx atopocranion on the Late Pleistocene plains of what is now Rusinga Island, Lake Victoria.

From the Christian Science Monitor in the USA:

Weird convergence: Extinct wildebeest cousin and dinosaur shared noses

Scientists discover two unrelated, extinct animals had the same strange nose.

By Eva Botkin-Kowacki, Staff writer February 5, 2016

You might not expect to find many similarities between a mammal and a reptile, particularly if they lived millions of years apart. But scientists have found that two such extinct beasts share a rare, distinctive facial feature.

An extinct relative of the wildebeest and a duck-billed dinosaur both had bizarre crests on their heads. But it wasn’t the protruding bump that has most intrigued scientists, it’s what they found beneath.

The bony crest is hollow, forming a trumpet-shaped nasal passage unlike any seen outside these two species. No other animal, living or dead, has been found with such a feature.

So how did two beasts from two very different taxa come to have such a mysterious commonality? Convergent evolution, scientists say in a paper published Thursday in the journal Current Biology.

“We have an animal that its skeleton looks a lot like a wildebeest – it’s actually very closely related to modern wildebeests – but its face looks a lot more like something you would see if you went way back in time to the Cretaceous and looked at hadrosaur dinosaurs,” study lead author Haley O’Brien tells The Christian Science Monitor in an interview.

Rusingoryx atopocranion, the mammal, lived about 65 thousand years ago, during the late Pleistocene, while Lambeosaurine hadrosaurs, the dinosaur, lived closer to 65 million years ago, during the late Cretaceous – and yet both animals evolved the same strange nose.

And not only do their nasal passages look alike, she said, the feature also appears to develop the same way as the animals grow up from juveniles to adults, as a variety of fossils display.

“When I first saw the complete skulls, I was blown away,” vertebrate paleontologist David C. Evans, who was not part of the study, writes in an email to the Monitor. “The resemblance between Rusingoryx and some hollow-crested dinosaurs in the form of their nasal structures is truly striking, and there are clear parallels in how they evolved and grew. Both groups elongated their noses to such a degree that they evolved highly domed skulls to house their nasal passages on top of their heads, above their eyes.”

Different origins, same result

“It’s probably one of the best examples of convergence in large animals that I’ve seen in a long time,” Ali Nabavizadeh, a researcher in evolutionary biology and anatomy at the University of Chicago, who was not involved in the study, tells the Monitor.

One was a mammal and the other a reptile, and millions of years elapsed between their tenure on Earth, but still, these animals developed the same adaptation.

Convergent evolution occurs when two species along different lineages independently evolve the same, or similar, features for the same function. One example is how insects, birds, and bats can all fly.

Convergence typically occurs when different species face the same ecological pressures. So what did Rusingoryx and the hadrosaurs have in common?

Both animals were herbivores and lived in herds. Rusingoryx was a ruminant and hadrosaurs have been called the cows of the Cretaceous, but the similarities, besides the shared nose, stop there.

Rusingoryx lived on the savanna, a dry wide open plain, while Lambeosaurine hadrosaurs were thought to have lived in a tropical rainforest.

Understanding this mysterious convergence might hinge on the purpose that these strange nasal passages served.

Inner trumpets

Without looking inside the animals’ skulls, the crest might appear to be simply for visual display or some other external use.

“We have known for decades that visual display and physical combat have strongly shaped skull evolution in many groups of animals with elaborate horns and crests,” Dr. Evans says. But the long, trumpet-shaped interior suggests a more complex purpose.

The hollow cavity, part of the respiratory tract, loops up over the animal’s head and seems to connect to the vocal tract.

To determine the purpose behind this strange nose, scientists focused on the mammal’s living cousins, wildebeests and antelopes. While researchers can look at their soft tissue for clues, all that’s left of the dinosaurs is bone.

The unusual nose could have helped the animals smell, bugle, or even regulate their temperature, Evans says. “The case for vocalization as the primary function of the nasal dome in Rusingoryx is by far the most convincing, as the authors advocate.”

The Rusingoryx are very social, says Ms. O’Brien. “They live in herds and they use a lot of vocal signals to communicate. When we looked into the function of what this skull type might be doing in Rusingoryx, we really couldn’t prescribe a function outside of that social vocalization.”

“There are obviously a lot of things that animals do with their faces,” she says. “But we don’t think that this crazy nasal dome would have really changed those more normal functions for this animal. We think that it was using the nasal crest to modify the way that it’s producing these vocalizations and communicating.”

That makes sense, says Thomas E. Williamson, curator of paleontology at the New Mexico Museum of Natural History and Science, who was not part of the study.

“When you have any kind of a tubing, it becomes naturally resonant,” he explains. “So the idea that it’s being used somehow to amplify certain frequencies of sound, it will do that,”

Not your average moo

O’Brien and her colleagues suggest that Rusingoryx, and perhaps the dinosaurs by extension, used this bizarre nasal dome to communicate at frequencies other animals cannot hear. This is called infrasound, and animals like elephants and cassowaries use it to communicate under the radar.

That’s possible, says Dr. Nabavizadeh. “If you have a very gregarious group of animals and they’re in a big arid, open environment, as these bovids are, then you are under the selective pressure to start to create more lower bellowing sounds that are possibly outside of the hearing range of carnivores, so they can communicate without being found in big open environments.”

But the environment doesn’t preclude the dinosaurs from needing this ability too, says Dr. Williamson. “Infrasound … is able to travel over great distances and open areas and in closed environments. It pretty much goes everywhere,” he says. And cassowaries, the living birds thought to communicate in infrasound, live in dense tropical rainforests.

Mice live longer with cell therapy


AGE STAGE By about 2 years old, mice that age normally (back left) are hunchbacked and nearly blind. A treatment that removes decrepit “senescent” cells makes mice the same age (front right) healthier: They look and act younger and live longer. Photo: Mayo Clinic

From Science News:

Removing worn-out cells makes mice live longer and prosper

Antiaging treatment shows promise for lengthening life span

By Tina Hesman Saey

1:00pm, February 3, 2016

Killing worn-out cells helps middle-aged mice live longer, healthier lives, a new study suggests.

Removing those worn-out or “senescent” cells increased the median life span of mice from 24 to 27 percent over that of rodents in which senescent cells built up normally with age, Mayo Clinic researchers report online February 3 in Nature. Clearing senescent cells also improved heart and kidney function, the researchers found.

If the results hold up in people, they could lead to an entirely new way to treat aging, says gerontology and cancer researcher Norman Sharpless at the University of North Carolina School of Medicine in Chapel Hill. Most prospective antiaging treatments would require people to take a drug for decades. Periodically zapping senescent cells might temporarily turn back the clock and improve health for people who are already aging, he says. “If this paper is right, I believe it will be one of the most important aging papers ever,” Sharpless says.

Senescent cells are ones that have ceased to divide and do their usual jobs. Instead, they hunker down and pump out inflammatory chemicals that may damage surrounding tissues and promote further aging. “They’re zombie cells,” says Steven Austad, a biogerontologist at the University of Alabama at Birmingham. ”They’ve outlived their usefulness. They’re bad.”

Cancer biologist Jan van Deursen of the Mayo Clinic in Rochester, Minn., and colleagues devised the strategy for eliminating senescent cells by making the cells commit suicide. A protein called p16 builds up in senescent cells, the researchers had previously discovered. The team hooked up a gene for a protein that causes cells to kill themselves to DNA that helps turn on p16 production, so that whenever p16 was made the suicide protein was also made.

The suicide protein needs a partner chemical to actually kill cells, though. Once mice were a year old — 40 to 60 years old in human terms — the researchers started injecting them with the partner chemical. Mice got injections about every three days for six months. Mice that got the cell-suicide cocktail were compared with genetically engineered mice that were injected with a placebo mix.

Senescent cells were easier to kill in some organs than others, the researchers found. Colon and liver senescent cells weren’t killed, for instance. But age-related declines in the function of organs in which the treatment worked — eyes, fat, heart and kidney —were slowed.

Genetic engineering and regular shots would not be feasible for use in people, but several companies are developing drugs that might clear the zombie cells from humans, Austad says. Some side effects to the treatment in mice also would be important to consider if those drugs are ever used in people. Senescent cells have previously been shown to be needed for wound healing, and mice that got the killing cocktail couldn’t repair wounds as well as those that didn’t get the treatment. Once treatment stopped, the mice were able to heal normally again. That result suggests that people undergoing senescent-cell therapy might need to stop temporarily to heal wounds from surgery or accidents.

Previously, the researchers had killed senescent cells in mice with a mutation that caused them to age prematurely (SN: 12/3/11, p. 11). Removing the worn-out cells helped the prematurely old mice live longer, but other researchers weren’t convinced that the results applied to normal aging. “It’s great when you find something that helps prevent premature aging, but there’s always this nagging doubt,” says Judith Campisi, a researcher at the Buck Institute for Research on Aging in Novato, Calif. It’s gratifying that the treatment works to extend life and health in normally aging animals, she says.

Campisi also studies the effect of senescent cells on aging, but doesn’t think the cells are entirely to blame for the ills of old age. “We don’t believe senescence is the only thing that drives aging,” she says. “That would be stupid. If this were the magic bullet, Jan’s mice would live forever, but they don’t.”

Hyena love life, video


This video says about itself:

Female Dominance Over Male Hyenas – Animals In Love – BBC

3 February 2016

Adult males, within hyenas society, are below every other female. A three week old female cub will be more dominant then a 20 year old male part of the clan. The team set out to observe some of these dominant females…

The video is about spotted hyenas.

Eurasian songbirds’ singing while wintering in Africa


This video shows a great reed warbler singing.

From The American Naturalist in the USA:

Why do migratory birds sing on their tropical wintering grounds?

Migratory songbirds may sing during the winter months to improve their song quality ahead of the springtime mating season

Marjorie C. Sorensen, Claire N. Spottiswoode, and Susanne Jenni-Eiermann

The first notes of bird song signal the arrival of spring as well as the beginning of mate attraction season, and for many songbird species males with the most elaborate songs do best when it comes to attracting females. But why do many migratory songbirds sing during the winter, when they are thousands of kilometers away from their breeding grounds and the prospect of attracting a mate? This was the long-unanswered question tackled by Marjorie Sorensen, Susanne Jenni-Eiermann, and Claire Spottiswoode.

To answer this question, the researchers test three hypotheses to explain why winter singing might benefit long-distance migratory songbirds. First, birds may sing to defend winter feeding territories; second, males may sing during winter to improve the quality of their songs; and third, high testosterone levels during breeding may linger over the winter months and promote singing as a byproduct.

To test these hypotheses, the scientists combine a field study of wintering great reed warblers (Acrocephalus arundinaceus) in Zambia and a comparison across all songbird species that breed in the Palearctic and migrate to sub-Saharan Africa. All the collected evidence points towards great reed warblers singing in winter to improve their song quality, and across species those with the strongest sexual selection for song quality sang most intensely in Africa. This suggests that males with the most to gain from singing complex songs during breeding sing most often in Africa for the purpose of song improvement. This study sheds light on this perplexing behavior and the far-reaching effects of sexual selection throughout the annual cycle.

Sea grass genome, new research


This 27 January 2016 video is called Gareth Pearson – Zostera marina genome published by Nature.

From the University of Gothenburg in Sweden:

Land plant became key marine species

February 1, 2016

Summary:

The genome of eelgrass (Zostera marina) has now been unveiled. It turns out that the plant, once land-living but now only found in the marine environment, has lost the genes required to survive out of the water.

Scientists from the University of Gothenburg participated in the research study, the results of which are published in the scientific journal Nature.

Eelgrass belongs to a group of flowering plants that have adapted to a life in water. As such, it is a suitable candidate for studies of adaptation and evolution.

‘Since flowering plants have emerged and developed on land, eelgrass can be expected to share many genetic features with many land plants. Studying differences between them can tell us how eelgrass has adapted to a marine environment,’ says Mats Töpel, researcher at the Department of Marine Sciences, University of Gothenburg, who participated in the sequencing of the eelgrass genome.

Töpel is part of an international research collaboration involving 35 research teams. As a result of their efforts, the eelgrass genome has now been published in Nature.

A life on land no longer possible

One interesting discovery made by the scientists is that eelgrass has lost not only the special cells that flowering plants need to be able to ‘breathe’ (meaning to absorb carbon dioxide and release oxygen) but also the genes required to form these cells.

‘This is a good example of how evolution extends beyond mere accumulation of useful traits; organisms can also benefit from losing certain genes and characteristics,’ says Töpel.

Eelgrass — a key species in trouble

Eelgrass belongs to a group of plants generally referred to as seagrass and forms gigantic submarine meadows along European, North American and Asian shores. The plant has adapted to many different environments, from the bitter Arctic cold to the warm waters further south.

In all of these environments, eelgrass serves an important function in the ecosystem by binding sediments and acting as a nursery for young fish and other animals. It also influences our own environment by binding large amounts of nutrients and carbon dioxide.

‘Lately, the eelgrass meadows have disappeared in many places, and a lot of research is underway to figure out how these ecosystems work and what we can do to protect them,’ says Töpel.

Further studies remain

The genome of an organism contains huge amounts of information.

‘So far we have only scratched the surface. A vast number of bioinformatic analyses of eelgrass remain to be done. And the increasing availability of genomes of other organisms enables us to make new comparisons,’ says Töpel.

Tardigrade species, new for the Netherlands, discovered


Batillipes pennaki, photo by Frans W. Roza

Translated from the Dutch Stichting ANEMOON marine biologists:

Jan 31, 2016 – Recently, the discovery of a new tardigrade animal species of the Dutch coast was published. This is the Batillipes pennaki waterbear. The animal is not greater than about 0.2 millimeter. With this, the number of Dutch waterbear species that are found on our beaches becomes six. This species has been found in many places throughout the world.

Spring mushrooms already in January


This video is called Pholiotina aporos – fungi kingdom.

Translated from the Dutch Mycological Society:

27 January 2016 – Pholiotina aporos mushrooms are almost exclusively known from spring. Especially in the months of April and May you have a chance to find them. In the Netherlands only a few have been found in late autumn. All the more remarkable is the finding of early January in the dunes of IJmuiden. When flawless Pholiotina aporos fungi were discovered on a thin layer of humus under high sea buckthorn.