Galápagos islands waters video


This video says about itself:

Dive Into the Wildlife-Rich Waters of the Galápagos | National Geographic

17 February 2018

The Galápagos Archipelago, Darwin’s living laboratory, is home to an abundance of wildlife. Isolated from the mainland for millions of years, it is that rare wilderness where animals have no instinctive fear of humans.

Featuring marine iguanas, sea turtles and others.

Advertisements

King penguins, male-female difference


This 2014 video says about itself:

Just above Antarctica, off the island of South Georgia, lies a breeding hot spot for elephant seals and king penguins known as Gold Harbour.

Filmmaker Richard Sidey captures incredible raw footage and the natural sound of this wild bounty for part of his series, Speechless. “[W]ith the absence of narrative, the viewer is left to create their own narrative and their own experience, without being told what to think … It gives everyone the possibility of seeing these places for what they are without the restrictions of cost and the environmental impact”, he says.

From ScienceDaily:

Distinguishing males from females among king penguins

February 22, 2018

It is difficult to distinguish males from females among King Penguins, but a new Ibis study reveals that King Penguins can be sexed with an accuracy of 100% based on the sex-specific syllable pattern of their vocalisations. Using the beak length, King Penguin individuals can be sexed with an accuracy of 79%.

The new findings may help investigators understand how King Penguins choose mates, and they offer a cost-effective, non-invasive technique for researchers to sex King Penguins in the field.

“The sex-specific syllable pattern in King Penguin calls is a very interesting finding, both from an evolutionary perspective as it is rare in non-passerine species, but also because it allows researchers with very little training to reliably identify the gender of King Penguins without handling the individuals,” said lead author Hannah Kriesell, of the Centre Scientifique de Monaco and the University of Strasbourg.

What makes dinosaurs dinosaurs?


This 2016 video says about itself:

Dinosaurs are a diverse group of animals of the clade Dinosauria.

They first appeared during the Triassic period, 231.4 million years ago, and were the dominant terrestrial vertebrates for 135 million years, from the start of the Jurassic (about 200 million years ago) until the end of the Cretaceous (66 million years ago), when the Cretaceous–Paleogene extinction event led to the extinction of most dinosaur groups at the end of the Mesozoic Era.

The fossil record indicates that birds are modern feathered dinosaurs, having evolved from theropod ancestors during the Jurassic Period. Birds were the only dinosaurs to survive the extinction event that occurred 66 million years ago.

By Carolyn Gramling, 4:00pm, February 21, 2018:

New fossils are redefining what makes a dinosaur

Defining what’s unique about these ‘fearfully great lizards’ gets harder with new finds

“There’s a very faint dimple here,” Sterling Nesbitt says, holding up a palm-sized fossil to the light. The fossil, a pelvic bone, belonged to a creature called Teleocrater rhadinus. The slender, 2-meter-long reptile ran on all fours and lived 245 million years ago, about 10 million to 15 million years before scientists think dinosaurs first appeared.

Nesbitt, a paleontologist at Virginia Tech in Blacksburg, tilts the bone toward the overhead light, illuminating a small depression in the fossil. The dent, about the size of a thumbprint, marks the place where the leg bone fit into the pelvis. In a true dinosaur, there would be a complete hole there in the hip socket, not just a depression. The dimple is like a waving red flag: Nope, not a dinosaur.

The hole in the hip socket probably helped dinosaurs position their legs underneath their bodies, rather than splayed to the sides like a crocodile’s legs. Until recently, that hole was among a handful of telltale features paleontologists used to identify whether they had their hands on an actual dinosaur specimen.

Another no-fail sign was a particular depression at the top of the skull. Until Teleocrater mucked things up. The creature predated the dinosaurs, yet it had the dinosaur skull depression.

The once-lengthy list of “definitely a dinosaur” features had already been dwindling over the past few decades thanks to new discoveries of close dino relatives such as Teleocrater. With an April 2017 report of Teleocrater’s skull depression (SN Online: 4/17/17), yet another feature was knocked off the list.

Today, just one feature is unique to Dinosauria, the great and diverse group of animals that inhabited Earth for about 165 million years, until some combination of cataclysmic asteroid and volcanic eruptions wiped out all dinosaurs except the birds.

“I often get asked ‘what defines a dinosaur’, ” says Randall Irmis, a paleontologist at the Natural History Museum of Utah in Salt Lake City. Ten to 15 years ago, scientists would list perhaps half a dozen features, he says. “The only one to still talk about is having a complete hole in the hip socket.”

The abundance of recent discoveries of dinosauromorphs, a group that includes the dinosaur-like creatures that lived right before and alongside early dinosaurs, does more than call diagnostic features into question. It is shaking up long-standing ideas about the dinosaur family tree.

To Nesbitt, all this upheaval has placed an even more sacred cow on the chopping block: the uniqueness of the dinosaur.

“What is a dinosaur?” Nesbitt says. “It’s essentially arbitrary.”

Dinosaurs’ and birds’ locomotion


This 2016 video is called Dinosaur Walk Theory Video.

From PLOS:

Locomotion of bipedal dinosaurs might be predicted from that of ground-running birds

BIRDS Model uses just two inputs to predict terrestrial locomotion in extinct avian and non-avian dinosaurs

February 21, 2018

A new model based on ground-running birds could predict locomotion of bipedal dinosaurs based on their speed and body size, according to a study published February 21, 2018 in the open-access journal PLOS ONE by Peter Bishop from the Queensland Museum, Australia and colleagues.

Previous research has investigated the biomechanics of ground-dwelling birds to better understand the how bipedal non-avian dinosaurs moved, but it has not previously been possible to empirically predict the locomotive forces that extinct dinosaurs experienced, especially those species that were much larger than living birds. Bishop and colleagues examined locomotion in 12 species of ground-dwelling birds, ranging in body mass from 45g to 80kg, as the birds moved at various speeds along enclosed racetracks while cameras recorded their movements and forceplates measured the forces their feet exerted upon the ground.

The researchers found that many physical aspects of bird locomotion change continuously as speed increases. This supports previous evidence that unlike humans, who have distinct “walking” and “running” gaits, birds move in a continuum from “walking” to “running.” The authors additionally observed consistent differences in gait and posture between small and large birds.

The researchers used their data to construct the biomechanically informative, regression-derived statistical (BIRDS) Model, which requires just two inputs — body mass and speed — to predict basic features of bird locomotion, including stride length and force exerted per step. The model performed well when tested against known data. While more data are needed to improve the model, and it is unclear if it can be extrapolated to animals of much larger body mass, the researchers hope that it might help predict features of non-avian dinosaur locomotion using data from fossils and footprints.