Triceratops dinosaur fossils, from the USA to Dutch museum


After the earlier video about this on this blog, these Dutch videos are about people from Naturalis museum in Leiden in the Netherlands going to the USA to fetch Triceratops dinosaur fossils.

This 15 July 2016 video is the most recent one of the series.

Birds nesting in California, new research


This video from the USA says about itself:

26 May 2013

This film is condensed from about a three hour fledging experience of Western Bluebirds being coaxed from their nest box. Both parents are seen feeding the nestlings but in between the feedings they perch nearby, sometimes with food and sometimes not, and try to coax the nestlings to leave the safety of the only home they know. You will hear the parents call to the nestlings and see they nestlings chirping back. You will also hear many other bird species in the background including Ash-throated Flycatcher, California Quail, Mourning Dove and Acorn Woodpecker.

There were also Violet-green Swallows checking out the nest cavity before the first nestling ever fledged. Once it leaves the nest, you will see the young bluebird perching for the first time in a nearby oak tree, the second nestling soon to follow. I watched three of the five nestlings fledge but had to leave before the last two left the nest box.

From the Cornell Lab of Ornithology in the USA:

Nest Box Occupancy Indicates Good Habitat Quality in California

The state motto of California is “Eureka! I have found it!” Perhaps that’s what a Western Bluebird thinks when it finds that perfect nest box in a good habitat. New research from the Cornell Lab of Ornithology, conducted in California’s oak woodlands, reveals that five species of cavity-nesting birds—Western Bluebird, House Wren, Oak Titmouse, Ash-throated Flycatcher, and Violet-green Swallow—divvy up the nesting habitat according to their specific vegetation preferences and, in the process, improve nesting success.

The researchers found that nest box occupancy rates were a good indicator of nesting success, which has management implications for the declining Oak Titmouse population. This work furthers our understanding of habitat preferences and the role that humans can play in the distribution of nest boxes. Read a brief summary of the research here.

Dinosaur extinction, new theory


This 2015 video is called National Geographic Documentary: Extinction Of Dinosaurs. What About Killer Dinosaurs.

From daily The Independent in Britain:

Dinosaur extinction mystery solved? Asteroid hit oil field causing smoke that filled Earth’s atmosphere

Temperatures would have plunged as soot blocked out the sun and the rain virtually stopped falling

Ian Johnston, Science Correspondent

21 minutes ago

The dinosaurs were wiped out 66 million years ago because a massive asteroid hit vast oil deposits in Mexico, sending thick black smoke into the atmosphere all over the world, according to a new study.

Soot blocked out the sun, causing the planet to cool significantly and experience devastating droughts.

The amount of sunlight would have fallen by up to 85 per cent, while the Earth would have cooled by as much as 16 degrees Celsius on land for about three years.

At the same time, rainfall would have fallen by up to 80 per cent causing extreme drought.

In a paper in the journal Scientific Reports, the researchers wrote: “Although small mammals and reptiles could have lived underground where it is warmer, the dinosaurs did not.

“The different habitats of the dinosaurs and small mammals and reptiles would also have been key factors in determining their extinction or survival.”

The six-mile-wide asteroid, which hit what is now the Yucatan Peninsula, created the third-largest crater on Earth, some 110 miles across.

It struck the Earth with the force of about a billion nuclear bombs of the size that destroyed the Japanese city of Hiroshima during World War Two.

It had been something of a mystery why some dinosaurs had died out while others, like the ancestors of crocodiles,

The ancestors of crocodiles were not dinosaurs. Though, like dinosaurs, they belonged to the bigger group called archosaurs.

did not.

Previously it was thought that the impact caused vapours of sulphuric acid in the sky, which reflected sunlight leading to global darkness, near-freezing conditions and widespread acid rain.

But the researchers, from Japan’s Meteorological Research Institute and Tohuku Univeristy, said: “If this had occurred, crocodilians and various other animals would have also gone extinct.

“Recent impact experiments and model calculations have demonstrated that condensed sulfuric acid aerosols cannot form and persist over long periods following asteroid impacts.”

It is estimated that just 12 per cent of life on land survived the chaos unleashed by the asteroid, but 90 per cent of freshwater species were able to ride out the sudden shock to the planet.

Extinct shellfish brought back to Europe by Vikings?


This video says about itself:

After reducing the level of water in the shallows sand seashells [soft-shell clams] (Mya arenaria) became visible.

Lower Tiligul Estuary (Liman). Ukraine. May 17, 2015.

From the Netherlands Journal of Geosciences, May 2016:

Are Medieval Mya arenaria (Mollusca; Bivalvia) in the Netherlands also clams before Columbus?

Abstract

During the Pleistocene [Ice Age], the coastal marine bivalve mollusc Mya arenaria became extinct in northwest Europe. The species remained present in North America. Datings of Mya shells found in northern Denmark and the southern Baltic Sea suggest that repopulation of northwest European coasts already occurred before Columbus’ discovery of America (1492), possibly facilitated by Viking (Norse) settlers at Greenland and northeast North America.

In this paper we report on findings of M. arenaria at five locations in the coastal landscape of the Netherlands: polders reclaimed from the Wadden Sea and the former estuaries of Oer-IJ and Old Rhine. The shells from four of these locations also date before 1492 AD.

Unusual carnivorous dinosaur described


This video says about itself:

13 July 2016

A newly discovered meat-eating dinosaur that prowled Argentina 90 million years ago would have had a hard time using strong-arm tactics against its prey. That’s because the beast, though a fearsome hunter, possessed a pitifully puny pair of arms.

Scientists said on Wednesday they have unearthed fossils in northern Patagonia of a two-legged, up to 26-foot-long (8-meters-long) predator called Gualicho shinyae with arms only about 2 feet (60 cm) long, akin to a human child’s.

The fossils of Gualicho, named after an evil spirit feared by Patagonia’s indigenous Tehuelche people, were discovered in Argentina’s Rio Negro Province.

Gualicho and other carnivorous dinosaurs like Tyrannosaurus rex are part of a group called theropods that included Earth’s largest-ever land predators. But a curious thing happened during their many millions of years of evolution. For some, as they acquired huge body size and massive skulls, their arms and their number of fingers shrank.

From the Christian Science Monitor in the USA:

T. rex wasn’t the only one with those strange little arms

Paleontologists discover a new dinosaur with T. rex-like arms, but it’s not a tyrannosaur.

By Eva Botkin-Kowacki, Staff writer

July 13, 2016

Quick! Make like a T. rex.

What is the first step to mimicking the famous, fearsome dinosaur? After roaring, a person probably pulls both arms in, contorting them to make them tiny relative to the rest of the body, mashing the five fingers together to have just two digits on each hand. One of the most characteristic features of the iconic tyrant lizard dinosaur is its strange, seemingly uselessly small forelimbs.

But Tyrannosaurus rex wasn’t the only two-legged carnivorous dinosaur to sport such teeny, two-fingered arms.

“Theropods in general do this quite often,” Lindsay Zanno, head of the Paleontology Research Lab at the North Carolina Museum of Natural Sciences, tells The Christian Science Monitor in a phone interview. “There are a lot of different groups of theropods that tend to reduce the size of their hands and their arms or change the way that they’re used.”

And another one is joining the bunch.

Gualicho shinyae, discovered in Argentina in 2007, is named and described in a paper published Wednesday in the journal PLOS ONE.

This new dinosaur’s “arms are short – about 2 ft long – which is less than the length of the thigh bone, and they have weak muscle attachments and poorly developed articulations indicating they had little strength,” Peter Makovicky, associate curator of dinosaurs at the Field Museum of Natural History in Chicago who co-led the team that discovered Gualicho, describes in an email to the Monitor.

The fingers on the 90-million-year-old fossil are similar to those of tyrannosaurs. The thumb has a large claw while the second finger is more slender. A third finger has become so reduced that it is just a tiny bone in the flesh of the animal’s hand. …

Gualicho has weak little arms with just two functional fingers like T. rex, but the similarities pretty much stop there.

“This animal has a kind of mosaic of features. There are aspects of its skeleton that show some affinities with some groups of dinosaurs and some affinities with other groups of dinosaurs, although none of those are really tyrannosaurs,” study co-author Nathan Smith, associate curator in the Dinosaur Institute at the Natural History Museum of Los Angeles County, tells the Monitor in a phone interview.

But the “oddball” dinosaur, as Dr. Smith describes it, could help researchers figure out why so many diverse theropod dinosaurs have evolved similar, reduced forelimbs. …

Some scientists have suggested that humongous predatory dinosaurs would have evolved smaller arms because their skulls were used more readily to wrangle prey, she says.

There seems to be a pattern among tyrannosaurs, for example, in which the arms became shorter and the fingers fewer as the animals’ skulls and bodies became larger over generations, says Stephen Brusatte, a paleontologist at the University of Edinburgh who was not part of the study, in an email to the Monitor. This would suggest that “the head was taking over many of the duties that the arms once had, like procuring and processing food.”

“Most theropods with reduced forelimbs, like tyrannosaurs, ceratosaurs, and carcharodontosaurs are clearly macropredators that rely on their massive skulls for hunting, so it seems likely that the same was true of Gualicho,” Makovicky says.

These diverse dinosaurs were likely under similar evolutionary pressures that lead to similarly reduced forelimbs. The feature would have evolved independently in the different groups, in a process called convergent evolution. …

The mosaic features of Gualicho “makes figuring out the evolutionary placement of this animal a little difficult,” Smith says.

Weighing an estimated 1,000 pounds, Gualicho appears to fit into the family neovenatoridae, a large-bodied branch of carnivorous theropod dinosaurs, Smith says, but it also seems to bear the closest resemblance to Deltadromeus, a large theropod from Africa.

But could a South American dinosaur be closely related to an African one?

Possibly. Scientists have previously noted a lot of similarities between dinosaurs unearthed in the Kem Kem Beds on the border of Morocco and Algeria, where Deltadromeus has been found, and the Huincul Formation in Argentina, where Guialicho was discovered, Smith says. “So it may not be surprising that these two carnivorous dinosaurs are close relatives.”

And at the time when Guialicho roamed the Earth, the two continents had only recently, geologically speaking, begun to separate as the supercontinent Gondwana broke up.

Wasp species found for first time in the Netherlands


This video says about itself:

27 April 2009

A parasitic wasp has injected her eggs into a caterpillar — and now they’re ready to hatch.

Today, warden Erik van der Spek on Texel island in the Netherlands writes that a wasp species has been discovered on Texel which had never been seen in the Netherlands before. It is Neorhacodes enslini.

This small parasitic wasp species of the Ichneumonidae family lays it eggs in the nests of bigger wasp species.

Unique swimming centipede discovered on honeymoon


Scolopendra cataracta, photo by Warut Siriwut

From National Geographic:

‘Horrific’ First Amphibious Centipede Discovered

This giant, venomous creepy-crawly is as comfortable swimming and walking underwater as it is on land, in a finding that surprised scientists.

Meet S. cataracta, a new species of centipede that hunts in the water, a first for the group.

By Mary Bates

PUBLISHED June 26, 2016

Just when you thought it was safe to go in the water—look out for giant, swimming centipedes!

Scientists have recently described the world’s first known amphibious centipede. It belongs to a group of giant centipedes called Scolopendra and grows up to 20 centimeters (7.9 inches) long.

Like all centipedes, it is venomous and carnivorous. Thankfully, this new water-loving species appears to live only in Southeast Asia. The creature’s description was published last month in the journal ZooKeys.

Centipede Serendipity

George Beccaloni of the Natural History Museum in London was on his honeymoon in Thailand in 2001. And like any good entomologist, he was looking for bugs.

“Wherever I go in the world, I always turn over rocks beside streams, and that’s where I found this centipede, which was quite a surprise,” says Beccaloni.

“It was pretty horrific-looking: very big with long legs and a horrible dark, greenish-black color,” he says.

When Beccaloni lifted the rock it was hiding under, the centipede immediately escaped into the stream, rather than into the forest. It ran along the stream bed underwater and concealed itself under a rock.

With some difficulty, Beccaloni captured the centipede and later put it in a large container of water. He says it immediately dove to the bottom and swam powerfully like an eel, with horizontal undulations of its body. When he took the centipede out of the container, the water rolled off its body, leaving it totally dry.

Beccaloni brought his specimen back to the Natural History Museum in London and asked a centipede expert about his observations. The expert was skeptical, because Scolopendra are found in dry habitats and no centipedes were known to be amphibious. So the specimen sat in the museum’s collection for years.

Finally, a New Species

Meanwhile, Beccaloni’s colleague at the Museum, Gregory Edgecombe, and his student in Thailand, Warut Siriwut, were on the verge of describing a new species of centipede.

They had collected two specimens near waterfalls in Laos, and DNA analysis confirmed it was a new species. They named the centipede Scolopendra cataracta, from the Latin for “waterfall.”

Beccaloni shared the observations of his specimen’s amphibious behavior with Edgecombe, and they confirmed that his honeymoon centipede was an example of S. cataracta.

The entire species is known from just four specimens: the two collected in Laos, Beccaloni’s swimming specimen from Thailand, and a fourth specimen that was collected in Vietnam in 1928 and was in the collection at the Natural History Museum in London, misidentified as a more common species.

Beccaloni believes S. cataracta exploits a different ecological niche from other centipedes.

“Other Scolopendra hunt on land,” he says. “I would bet this species goes into the water at night to hunt aquatic or amphibious invertebrates.”

Like all centipedes, this new amphibious species is venomous. Although you would not want to be bitten by one, it probably wouldn’t kill you—it would just cause agonizing pain.

“All large Scolopendra can deliver a painful bite, the ‘fang’ of the venom-delivery system being able to pierce our skin,” says Edgecombe.

Bites from related centipedes of about the same size as S. cataracta cause a burning pain that can spread the length of the entire arm or leg if a finger or toe is envenomated. Edgecombe says the pain may persist for a few days, but probably won’t leave one with any longer-lasting effects.

It sounds like some people’s worst nightmare: if you go for a dip in a nice stream at night, there might be giant centipedes lurking in the water.

But to scientists like Beccaloni and Edgecombe, the new discovery is further proof of all the wonders of nature that are still unknown to us.

“People tend to study streams in the tropics during the day, but there is probably a whole other range of interesting amphibious things that come out at night,” says Beccaloni. “It would be good to study these streams and their fauna then to see what is actually going on under the cover of darkness.”