Missing link dinosaur nests-bird nests discovery

This video from Canada says about itself:

First feathered dinosaur from North America introduced by Darla Zelenitsky

26 October 2012

Canadian researchers discover fossils of first feathered dinosaurs from North America.

From Science magazine:

Missing link between dinosaur nests and bird nests

By Sid Perkins

25 November 2015 2:00 pm

The links between dinosaurs and birds keep getting stronger: skeletal structures, feathers—and now nests. Whereas some dinosaurs buried their eggs crocodile-style, a new analysis suggests that other dinosaurs built open nests on the ground, foreshadowing the nests of birds.

Interpreting the fossil record is always tough, but analyzing trace fossils such as nests is especially daunting. Those structures, and the materials used to make them, usually aren’t preserved, says Darla Zelenitsky, a paleobiologist at the University of Calgary in Canada. When paleontologists do find a nestlike structure that includes material such as sticks or other vegetation, the question arises: Was this stuff part of the original nest, or just carried there with the sediment that buried the nest and helped preserve it?

To gain insight into dinosaur nesting habits, Zelenitsky and her colleagues studied the most durable parts of nests—the eggs themselves. (Being largely made of the mineral calcium carbonate, they’ve got a head start on fossilization and are sometimes incredibly well preserved.) In particular, the team looked at the size and arrangement of small pores in the ancient shells, because those details are telling in modern creatures.

In crocodiles’ buried nests, the heat needed to incubate the eggs comes from decomposition of overlying organic matter or the sunlight absorbed by the soil. Plus, in buried nests airflow is somewhat limited, thus requiring eggs to be relatively porous to help increase the flow of oxygen into and carbon dioxide out of the eggs. But birds that brood in open nests can get by laying eggs with fewer or smaller pores.

So the team compared the porosity of eggshells from 29 species of dinosaurs (including large, long-necked herbivores called sauropods; bipedal meat-eaters called theropods; and duck-billed dinosaurs) with that of shells from 127 living species of birds and crocodiles.

Most of the dinosaur eggs were highly porous, suggesting that they buried their eggs to incubate them, the researchers report online today in PLOS ONE. But some of the dinosaur species in one group—a subset of well-evolved theropods considered to be the closest relatives of modern-day birds—laid low-porosity eggs, which suggests they incubated their eggs in open nests.

“This is a well done paper; the results make a lot of sense,” says Luis Chiappe, a vertebrate paleontologist at the Natural History Museum of Los Angeles County in California. The findings, he says, line up other studies suggesting that some birdlike dinosaurs were warm-blooded, which would have enabled them to incubate eggs in an open nest rather than depend on rotting vegetation or sunlight. Chiappe adds that the trend toward open nests could have allowed some dinosaurs to take another step toward birdlike nesting by moving their nests into the trees.

But considering only two types of nests—open versus buried—may be too simplistic, suggests Anthony Martin, a paleontologist at Emory University in Atlanta. Some dinosaurs—like a few of today’s birds—may have nested in burrows, which could have offered the stable temperature and protection from predators of a buried nest but resulted in low-porosity shells. Also, covered nests come in different types: Loose vegetation piled atop a buried nest can have a lot of airflow through it, allowing eggs to have relatively small pores, whereas eggs buried in soil or similar materials might not breathe as well and thus require larger pores, he notes. Nevertheless, Martin adds, the team’s study “is a good first start toward answering the question about what early dinosaur nests looked like.”

See also here.

The findings were published online on Nov. 25 2015 in the journal PLOS ONE.

What is wildlife crime?

Wildlife crime

This picture is part of a governmental publication in Northern Ireland; about what they consider to be wildlife crime.

Corn snakes, why some are white

This video from the USA says about itself:

15 August 2014

The corn snake (Pantherophis gutattus gutattus) is a medium sized non-venomous colubrid that lives in the southeastern United States. Their bright colors, docile temperament, and minimum care requirements make them great for pets but it’s important to note that those you find in the wild are facing a decline in numbers and should be left alone if at all possible.

From Reptiles magazine:

Corn Snake Genome Sequenced, Albinism Mutation Detailed

November 25, 2015

By John Virata

Scientists with the University of Geneva (UNIGE), Switzerland have sequenced the corn snake Pantherophis guttatus (Elaphe guttata) genome for the first time, and discovered the mutation in the snake that causes albinism in the species, according to a paper published in Scientific Reports.

“Our aim was to produce ourselves a substantial portion of the missing data by sequencing all genes from several reptilian species. To reach this goal, we used tissues, such as the brain and the kidney, expressing the largest number of genes,” said Athanasia Tzika, researcher in the Department of Genetics and Evolution at UNIGE. “The objective was to obtain a genuine reptilian genomic model that people could rely on,” said Athanasia Tzika. “Here, we covered about 85% of the snake total genome size. There is much additional work ahead.”

The data compiled by Tzika will be freely available to researchers around the world who are working on developmental and evolutionary studies of reptiles.

UNIGE researcher Suzanne Saenko, working with Swedish scientists identified the mutation responsible for amenalism. The researchers bred a wild corn snake with a captive bred amenalistic corn snake and DNA sequenced all offspring from the cross and identified the malfunctioning gene. The gene OCA2 codes for a receptor located in the membranes of melanosomes, where melanin is found, according to the study. The receptor controls the acidity that enables the synthesis of melanin.

The researchers say that they will look into how some corn snakes are born with modified colors and patterns like longitudinal lines rather than transversal saddles that are typical of the species.

Helping hedgehogs in England

This video from England says about itself:

24 November 2015

LB Loxley takes a look behind the scenes at the busy Prickles Hedgehog Rescue. Looking at the work involved, the problems facing hedgehogs and what we can do to help. WARNING – Guaranteed Aahh factor.

Giraffe ancestry, new research

This video is about giraffes in Africa.

From Science journal:

Odd creature was ancient ancestor of today’s giraffes

By Sid Perkins

24 November 2015 7:15 pm

A distant relative of today’s giraffes was a bit of an odd creature: It was about the size of a bull moose, but it had a long neck that could stretch both up to eat tree leaves and down to eat grass. That’s the conclusion of the first comprehensive analysis of a complete set of fossilized neck bones from the animal, known as Samotherium major. Samotherium, which lived in the open woodlands of Eurasia about 7 million years ago, had a neck about 1 meter long—about half the length of that of today’s giraffes. (And like the vast majority of mammals, from tiny mice to towering giraffes, it had seven neck vertebrae.)

Some scientists have long presumed today’s giraffe (Giraffa camelopardalis), which includes a handful of subspecies scattered throughout sub-Saharan Africa, evolved from an animal that looked like its close cousin the okapi (Okapia johnstoni), which lives in the tropical forests of central Africa. The team’s analyses of bones from all three animals bolster that notion—and not just because the neck bones are of a length between the giraffe’s and the okapi’s. For example, ridges and other features that are prominent on the okapi’s neck bones and missing entirely on the giraffe’s are typically present but smaller on Samotherium’s, the researchers report online today in Royal Society Open Science.

See also here.

English bird news today

This is a short-eared owl video from Scotland.

By Debby Saunders in England, on Twitter today:

Ferrybridge this morning Short-eared Owl, 5 Curlew, 36 Oystercatcher, Redshank, 14 Pale-bellied Brent [Goose] with 1400 D[ark]-b[ellied] Brent.