Big Triassic fossil fish discovered in Nevada, USA


Possible look of the newly discovered predatory fish species Birgeria americana with the fossil of the skull shown at bottom right. Artwork: Nadine Bösch

From the University of Zurich in Switzerland:

Large-mouthed fish was top predator after mass extinction

July 26, 2017

Summary: The food chains recovered more rapidly than previously assumed after Earth’s most devastating mass extinction event about 252 million years ago as demonstrated by the fossilized skull of a large predatory fish called Birgeria americana discovered by paleontologists from the University of Zurich in the desert of Nevada.

The most catastrophic mass extinction on Earth took place about 252 million years ago — at the boundary between the Permian and Triassic geological periods. Up to 90 percent of the marine species of that time were annihilated. Worldwide biodiversity then recovered in several phases throughout a period of about five million years. Until now, paleontologists have assumed that the first predators at the top of the food chain did not appear until the Middle Triassic epoch about 247 to 235 million years ago.

Unexpected find of a large predatory fish

Swiss and U.S. American researchers led by the Paleontological Institute and Museum of the University of Zurich have discovered the fossil remains of one of the earliest large-sized predatory fishes of the Triassic period: an approximately 1.8-meter-long primitive bony fish with long jaws and sharp teeth. This fish belongs to a previously unknown species called Birgeria americana. This predator occupied the sea that once covered present-day Nevada and the surrounding states already one million years after the mass extinction.

Triassic “Jaws

In the United States, almost no vertebrate fossils from the Early Triassic epoch (252 to 247 million years ago) have been scientifically described until now. “The surprising find from Elko County in northeastern Nevada is one of the most completely preserved vertebrate remains from this time period ever discovered in the United States,” emphasizes Carlo Romano, lead author of the study. The fossil in question is a 26-centimeter-long partial skull of a fierce predator, as evidenced by three parallel rows of sharp teeth up to 2 centimeters long along the jaw margins, as well as several smaller teeth inside the mouth.

Birgeria hunted similarly to the extant great white shark: the prey fish were pursued and bitten, then swallowed whole. Species of Birgeria existed worldwide. The most recent discovery is the earliest example of a large-sized Birgeria species, about one and a half times longer than geologically older relatives.

Predators appeared earlier than assumed

According to earlier studies, marine food chains were shortened after the mass extinction event and recovered only slowly and stepwise. In addition, researchers assumed that the ancient equatorial regions were too hot for vertebrates to live during the Early Triassic. Finds such as the newly discovered Birgeria species and the fossils of other vertebrates now show that so-called apex predators (animals at the very top of the food chain) already lived early after the mass extinction. The existence of bony fish close to the equator — where Nevada was located during the Early Triassic — indicates that the temperature of the sea was a maximum of 36°C. The eggs of today’s bony fish can no longer develop normally at constant temperatures above 36°C.

“The vertebrates from Nevada show that previous interpretations of past biotic crises and associated global changes were too simplistic,” Carlo Romano says. Despite the severity of the extinctions of that time and intense climatic changes, the food webs were able to redevelop faster than previously assumed.

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Rembrandt’s drawings online


Rembrandt, The Pancake Woman, from the Rijksmuseum Amsterdam collection

From the Rijksmuseum in Amsterdam, the Netherlands:

Drawings by Rembrandt

Biblical and genre scenes, figure and animal studies, landscapes and portraits: an impressive selection of 64 drawings by the master that demonstrate his profound skill and penetrating psychological insight.

See all the works included in this catalogue.

Each entry can be found by scrolling down on the artwork page and clicking on ‘Catalogue entry’ below the image.

This online catalogue, an update of Peter Schatborn’s 1985 collection catalogue Tekeningen van Rembrandt, zijn onbekende leerlingen en navolgers/Drawings by Rembrandt, his Anonymous Pupils and Followers, features 58 sheets now considered genuine drawings by Rembrandt (1606–1669) in the Rijksprentenkabinet; with autograph versos, the tally comes to 64 drawings. If our holdings constitute only a fraction of Rembrandt’s surviving drawings, they provide a representative selection from his whole career.

The first seven drawings by Rembrandt to enter our collection – including the genre masterpiece The Pancake Woman – came through the Vereniging Rembrandt, a society founded by private individuals to save works for the nation from the 1883 sale of Jacob de Vos Jbzn. Nearly half of the collection comes from the 1906 donation of Dr Cornelis Hofstede de Groot, briefly director of the Rijksprentenkabinet, whose comprehensive catalogue of Rembrandt drawings appeared in the same 300th anniversary year. His bequest includes Three Scribes (a study for the artist’s most important early painting) on the verso of the beautiful Study of a Woman’s Legs. The rare early Self-portrait belongs to another major gift, the bequest of Mr and Mrs I. de Bruijn-van de Leeuw, which arrived in 1961. Outstanding purchases in recent decades are the Studies for the Sick Woman in the ‘Hundred Guilder Print’ and the Cottage with White Paling among Trees, both connected to etchings by the artist. The only acquisition to post-date Schatborn’s 1985 catalogue, Portrait of the Actor Willem Bartholsz Ruyter, was completely unknown before a photocopy of it was sent to him for his opinion in 1995.

In the coming months, this online catalogue will be augmented with texts on drawings by named artists from the school of Rembrandt, as well as those by anonymous pupils and followers.

See also here.

New lantern shark species discovery


This video says about itself:

23 December 2015

In the Pacific Ocean, near the coasts of Costa Rica, Panama and Nicaragua, scientists discovered a new species of shark: Ninja Lanternshark. The species was named Etmopterus benchleyi, in honor of Peter Benchley, author of Jaws. Etmopterus benchleyi is a small shark, growing up to 50 cm, and lives at depths ranging between 836 and 1443 meters. In the darks of the ocean, Etmopterus benchleyi emits a faint glow.

And now, a relative of this small luminescent shark has been found.

From Florida Atlantic University in the USA:

New shark species glows in the dark, weighs about 2 pounds and has a huge nose

July 25, 2017

Summary: Just as “Shark Week” is gearing up, researchers have discovered a new species of shark 17 years in the making. Like finding a needle in a haystack, it was well worth the wait as this elusive creature is yet to be seen in the wild.

Like finding a needle in a haystack, a team of scientists has discovered a new species of shark measuring less than a foot long and weighing under 2 pounds full-grown. This miniature, “glow-in-the-dark” shark is a member of the Lanternshark family (Squaliformes: Etmopteridae), which was serendipitously found 1,000 feet below the Pacific Ocean off the coast of the Northwestern Hawaiian Islands. It has taken more than 17 years to identify this new species (Etmopterus lailae) since it was first discovered but was well worth the wait as this elusive creature is yet to be seen in the wild.

It often takes many years to identify a new species from the time it is discovered to the moment the news is shared with the scientific community. Results of the discovery of Etmopterus lailae were published in the journal Zootaxa. Stephen M. Kajiura, Ph.D., study co-author, a professor of biological sciences and director of the Elasmobranch Research Laboratory in the Charles E. Schmidt College of Science at Florida Atlantic University, is among the team of scientists who painstakingly worked on this project, which began while he was still in graduate school at the University of Hawaii.

“There are only about 450 known species of sharks worldwide and you don’t come across a new species all that often,” said Kajiura. “A large part of biodiversity is still unknown, so for us to stumble upon a tiny, new species of shark in a gigantic ocean is really thrilling. This species is very understudied because of its size and the fact that it lives in very deep water. They are not easily visible or accessible like so many other sharks.”

At first, Kajiura and his collaborators did not realize that they had discovered a new species until they submitted their research findings to a journal. The reviewer told them that the shark was not what they originally thought it was and that it might be a new species. Kajiura worked with David A. Ebert, Ph.D., study author, a taxonomist and program director of the Pacific Shark Research Center at Moss Landing Marine Laboratories in California, to identify this new species, now housed in the Bernice P. Bishop Museum in Hawaii.

Identifying the Etmopterus lailae required an extensive list of measurements, diligent categorization and thorough comparisons with other museum specimens.

“The unique features and characteristics of this new species really sets it apart from the other Lanternsharks,” said Kajiura. “For one thing, it has a strange head shape and an unusually large and bulgy snout where its nostrils and olfactory organs are located. These creatures are living in a deep sea environment with almost no light so they need to have a big sniffer to find food.”

Some of the other distinctive characteristics of this new species are its flank markings that go forward and backward on their bellies, a naked patch without scales on the underside of its snout, as well as internal differences such as the number of vertebrae they have as well as fewer teeth than the other sharks. Like other Lanternsharks, the Etmopterus lailae is bioluminescent and the flanks on the bottom of its belly glow in the dark. These markings on its belly and tail also were specific to this new species.

There are a number of hypotheses for why Lanternsharks glow in the dark including mate recognition to ensure they are mating with the right species, serving as a form of camouflage to protect them from predators in the deep sea and using bioluminescence to act as a lure to attract little fish or shrimp.

“The research team’s discovery of a new shark species is evidence of how much is still undiscovered in our world,” said Ata Sarajedini, Ph.D., dean of FAU’s Charles E. Schmidt College of Science. “This new species is the tip of the iceberg for what else might be out there and the great potential for all of the yet-to-be undescribed species that still need to be explored.”

The team of scientists also include Yannis P. Papastamatiou, Ph.D., Florida International University and Bradley M. Wetherbee, Ph.D., University of Rhode Island.

In 2000, Kajiura and Wetherbee discovered the Trigonognathus kabeyai or the Viper Dogfish in Hawaii, which also is part of the Lanternshark family. The Viper Dogfish’s distinctive feature is its snake-like mouth filled with crooked nail-like teeth that sets them apart from other Lanternsharks.

American red squirrel eats potato chips


This video from the USA says about itself:

Red Squirrel Loves Spicy Potato Chips – A Documentary

26 July 2017

One Red Squirrel craves hot red pepper potato chips – a mini-documentary on how Backyard creatures respond to the introduction of something new into their environment. Just a two-day experiment.