Rare baboons in Zambia, Africa, new research


This 7 December 2017 video from Zambia says about itself:

An American biologist sets out to study the little-known Kinda baboon species – and this involves getting close to them in their natural habitat. Everything is of interest, from their fur patterns to their mannerisms.

Herbivorous dinosaurs, new research


This May 2018 video is called 10 LARGEST Herbivorous Dinosaurs That Ever Lived.

From ScienceDaily:

Dull teeth, long skulls, specialized bites evolved in unrelated plant-eating dinosaurs

December 5, 2019

Herbivorous dinosaurs evolved many times during the 180 million-year Mesozoic era, and while they didn’t all evolve to chew, swallow, and digest their food in the same way, a few specific strategies appeared time and time again. An investigation of the skulls of 160 non-avian dinosaurs revealed the evolution of common traits in the skulls and teeth of plant-eating members of otherwise very different families of these extinct reptiles. These new examples of convergent evolution in plant-eating dinosaurs appear December 5 in the journal Current Biology.

“People often think of dinosaurs as a swansong for extinction or that they were a failed species. But they were actually extremely successful in terms of how different species’ anatomies evolved — particularly in herbivores,” says co-senior author David J. Button (@ItsDavidButton), a paleontologist at the Natural History Museum, London.

By looking at herbivorous and carnivorous dinosaur skulls, Button and co-senior author Lindsay Zanno, a professor at North Carolina State University and the head of paleontology at the North Carolina Museum of Natural Sciences, found that while there are many ways for dinosaurs that eat similar foods to evolve, some traits reappear during evolution, even in unrelated species.

Herbivorous dinosaurs came in all shapes and sizes. Some exhibited dull, flat teeth like horses, while others had beaked faces like tortoises; some developed towering necks like giraffes, while others mimicked the short and stout build of a rhino. “Nonetheless, we see the evolution of common traits in the skull between these otherwise very different herbivorous dinosaur groups,” explains Button.

“For example, both the ostrich-like ornithomimosaurs and giant titanosaurs independently evolved elongate skulls and weaker bites, whereas the horned ceratopsians and gazelle-like ornithopods sported more powerful jaws and grinding teeth,” he says. These are results of convergent evolution, where adaptation to a diet of plants led to the evolution of common characters in different dinosaur groups.

The researchers hypothesized that some traits would be most common in plant-eaters. Slow-moving dinosaurs with small heads and dull teeth would likely have a difficult time wrapping their jaws around the neck of another dinosaur, in the way a carnivore like the Tyrannosaurus is thought to have done with ease. Instead, eating plants poses other challenges, such as grinding down tough plant stems.

“There’s a tradeoff between biting speed and biting efficiency,” says Button. “If you’re a herbivorous animal, you don’t really need speed because plants don’t move very fast.”

Some of the results of this functional analysis surprised the researchers, however. That was the case when investigating the eating habits of ankylosaurs, armored, armadillo-like plant-eating dinosaurs with small teeth and a large stomach cavity. Researchers previously thought dinosaurs with these traits usually swallowed their food nearly whole and let their gut break it down. “In our results, we found that ankylosaurs actually may have chewed their food more thoroughly than is often thought. So, that was interesting,” says Button.

In the future, Button and Zanno hope to look at the entire skeleton of herbivorous dinosaurs for similar, reoccurring traits. They also plan to expand this work to better understand predominate traits in carnivores, though Button admits plant-eaters will always be his favorite dinosaurs to study.

“People think that carnivorous dinosaurs are super exciting and cool because they run fast, and kill stuff,” he says. “But I think the plant-eating dinosaurs evolved in much more interesting and sophisticated ways. That’s what makes this work so exciting.”

Kemp’s ridley turtles beaching in Massachusetts, USA


This 6 December 2016 video from the USA says about itself:

Kemp’s Ridley Sea Turtle Rescue, Cape Cod, MA

I visited a few friends who volunteer saving Kemp’s Ridley Sea Turtles (and others) on the shore of Cape Cod Bay in Massachusetts. Every November, migrant turtles get caught in the bay as they travel South. As the water cools, they become cold-stunned and wash ashore. They need human intervention to rescue them.

Volunteers scour the beaches and get the sea turtles to an aquarium that nurses them back to health and eventually releases them. It’s GREAT work!

90% of the turtles that wash up on Cape Cod are Kemp’s Ridley… the most critically endangered sea turtle in the world. Every single turtle is worth saving and the rescue efforts have been incredible.

The day was amazing and I was honored and privileged to be a part of it. We found three Kemp’s Ridley turtles (two were pronounced dead) and one 88 lb., five-year-old Loggerhead who should do well in rehab! Incredible.

From PLOS:

How do world’s smallest sea turtles become stranded in Cape Cod?

Computer simulations help reconstruct ocean conditions behind stranding

December 4, 2019

A computational analysis has surfaced new insights into the wind and water conditions that cause Kemp’s ridley sea turtles to become stranded on beaches in Cape Cod, Massachusetts. Xiaojian Liu of Wuhan University, China, and colleagues present these findings in the open-access journal PLOS ONE on December 4, 2019.

The Kemp’s ridley sea turtle is smaller and in greater danger of extinction than any other sea turtle in the world. This species is found in coastal waters ranging from the Gulf of Mexico to Nova Scotia, Canada. While Kemp’s ridley populations have slowly risen since conservation efforts began in the 1970s, the number of turtles found stranded on Cape Cod beaches in the last few years is nearly an order of magnitude higher than in earlier decades.

To help clarify the conditions that lead to stranding, Liu and colleagues combined computational modeling with real-world observations. This enabled them to investigate circumstances that could trigger hypothermia in Kemp’s ridley turtles — the primary cause of most strandings — and subsequent transport of the cold-stunned animals to shore.

The researchers used the Finite Volume Community Ocean Model to simulate ocean currents in Cape Cod Bay. To validate these simulations, they also released drifting instruments into the currents and tracked their movements via satellite. Then, they looked for links between the simulations, the drifter data, water temperature data, and records of where and when Kemp’s ridley turtles were found stranded.

The findings suggest that Kemp’s ridley sea turtles are more likely to become stranded at certain beach locations along Cape Cod when water temperatures drop below 10.5° Celsius and, concurrently, winds blow with high wind stress in certain directions. Once stranded, hypothermic turtles usually require assistance from trained volunteers in order to survive.

While these findings provide new insights that could help guide future search and rescue efforts, questions remain. Further research is needed to clarify the depth of water at which Kemp’s ridley sea turtles typically become hypothermic, and how processes like wind and waves may impact stranding events at those depths.

Co-author James Manning notes: “While the state-of-the-art ocean model can help simulate the process, both the student-built drifters and bottom temperature sensors deployed by local fishermen are critical to the investigation.”

Big chromosome discovery in larks


This video is about skylarks singing in Belarus.

From Lund University in Sweden:

Record-size sex chromosome found in two bird species

December 4, 2019

Researchers in Sweden and the UK have discovered the largest known avian sex chromosome. The giant chromosome was created when four chromosomes fused together into one, and has been found in two species of lark.

“This was an unexpected discovery, as birds are generally considered to have very stable genetic material with well-preserved chromosomes,” explains Bengt Hansson, professor at Lund University in Sweden.

In a new study, the researchers charted the genome of several species of lark, a songbird family in which all members have unusually large sex chromosomes. The record-size chromosome is found in both the Eurasian skylark, a species that is common in Europe, Asia and North Africa, and the Raso lark, a species only found on the small island of Raso in Cape Verde.

This 8 May 2018 video, in Portuguese with English subtitles, says about itself:

A new home for the Raso Lark

The Raso Lark (Alauda razae) is confined to the small Raso islet on Cape Verde and it is one of the most threatened birds in the world. Its small population was once reduced to less than 100 birds worldwide! To increase its chances of survival Biosfera 1 joined SPEA and DNA and, with the support of the MAVA Foundation, translocated 37 birds to the neighbour island of Santa Luzia.

The translocation was successful and now we wait for the first breeding signs of this new population.

The Lund University article continues:

“The genetic material in the larks’ sex chromosome has also been used to form sex chromosomes in mammals, fish, frogs, lizards and turtles. This indicates that certain parts of the genome have a greater tendency to develop into sex chromosomes than others,” says Bengt Hansson.

Why the two species have the largest sex chromosome of all birds is unclear, but the result could be disastrous lead to problems for female larks in the future. Studies of different sex chromosome systems have shown that the sex-limited chromosome, for example the Y chromosome in humans, usually breaks down over time and loses functional genes.

“Among birds, the females have a corresponding W chromosome in which we see the same breakdown pattern. As three times more genetic material is linked to the sex chromosomes of these larks compared to other birds, this could cause problems for many genes,” says Hanna Sigeman, doctoral student at the Department of Biology, Lund University.

Horseshoe crab eyes, 400 million years old


This July 2018 video is called What If The Jaekelopterus rhenaniae Didn’t Go Extinct?

From the University of Cologne in Germany:

Compound eyes: The visual apparatus of today’s horseshoe crabs goes back 400 million years

December 3, 2019

The eyes of the extinct sea scorpion Jaekelopterus rhenaniae have the same structure as the eyes of modern horseshoe crabs (Limulidae). The compound eyes of the giant predator exhibited lens cylinders and concentrically organized sensory cells enclosing the end of a highly specialized cell. This is the result of research Dr Brigitte Schoenemann, professor of zoology at the Institute of Biology Didactics at the University of Cologne, conducted with an electron microscope. Cooperation partners in the project were Dr Markus Poschmann from the Directorate General of Cultural Heritage RLP, Directorate of Regional Archaeology/Earth History and Professor Euan N.K. Clarkson from the University of Edinburgh. The results of the study ‘Insights into the 400 million-year-old eyes of giant sea scorpions (Eurypterida) suggest the structure of Palaeozoic compound eyes’ have been published in the journal Scientific Reports — Nature.

The eyes of modern horseshoe crabs consist of compounds, so-called ommatidia. Unlike, for example, insects that have compound eyes with a simple lens, the ommatidia of horseshoe crabs are equipped with a lens cylinder that continuously refracts light and transmits it to the sensory cells.

These sensory cells are grouped in the form of a rosette around a central light conductor, the rhabdom, which is part of the sensory cells and converts light signals into nerve signals to transmit them to the central nervous system. At the centre of this ‘light transmitter’ in horseshoe crabs is a highly specialized cell end, which can connect the signals of neighbouring compounds in such a way that the crab perceives contours more clearly. This can be particularly useful in conditions of low visibility under water. In the cross-section of the ommatidium, it is possible to identify the end of this specialized cell as a bright point in the centre of the rhabdom.

Brigitte Schoenemann used electron microscopes to examine fossil Jaekelopterus rhenaniae specimens to find out whether the compound eyes of the giant scorpion and the related horseshoe crabs are similar or whether they are more similar to insect or crustacean eyes. She found the same structures as in horseshoe crabs. Lens cylinders, sensory cells and even the highly specialized cells were clearly discernible.

‘This bright spot belongs to a special cell that only occurs in horseshoe crabs today, but apparently already existed in eurypterida,’ explained Schoenemann. ‘The structures of the systems are identical. It follows that very probably this sort of contrast enhancement already evolved more than 400 million years ago,’ she added. Jaekelopterus most likely hunted placoderm[i fish]. Here, its visual apparatus was clearly an advantage in the murky seawater.

Sea scorpions, which first appeared 470 million years ago, died out about 250 million years ago, at the end of the Permian age — along with about 95 percent of all marine life. Some specimens were large oceanic predators, such as Jaekelopterus rhenaniae. It reached a length of 2.5 meters and belonged to the family of eurypterida, the extinct relatives of the horseshoe crab. Eurypterida are arthropods, which belong to the subphylum Chelicerata, and are therefore related to spiders and scorpions.

Among the arthropods there are two large groups: mandibulates (crustaceans, insects, trilobites) and chelicerates (arachnid animals such as sea scorpions). In recent years, Schoenemann has been able to clarify the eye structures of various trilobite species and to make decisive contributions to research into the evolution of the compound eye. ‘Until recently, scientists thought that soft tissues do not fossilize. Hence these parts of specimens were not examined until not so long ago’, she concluded.

The new findings on the eye of the sea scorpion are important for the evolution of the compound eyes not only of chelicerates, but also for determining the position of sea scorpions in the pedigree of these animals and for the comparison with the eyes of the related group of mandibulates.

Brontosaurus dinosaur video


This 1 December 2019 video says about itself:

Brontosaurus – The Story of the Thunder Lizard

The history of Brontosaurus is one of the most fascinating tales in palaeontology, full of controversies, missing heads and charismatic yet unpleasant people.

Indonesian coral reefs video


This 12 November 2019 video says about itself:

Indonesia’s Coral Reefs

In the second installment of National Geographic’s “Into Water” 360 series, dive into the crystal clear waters of Indonesia with marine social ecologist and National Geographic Explorer Shannon Switzer Swanson. More than a quarter of the world’s aquarium fish population comes from Indonesia. Shannon works with local communities, documenting fishing practices. She is hoping to learn why some fishing families have developed sustainable practices while others have not. “Into Water: Indonesia” is the second stop on an around the world 360 tour that documents the work of female Explorers who’ve dedicated their careers to water-related issues.