Over 200 million years ago, nature called. It was full of beetles.
News and notes about science
Imagine a bunch of beetles minding their own business on an algae-covered rock. All of a sudden, they get hoovered up whole into the beak of a slim, long-necked dinosaur ancestor. RIP — but on the bright side, through a complex combination of luck and microbial activity, their tiny corpses become frozen in time. And over 200 million years later, scientists uncover them while rooting around in fossilized feces.
These coprolites, as they’re called, can provide extraordinarily detailed insight into longlost ecosystems, according to new research published in Current Biology. A team of researchers found nearly unscathed beetles, now extinct, that are new to science, suspended inside a piece of excrement from the Triassic Period. The scientists suspect that the waste belonged to Silesaurus opolensis, a close relative of dinosaurs that lived about 230 million years ago.
“We decided to look at coprolites to try to understand who ate whom in this ecosystem,” said the paper’s lead author, Martin Qvarnstrom, a paleontologist at Uppsala University in Sweden. “And in one of the fragments of coprolites, all these beetles popped up.”
The coprolite was collected near the village of Krasiejow in southern Poland, at a quarry where remains of S. opolensis and other Late Triassic vertebrates have been excavated.
“We have been discovering over time that coprolites can provide fossil evidence for ancient organisms that are not often otherwise preserved,” said Karen Chin, a paleontologist at the University of Colorado, Boulder, who was not involved in the study.
But looking inside coprolites can be difficult, Qvarnstrom said. So the researchers took this specimen to the European Synchrotron Radiation Facility in France to scan its contents and render them in 3D.
“I was so blown away by how well these things were preserved,” said Sam Heads, curator of paleontology at the Illinois Natural History Survey, who was not involved in the study.
The researchers determined that the new species and genus, Triamyxa coprolithica, belongs to an extinct and previously unidentified family in a lineage of small beetles, Myxophaga, that today tend to live around algal mats. According to the authors, this is the first insect species described in the fossilized feces of a vertebrate animal.
As for how some beetles made it through the animal’s gut without much damage, Qvarnstrom thinks there are a few possibilities. The beetles were tiny, and might have been accidentally sucked up en masse by a Silesaurus opolensis; they also seem to have been well-defended by their exoskeleton, like modern beetles. The ones who weren’t chewed up still probably died quickly, Qvarnstrom said. “They didn’t have to suffocate in the poop.”
— Ellie Shechet
A new kind of ice that bends like a noodle without breaking
Ice is rigid and brittle — it would be astonishing to bend an icicle around a softball and have it spring back to its original straight shape. But that’s what researchers have now done, although on a much smaller scale.
They produced microscopic ice crystals that are not only elastic and flexible but that also transmit light remarkably well along their lengths. These “ice microfibers” could one day be used to study air pollution, the research team suggested in a paper published this month in Science.
Limin Tong, a physicist at Zhejiang University in China, and his colleagues said they were inspired to study ice after working with a type of silica glass. Everyday experience teaches us that glass shaped into windows or drinking vessels is brittle, Tong said. But long, thin pieces of glass, like fiber optic strands, are flexible. Maybe the same is true of ice, the researchers hypothesized.
Tong and his colleagues needed to make frozen water that matched very particular specifications.
The team began by making a circular chamber just over an inch in diameter in a 3D printer. Using liquid nitrogen, they cooled the space within the chamber to negative 58 degrees Fahrenheit. They then inserted tiny tools into this miniature laboratory, including a metal needle with 2,000 volts of electricity applied to it. That voltage created an electrical field, and water molecules present in the air responded to the field by settling on the needle. Very slowly, at a rate of roughly a hundredth of an inch per second, rodlike microfibers of ice grew from the tip of the needle.
The microfibers never got very long — they could barely be seen with the naked eye — but high-resolution imaging revealed that they were single crystals. That means that the atoms within them are arranged in repeating patterns. “The atoms are ordered like honeycombs,” Tong said.
This structural perfection renders them much more flexible than naturally occurring ice, said Erland Schulson, an ice scientist at Dartmouth College, who was not involved in the research.
To demonstrate that flexibility, Tong and his colleagues showed that the ice could be bent like a cooked noodle into almost complete circles before returning, unchanged, to its original rodlike shape. “There was no permanent deformation,” said Schulson, who wrote a perspective article that accompanied the study in Science.
By building a microfiber from polluted ice and studying how light propagates through it, it may be possible to better understand the amount and type of pollution in a region, the team suggests.
— Katherine Kornei
These plants act like bees in a hive
On a hike on Australia’s Lord Howe Island, K.C. Burns came across a cluster of staghorn ferns. They are common potted plants, but in nature they grow in dense colonies that cling to treetops. In the volcanic island’s stunted forest, those treetops are right at eye level.
“I almost looked beyond it,” said Burns, a biologist at Victoria University of Wellington in New Zealand. Then he peered closer and realized the plants within the colony were doing different jobs to survive. Ferns growing higher up had waxy fronds that seemed to direct rainwater into the colony’s center. Farther down, ferns grew spongier leaves that were damp to the touch. Some plants weren’t reproducing at all — they seemed to have dedicated their lives to collecting water for their neighbors’ entangled roots.
It struck Burns that the ferns were working together as a kind of superorganism, perhaps like bees in a hive.
“I sat down and thought, oh, my God,” he said. In a paper published last month in Ecology, Burns and his co-authors argued that colonies of the staghorn fern Platycerium bifurcatum show a kind of collective behavior known as eusociality. Until now, scientists had only recognized eusociality in some species of animals like bees or ants that live in colonies and divide their labor.
To measure how ferns divided labor, the researchers sampled plants growing at different heights within 24 colonies. They counted two types of leaves on each plant. One type, which they called nest fronds, are rounded and mostly brown, clasping the tree like cupped hands. The other fronds, long, green and forked like antlers, can grow spores on their undersides that will become the next generation of ferns.
Plants closer to the top of each colony had more spore-bearing fronds. Plants near the bottom had more of the cupped, non-reproducing nest fronds. About 40% of individual plants weren’t reproducing at all, like worker bees.
Next the scientists cut out wedges from nest fronds, dried them, then soaked them in water to measure how much they sopped up. They found that nest fronds from the bottom of a colony were more absorbent.
When researchers analyzed DNA from 11 fern colonies, they found that most plants within a colony were as closely related as possible: They were clones. New plants arise from buds in the root systems of others, Burns said.
Being clones “means that the different individuals have aligned interests genetically,” said Guy Cooper, an evolutionary biologist at the University of Oxford. By helping a neighboring clone, a plant is also helping its own genes survive.
— Elizabeth Preston
Shrinking elephants once called Sicily home
Elephants today are confined to the African and Asian continents. But their extinct relatives once roamed far and wide across the planet. When they settled onto islands, some species’ evolutionary course changed direction in a dramatic fashion.
In a paper published this month, scientists found clues to just how much island living can rapidly alter the evolution of these animals. “Evolution on islands is a quite intriguing field of science, since it can be seen as an experiment of nature or evolution in action,” said Sina Baleka, the paper’s lead author and a paleogeneticist at Mcmaster University in Canada. She and her co-authors hope their findings can offer insights into how species living today are affected by geographic isolation on islands and in other habitats.
Evidence of smaller versions of extinct elephants has been found worldwide. Fossils of elephant species on islands off California and Siberia as well as in the Mediterranean and Indonesia show that these giants became much, much smaller. In some cases, these dwarves evolved down to the size of a large horse.
But much remains to be learned about how many millenniums of evolution it may take for mammals as massive as elephants to shrink to a horselike size. To make sense of this mystery, the scientists focused on fossils of a species of dwarf elephant from Sicily. The fossils were excavated in the late 19th century from the Puntali Cave, not far from the city of Palermo, and are believed to be 50,000 to 175,000 years old.
Baleka and her colleagues used a variety of techniques to study the rate at which the species’ ancestors became dwarves, including paleogenetics, paleontology, geochronology and different dating methods.
“We were able to define the dwarfing rate with much more accuracy than any source of evidence in isolation,” said Johanna L.A. Paijmans, a co-author and paleogenomics fellow at the University of Cambridge.
At the higher end, that rate was less than 352,000 years. But it might have occurred within 1,300 years, which equates to “about 40 generations” of elephants, said Victoria Herridge, a co-author and evolutionary biologist at the Natural History Museum, London.
Ancient DNA from the Puntali elephant’s fossilized petrous bone indicated it descended from a mainland counterpart, Palaeoloxodon antiquus, around 400,000 years ago. Those beasts weighed an estimated 10 tons each and were about 12 feet tall.
Descendants of the large elephants that colonized Sicily were almost 6.5 feet smaller, and almost 8 tons lighter. That change is comparable, the authors wrote, to a human becoming the size of a Rhesus monkey.