Curio Cabinet

Even in the world of paleontology, some things are only obvious in hindsight. A paleontologist recently discovered a new reptile species that lived around 145 million years ago, and he did it just by visiting a couple of museums. In the 1930s, an enterprising—albeit not particularly ethical—individual sold a fossil of an ancient reptile. That would have been fine, except for the fact that they’d cut the original fossil in two and sold the other half to another, unwitting buyer.
 
Decades later, along came paleontology student Victor Beccari, who visited Senckenberg Natural History Museum in Frankfurt, Germany, and the Natural History Museum in London, U.K., both of which were displaying their half of this fossil. Thanks to Beccari’s extremely keen eye and good memory, the fossil halves have now been reunited. Beccari and his colleagues named the “newly” discovered reptile Sphenodraco scandentis, and published their findings in a scientific journal. According to Beccari, S. scandentis belonged to a group of reptiles called rhynchocephalians, from which only one extant species remains, the tuatara. Although the fossil clearly shows a reptile from the Late Jurassic period, it's not a dinosaur. Based on its skeletal structure, which forms a short body with long limbs and long digits, Beccari and his colleagues believe that it was a tree-dwelling lizard.
 
As for why it took nearly a century for anyone to notice that the two fossil halves were related, the one at the Senckenberg Natural History Museum had been misidentified as one belonging to Homoeosaurus maximiliani, another rhynchocephalians found in the same region in southern Germany. It’s also rare for a fossil to be split in two and for each half to retain parts of the skeleton. Usually, one half gets the skeleton and the other only gets an impression of it. No wonder the original buyers had no bones to pick—they thought they were getting it all.

 
[Image description: A fossil of Homeosaurus maximiliani, a species related to the newly discovered Sphenodraco scandentis.] Credit & copyright: Daderot Wikimedia Commons. This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.

How granular do you like your clock to be? When it comes to timekeeping, it doesn’t get nittier or grittier than the aluminum ion atomic clock developed by researchers at the National Institute of Standards and Technology (NIST), according to a paper published in Physical Review Letters. Far from their pendulum or spring-based predecessors, atomic clocks, first invented in 1947, used atoms to keep track of time. Atomic clocks mostly use cesium atoms today, and they work by energizing the atoms with laser light tuned to its resonant frequency to make them “tick.” Early atomic clocks weren’t particularly accurate because the instruments used to measure the frequencies and deliver the light weren’t accurate themselves. Today, though, atomic clocks are so accurate that if they had existed since the beginning of the universe 13.8 billion years ago, they would still be accurate to within one second. The newest atomic clock developed by NIST goes even further using aluminum ions. Despite having the potential to be more accurate, aluminum ions weren’t used before because they don’t react much to lasers. The solution was to pair them with magnesium ions, which don’t have the steady ticking rate of either cesium or aluminum. What they can do is be controlled by lasers and cool down aluminum ions, allowing the laser to interact with the aluminum ions in a process called quantum logic spectroscopy. The result is a clock that can measure time with 19 decimal places of accuracy. Try that with a vintage grandfather clock!

[Image description: A clock face with Roman numerals inside a glass dome atop a wooden stand.] Credit & copyright: Simon Willard, American, 1825–30. The Metropolitan Museum of Art, Gift of Mary B. Walton, in memory of her husband, John S. Walton, 1991. Public Domain.
 

Stroll by a stream this summer, and you’ll almost certainly see these colorful sunbathers…even in places they’re not supposed to be. Red-eared sliders are some of the most common freshwater turtles on the planet, both in the wild and in pet stores, but they’re native only to the southeastern U.S. and northern Mexico. Beloved as they are in many places as a sign of sunny weather, these beautiful turtles wreak havoc as an invasive species in places as far away as Australia.
 
Red-eared sliders are medium-sized, freshwater aquatic turtles. Females are slightly bigger than males, growing to around 12 inches long while males reach average lengths of just nine inches. Like many turtle species, they’re fairly long-lived, with a lifespan of around 30 years in the wild and up to 40 years in captivity. While baby red-eared sliders eat mostly insects, adults eat mostly aquatic plants, but they won’t pass up a chance to eat small fish or scavenge meat if the opportunity arises. Their varied diets make them adaptable to any environment with plentiful water and sunlight. In places with cold winters (including parts of their natural range) they can go into a semi-dormant state called brumation to survive the lower temperatures.
 
As for how these seemingly harmless turtles became worldwide pests, the problem isn’t them—it’s us. Red-eared sliders are named for the bright red stripes on their heads, and they also have bright yellow stripes on the rest of their green bodies, making them attractive pets. In the 1950s and 60s, baby red-eared sliders were sold at many American dime stores en masse as a novelty, and were even shipped through the mail in some places to be cheap pets. While hatchlings are just a few inches long, they quickly grow into adult turtles who need plenty of space and a specialized diet. Rather than adapt to their pet’s needs, some owners instead released them into the wild, even in areas far removed from red-eared sliders’ natural habitats. Today, invasive red-eared sliders can be found on every continent except Antarctica. In places like Japan and Australia, red-eared sliders’ adaptability makes them extremely dangerous, as they upend fragile ecosystems by gobbling up the plants, fish, and insects that native species need to survive. Although conservationists the world over are working to remove the invasive turtles from places they don’t belong, they’ve got a long road ahead of them…and turtles aren’t exactly known for their speed.

 
[Image description: A red-eared slider swimming with its head out of water, surrounded by duckweed.] Credit & copyright: Vassil, Wikimedia Commons.

We might need to redefine what qualifies as hardwood! Fig trees are known for their delicious fruit, but they may soon be useful as a means of carbon sequestration after scientists discovered that they can turn themselves into stone. It’s not exactly news that trees, like all living things, are made out of carbon. Compared to most organisms, though, trees are great at sequestering carbon. They turn carbon dioxide into organic carbon, which they then use to form everything from roots to leaves. Since trees live so long, they can store that carbon for a long time. That’s why, to combat climate change, it’s a good idea to plant as many trees as possible. It’s a win-win, since trees can also provide food and lumber to people and form habitats for other organisms. One tree, however, seems to be a little ahead of the curve. The Ficus wakefieldii is a species of fig tree native to Kenya, and scientists have found that it can turn carbon dioxide into calcium carbonate, which happens to be what makes up much of limestone. Apparently, other fig trees can do this to some extent, but F. wakefieldii was the best at it out of the three species studied.
 
The process is fairly simple. First, the trees convert carbon dioxide into carbon oxalate crystals, and when parts of the tree begin to naturally decay from age, bacteria and fungi convert the crystals into calcium carbonate. Much of the calcium carbonate is released into the surrounding soil, making it less acidic for the tree, but much of it is also stored in the tissue of the tree itself. In fact, scientists found that in some specimens, their roots were completely converted to calcium carbonate. Surprisingly, F. wakefieldii isn’t the only tree capable of doing this. The iroko tree (Milicia excelsa), also native to Africa, can do the same thing, though it’s only used for lumber. Fig trees,on the other hand, can produce food. Either way, carbon minerals can stay sequestered for much longer than organic carbon, so both species could one day be cultivated for that purpose. The real question is, if you wanted to make something from these trees’ wood, would you call a carpenter or a mason?

 
[Image description: A brown, slightly-split fig on a bonsai fig tree.] Credit & copyright: Tangopaso, Wikimedia Commons.