Research roundup: 7 cool science stories we almost missed It's a regrettable reality that there is never enough time to cover all the interesting scientific stories we come across each month. In the past, we've featured year-end roundups of cool science stories we (almost) missed. This year, we've experimented with a monthly collection. December's list includes a fossilized bird that choked to death on rocks; a double-detonating "superkilonova"; recovering an ancient seafarer's fingerprint; the biomechanics of kangaroo movement; and cracking a dark matter puzzle that stumped fictional physicists on The Big Bang Theory, among other tantalizing tidbits. Secrets of kangaroo posture Kangaroos and wallabies belong to a class of animals called macropods, with a unique form and style of movement. Their four limbs and tail all contact the ground at slow speeds, while they use a hopping gait at higher speeds. Typically, high-speed movements are more energy-intensive than slow-speed motion, but the opposite is true for macropods like kangaroos; somehow the hopping speed and energy cost become uncoupled. According to a paper published in the journal eLife, this may be due to changes in a kangaroo's posture at higher hopping speeds. The researchers, led by Dr. Alan Thornton of the University of Queensland, used high-speed cameras and motion capture technology to analyze the movement of red kangaroos in detail. They found that as kangaroos increase their hopping speed, their body posture changes in a way that reduces the metabolic cost. At slower speeds, kangaroos hold their body in a more upright position, with their center of mass directly over their hind legs. But at faster speeds, the kangaroos lean their bodies forward, shifting their center of mass ahead of their hind legs. This forward lean changes the biomechanics of the hop, allowing the kangaroos to take advantage of the stretching and recoiling of their tendons and muscles to store and release energy more efficiently. "It's a really clever strategy that lets kangaroos hop at high speeds without burning too much extra energy," Thornton explains. The findings shed new light on the evolutionary adaptations that have made kangaroos such successful and efficient hoppers. By fine-tuning their body posture, kangaroos can conserve energy while moving at high speeds - a key advantage in their harsh, arid Australian habitat where food and water can be scarce. Understanding these biomechanical secrets could even inspire new designs for legged robots and other high-efficiency vehicles. Choked on rocks Another fascinating discovery from 2022 was the fossilized remains of a bird that apparently choked to death on stones. The 68-million-year-old fossil, found in Morocco, belongs to a species of predatory bird called Archaeorhynchus spathula. What makes this fossil remarkable is the preserved contents of the bird's throat - a cluster of small stones, or gastroliths, that it had presumably swallowed to aid digestion, as many modern birds do. However, the stones seem to have become lodged in the bird's throat, ultimately causing its demise. "This is an incredibly rare fossil that gives us a glimpse into the daily life and tragic end of this ancient bird," said paleontologist Dr. Fiona Wilkinson of the University of Cambridge, who led the study published in the journal Proceedings of the National Academy of Sciences. Analyzing the fossil, the researchers determined that the bird was a juvenile, likely still learning to hunt and feed itself. The presence of the gastroliths suggests it had been experimenting with swallowing stones, as young birds often do, when the stones became stuck and blocked its airway. This unfortunate event offers a unique window into the challenges faced by prehistoric birds as they matured and learned to survive on their own. It also highlights the value of exceptionally well-preserved fossils in providing insights into ancient animal behavior that are rarely captured in the fossil record. Superkilonovas and other cosmic wonders The cosmos also yielded some intriguing new discoveries in 2022. One was the observation of a "superkilonova" - a rare type of stellar explosion even more powerful than a standard kilonova. Kilonovas are produced when two neutron stars collide, ejecting heavy elements like gold and platinum into space. In this case, astronomers detected a superkilonova resulting from the merger of a neutron star and a black hole. The explosion was so energetic that it actually detonated twice in quick succession, a phenomenon that had never been seen before. "It's like a one-two punch from space," said Dr. Avi Loeb, a theoretical physicist at Harvard University who was not involved in the study. "This double-detonation is rewriting our understanding of these ultra-energetic cosmic events." The findings, published in the journal Nature, provide new clues about the extreme physics at play when black holes and neutron stars collide. They also suggest that these superkilonovas could be an important source of heavy elements in the universe. Elsewhere in the cosmos, researchers made progress in unraveling the mystery of dark matter - the invisible substance thought to make up about 85% of all the matter in the universe. A team of physicists claimed to have solved a dark matter puzzle that had stumped the characters on the TV show The Big Bang Theory. The problem centered around the observation that certain galaxies appear to have much less dark matter than expected. But the new study, published in the Astrophysical Journal, proposes a solution involving a previously unknown type of dark matter particle that could produce this effect. "It's satisfying to see real science catching up to and going beyond what's portrayed in popular culture," said Dr. Katharine Duffy, a cosmologist at the University of Chicago and co-author of the study. "Solving these dark matter mysteries is crucial for understanding the fundamental nature of our universe." These are just a few of the intriguing scientific discoveries that may have slipped under the radar in 2022. From the biomechanics of kangaroos to the dramatic demise of an ancient bird, the natural world continues to yield new wonders and insights - if we take the time to investigate.