Surprising Animals Old and New
Moving creatures, whether extant or extinct, never cease to hold fascination for human observers.
How small can a frog get? “Absurdly tiny frogs” have been found in Brazil, Live Science reports. Smaller than a thumbnail, some are brightly-colored, while others are camouflaged; “they come in a jellybeanlike array of bright colors,” Jeanna Brynner writes. They live deep in the remote, misty rainforest where other species likely remain to be discovered.
Silver ants deflect heat: How can ants in the Sahara desert, where surface temperatures can soar to 158° F, survive? Science Daily says that “they must keep their body temperature below their critical thermal maximum of 53.6°C (128.48°F) most of the time.” Their secret is with silvery hairs that cover their bodies. Triangular in cross-section, these tiny hairs deflect heat over a wide spectrum into the infrared range, allowing them to shed heat and keep their cool even as they scurry at 0.7 meters per second across the sand, looking like little drops of mercury racing across a smooth surface. The heat-shedding properties of these hairs could give architects ideas. “Such biologically inspired cooling surfaces will have high reflectivity in the solar spectrum and high radiative efficiency in the thermal radiation spectrum,” Yanfang Yu [Columbia U] explains. “So this may generate useful applications such as a cooling surface for vehicles, buildings, instruments, and even clothing.” See also New Scientist and Science Magazine.
Shark buoyancy: Sharks don’t have air bladders like bony fish do, so how do they keep from sinking? “Unlike other fish, which inflate air bladders to adjust their buoyancy on the fly, sharks rely on a skeleton of cartilage and a liver filled with lighter-than-water oil to help beat gravity’s pull,” Science Magazine explains. This should normally allow them to park without rising or falling. Two deep-sea sharks have been discovered with a slight negative buoyancy, researchers have found. They were observed to spontaneously rise without beating their fins. “This propensity to rise could be an adaptation that allows the sharks to sneak up on prey from below, the team writes, or merely a way to allow muscles to relax after a day spent hunting for meals in colder, deeper water.”
Jellyfish repair: Certain jellyfish called moon jellies can rearrange themselves within a few days if they lose an arm, restoring their original symmetry. They do this using a mechanically-driven reorganization process, a team of international researchers reported in PNAS. “This unique strategy of self-repair, which we call symmetrization, requires mechanical forces generated by the muscle-based propulsion machinery,” they say with an engineer’s gleam in their eye: “Beyond biology, this finding may inspire a mechanically driven, self-organizing machinery that recovers essential geometry without regenerating precise forms.” National Geographic added some emotion to “the surprising way jellyfish put themselves back together,” quoting a Caltech biologist yelling to his colleagues, “You won’t believe this, you’ve got to come here and see what’s happening.” Science Daily shows pictures of the restored symmetry. NG includes a video clip of the graceful swimmers you can watch to de-stress.
Starfish repair: Speaking of repair, starfish have “a surprising talent for squeezing foreign bodies out through the skin,” Science Daily reports from research at the University of Southern Denmark. “Two biology students have revealed that starfish are able to squeeze foreign bodies along the length of their body cavities and out through their arm tips,” the article says. “This newly discovered talent gives insight into how certain animals are able to quickly heal themselves.” See? There are new discoveries students can make. Wouldn’t be nice if humans could regenerate lost arms or livers? “Previous research has documented that starfish are able to regenerate whole limbs and organs, but this trick of ejecting deeply embeded [sic] foreign bodies has never before been demonstrated in any organism.”
Bat focus: PhysOrg printed another article on bat sonar, “How bats fly to find their prey.” One fact that stands out is that bats have noise filters. To echolocate in their noisy environment, they have to be able to tune out other bats, wind, weather, and even the sounds of their own wings. (And yes, they can use their eyes to see in daytime, when they tend to fly straight.) “Bats are able to filter out the ambient noise around them using low-pass filtering. Useless sounds are cleared out, which makes conditions more transparent,” Nadav Bar explains. “The bat also has a highly developed sensorimotor system, which controls the mammal’s movements. These characteristics enable the bat to move quickly and with incredible precision.” Incidentally, another species of fossil bat was found in New Zealand. It appears to have used its wings for walking on the ground part of the time, Science Daily reports. In all other respects, it was just as good a flying echolocator as extant members of its genus. And a new paper in PNAS describes how certain bats are able to widen their sonar beams by emitting high-intensity clicks. “Thus, beam broadening is not a general property of echolocation, but we hypothesize that maintaining a broad acoustic field of view is crucial for all echolocators hunting moving prey.”
Butterfly poetry: A BBC News Magazine article waxes philosophical, asking, “Do butterflies hold the answer to life’s mysteries?” The article reviews some of the ways artists, poets and theologians have been inspired by the winged beauties, and how scientists are uncovering the secrets of their life habits. The anonymous author found a way to apply the subject to the politics of climate change.
Plant-eating theropod dinosaur: Nature reported “An enigmatic plant-eating theropod from the Late Jurassic period of Chile.” If you thought all theropods are carnivores, think again: this is the third known species of theropod that switched from carnivory to herbivory, the discoverers believe. “The bizarre anatomy of Chilesaurus raises interesting questions about its phylogenetic relationships,” the authors say as they begin to puzzle over where to put it. “For a basal tetanuran, Chilesaurus possesses a number of surprisingly plesiomorphic traits [convergences] on the hindlimbs, especially in the ankle and foot, which resemble basal sauropodomorphs.” Sauropods like Brontosaurus were very different from theropods.
Museum of the bizarre: Charlotte Stephenson [U of Hull] posted a list of “Five amazing extinct creatures that aren’t dinosaurs” on The Conversation, along with artist renderings, including the “which-way-is up?” Hallucigenia from the Cambrian explosion, a two-foot scorpion from Scotland, a tiny horse from Germany, and a spiral-lipped Permian shark. Artistic license should always be questioned, such as in the rendering of Tiktaalik and its description as a “part fish, part four-legged animal.” Stephenson glosses over Darwin’s Doubt by saying the Cambrian was a time “when complex lifeforms started to rapidly evolve.” Why that statement cannot stand up to the evidence is explained in Illustra’s film about the Cambrian fossil record, Darwin’s Dilemma.
Illustra’s new film on marine biology, Living Waters, is going to pose severe challenges to evolutionary theory on several fronts. It also puts up on the big screen some of the most beautiful shots of marine animals anywhere, including some mentioned in these articles (e.g., jellyfish, sharks and bony fish). It will be a film to shut the mouths of the Darwin defenders who speak recklessly about what mutation and selection can achieve. It’s just now being replicated to DVD; Blu-ray editions will be available soon. Plan to get a copy and look for ways to get it shown to reasonable people; it could be a game-changer.