You are currently browsing the tag archive for the ‘sabre’ tag.
Back in 2011, as the space shuttle program wound down, Ferrebeekeeper published what seemed like an elegy to spaceplanes—mixed-use vehicles capable of operating both as spacecraft and aircraft (most notably the space shuttles). The dwindling national interest in science and exploration once seemed to indicate that the shuttle program would be the last spaceplane program for a long time. However, as the United States abandons its interest in cutting-edge Aerospace projects, other nations and private interests are picking up the slack.
Skylon is a British spaceplane concept from a private company, Reaction Engines Limited. During the eighties, Rolls Royce and British Aerospace, poured money and knowledge into the creation of a vehicle named HOTOL (an awkward acronym which stands for HOrizontal TakeOff and Landing). Although huge amounts of human energy went into HOTOL, it was canceled because of lack of funding. Reaction Engines Limited is trying to build on the extensive HOTOL designs.
Skylon certainly has a futuristic look. It has a long slender needle-like fuselage with stubby delta wings sticking out midway. Each of these wings is mounted at the end with a SABRE (Synthetic Air Breathing Engine). These next-generation engines are the real key to achieving single-stage-to-orbit spaceflight (a milestone which has long proven elusive for space engineers). Ideally the plane could take off from a runway and speed up to Mach 5.4 as it left the atmosphere and entered orbit. After deploying its payload it could then glide back down to Earth like a normal plane.
Skylon would be constructed of a carbon fiber frame with heat resistant ceramic tiling and it would employ liquid hydrogen as a fuel to loft its 82 meter long (269 ft) body into near-space (before switching to internal liquid oxygen as it left the atmosphere). Like HOTOL before it, Skylon was stuck in funding purgatory for a long time, but recently a huge chunk of funding became available to test the viability of the various systems. These tests were successfully completed in November of 2012 and Reaction is now moving forward with the building of Skylon.
Skylon is designed to be vastly cheaper than the shuttle or any current rocket programs (and it would cut down on space debris). Engineers estimate that one of the crafts could be ready to launch again in only two days after a successful landing (as opposed to the shuttle which required months of refitting). Let’s hope the technology works out. Although unmanned interplanetary craft are accomplishing great things, it has been too long since there was a flashy achievement
During the Mesozoic, the age of dinosaurs, mammals were widespread, but they kept a low profile so as to avoid the baleful attention of the great reptiles. A fossil of one of these furtive early mammals was discovered last November (2011) in Argentina. The creature was christened as Cronopio dentiacutus, and not only does the animal’s partial skull give us a window into mammalian form in the late Cretaceous it also provides a special treat for regular readers of Ferrebeekeeper, for like the Smilodon, the walrus, and the Odobenocetops, Cronopio has distinctly pronounced saber teeth (despite being a small scurrying squirrel-like creature).
Cronopio dentiacutus was probably actually more shrew-like than squirrel-like and used its saber teeth for hunting insects. Based on its large eye sockets, Cronopio most likely hunted its prey at night (when it could also more easily escape the attention of the dinosaurs and other larger predators.
Cronopio dentiacutus takes its species name from a Greek phrase meaning sharp teeth, but the origin of its genus name is rather more literary. The Argentine surrealist writer Julio Cortázar wrote several books about abstracted categories of fictional entities and the Cronopio was the idealistic but disorganized type of being (as opposed to rigid, highly-organized “famas” and indolent, dull “esperanzas”). It is unclear what creative/idealistic features of this insectivorous early mammal struck the fancy of the discovering paleontologist to provoke such a name, but it is nice to see scientists pay Argentine belles-lettres such an acknowledgement.
Continuing our series of posts about saber toothed mammals we come to a second family of living creatures. Half way between the primitive chevrotains (mouse deer) and the familiar true deer (cervids) are the Moschidae, a family of small artiodactyls consisting of one genus with several similar species. The musk deer are small delicate grazers which live in the forested mountains or alpine scrubland of Asia. Musk deer weigh between 7 and 17 kilograms (15 and 37 lb) depending on gender, age, and species. Unlike true deer, the little creatures lack antlers, but male musk deer make up for this absence with a pair of elongated canine teeth which they use to fight for breeding rights.
Like true deer, musk deer eat the tender shoots of trees and grasses, as well as berries, lichens, and mosses. Females live in small territories of approximately 100 to 200 acres. The territory of a dominant male will overlap several of the females’ territories. Female musk deer give birth to a single fawn. Musk deer are nocturnal or crepuscular. They use their acute hearing and excellent sense of smell to flee from predators at the slightest hint of danger.
Male adult musk deer have a musk pouch located between their genitals and their umbilicus which they use to attract mates. Unfortunately for the little saber toothed deer this pouch also attracts human hunters. For centuries (or longer) musk has been a prized luxury good, so much so that, at times, prices have soared to $45,000/kg on the black market. The musk is said to have an incredibly complex aroma but the main notes are earthy, woody, and “animalic” (i.e. fecal). Dried musk grain must be substantially tinctured with alcohol before it produces a perfume which is pleasant to humans. The resultant substance however served as a mainstay of the perfume industry and as a cure-all nostrum in ayurvedic medicine until the creation of synthetic musk. Poor musk deer from several species were nearly wiped out because of whatever mysterious power their sexual marking fluid has on humankind.
This blog has featured posts concerning saber-toothed seals and saber-toothed marsupials but did you know that the oceans around South America once contained a saber-toothed whale? Odobenocetops lived during the Pliocene era (around 2.5 to 5 million years ago). Two similar species are known in the genus from fossils discovered in coastal Peru. An early member of the dolphin superfamily, Odobenocetops was probably more closely related to narwhals and belgugas then to modern dolphins and killer whales.
Measuring only a little longer than 2 meters (6 feet) in length, Odobenocetops was remarkable (at least among whales) for its flexible neck–which could turn 90 degrees. The powerful blunt snout of the endearing little whale suggests that it fed from beds of mollusks and other bottom dwelling shellfish, which it rasped from their shells with a muscular tongue. Additionally, the Odobenocetopsidae had echolocation abilities like modern dolphins–although probably not so amazingly precise, since the extinct whales’ echolocation melons were much smaller than those of living dolphins.
Of course the most distinctive features of Odobenocetops were their long spiky teeth running parallel along their sides. Scientists speculate that these tusks could have been used to seek food or as a sensory organ–like the narwhal’s sensitive tusk. Perhaps male whales used their tusks to battle for females, like walruses do (although they seem awfully brittle for such battles). Some males had uneven tusks. The sole known skull of a male Odobenocetops leptodon features a right-hand tusk 1.2 m (4 ft.) long, while the left-hand tusk is only 25 cm (10 in.) long. Since this is the only male O. leptodon skull currently known, it is unclear whether such asymmetry was normal.
It is striking that the whales’ saber teeth were held next to the body and it makes one think that the whale did not execute many sharp turns. A humorous but somewhat sad cartoon which I found unattributed on the web demonstrates the potential drawbacks of the Odobenocetops’ striking saber toothed design.
I have always been fascinated by saber-toothed animals. Only a few saber toothed creatures remain in today’s world (like the estimable walruses and a few tiny saber-toothed deer) but in fearsome ages past, the design was widespread. Most readers are probably familiar with the smilodons, the magnificent saber-toothed cats which hunted the megafauna of Pleistocene North and South America, however the story of the saber-toothed cats intersects the story of another giant saber-toothed predator which was nearly as fearsome and even stranger. Thylacosmilus was a genus of saber toothed marsupial predators which ruled South America during the Miocene and Pliocene. Like the smilodons, Thylacosmilidae were large, agile predators which used their long fangs to slash the throats of huge prey. Unlike Smilodons, Thylacosmilidae were marsupials which gave birth to a tiny helpless larva which they then nurtured in a pouch.
The prominent teeth of Thylacosmilus were a result of convergent evolution and the creatures did not share any direct ancestors with cats since the divergence of placental and marsupial mammals (deep in the depths of the Mesozoic). Thylacosmilus’ teeth were also different in that they continuously grew throughout the animal’s life. The teeth were probably worn down as the predators gnawed on bones. Additionally Thylacosmilidae possessed scabbard-like bone flanges built into its lower jaw to protect its teeth (a feature missing entirely from Smilodons). Who knows what sort of noises Thylacosmilidae made with these peculiarly shaped mouths? For millions of years Thylacosmilidae lorded over the strange mammals of South America. The glyptodonts (and possibly other armadillos) developed their armor to ward off the mighty beasts. However the fickle play of tectonics undid the mighty killers.
In the beginning of the Pliocene, a land bridge joined North America and South America and suddenly the true cats arrived on what had been an island continent. As the climate dried out, Smilodons competed directly with Thylacosmilidae. Strange new herbivores appeared to displace the old prey animals. The Great American Interchange of long sundered mammalian lineages proved too much for the saber toothed marsupials. Thylacosmilidae were giant and fierce but they were no match for invasive cats.