Though not generating the fanfare that its new ConceptD computers have, Acer also introduced a pair of new Chromebooks at its press event this week. Unlike its numerous education models, however, these new laptops are designed to appeal to enterprises that want to add Chromebooks to their mobile fleet.
The Chromebook 714 and 715 may include some of the same durability features that schools rely on from education Chromebooks (such as drop resistance up to four feet), but otherwise come with a more polished feature set for business users. The 14-inch 714 and the 15.6-inch 715 come with full HD IPS displays (with optional touch-screen capabilities) as well as Gorilla Glass touchpads. They also integrate fingerprint readers to deliver an extra layer of corporate security, while the 715 is the first Acer Chromebook that comes with a numeric keypad for employees who perform number-crunching tasks
Inside, the new Chromebooks can be powered by up to Intel’s eighth-generation Core i3 or i5 processors, 8GB or 16GB of RAM, and either 32GB, 64GB, or 128GB of built-in storage. They also sport a pair of USB 3.1 Type-C ports along with dual-band Wi-Fi and an optional USB Type-C dock to connect to an external display, keyboard, and other input and output devices. Acer claims up to 12 hours of battery life from the Chromebook 714 and 715 between charges.
The new Chromebooks are certified Citrix Ready to be compatible with that company’s apps and services, and Acer says they will “work well” with Google’s Chrome Enterprise cloud-based work environment platform. Google’s service is also designed to ease IT deployment of software updates and to secure a fleet of devices.
Not surprisingly, more full-featured Chromebooks mean higher-priced Chromebooks. The Acer Chromeboook 714 and 715 will each have a starting price of $499 when they become available in July, which puts them squarely in competition with similarly configured laptops running Windows. It remains to be seen if enterprises will find the Chromebook experience to be preferable at a similar price point for their mobile workers to abandon the dominant Windows platform.
Given the unusual attention granted to turkeys this week, let’s talk dinosaurs. Today’s birds are, of course, descendants of the only branch of the dino tree that made it through the end-Cretaceous mass extinction. In the dinosaurs’ halcyon days, the early birds were a bit different, still retaining teeth and foreclaws among some subtler anatomical differences with their modern descendant. A new fossil find reveals an unexpected bird from that time—one with a whopping-great, toucan-like beak.
The fossil, named Falcatakely forsterae, comes from late Cretaceous rocks in Madagascar. Many of the early bird fossils we’ve discovered so far come from older, early-Cretaceous rocks in China, with the timeframe between then and the end-Cretaceous extinction more of a question mark. The new fossil is a nicely preserved head of a crow-sized bird with a strikingly long, tall, and narrow beak.
The early Chinese bird fossils don’t show much diversity in beak shape. That’s a big contrast with modern birds, which have a wild variety of beak shapes befitting their many different ecological niches. Pelicans, woodpeckers, and parrots have very different diets that require a beak adapted to the job. It had been thought that enlarged beaks may not have been possible until some anatomical shifting in the parts of the skull took place, meaning that the early birds were simply limited. But the new find shows that wasn’t entirely true. This species could have inhabited an ecological niche that was empty after the extinction—until a more modern bird drifted back into it much later.
The researchers used 3D imaging to precisely determine the dimensions of each anatomical component. That showed some differences compared to both non-bird theropod dinosaurs or more modern birds. The fossil critter may have ended up with an overall beak shape similar to some modern birds, but that’s despite the fact that the underlying structure is different.
There are some visible teeth near the tip of the beak rather than farther back, like its relatives. And the height of its upper beak is achieved through a very large maxillary bone (brown in the image above), where other fossilized species from this time had a thin, more V-shaped bone. Modern birds, on the other hand, have tiny maxillary bones and beaks supported by a large premaxillary bone (green near the beak tip in the image above).
If there is one oddball Cretaceous bird, there could well be others, adding more diversity to the Cretaceous collection. The find also raises interesting questions about the evolution of skull structure and beak shape, given that the modern anatomy was apparently not required for a large beak of that shape. That takes a simple story and complicates it somewhat, given that the same form evolved at different times and in different ways.
And that’s good. Surprising fossils are even more fun than the unsurprising ones, further enriching our picture of the past.
First, the confession: I’m an arachnophobe, spooked by the most harmless everyday spiders. Close encounters with the scarier sort—the goliath bird-eating spider in an undergraduate zoology class, the venomous redbacks sharing my tent on a research trip to Australia—well, let’s just say they taught me more about myself than about arachnids. And yet I’ve discovered a soft spot for one group of spiders: those undersized males faced with the daunting prospect of sex with a giant mate, often one with murder in mind. Think Attack of the 50 Foot Woman, only with spiders.
Why the sympathy? It’s not because these puny males risk their lives for love. It’s because they’ve evolved such a bizarre array of ways to achieve their ultimate goal of siring spiderlings with a monster of a mother.
Sexual size dimorphism—where one sex is bigger than the other—is nothing too much out of the ordinary: Picture a massive male orangutan, or the bull elephant seal towering over his harem. And many insects and other terrestrial arthropods have large females, because a bigger body can produce more eggs.
Spiders, though, beat all comers: Females can be 3 to 10 times the size of males, and occasionally more. Most of these mismatched pairs are web-spinning spiders, notably orb weavers and widows. Female giant golden orb weavers (Nephila pilipes) are 10 times as long as males, for example, and a formidable 125 times heavier.
Welcome to the world of eSSD—extreme sexual size dimorphism.
Such spectacular discrepancies have consequences, and the most notorious is cannibalism. Giant female spiders that sit in their webs waiting to be wooed are the very definition of femmes fatales, prone to snacking on their suitors before, during or after copulation. Why? Because they are big and so they can, getting not only a half-decent dinner out of it, but also controlling who gets lucky and who doesn’t.
Less familiar is the amazing repertoire of male behavior in these species, all aimed at enhancing paternity. While females merely wait, males must roam in search of mates. When they find one, they may have to fight off rivals, must avoid being eaten long enough to copulate, and must try to stop other males from impregnating the female after they’re done. And that has led to some astonishing tactics.
“Sex in animals can be weird, but this is really weird. It’s like a soap opera,” arachnologist Jonathan Coddington tells me. As curator of arachnids at the Smithsonian National Museum of Natural History in Washington, DC, he’s spent decades investigating the evolution of spiders and observing their odd sexual habits.
Spider sex is unique even leaving aside extreme size differences. Mature males squirt their sperm onto a tiny “sperm web,” then siphon up the sperm into appendages on the sides of the head for storage until mating. In females, these appendages—called pedipalps—are leg-like structures used to prod and probe prey, but in males the tips are transformed into sperm-delivery organs.
During copulation, the male inserts one palp into an opening in the female’s abdomen, and pumps in sperm. If he gets the chance, he’ll insert his second palp into the female’s other opening. There, his sperm—and that of any subsequent successful male—is stored in pouches called spermathecae until the female begins laying eggs. At that point, the sperm are activated, travel into the egg-laying canal and fertilize the eggs.
For odd-sized mates, this process poses some tough challenges, but before you jump to conclusions, badly fitting sex organs isn’t one of them. “Evolution has taken care of things so the genitals of gigantic females are relatively small and those of small males are relatively large,” explains Slovenian spider specialist Matjaž Kuntner of the National Institute of Biology in Ljubljana. A bigger problem is surviving long enough to finish copulation and fertilize all or most of the female’s eggs.
Male orb weavers approach with caution from behind, keeping as far from female jaws as possible. In many species, males pick a time of least peril if they get the chance: when the female is already eating or when she is molting for the last time before adulthood. Molting females can’t attack until their soft new exoskeletons harden.
German zoologist Gabriele Uhl at the University of Greifswald checked how well this strategy serves the black-and-yellow-striped wasp spider (Argiope bruennichi). In lab studies, 97 percent of males that mated with the soft, molting females survived, compared with 20 percent that tried to mate with a hardened one. What’s more, mating a still-soft female allowed males to copulate for longer and gave them the option of emptying both palps or trying their luck with a second mate.
In her study, Uhl estimated that about 45 percent of the wasp spider males mated with molting females. It’s hard to know how common a tactic this is among other spiders, because molting happens fast, and often at night. “Researchers would have to stay up all night to observe it,” Uhl says. But she assumes it’s widespread, because males of many species are known to hang out in and around the webs of immature females. And it’s a tactic that pays, she says. “It’s highly likely that males mating molting females sire all of their offspring.”
Some male spiders resort to soothing gestures when danger looms. If the female giant golden orb weaver breaks off mating (a bad sign), the male binds her with silken threads. The bonds aren’t strong enough to immobilize her, but the caressing action relaxes her enough to resume mating. That might also explain why Darwin’s bark spider (Caerostris darwini) performs oral sex, salivating on the female’s genitals before copulation. This recently discovered behavior has been observed only in this particular spider species, but researchers suspect it could be widespread.
And then there’s the sensible if impossible-sounding strategy of remote copulation. That’s not quite what it seems, as demonstrated by the Asian hermit spider (Nephilengys malabarensis). When danger threatens, the male snaps off his pedipalps and makes good his escape, leaving the palps to pump sperm without him.
So far, so bizarre. But that’s not the end of it. The evolutionary interests of male and female aren’t always the same, making sex a battleground in more ways than one. His interests lie in passing on his genes, so he benefits from fathering all of his mate’s offspring. For the female, monogamy is not such a good idea: She wants offspring with the best possible genes, so she can either be picky or mate with multiple males, increasing the odds that some of her spiderlings will turn out well.
This conflict has led to the evolution of measures and countermeasures by each sex to get what they want. Females eat males they don’t want to mate with, or to avoid being monopolized by a single partner. Males have acquired ways to thwart females. “For males, the chances of finding a second female to mate with are practically nil, so he invests everything in success with one mate—and that’s led to a lot of bizarre behaviors,” Coddington says.
For example, males often congregate in a female’s web, where they fight to be first in line to try their luck. Successful males try to secure paternity by preventing rivals from adding their sperm to her store. They may try to plug the female’s copulatory openings by leaving behind the ends of their palps, or even entire palps. Even then, and assuming they survived mating, they often guard the female jealously, fighting to fend off other suitors. Asian hermit spiders that complete copulation without having to flee part way through and finish the job remotely still leave their palps behind when they’re done. A study from Kuntner’s lab showed that 87 percent of them abandon their palps this way, chewing them off if necessary. The team also showed that these “eunuch” males are more agile, superior fighters, better able to guard their mate.
Not all genital plugs work, though, as Coddington is at pains to point out. The giant golden orb weaver’s pedipalps end in long, hair-like extensions. “He sticks it in the female; it breaks off and it doesn’t do any good at all,” Coddington says. “We find females with eight or more stuck inside them.”
Indigenous Pueblo populations in the American Southwest—ancestors of today’s Hopi, Zuni, and Rio Grande Pueblo tribes—typically wove blankets, cloaks, and funeral wrappings out of animal hides, furs, and turkey feathers. Anthropologists at Washington State University (WSU) have examined one such ancient turkey-feather blanket and determined it took thousands of those feathers, wrapped around nearly 200 yards to yucca fiber, to make, according to a new paper published in the Journal of Archaeological Science: Reports.
“Blankets or robes made with turkey feathers as the insulating medium were widely used by Ancestral Pueblo people in what is now the Upland Southwest, but little is known about how they were made because so few such textiles have survived due to their perishable nature,” said co-author Bill Lipe, emeritus professor of anthropology at WSU. “The goal of this study was to shed new light on the production of turkey feather blankets and explore the economic and cultural aspects of raising turkeys to supply the feathers.”
For their study, Lipe and his WSU colleague and co-author, Shannon Tushingham, studied a blanket framework on display at the Edge of the Cedars State Park Museum in Blanding, Utah. Although insects had devoured the original feather vanes and barbs, the shafts were still visible, wrapped around yucca fiber cords. They were also able to look at a second, smaller blanket which still had most of its feathers intact. Both blankets roughly date to the early 1200s CE.
According to the authors, such blankets were likely made from the body feathers that cover the breast and back of turkeys. Such feathers have a visible “after feather,” as well as a downy portion—a key factor in how feathers keep turkeys and people warm. Both the distal tips and the quills at the base are typically overwrapped during the weaving process, with the downy portions exposed. They are held together by rows of nonwrapped yucca fiber cords, which comprise the weave of the blanket. They measured the length of the cordage used to make the warps and wefts, the two components in weaving used to turn thread or yarn into fabric (lengthwise yarns are called warp; crosswise yarns are called weft).
The blanket might have been created all at once, but the authors surmise that additional lengths of cordage and feather batches were probably added over time. However, they do think the feathers were added to the full warp cord before the final blanket took shape, “before the cord was repeatedly doubled back on itself to form the individual warp segments,” they wrote.
They also counted the number of individual feather shafts on several segments of the warp cords. However, it wasn’t possible to examine the quills or ends of the feathers, or the distal tips, since they had been overwrapped by adjacent feathers. Ultimately, the researchers estimated that approximately 11,500 turkey feathers would have been needed to make the blanket. “This estimate would of course change if different lengths of feather were used,” they wrote, depending on the feathers that were available and on the personal preferences of whoever wove the blanket.
Next, the researchers obtained the pelts of two adult male wild turkeys from Idaho hide and fur dealers, the better to estimate how many adult turkeys would be needed to provide 11,500 or so feathers. They concluded such pelts would yield a little over 2,700 feathers from an adult male turkey. From that, they extrapolated that a blanket-maker would need to collect feathers from 4.26 adult males. But since only 1,200 feathers per bird were in the preferred size range, it may have taken as many as 9.6 adult birds to collect enough feathers for the blanket. The good news: “Once a blanket was made, it likely would have lasted for a number of years,” the authors wrote.
Turkey feathers likely began to replace strips of rabbit skin for blankets sometime during the first two centuries CE. “As ancestral Pueblo farming populations flourished, many thousands of feather blankets would likely have been in circulation at any one time,” said Tushingham. “It is likely that every member of an ancestral Pueblo community, from infants to adults, possessed one.”
As for how the feathers were collected, Lipe and Tushingham cited three possibilities: the birds were killed and their feathers harvested; feathers were collected during the birds’ natural molting season; or people selectively plucked mature feathers from living turkeys. Turkeys didn’t become a major food source in this region until between 1100 and 1200 CE, and even then, they were typically killed before they were a year old—too soon to harvest mature feathers. Furthermore, “Killing turkeys for their feathers is a wasteful strategy, because it removes the possibility of harvesting feathers as a sustainable food source,” the authors wrote.
“Reverence for turkeys”
As for collecting feathers during the natural molting season, this typically occurs gradually over weeks or months. If the turkeys were roaming freely, it would be difficult to collect the best feathers, and if they were penned, the feathers would be trampled in the ground—no doubt also littered with turkey droppings. (The authors note that modern wild turkeys produce 2.5 pounds of “fresh manure” per bird each week.) Thus, the authors conclude that the most likely practice was to selectively pluck feathers from live birds, which can be done quite easily once feathers have matured.
“When the blanket we analyzed for our study was made, we think in the early 1200s CE, the birds that supplied the feathers were likely being treated as individuals important to the household and would have been buried complete,” Lipe said. “This reverence for turkeys and their feathers is still evident today in Pueblo dances and rituals. They are right up there with eagle feathers as being symbolically and culturally important.”
“Turkeys were one of the very few domesticated animals in North America until Europeans arrived in the 1500s and 1600s,” Tushingham added. “They had and continue to have a very culturally significant role in the lives of Pueblo people, and our hope is this research helps shed light on this important relationship.”
DOI: Journal of Archaeological Science: Reports, 2020. 10.1016/j.jasrep.2020.102604 (About DOIs).