Black Death Bacteria Found on Frozen-in-Time Flea
An ancestral form of Black Death bacteria has been found near the butt of a prehistoric flea.
A 20-million-year-old flea preserved in amber harbors the likely ancestor of bacteria that caused one of the world's deadliest plagues, the Black Death, according to a new study.
Researchers believe the bacteria, described in the Journal of Medical Entomology, was an ancient strain of Yersinia pestis, which caused the bubonic plague, aka the Black Death. More than a third of Europe's population - at least 30 million people - succumbed from the scourge in the 14th century.
Droplets of the bacteria were found on the flea's proboscis (sucking mouthpart) and in the rectum of the flea, near its butt.
"Aside from physical characteristics of the fossil bacteria that are similar to plague bacteria, their location in the rectum of the flea is known to occur in modern plague bacteria," author George Poinar, Jr., an entomology researcher in the College of Science at Oregon State University, said. "And in this fossil, the presence of similar bacteria in a dried droplet on the proboscis of the flea is consistent with the method of transmission of plague bacteria by modern fleas."
The amber containing the flea was found in amber mines at what is now the Dominican Republic, between Puerto Plata and Santiago. Millions of years ago the area was a tropical forest.
Poinar, Jr., studied the size, shape and characteristics of the flea's bacteria under extremely high magnification. All of its features are consistent with modern forms of the bubonic plague bacteria. Only Y. pestis exhibits unique rod and spherical shapes, which the flea's bacteria displays as well.
Previously it was thought that fleas became disease vectors, causing illness in animals, around 20,000 years ago. Now scientists like Poinar, Jr., are rethinking that supposition.
Aside from the preserved-in-amber flea, there is evidence that past outbreaks of bubonic plague were caused from different strains, some of which are now extinct. In theory, the bacteria could have been evolving for millions of years.
While dinosaurs went extinct around 66 million years ago, long before this flea was alive, fossilized flea-like creatures have been found dating to the Dino Era. It's long been theorized that a meteor strike coupled with volcanic activity did in the dinos, but perhaps disease played a factor too. Time will tell if evidence is found to support that possibility.
"If this is an ancient strain of Yersinia, it would be extraordinary," Poinar said. "It would show that plague is actually an ancient disease that no doubt was infecting and possibly causing some extinction of animals long before any humans existed. Plague may have played a larger role in the past than we imagined."
This flea preserved about 20 million years ago in amber may carry evidence of an ancestral strain of the bubonic plague.
Sept. 15, 2011 --
A stunning array of prehistoric feathers, including dinosaur protofeathers, has been discovered in Late Cretaceous amber from Canada. The 78 to 79-million-year-old amber preserved the feathers in vivid detail, including some of their diverse colors. The collection, published in this week's Science, is among the first to reveal all major evolutionary stages of feather development in non-avian dinosaurs and birds. In this slide, an isolated barb from a vaned feather is visible trapped within a tangled mass of spider's web.
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"These specimens were most likely blown into the tacky resin, or were plucked from an animal as it brushed against resin on a tree trunk," lead author Ryan McKellar told Discovery News. "The fact that we have found some specimens trapped within spider webs in the amber would suggest that wind played an important role in bringing the feathers into contact with the resin," added McKellar, a postdoctoral fellow at the University of Alberta's Department of Earth and Atmospheric Sciences. The feather filaments shown here are similar to protofeathers that have been associated with some dinosaur skeletons.
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McKellar and his team made the discovery after screening over 4,000 amber samples from Grassy Lake, Alberta. The amber, collected by the Leuck family, is now housed at the Royal Tyrrell Museum. The researchers ruled out that the inclusions were mammal hairs, plant or fungal remains based on their structure. Some dinosaur fossils retain skin impressions, so the scientists could match dinosaur protofeathers (hair-like projections) to some of the objects within the amber. Here, a feather is visible near a plant bug. The high number of coils in the this feather suggests it could have come from a water-diving bird.
The translucent tree resin provides a window into feather evolution, from non-avian dinosaurs to birds. "Part of what makes this particular set of feathers interesting is that we find the very simple Stage I and II feathers alongside advanced feathers that are very similar to those of modern birds, Stages IV and V," McKellar said. The researchers aren't yet certain why feathers first evolved, but the density of the protofeathers suggests that they helped dinosaurs with regulating temperature. Dinosaurs such as Troodon or Deinonychus may have produced the feathers. The cork-screw shaped structures in this slide are the tightly coiled bases of feather barbules.
As feathers continued to change, they developed tufts, barbs, branching features, little hooks, and more. Some of the most advanced feathers in the collection are comparable to those of modern grebes. They appear to help diving, indicating that some of the prehistoric birds were divers. McKellar suspects the marine birds might have been Hesperornithiformes, a specialized flightless diving bird from the Dinosaur Era. This is a white belly feather of a modern grebe, showing coiled bases comparable to those seen in the Cretaceous specimen.
Some of the feathers appear transparent now, but would have been white in life. A range of colors for the feathers is evident, though, with grays, reds and various shades of brown preserved. This, and prior research, suggests that non-avian dinosaurs and prehistoric birds could be quite flashy. The pigment within this fossilized feather suggests it would have originally been medium- or dark-brown in color.
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In an accompanying "Perspectives" article in Science, Mark Norell points out that the dinosaur Sinosauropteryx is thought to have had a reddish banded tail, while Anchiornis likely possessed a striking black body, banded wings and a reddish head comb. Norell, chair and curator of the American Museum of Natural History's Division of Paleontology, told Discovery News that the newly discovered feathers are "very exciting." Here, a feather barb within Late Cretaceous Canadian amber shows some indication of original coloration.
Some dino aficionados have wondered if DNA could be extracted from the feathers. "Almost anything is possible," Norell said, quickly adding that most DNA-extraction studies have been conducted on much younger amber, dating to around 20-30 million years ago, and even those led to questionable results. "Maybe bits and pieces could be identified, but not the whole genome." Shown are 16 clumped feathers in Late Cretaceous amber.
People with amber objects, such as jewelry, also probably don't have prehistoric feather inclusions, since such items are extremely rare and dealers isolate the best pieces. Nevertheless, McKellar said, "There is some hope that you could have small feather fragments that have been overlooked." An unpigmented feather and a mite in Canadian Late Cretaceous amber.