Tag Archives: trichloroethylene

Triceratops horridus skeleton at the American Museum of Natural History in New York City

Youngest dinosaur found adds weight to asteroid extinction theory

Paleontologists have unearthed in Montana the fossilized bone of a the last known dinosaur  so far, dating back from 65.5 million years ago. The finding carries a big weight in supporting the currently leading asteroid impact dinosaur extinction theory.

Triceratops horridus skeleton at the American Museum of Natural History in New York City

Triceratops horridus skeleton at the American Museum of Natural History in New York City

What paleontologists found was actually the horn of a thought to be triceratops in a sediment bank while hunting for fossils the Hell Creek Formation, a 100m-thick slab of mudstone in south eastern Montana. The region is famous for fossil findings which range from both before and after the extinction period. Other dinosaur fossils found up to now were either much older, or were unearthed after being washed from their original graves into much younger sediments, long after they died.

Although the theory of an asteroid hitting the Yucatan peninsula around 65 million years ago has been so far regarded as the most plausible one by the scientific community, little evidence has been found up until now, apart from the giant crater itself whose date perfectly corresponds with the dinosaur extinction period. The 18-inch-long horn, however, was found and dated 5 inches below the K-T boundary, the geological line in sedimentary rock that signifies the impact of the asteroid. The latest fossil was discovered a mere 13cm below that line.

This suggests that the dinosaur—and, likely, other dinosaurs—may have been alive shortly before the asteroid hit. Other finds from recent years uncovered fossils and even T. rex footprints in the timeline extinction gap, some less than a foot below the K-T boundary, but none have narrowed the gap as much as this discovery has.

“This demonstrates that dinosaurs did not go extinct prior to the impact and that at least some dinosaurs were doing very well right up until we had the impact,” paleontology grad student Tyler Lyson, the study’s lead author, told the Guardian.

Scientists warn however that this leading has come from only one bone and further research and uncovering must be made before a sturdy conclusion can be formulated. Some researchers suspect more such fossils are waiting to be found.

Genetically Engineered Poplar Plants Disarm Toxic Pollutants 100 Times Better Than Controls

 

poplar plants

Scientists are working out different ways to improve air quality and clean up contaminated sites. In numerous cases the simplest, most natural solution is the most efficient. This could be the case here as they try to break certain kinds of pollutants into harmless byproducts, the key answer could be held by some plants.

These plants are able to take up nasty groundwater pollutants and incorporate them into their roots, stems and leaves or release into the air. The problem is that plants stop growing in winter and this means that the cleaning stops for the colder period.

But scientists believe they have found a solution to that problem; a group led by the University of Washington’s Sharon Doty, reporting in the Proceedings of the National Academy of Sciences, say that some genetically engineered poplar plants which are grown in labs are able to take as much as 91 percent of trichloroethylene; trichloroethylene is the groundwater contaminant which does the most damage in the U.S. and probably, not just there. The poplar plants also are able to break down, or metabolize, the pollutant into harmless byproducts and they do this with 100 times the efficiency of a control plants.

“Small, volatile hydrocarbons, including trichloroethylene, vinyl chloride, carbon tetrachloride, benzene, and chloroform, are common environmental pollutants that pose serious health effects. Some of these are known carcinogens,” Doty, an assistant professor of forest resources, said.

The poplar tree.

The poplar tree.

The contaminated groundwater is treated with a variety of chemical, physical and microbial methods but the results are not that good. Stuart Strand, UW professor of forest resources and a co-author of the paper says that “[the existing process] It’s destructive, disruptive and expensive,” so a solution is needed.

“We overcame the rate-limiting step by causing the poplar plants to overexpress the first enzyme in the degradative pathway,” Doty said. “Using the mammalian gene is just a step toward the day when we understand the poplar P450 genes well enough to use promoters to enhance production of their own enzymes that degrade contaminants. With the plant’s own genes, the results should be even better.”.

They are going to do some more tests but transgenic trees planted at contaminated sites could be something very useful.