New analysis of a fossilized plant found in Central Spain and the Pyrenee Mountains indicate that it may be the world’s first known flowering plant. At 125-130 million years old, Montsechia vidalii dates back to the start of the Cretaceous Period when feathered dinosaurs roamed Earth.
Previously, the oldest known flowering plant was Archeafructus sinensis, found in Liaoning province, China and which dates from 125 million years ago. Like Archeafructus sinensis, Montsechia vidalii grew underwater in shallow lakes and appears to have no roots or petals and only one seed per flower. Its leaves formed either in a spiral or opposite one another.
To get to the fossilized plant, study the ancient plant, Dilcher and his team painstakingly dissolved the limestone around more than 1000 fossils on a “drop-by-drop basis”. The resulting plant fragments were then examined under both light microscopes and scanning electron microscopes.
The plant has been known for years. First discovered over 100 years ago, Dilcher reports that it was misdiagnosed because it “possesses no obvious flower parts, such as petals or nectar-producing structures for attracting insects, and lives out its entire life cycle under water.”
This is what makes it interesting. As Dilcher pointed out, at that time animals had not developed any role in dispersing seeds. How the plants were fertilized and reproduced may help us understand and mitigate against the risk of pollinator failure in the modern day. Dilcher thinks the plant had separate male and female flowers. The seeds may have been released straight into the water and then floated away to fertilize another plant.
“We need to understand as much as we can about flowering plant evolution because right now we’re facing a world crisis.” Says Dilcher. Most present-day plants require animal pollinators and of course, bees, which are critical, food crop pollinators are declining in Europe and the US.
“This plant shows us where it all began,” says Dilcher. “If we know more about their evolution, we might come across alternative pollinators that are hidden out of sight today but played a role in the past that we could encourage again.”
- David L. Dilcherd et al. Montsechia, an ancient aquatic angiosperm.PNAS, August 2015 DOI: 10.1073/pnas.1509241112
As much as scientists have learned about the dinosaurs through years of study, the color of dinosaurs has always been difficult to determine. A group of scientists have figured out through studying feathers under a microscope, that the colors can be determined by observing the shape differences of melanin containers.
Read more here….http://www.nytimes.com/2010/01/28/science/28dino.html
Stanford University researchers have created a microscope that is small enough to be mounted to the head of a freely moving mouse to watch brain cell activity, and whole animal behaviour simultaneously.
The researchers say that their tiny microscope offers a new way to study human diseases using transgenic mice.
Project leader Mark Schnitzer says that the device weighs just 1.1 grams, and thus can be worn by a mouse without significantly impairing its movement.
He has revealed that his team has already used the device to study the circulation of blood through the one-cell-wide capillaries in the brain of active mice.
The researcher says that the microscope is attached to the head of a mouse under anaesthetic, while a marker dye is injected into the brain to label blood plasma, but leave blood cells unaffected.
According to him, the device uses light delivered by a mercury arc lamp through a bundle of optical fibres, which causes the dyed blood plasma to fluoresce, showing up individual blood cells as dark spots.
The image is sent back up the fibre-optic bundle to a camera that records the image, he adds.
Schnitzer says that nearly 100 images can be taken every second, something that makes it possible for the researchers to watch high-speed video of individual blood cells flowing in the brain.
Once the mouse wakes up from the anaesthetic, according to him, it is possible to watch the movement of cells as it behaves normally.
The researchers have revealed that combining the technique with a dye that makes the activity of brain cells visible, they could see how Purkinje neurons, involved in controlling movement, become more active when a mouse is moving than when resting.
Source: Thaindian News
Who would have thought that hammerhead sharks have so much in common with a binocular microscope? Remarkable new research by Dr Michelle McComb, Florida Atlantic University demonstrates that contrary to previous thinking, hammerhead sharks have terrific binocular vision. They can also see through the entire vertical plane – up and down! As if that isn’t enough, with a marginal turn of their head, they can see backwards too. Now there’s an idea for a microscope! See the full article at http://news.bbc.co.uk/earth/hi/earth_news/newsid_8376000/8376740.stm