Sentences with word «ostracods»

Hunt and his colleagues drew on large collections of ostracod fossils from the Smithsonian's National Museum of Natural History, the University of Southern Mississippi, and Louisiana State University, as well as additional fossils they collected themselves, to investigate whether species in which this male / female distinction was most prominent had been more vulnerable than others to changes in their environments.

There are two separate instances of bioluminescence in ostracods.

Cross-section of fossil ostracod sperm.

They were sent to John Neil, a specialist ostracod researcher at La Trobe University, who realised they contained fossilised soft tissues.

There are around 60 species of ostracods with this type of bioluminescence, but they are only found in the Caribbean.

The fossil was a 17 - million - year - old ostracod, or mussel shrimp.

The images show two large sperm pumps called Zenker's organs, resembling those found in living giant - sperm - producing ostracods (Science, DOI: 10.1126 / science.1173898).

Renate Matzke - Karasz at Ludwig Maximilian University in Munich, Germany, and colleagues produced 3D images of 100 - million - year - old fossil ostracods by firing X-rays through them.

And that's where bioluminescent ostracods come in.

One type is used as a defense mechanism, in which threatened ostracods emit a cloud of bioluminescence to distract predators.

Tiny ostracods thrived in a pool of water in the cave that was continually enriched by the droppings of thousands of bats,» says Professor Archer.

The giant sperm are thought to have been longer than the male's entire body, but are tightly coiled up inside the sexual organs of the fossilised freshwater crustaceans, which are known as ostracods.

However, while he was familiar with their hard parts, Neil didn't have much experience with analyzing ostracods» softer tissues.

Matzke - Karasz read his appeal in the 2009 issue of Cypris, a newsletter for ostracod researchers, and when Neil sent the data, she was impressed.

Such fellowships have enabled Antarctic scientists to participate in a range of significant research including using ice cores to determine proxies for the Southern Annular Mode, a molecular study of Antarctic ostracods, and investigating particulate carbon and biogenic silica in sea ice in both the Arctic and Antarctic regions.

Researchers found that male ostracods, also known as seed shrimp, evolved heavily in terms of their appearance to the point that they missed on other survival factors.

However, Payne further said that information from the fossilized ostracods may not necessarily apply to human beings and other animals.

Their final analysis included 93 different species of ostracods that lived during the late Cretaceous period, between about 85 and 65 million years ago.

A UNSW research team led by Professor Archer, Associate Professor Suzanne Hand and Henk Godthelp collected the fossil ostracods from Bitesantennary Site at Riversleigh in 1988.

Now it seems that ostracods, or seed shrimp, have been producing giant sperm for at least 100 million years.

Female (top) and male (below) of the ostracod Cypideis salebrosa.

There are an estimated 20,000 species of ostracods, but only about 200 that produce bioluminescence.

By comparing the numbers of species of ostracods that have evolved bioluminescence for either mating displays or defensive purposes to related species without bioluminescence, Ellis realized she could gain very useful evidence to support or refute the theory of sexual selection as a driver of species diversification.

However, this is just the tip of the iceberg of what it might be possible to learn about evolution from the ostracod.

She found 8 useful phylogenies for bioluminescent mating displays and 12 for defensive bioluminescence, across a broad group of marine animals including octopuses, crustaceans (including the ostracods), fish, and a worm.

As it turns out, there is only one evolutionary origin for mating - display bioluminescence in ostracods, which means there is not enough statistical strength to investigate the sexual selection question with just ostracods.

In particular, the bioluminescence produced by a little - studied microscopic crustacean, the ostracod.

The researchers estimate the fossil sperm are about 1.3 millimetres long, about the same length or slightly longer than the ostracod itself.

UNSW's Associate Professor Suzanne Hand, who is a specialist in extinct bats and their ecological role in Riversleigh's ancient environments, says the bats could have played a role in the extraordinary preservation of the ostracod sperm cells.

The microscopic study revealed the fossils contain the preserved internal organs of the ostracods, including their sexual organs.

The scanners revealed the creatures» sperm — along with sperm pumps and female canals and seminal receptacles — coiled up in the ostracods» double reproductive system.

But Neil's samples came from a freshwater cave in Riversleigh, Australia, where millions of years» worth of bat droppings left the sediment rich in phosphate, which petrified the ostracods» soft parts.

And at about 1.3 millimeters, the uncoiled sperm were relatively gigantic, longer than the ostracods» bodies.

Researchers cited the ostracods» size and their ability to regulate body temperature in water as major limitations of the study.

Fossils of 93 species of ostracods that existed some 84 million years ago during the Late Cretaceous period were analyzed based on their physical traits and the approximate time of extinction.

The ostracods are like sages; they've lived a very long time, have seen many things and are able to tell us a lot about the past and the future, including climate change.