Wolf-sized otters roamed Earth over 6 million years ago

January 25, 2017

Washington, Jan 25: Prehistoric otters may have been of the size of a modern wolf, say scientists who have discovered 6.24 million-year-old fossils of one of the largest otter species known to science. Remains of the large extinct otter, which had large, powerful jaws and is estimated to have weighed about 50 kilogrammes, was found in the northeastern Yunnan Province in China.

Wolf

The species, named Siamogale melilutra, belongs to an ancient lineage of extinct otters that was previously known only from isolated teeth from a different, much older species that was recovered in Thailand. Researchers from Cleveland Museum of Natural History in the US recovered a complete cranium, mandible, dentition and various skeletal elements - offering a wealth of insight into the taxonomy, evolutionary history and functional morphology of this new species.

"While the cranium is incredibly complete, it was flattened during the fossilisation process," said Denise Su, from the Cleveland Museum of Natural History. "The bones were so delicate that we could not physically restore the cranium. Instead, we CT-scanned the specimen and virtually reconstructed it in a computer," said Su.

The CT restoration showed a combination of otter-like and badger-like features, giving way to the species name "melilutra," which combines the Latin names for badger (meles) and otter (lutra). Siamogale melilutra had a large, powerful jaw with the enlarged, bunodont (rounded-cusped) teeth typical of many otter lineages.

This raises the question of whether these bunodont teeth were inherited by all otters from a common ancestor or evolved independently in different otter lineages over time because of the evolution of similar adaptations to thrive in similar environments - a phenomenon called "convergent evolution."

Through their analysis, researchers found that bunodont teeth independently appeared at least three times over the evolutionary history of otters, suggesting convergent evolution to be the cause. The completeness of the specimens from Shuitangba allows the scientists to better understand the evolutionary history of otters and specifically this enigmatic genus from the Miocene, of which there had been little information.

The findings show that Siamogale belongs to one of the oldest and most primitive lineages of the otter family, which goes back at least 18 million years in the form of Paralutra from Europe. The scientists are working to understand other aspects of the life of Siamogale melilutra.

"The discovery of the otter helps solve some questions about otter relationships, but has opened the door to new questions," said Xiaoming Wang from the Natural History Museum of Los Angeles County in the US. The study was published in The Journal of Systematic Paleontology.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
Agencies
February 6,2020

Washington D.C., Feb 6: An international team of astronomers has found an unusual monster galaxy that existed about 12 billion years ago when the universe was only 1.8 billion years old.

The team of astronomers was led by scientists at the University of California, Riverside.

Dubbed XMM-2599, the galaxy formed stars at a high rate and then died. Why it suddenly stopped forming stars is unclear.

"Even before the universe was 2 billion years old, XMM-2599 had already formed a mass of more than 300 billion suns, making it an ultra massive galaxy," said Benjamin Forrest, a postdoctoral researcher in the UC Riverside Department of Physics and Astronomy and the study's lead author.

"More remarkably, we show that XMM-2599 formed most of its stars in a huge frenzy when the universe was less than 1 billion years old and then became inactive by the time the universe was only 1.8 billion years old," Forrest added.

The team used spectroscopic observations from the W. M. Keck Observatory's powerful Multi-Object Spectrograph for Infrared Exploration or MOSFIRE, to make detailed measurements of XMM-2599 and precisely quantify its distance.

The study results appear in the Astrophysical Journal.

"In this epoch, very few galaxies have stopped forming stars, and none are as massive as XMM-2599," said Gillian Wilson, a professor of physics and astronomy at UCR in whose lab Forrest works.

"The mere existence of ultramassive galaxies like XMM-2599 proves quite a challenge to numerical models. Even though such massive galaxies are incredibly rare at this epoch, the models do predict them."

"The predicted galaxies, however, are expected to be actively forming stars. What makes XMM-2599 so interesting, unusual, and surprising is that it is no longer forming stars, perhaps because it stopped getting fuel or its black hole began to turn on. Our results call for changes in how models turn off star formation in early galaxies," the professor stated.

The research team found XMM-2599 formed more than 1,000 solar masses a year in stars at its peak of activity -- an extremely high rate of star formation. In contrast, the Milky Way forms about one new star a year.

"XMM-2599 may be a descendant of a population of highly star-forming dusty galaxies in the very early universe that new infrared telescopes have recently discovered," said Danilo Marchesini, an associate professor of astronomy at Tufts University and a co-author on the study.

"We have caught XMM-2599 in its inactive phase," Wilson said, who led the W. M. Keck Observatory data acquisition
Co-author Michael Cooper, a professor of astronomy at UC Irvine, said this outcome is a strong possibility.

"Perhaps during the following 11.7 billion years of cosmic history, XMM-2599 will become the central member of one of the brightest and most massive clusters of galaxies in the local universe," he said.

"Alternatively, it could continue to exist in isolation. Or we could have a scenario that lies between these two outcomes," he stated.

The study was supported by grants from the National Science Foundation and NASA.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
News Network
March 13,2020

Bengaluru, Mar 13: In the wake of fresh cases of Covid-19 reported in Karnataka, Infosys Foundation chairperson Sudha Murty has urged the Karnataka government to take steps to shut malls and theatres, saying the coronavirus multiplies in air-conditioned areas.

In a letter to the government, she said preventive measures should be taken to control the spread of coronovirus before it gets worse.

Murty, who also leads the State government-constituted Karnataka Tourism Task Force, said she has discussed the current situation with Chairman and Executive Director of Narayana Health, Devi Prasad Shetty.

She suggested closure of all schools and colleges with immediate effect, malls, theatres and “all air-conditioned areas where the virus multiplies”, and allow only essential services like pharmacy, grocery and petrol bunks.

“It is not scientifically proven that the virus dies in high temperature,” she said pointing to spread of the virus -- despite heat -- in peak summer in Australia and Singapore, which have “summer all 12 months”.

“I request you to vacate one government hospital with at least 500 - 700 beds for this purpose (to deal with coronavirus cases), which requires oxygen lines and pipes,” she said.

“Infosys Foundation, the philanthropic and CSR arm of software major Infosys, would do the civil work and Devi Shetty has agreed to share resources like medical equipment,” she added.

“We would like to work with the government proactively so that we can prevent this as early as possible,” Sudha Murty said.

The total number of confirmed coronavirus positive cases in Karnataka is five, including the 76-year old man from Kalaburagi who died on Tuesday night.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
Agencies
March 16,2020

While Google is still working on a coronavirus screening and tracking website, Microsoft Bing team has already launched a web portal for tracking COVID-19 infections worldwide.

The website, accessible at bing.com/covid, provides up-to-date infection statistics for each country.

The COVID-19 Tracker currently lists 168,835 as total confirmed cases, 84,558 active cases, 77,761 recovered cases and 6,516 deaths.

There are at least 3,244 confirmed cases of novel coronavirus in the US and at least 61 deaths.

"Lots of Bing folks worked (from home) this past week to create a mapping and authoritative news resource for COVID19 info," Michael Schechter, General Manager for Bing Growth and Distribution at Microsoft, was quoted as saying in a ZDNet report on Sunday.

An interactive map allows site visitors to click on the country to see the specific number of cases and related articles from a variety of publishers.

Data is being aggregated from sources like the World Health Organization (WHO), the US Centers for Disease Control and Prevention (CDC), and the European Centre for Disease Prevention and Control (ECDC).

Microsoft announced the website two days after US President Donald Trump said Google has begun working on COVID-19-related portal for US citizens.

Google's website is being built by Verily, a subsidiary of Alphabet focused on healthcare services.

"More than 1,700 engineers are currently working on the site", Trump said during a press briefing last week.

The tool will triage people who are concerned about their COVID-19 risk into testing sites based on guidance from public health officials and test availability.

Initially, there was some confusion on Google's coronavirus portal but the company later announced that it is "partnering with the US Government in developing a nationwide website that includes information about COVID-19 symptoms, risk, and testing information."

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.