Navigation Links
Paleontologists discover new fossil organism
Date:5/9/2014

RIVERSIDE, Calif. Scientists at the University of California, Riverside have discovered a fossil of a newly discovered organism from the "Ediacara Biota" a group of organisms that occurred in the Ediacaran period of geologic time.

Named Plexus ricei and resembling a curving tube, the organism resided on the Ediacaran seafloor. Plexus ricei individuals ranged in size from 5 to 80 centimeters long and 5 to 20 millimeters wide. Along with the rest of the Ediacara Biota, it evolved around 575 million years ago and disappeared from the fossil record around 540 million years ago, just around the time the Cambrian Explosion of evolutionary history was getting under way.

"Plexus was unlike any other fossil that we know from the Precambrian," said Mary L. Droser, a professor of paleontology, whose lab led the research. "It was bilaterally symmetrical at a time when bilateriansall animals other than corals and spongeswere just appearing on this planet. It appears to have been very long and flat, much like a tapeworm or modern flatworm."

Study results appeared online last month in the Journal of Paleontology.

"Ediacaran fossils are extremely perplexing: they don't look like any animal that is alive today, and their interrelationships are very poorly understood," said Lucas V. Joel, a former graduate student at UC Riverside and the first author of the research paper. Joel worked in Droser's lab until June 2013.

He explained that during the Ediacaran there was no life on land. All life that we know about for the period was still in the oceans.

"Further, there was a complete lack of any bioturbation in the oceans at that time, meaning there were few marine organisms churning up marine sediments while looking for food," he said. "Then, starting in the Cambrian period, organisms began churning up and mixing the sediment."

According to the researchers, the lack of bioturbators during the Ediacaran allowed thick films of (probably) photosynthetic algal mats to accumulate on ocean floorsa very rare environment in the oceans today. Such an environment paved the way for many mat-related lifestyles to evolve, which become virtually absent in the post-Ediacaran world.

"The lack of bioturbation also created a very unique fossil preservational regime," Joel said. "When an organism died and was buried, it formed a mold of its body in the overlying sediment. As the organism decayed, sediment from beneath moved in to form a cast of the mold the organism had made in the sediment above. What this means is that the fossils we see in the field are not the exact fossils of the original organism, but instead molds and casts of its body."

Paleontologists have reported that much of the Ediacara Biota was comprised of tubular organisms. The question that Droser and Joel addressed was: Is Plexus ricei a tubular organism or is it an organism that wormed its way through the sand, leaving a trail behind it?

"In the Ediacaran we really need to know the difference between the fossils of actual tubular organisms and trace fossils because if the fossil we are looking at is a trace fossil, then that has huge implications for the earliest origins of bilaterian animalsorganisms with bilateral symmetry up and down their midlines and that can move independently of environment forces," Joel said. "Being able to tell the difference between a tubular organism and a trace fossil has implications for the earliest origins of bilaterian organism, which are the only kinds of creatures that could have constructed a tubular trace fossil. Plexus is not a trace fossil. What our research shows is that the structure we see looks very much like a trace fossil, but is in fact a new Ediacaran tubular organism, Plexus ricei."

Plexus ricei was so named for plexus, meaning braided in Latin, a reference to the organism's morphology, and ricei for Rice, the last name of the South Australian Museum's Dennis Rice, one of the field assistants who helped excavate numerous specimens of the fossil.

"At this time, we don't know for sure that Plexus ricei was a bilateral but it is likely that it was related to our ancestors," Droser said.


'/>"/>

Contact: Iqbal Pittalwala
iqbal@ucr.edu
951-827-6050
University of California - Riverside
Source:Eurekalert  

Related medicine news :

1. Discovery links rare, childhood neurodegenerative diseases to common problem in DNA repair
2. Extinct kitten-sized hunter discovered
3. GW researcher discovers the mechanisms that link brain alertness and increased heart rate
4. Discovery of anti-appetite molecule released by fiber could help tackle obesity
5. UNC researchers discover master regulator role for little-known protein in cancer cells
6. Oxygen diminishes the hearts ability to regenerate, researchers discover
7. Novel therapeutic agent for Tamiflu-resistant pH1N1 influenza virus discovered
8. Scientists discover a new way to enhance nerve growth following injury
9. Scientists discover brains anti-distraction system
10. First genetic link discovered to difficult-to-diagnose breast cancer sub-type
11. New pain relief targets discovered
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Paleontologists discover new fossil organism
(Date:2/5/2016)... Ontario (PRWEB) , ... February 05, 2016 , ... After ... Scarborough General Hospital Burn Unit, plastic and cosmetic surgeon Dr. Wayne Carman transitioned to ... Scarborough Hospital. He successfully completed his first three-year term as chief and began a ...
(Date:2/5/2016)... ... February 05, 2016 , ... Regular gym users know the ... to wait longer to access the treadmills. It’s a predictable trend. After the excesses ... weight and get in shape by joining gyms, starting new walking or running routines, ...
(Date:2/5/2016)... ... February 05, 2016 , ... Dr. Justin Scott and Dr. ... Annual No Cost Dental Day to individuals in need. The event is scheduled to ... No Cost Dental Day is to provide dental care to community members in need. ...
(Date:2/5/2016)... ... 05, 2016 , ... Health and wellness is a topic that should concern ... they are experiencing an illness. Migraines are a severe form of a headache and ... would not wish the pain on their worst enemy, the feeling can last for ...
(Date:2/5/2016)... CA (PRWEB) , ... February 05, 2016 , ... –This ... on the benefits of having a tankless water heater. To view the report, ... water heaters: tank and tankless. While each has their pros and cons, the type ...
Breaking Medicine News(10 mins):
(Date:2/5/2016)... 2016 --> ... "Fetal (Labor & Delivery) and Neonatal Care Equipment Market ... Oximeter, Phototherapy/Jaundice Management Devices, CPAP, Capnograph, & Resuscitator) - ... studies the global market over the forecast period of ... 6.28 Billion in 2015 and is poised to grow ...
(Date:2/4/2016)... -- For hospitals considering enrollment in the Federal 340B ... program, the Health Resources and Services Administration,s (HRSA) recent ... , could have significant impact on plans and operations, ... Essential Insights , Daniel Neal, director ... Mega-Guidance,s key proposed changes, including a new requirement that ...
(Date:2/4/2016)... CITY, Calif. , Feb. 4, 2016 /PRNewswire/ ... "Company") today announced it has entered into a ... Exchange Commission (SEC) fully resolving the SEC,s investigation ... Act (FCPA).  Under the terms of the settlement ... of $12.8 million, including disgorgement, pre-judgment interest and ...
Breaking Medicine Technology: