Jack Matthews / Oxford Univ.

This juvenile example of the rangeomorph fossil Charnia measures just two-thirds of an inch (17 millimeters) in length. Note the fine detail of the branches.

Researchers have found the weird shapes of the world's earliest-known baby animals preserved in rock on Newfoundland's coast, apparently thanks to a Pompeii-like volcanic blast that covered the little critters with ash about 579 million years ago.

Like Pompeii's famous ash-encased forms, the ash layer solidified over soft bodies that otherwise might have been lost in the process of fossilization. In this case, the preserved animals are bizarre, fern-shaped animals from a little-known geological age known as the Ediacaran Period, which ran from 635 million to 542 million years ago. This is the age that marked the appearance of the first complex multicelled organisms — strange-looking creatures that disappeared when the Ediacaran Period gave way to the Cambrian Period.

These particular creatures were rangeomorphs, fern-shaped organisms that lived deep below the sea surface. They bear a superficial resemblance to sea-pen corals, but their detailed body plan is like nothing that exists in the world today. Because they lived so far underwater, they didn't make use of photosynthesis, as most plants do — but they may not have had all the charactistics of animals, either.

Scientists from Oxford and Cambridge University, in collaboration with the Memorial University of Newfoundland, found more than 100 of the fossil shapes in rocks at Newfoundland's Mistaken Point Ecological Reserve. Oxford's Martin Brasier said a volcanic eruption on a nearby island apparently overwhelmed "an underwater 'nursery' of baby Ediacaran fronds." Brasier is one of the authors of a report on the research due to appear in the July issue of the Journal of the Geological Society.

"The fossilized 'babies' we found are all less than three centimeters long and are often as small as six millimeters — many times smaller than the 'parent' forms, seen in neighboring areas, which can reach up to 2 meters in length," Brasier said in an Oxford news release. "This new discovery comes from the very bottom of the fossil-bearing rocks, making it one of the oldest bedding planes to preserve 'animal' fossils in the whole of the geological record."

Another co-author, Cambridge's Alexander Liu, said "these juveniles are exceptionally well-preserved, and include species never before found in rocks of this age. ... The discovery confirms a remarkable variety of rangeomorph fossil forms so early in their evolutionary history."

Alex Liu / Oxford

This fossil shows the fine detail of a juvenile Trepassia wardae's branching pattern. The specimen is just 3 millimeters wide - about a tenth of an inch.

Alex Liu / Oxford

This photo shows what may be a previously unknown type of fossilized organism. The organism has a long, curved stem with fine "branches" at its tip. The branches represent some of the smallest organic features found within the rocks at the Mistaken Point Ecological Reserve in Newfoundland.

Alex Liu / Oxford

Oxford University's Jack Matthews photographs rangeomorph fossils at Newfoundland's Mistaken Point Ecological Reserve.

Martin Brasier / Oxford

Waves crash against Newfoundland's rocky shore at Mistaken Point Ecological Reserve.

The Ediacaran Period was an crucial era in evolution because it's thought to mark life's transition from mostly microbial forms to a profusion of complex, multicellular organisms.

"We are now exploring even further back in time to try and discover exactly when these mysterious organisms first appeared, and learn more about the processes that led to their diversification in an 'Edicarian Explosion' that may have mirrored the profusion of new life forms we see in the Cambrian," Brasier said.

More about the earliest creatures:

• Tiny tracks of first complex animal life discovered
• Meet Earth's earliest animal with a skeleton
• Plant or animal? Odd fossils defy classification
• Earth's earliest creatures had muscles
• Flash interactive: Earth's timeline

In addition to Brasier and Liu, the authors of "A New Assemblage of Juvenile Ediacaran Fronds From the Drook Formation, Newfoundland" include Jack Matthews and Duncan McIlroy.

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Roberts et al. / AGU / HiRISE / NASA

Scientists have found evidence of relatively recent quakes on the surface of Mars by studying boulders that fell off cliffs, leaving tracks behind.

Geologists see signs that seismic shocks as powerful as magnitude-7 quakes on Earth have rumbled on the Red Planet recently, and such "marsquakes" could be a good thing for the search for life on Mars.

"The fact that Mars is geologically active means that it may offer geothermal power, subsurface liquid water, and extant life," Robert Zubrin, a rocket scientist and president of the nonprofit Mars Society, told me in an email.

The study that's getting Zubrin's juices flowing appears in Thursday's issue of the Journal of Geophysical Research-Planets.

A research team led by Gerald Roberts, a geologist at the University of London's Birkbeck center, charted ruptures in the Martian crust and the trails left behind by dislodged boulders, as seen in high-resolution images from NASA's Mars Reconnaissance Orbiter. The researchers compared the images with earthly faults to gauge what kinds of disturbances could have caused the changes they saw. They also looked at how much Martian dust was covering over the evidence, to estimate how long ago the disturbances happened.

Their conclusion? Powerful earthquakes have rattled Mars in recent geologic time, and may well be rumbling on Mars today.

The researchers acknowledged there could be other ways for boulders to loosen up and go tumbling on Mars. For example, ice or frozen soil could thaw along the rim of a crater, setting off an avalanche. Other researchers have said meteor strikes can cause avalanches as well. But Roberts and his colleagues saw a pattern in which the size and the number of dislodged boulders gradually decreased over a radius of 62 miles (100 kilometers), moving out from a central point on a fault line in Mars' Cerberus Fossae region. The biggest dislodged boulders were 65 feet (20 meters) wide.

"This is consistent with the hypothesis that boulders had been mobilized by ground-shaking, and that the severity of the ground-shaking decreased away from the epicenter of marsquakes," Roberts said in a news release from the American Geophysical Union, which publishes JGR-Planets.

An image from Mars Reconnaissance Orbiter's HiRISE camera shows an avalanche in progress in Mars' north polar region. Such avalanches could be caused by thawing ice, or meteor impacts, or marsquakes.

The fact that the trails left behind by the boulders have not yet been erased by Martian winds suggested to the researchers that the rumbling happened relatively recently, perhaps sometime in the past few million years. And the pattern of the disruption suggested that the seismic activity at Cerberus Fossae hit magnitude 7, which is comparable to the strength of the quake that hit Haiti in 2010.

"The magnitude 7 is based on comparison on the size of the ruptured piece of crust," Roberts told me in an email. "On Earth, a rupture of several hundred kilometers and 15-kilometer depth would be typical for, say, a California magnitude-7 earthquake. The energy release is proportional to the size of the rupture. ... Thus, on Mars the same energy would be released, but the weaker gravity would mean the effect of shaking would be more severe in terms of vertical motions of particles on the surface — things would be thrown in the air more easily."

You might think that would be bad news for future Mars exploration. If you were an astronaut on Mars, a magnitude-7 quake is not the sort of thing you'd want to go through. If you're an astrobiologist, however, it might be very good news. Seismic activity could serve as a source of energy for microbes beneath the Martian surface. And as Zubrin suggests, seismic activity could be harnessed as an energy source for future settlements.

But is it for real? Right now, the evidence is based merely on image analysis rather than on-the-ground measurements. Roberts noted that the Mars Viking landers, which touched down on the Red Planet in 1976, had seismometers. They also had wind-speed sensors.

"The problem was that when the wind was strong ... the lander shook, setting off the seismometers," Roberts said. "The problem was the design, as it would have been better to have put the seismometers on the ground, as in the Apollo lunar instruments."

NASA has been considering a mission known as InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) as one of three options for future funding as part of the space agency's Discovery Program. If InSight is selected, a spacecraft equipped with a seismometer, a heat-flow probe and other sensors would be sent to Mars in 2016.

NASA's Mars program is currently up in the air, but if InSight or something like it gets off the ground, we might find out how frequent and how powerful those marsquakes can get.

More about Mars:

• Seismic study hints at a rumbling Mars
• Martian life might thrive in lava tubes
• Are Martian volcanoes still ready to rumble?
• Volcano vents could point to Martian life

In addition to Roberts, the authors of "Possible Evidence of Palaeomarsquakes From Fallen Boulder Populations, Cerberus Fossae, Mars" include Brian Matthews, Chris Bristow, Luca Guerrieri and Joyce Vetterlein.

Alan Boyle is science editor for msnbc.com. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding the Cosmic Log Google+ page to your circles. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

A polar-projection map shows how the next supercontinent, dubbed Amasia, may shape up 50 million to 100 million years from now, based on an orthoversion model of continental drift.

Fifty million to 200 million years from now, geologists expect Earth's continents to smash together into one big supercontinent, just as they've done repeatedly in our planet's distant past — and a new computer model suggests that the Arctic Ocean and Caribbean Sea will be among the first things to go.

That hasn't been the conventional wisdom: In the past, scientists have assumed that either the Atlantic Ocean will close up, reversing the trend that broke apart the last supercontinent ... or that the current spreading zone in the Atlantic will push the continents 180 degrees around the world to close up the Pacific instead.

The third possibility, outlined in this week's issue of the journal Nature, goes in a different direction.

"Our model says that with every supercontinent cycle the whole arrangement needs to be shifted 90 degrees. So it's quite a shift." Yale geologist Ross Mitchell told me. "A tectonic shift."

The model is based on an analysis of the magnetism of ancient rocks. Mitchell, a doctoral student at Yale, took on the project with fellow student Taylor Kilian and Professor David Evans, the Nature paper's senior author. The rocks record how the orientation of Earth's continental plates has changed with respect to the magnetic poles over billions of years, and the researchers looked for the characteristic back-and-forth magnetic signature of a supercontinent taking shape.

"By identifying these back-and-forth motions around a stable axis, we had a measure of the center of that axis," Mitchell said. "All we had to do was find continents which had that axis from two successive supercontinents, and you could measure the angle between two successive axes."

The readings from the rocks were fed into a computer program that could essentially wind the clock back on the crashes that formed past supercontinents, as well as the smashes that broke them apart. Scientists say that there have been at least three supercontinents in Earth's distant past: Pangaea, which goes back 300 million years; Rodinia, which dates to roughly 1 billion years ago; and Nuna, which existed about 1.8 billion years ago.

Amazing Amasia
Mitchell and his colleagues saw a pattern where rocks on the edge of one supercontinent became the central point for the next. That translates roughly into a 90-degree angle on the globe. For Pangaea, the central point was in present-day Africa. The newly published model, known as the orthoversion model, suggests that the central point for the next supercontinent, known as "Amasia," will be around the present-day North Pole.

The model shows North and South America pushing together to close up the Caribbean. North America would be drawn along the Pacific "Ring of Fire" to crash into Eurasia and close the Arctic Ocean. The Mediterranean Sea would disappear when Africa smashes into Europe. Australia would continue its current northward drift, becoming part of Asia somewhere between India and Japan. Antarctica, meanwhile, would be left out of the supercontinent, at least at first.

"We'd probably have a thick ice cap at the center of the supercontinent," Mitchell said. But Amasia wouldn't stay frigid. The model suggests that the supercontinent would twist around to bring more of its land mass closer to the equator.

The model can't set a time frame for the creation of Amasia, but it looks as if the continental cycle is quickening somewhat, based on the rise and fall of past supercontinents. That leads the Yale researchers to suggest that Amasia will take shape during the next 50 million to 200 million years.

'A leap ahead'
J. Brendan Murphy, a geologist at St. Francis Xavier University in Nova Scotia, said the Nature paper "provides a unified and plausible explanation of events that for many of us are enigmatic."

"It is certainly a leap ahead in the debate," he said, but he added that the debate is far from over.

"As you go deeper into time, the database, like most things in geology, becomes less reliable. ... We really need more accurate data for the episodes that they're talking about," he said.

A more thorough analysis of magnetic rocks could provide more evidence to support the orthoversion model, or knock it down. It might even turn out that continents can follow a variety of models to bunch up into supercontinents. "Even if the model doesn't stand up to the test of time, we'll learn a lot by testing it," Murphy said.

Mitchell told me that learning more about the clash of continents can provide insights into the migration of biological species over the course of deep time. For example, the rise and fall of Pangaea played a key role in the dispersal and specialization of species across the world. But it's impossible to predict how the rise of the next supercontinent will affect Earth's future inhabitants.

"I would be quite surprised if humans lasted long enough to see the next supercontinent come to fruition," Mitchell said. "The truth is that none of the present scientific community will be around 100 million years from now to test these models."

More about tectonic shifts:

• Flash interactive: Earth's timeline
• Upside-down mountain revealed inside Earth
• Plate tectonics could be essential for alien life
• Rock links Antarctica and North America

Mitchell, Kilian and Evans are co-authors of "Supercontinent Cycles and the Calculation of Absolute Palaeolongitude in Deep Time." The research was supported by the National Science Foundation.

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.