Fossil found near Bonavista one of 'the most important fossils in the world,' scientist says
Haootia quadriformis might look like a squished bat, but it's an important part of the fossil record
CBC News ·
The Haootia quadriformis fossils may be the earliest evidence of animal muscle tissue on earth. (Submitted by Duncan McIlroy)
It
might just look like the imprint of a bat squashed into a rock, kind of
like the imprint an unfortunate bird leaves when it collides with a
window. But paleontologist Duncan McIlroy says this unassuming item is
an amazing find.
The Haootia quadriformis fossil, found
in the Bonavista area a few years ago, may be the earliest evidence of
animal muscle on earth, said McIlroy, from MUN's department of earth
sciences.
"In my
opinion, this is one of the most important fossils in the world and it's
certainly the most beautiful thing that I've ever worked with," he told
The St. John's Morning Show.
"Haootia"
derives from a Beothuk word that means "demon," McIlroy said, but the
animal itself was a jellyfish relative with four tentacles and was only
about 10 centimetres tall. But despite its small stature and
all-plankton diet, the Haootia fossil is important enough that it will be featured in the First Animal episode of The Nature of Things on Friday night.
When life exploded
A significant part of the Nature of Things documentary is based on the Burgess Shale, one of the world's most important fossil sites.
"This
is shortly after, actually, the start of the Cambrian explosion, when
there was a lot more sort of freedom in the world in that there weren't a
lot of animals, so a lot of different body forms could actually be
experimented with," McIlroy said.
Duncan McIlroy of Memorial University says the Haootia quadriformis fossil find is significant. (Paula Gale/CBC)
There
are several hypotheses about why the Cambrian explosion happened, he
said. Some scientists believe it was part of the evolution of predation,
when animals began to eat other animals and evolved in an attempt to
try to protect themselves. Others think it could be related to the
appearance of the first burrowing animals who dug below the earth's
sediment for food or protection, increasing productivity on the bottom
of the sea floor.
"They eat microbes, they poop, the microbes
eat the poop, the animals eat the microbes, so it started escalating the
amount of food that was available," McIlroy said. More available food,
and different kids of food, may have helped animals become increasingly
complex — for example, giving them the minerals needed to grow teeth or shells.
But Haootia is from 40 to 50 million years before the Cambrian explosion.
"Haootia is basically part of what we would call the long fuse to the Cambrian explosion," he said.
"There
are animals there, we just don't see very many of them, but then they
explode in terms of diversity and in terms of abundance during the
fossil record during the Cambrian."
Haootia's significance
But even if Haootia predates the Cambrian explosion, don't assume it's not important.
The fossil's appearance doesn't make it entirely clear just what a Haootia quadriformis was. "When
we first found it, before we described it, we used to call it the
squished bat," McIlroy said. "It looks like a bat that's been
spread-eagled on the rock."
You need something that people accept as being definitely an animal, and this is what most people have been accepting.
- Duncan McIlroy
The
fossil was found in 2013 and described in 2015. The researchers sat on
the find for a bit to figure out what it was, McIlroy said, but in 2015
found another fragment in the Bonavista area that gave them some
confidence there were more of these animals nearby.
Essentially,
he said, the animal had a disk on a stalk and a cup, with four
tentacles. It would have sat a few centimetres above the sea floor,
using its tentacles to grab at bits of plankton and pop them in its
mouth.
Despite the Haootia's primitive form, its fossil
has been used to calibrate molecular clocks for dating when things
evolve and has yet to be refuted, which McIlroy said is notable in the
critical scientific world.
"You need something that people
accept as being definitely an animal, and this is what most people have
been accepting," he said. "It's a big deal."
In addition to learning more about Haootia quadriformis and the many animals that came after it by watching The Nature of Things on television or on CBC Gem, there will an event at The Rooms on Saturday from 3 p.m. to 4 p.m.
In addition to airing the episode, Jean-Bernard Caron of the Royal Ontario Museum will be on hand to talk about its creation and McIlroy will speak about Haootia — and to share a few new discoveries that are as-yet unpublished.
And for those interested in seeing the fossil, it's on permanent display in the third level of the Rooms.
sexta-feira, 8 de junho de 2018
Images: Bizarre, Primordial Sea Creatures Dominated the Ediacaran Era
By Laura Geggel, Senior Writer |
During the Ediacaran period, about 635 million to 541 million years
ago, oxygen was sparse, the oceans were murky and marine organisms ate
by absorbing nutrients floating around in the water.
It was a very different world, according to fossils left behind by the soft-bodied life-forms that dominated the era.
"The Ediacaran period is the first time in Earth's history where you
don't need a microscope to look at the fossils," said Marc Laflamme, an
assistant professor of Earth science at the University of Toronto
Mississauga. "This is the first time that life is big enough that you
can look at it with the naked eye." [See Photos of These Life-Forms Discovered in Newfoundland, Canada]
Here's a look at the wacky organisms that called Earth home at the time: Bizarre creature
During the Ediacaran — a period named for South Australia's fossil-rich Ediacara Hills — animals weren't the major players.
"There are some animals there, but they're not dominating the system
like we have in the modern world," Laflamme told Live Science. "Animals
churn up sediment, they burrow, they dig" — without them, the seafloor
was likely incredibly firm and covered with thick bacterial mats, he
said.
However, researchers have found a few exceptions. For instance, this seafloor-dwelling tapewormlike animal, named Plexus ricei,
dates to the Ediacaran period. The tubular critter measured about 5 to
80 centimeters (2 to 31 inches) long and 5 to 20 millimeters (0.2 inches
to 0.8 inches) wide.
"Plexus was unlike any other fossil that we know from the
Precambrian," study researcher Mary Droser, a paleobiologist at the
University of California, Riverside, said in a statement. (Image credit: Credit: Droser Lab | UC Riverside) Different roots
A plethora of bacteria probably covered the seafloor like a leathery
carpet, Laflamme said. Likewise, many of the organisms that lived during
that time didn't have root systems
like today's plantsdo but instead had bottoms that were either disc- or
ball-shaped (depending on whether they were inflated — it's hard to
tell by looking at the fossils), Laflamme said.
The two seaweedlike fossils, pictured here, are small — about 2 inches
(5 cm) long. It's unclear if they are plants or animals, as the bulbous
structure at the bottom of their stalk could serve as an anchor for a
plant. Or, it could be a proboscis, a tubelike feeding structure, of a
wormlike creature, Live Science reported. (Image credit: Zhe Chen) Rangeomorphs
Other Ediacaran organisms, called rangeomorphs, had these disc-shaped root systems.
"It makes sense if they're living on a firm, rigid substrate," Laflamme
said. "They don't dig roots into [the ground]; they just lie flat on
it. Or, they burrow within, and this microbial mat that grew around it
and held it in place."
Rangeomorphs were bizarre, fractal creatures with self-similar patterns
found from the smallest to the largest scale of the organisms, Live Science reported in 2014. (Image credit: Jennifer Hoyal Cuthill | University of Cambridge) Next generation
Some rangeomorphs displayed complex procreation. For instance, the soft-bodied rangeomorph known as Fractofusus (shown here) likely reproduced much like a strawberry plant does today, according to a study published Aug. 3, 2015, in the journal Nature. (Image credit: C. G. Kenchington) Baby rangeomorph
Researchers have even found juvenile rangeomorphs, including this
0.7-inch-long (17 millimeters) one shown here; the juvenile specimen
was found at Mistaken Point Ecological Reserve in Newfoundland, Canada.
Notice the detail on its branches. (Image credit: OU | Jack Matthews) Suspension feeder
Tribrachidium, a bizarre sea creature that lived some
550 million years ago, is unlike any modern organism. It has three-fold
symmetry — a feature that no living thing today has, Live Science reported in November. New research suggests that the creature fed on particles suspended in the water. (Image Credit: M. Laflamme) Muscle maniac
Haootia quadriformis, the first known life-form to have
muscles, lived during the late Ediacaran, about 560 million years ago.
The creature's body looks like a circular disc, which it likely used to
anchor itself to the seafloor.
The disc is connected by a short stalk to a sheetlike body made of
fibrous bundles — believed to be muscles — arranged in a four-fold
symmetry, Live Science reported in 2014. (Image credit: Credit: Martin Brasier) Newfoundland fossils
The Ediacaran had low levels of oxygen — likely one to two orders
of magnitude lower than oxygen levels on today's Earth, Laflamme said.
However, as marine animals evolved into filter feeders, they started
eating the bacteria and nutrients in the murky water. The resulting
clear water would have allowed sunlight to deliver energy to
photosynthesizing bacteria, which, in turn, would have made more oxygen.
Once oxygen levels increased,
animals thrived, and larger predators entered the environment. These
animals tunneled and tore at the ocean floor, bringing an end to the
rangeomorphs and other organisms, Laflamme said. ( Image Credit: OU |
Jack Matthews) Oldest animal skeleton
Pictured here is Coronacollina acula, an organism with a round center and four needlelike "spicules" that point outward. C. acula lived between 550 million and 560 million years, and is thought to be the oldest animal with a skeleton on record. It likely survived by filtering food from the water, experts told Live Science. (Image Credit: James Gehling) Follow Laura Geggel on Twitter @LauraGeggel. Follow Live Science @livescience, Facebook & Google+.
