[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: A 312 million year old fossil is discovered near the Emerald Square Mall in North Attleboro
Rhyniella praecursor / Rhyniognatha hirsti
In 1926 Hirst and Maulik first named an arthropod Rhyniella praecursor that
was found in the Rhynie chart beds, dated 410mya. Tillyard, in 1928
described Rhyniella praecursor mouth parts, suggesting Rhniella praecursor
was insect-like and renamed the fossil remains Rhyniognatha hirsti, but did
not place it in a group. For the next 76 years researchers considered the
fossil too fragmented to determine that it was an insect or it to be a later
contaminant. With the advance of technology Engel and Grimaldi in 2004
using the same specimen described by Hirst and Maulik confirmed that
Rhyniognatha hirsti is the oldest springtail known. Furthermore, Engeland
and Grimaldi placed the Rhyniognatha hirsti in the Metapterygota Group,
implying that Rhyniognatha had wings. This study places the origin of wings
at least 80 million years earlier. Additional specimens and studies by
Greenslade, Jarzembowski, Massoud, Scourfield and Whalley have established
that springtails were present 410mya in Scotland. These specimens and
studies are also supported with other DNA studies estimating that insects
originated before the Devonian period perhaps Early Silurian (500+mya). I
do need to add, because there are huge gaps in the early fossil records that
no fossilized wings have been found in the Devonian and no transitional
forms have been recovered.
----- Original Message -----
From: "Yasmani Ceballos Izquierdo" <email@example.com>
To: "dinos" <firstname.lastname@example.org>; <VRTPALEO@usc.edu>
Sent: Friday, December 05, 2008 7:56 PM
Subject: A 312 million year old fossil is discovered near the Emerald Square
Mall in North Attleboro
A 312-million-year-old fossil is discovered near the Emerald Square Mall in
NORTH ATTLEBORO - Fossil hunter Richard J. Knecht had been hammering at
the rocks near Emerald Square mall looking for traces of ancient creatures
when a piece of prehistoric treasure just broke off in his hand.
Locked in a layer of fragile burgundy-colored rock was the oldest known
imprint ever made of an insect while still alive.
The three-inch-long bug, believed to be a very, very, very distant
relative of the mayfly, apparently made its mark by briefly landing on a
pool of mud 312 million years ago, during an era when continental drift
had brought Southern New England much closer to the equator.
Knecht and his professor, paleontologist Jake Brenner of Tufts University,
are hoping it, along with the subsequent discovery of a fossilized wing at
the site last week, will yield new insights into insect behavior at a time
when such bugs were much larger, amphibians were the dominant life form,
and reptiles were just beginning to get a foothold, still many million of
years away from ruling Earth.
"The level of detail is really unseen in continental deposits," said
Brenner. "It's unusual to see a flying insect make such a deep impression
in this muddy sediment . . . and we don't have many good body fossils from
this time period with these early flying insects."
Usually when fossil hunters discover bones or body remnants in the rocks,
the pieces and impressions come from creatures that were dead when the
preservation process began. The body parts tend to be either broken up or
Alternatively, they find "trace" fossils, such as footprints, which show
marks made by living creatures. Those offer clues to how the animals
This fossil has both.
"It's not squished. It's not deformed. We don't have to try to piece it
back together. We can see it as it was, and we get the behavior," said
The long abdomen is the most obvious feature. Look closely and you can
even see its individual segments.
Coming off the abdomen are six projections that mark the animal's legs.
They may look stubby, but that's because those are the parts that were
pressed into the mud.
"If you saw it quickly, you might think it's a plant because it's kind of
stick-like," Knecht said.
But follow the lines of the legs and you can see where the rest of the
legs made impressions as well.
"Picture this thing squatting, so the 'elbows' are not touching the
sediment," he said.
"In the top left leg, you can see that it moved a couple times when it was
in place. There's almost two depressions right on top of each other, so
you actually see movement," according to Knecht.
He and Brenner went hunting in that area because they had uncovered a 1929
master's thesis from Brown University suggesting that rocks in the area
might be a good source of fossils. New England isn't a particularly rich
source of prehistoric remains.
How serendipitous was the discovery?
First of all, these types of impressions probably weren't made very often,
even if the climate in that era was warmer, Knecht said. "Imagine
following a modern dragonfly, waiting for it to land and leave a perfect
impression. You'd have to follow it for weeks."
The fact that the impression was preserved is just as remarkable.
You'd need just the right kind of conditions to cover up the mud at just
the right time. Then, after it became rock, the impression would have to
be brought back to the surface as the continents shifted, split and bashed
into each other.
In the end, Knecht admits, he got lucky by being lost.
The day before the discovery last spring, he had come up dry looking for
fossils in North Attleboro. But as darkness closed in, he hammered one
rock, it split open and he found a perfect footprint from a four-fingered
amphibian, complete with knuckles and creases. He decided to return the
Instead, the next day, he got lost.
At one rock outcrop, he gripped a broken edge, it came off in his hand,
"and there was the dragonfly, or what we're calling the dragonfly. I
didn't even use a hammer. It was already split from natural erosion. I
just opened it and there it was" in a layer of dark-red rock unique to
this area, called the Wamsutta formation, he said.
The estimated age of 312 million years, give or take 3 million years, is
based on chemical testing of the rock type below and the types of younger
fossils typically found in the type of rock above.
"It was a really lucky find. Had a couple more years gone by, it might
have been lost forever," said Knecht. "Because it was on the outside of
this rock formation, wind and rain would have gotten in there. It would
have frozen. It probably would have cracked, and then it would have been
"That was a good day."
Ing. Yasmani Ceballos Izquierdo <email@example.com
__________ Information from ESET NOD32 Antivirus, version of virus
signature database 3667 (20081205) __________
The message was checked by ESET NOD32 Antivirus.