Study methods may help with future interpretation of evolutionary history.
COLUMBIA, Mo. – The Cambrian Period is a time when most phyla of marine invertebrates first appeared in the fossil record. Also dubbed the “Cambrian explosion,” fossilized records from this time provide glimpses into evolutionary biology when the world’s ecosystems rapidly changed and diversified. Most fossils show the organisms’ skeletal structure, which may or may not give researchers accurate pictures of these prehistoric organisms. Now, researchers at the University of Missouri have found rare, fossilized embryos they believe were undiscovered previously. Their methods of study may help with future interpretation of evolutionary history. (more…)
A fossil creature buried in an “invertebrate version of Pompeii” more than half a billion years ago reveals the first-known cardiovascular system in exquisitely preserved detail.
An international team of researchers from the University of Arizona, China and the United Kingdom has discovered the earliest known cardiovascular system, and the first to clearly show a sophisticated system complete with heart and blood vessels, in fossilized remains of an extinct marine creature that lived over half a billion years ago. The finding sheds new light on the evolution of body organization in the animal kingdom and shows that even the earliest creatures had internal organizational systems that strongly resemble those found in their modern descendants. (more…)
Christopher Cameron of the University of Montreal’s Department of Biological Sciences and his colleagues have unearthed a major scientific discovery – a strange phallus-shaped creature they found in Canada’s Burgess Shale fossil beds, located in Yoho National Park. The fossils were found in an area of shale beds that are 505 million years old.
Their study published online in the journal Nature on March 13, 2013, confirms Spartobranchus tenuis is a member of the acorn worms group which are seldom-seen animals that thrive today in the fine sands and mud of shallow and deeper waters. Acorn worms are themselves part of the hemichordates, a group of marine animals closely related to today’s sea stars and sea urchins. “Unlike animals with hard parts including teeth, scales and bones, these worms were soft-bodied, so their fossil record is extremely rare,” said author Dr. Chris Cameron of the University of Montreal. “Our description of Spartobranchus tenuis, a creature previously unknown to science, pushes the fossil record of the enteropneusts back 200 million years to the Cambrian period, fundamentally changing our understanding of biodiversity from this period.” (more…)
When it comes to evolution, humans can learn a thing or two from primeval sea lampreys.
In the current issue of Nature Genetics, a team of scientists has presented an assembly of the sea lamprey genome – the first time the entire sequence has been decoded. The data is compelling as the sea lamprey is one of the few ancient, jawless species that has survived through the modern era.
The paper not only sheds light on how the venerable invasive species adapted and thrived, but it also provides many insights into the evolution of all vertebrates, species with backbones and spinal cords, which includes humans, said Weiming Li, Michigan State University fisheries and wildlife professor, who organized and coordinated the team. (more…)
Complex brains evolved much earlier than previously thought, as evidenced by a 520-million-year-old fossilized arthropod with remarkably well-preserved brain structures.
The remarkably well-preserved fossil of an extinct arthropod shows that anatomically complex brains evolved earlier than previously thought and have changed little over the course of evolution. According to University of Arizona neurobiologist Nicholas Strausfeld, who co-authored the study describing the specimen, the fossil is the earliest known to show a brain.
The discovery will be published in the Oct. 11 issue of the journal Nature. (more…)
A fossil unearthed in Great Britain may end a long-running debate about the mollusks, one of life’s most diverse invertebrate groups: Which evolved first, shelled forms like clams and snails, or their shell-less, worm-like relatives?
The small new fossil, found in marine rocks along the English-Welsh border, provides the best fossil evidence yet that the simpler worm-like mollusksevolved from their more anatomically complex shelled brethren, rather than the other way around. (more…)
There is evidence that some microbial life had migrated from the Earth’s oceans to land by 2.75 billion years ago, though many scientists believe such land-based life was limited because the ozone layer that shields against ultraviolet radiation did not form until hundreds of millions years later.
But new research from the University of Washington suggests that early microbes might have been widespread on land, producing oxygen and weathering pyrite, an iron sulfide mineral, which released sulfur and molybdenum into the oceans. (more…)
Paleontologists have discovered that a group of remarkable ancient sea creatures existed for much longer and grew to much larger sizes than previously thought, thanks to extraordinarily well-preserved fossils discovered in Morocco.
The creatures, known as anomalocaridids, were already thought to be the largest animals of the Cambrian period, known for the “Cambrian Explosion” that saw the sudden appearance of all the major animal groups and the establishment of complex ecosystems about 540 to 500 million years ago. Fossils from this period suggested these marine predators grew to be about two feet long. Until now, scientists also thought these strange invertebrates-which had long spiny head limbs presumably used to snag worms and other prey, and a circlet of plates around the mouth-died out at the end of the Cambrian. (more…)
