Microtomographic reconstruction of the head and anterior trunk (“body”) limbs of the trilobite Protolenus (Hupeolenus) in ventral view.
© Arnaud MAZURIER, IC2MP, Univ. Poitiers
Paleontologists have discovered a site in Morocco where hundreds of trilobites and other Cambrian species have been preserved by a pyroclastic flow of hot volcanic ash that preserved them in exquisite details. They have nicknamed them 'Pompeii' trilobites after the town near Naples in Italy similarly preserved by volcanic ash from Vesuvius, almost as a snapshot of a living Roman town, complete with molds of the bodies of people killed as they slept.
The trilobites were quickly embedded in volcanic ash and even their digestive tracts were preserved as they filled with the ash.
This means, of course, that the fossils can be dated extremely accurately using the uranium/lead (U-Pb) ratios in zircon crystals in the volcanic ash.
Tell me about Cambrian trilobites from what is now Morocco. Cambrian trilobites from what is now Morocco are among the most well-preserved and diverse examples of these ancient marine arthropods. During the Cambrian period, which lasted from approximately 541 to 485 million years ago, Morocco was part of the ancient continent of Gondwana. This region was covered by shallow seas that provided an ideal environment for the flourishing of trilobites and other marine life.The scientists, led by Professor Abderrazak El Albani, a geologist based at University of Poitiers, France and originally from Morocco, and including Harry Berks and Philip Donoghue from the University of Bristol’s School of Earth Sciences, are now able to describe trilobite anatomy, complete with soft body parts and even the commensal lamp shell brachiopods that attached themselves to them by delicate stalks. Their findings are published in the journal Science and described in a press release from the University of Bristol:
Key Points about Cambrian Trilobites from Morocco:
Examples of Specific Fossil Sites:
- Diversity and Abundance:
- Moroccan Cambrian trilobites exhibit a wide range of forms and sizes, reflecting the high biodiversity of the Cambrian seas. Over 150 species of Cambrian trilobites have been described from Morocco, highlighting the region's importance as a site for studying early trilobite evolution.
- Preservation:
- The trilobites found in Morocco are often exceptionally well-preserved, with detailed exoskeletons that allow paleontologists to study their morphology in great detail. This excellent preservation is due to the fine-grained sediments that covered these organisms rapidly after death, preventing decomposition and scavenging.
- Notable Genera:
- Some notable genera of Cambrian trilobites from Morocco include Olenellus, Paradoxides, and Ellipsocephalus. These genera are important for biostratigraphic studies, helping scientists to correlate rock layers across different geographic regions.
- Geological Formations:
- The Cambrian trilobites in Morocco are primarily found in the Anti-Atlas region, particularly within the Fezouata Formation. This formation is renowned for its rich fossil content and has provided critical insights into the early Cambrian ecosystems.
- Scientific Significance:
- The discovery of Cambrian trilobites in Morocco has significantly contributed to the understanding of early arthropod evolution and the Cambrian Explosion, a period marked by a rapid diversification of life forms. The Moroccan trilobite fossils have provided evidence of early developmental stages, feeding structures, and behaviors.
- Economic and Cultural Impact:
- Fossil collecting and trade have become an important economic activity in Morocco. The sale of trilobite fossils to collectors and museums around the world has brought economic benefits to local communities. Additionally, these fossils have fostered a greater appreciation of Morocco's rich natural heritage.
- Jbel Wawrmast: Known for well-preserved specimens of Paradoxides and other genera.
- Tazemmourt: A site where many new species have been described, contributing to the understanding of trilobite diversity and distribution during the Cambrian.
In conclusion, Cambrian trilobites from Morocco are a vital part of the paleontological record, offering a window into the ancient marine ecosystems of the Cambrian period. Their diversity, excellent preservation, and the scientific insights they provide make them invaluable to researchers and enthusiasts alike.
Prehistoric Pompeii’ - Trilobites killed by volcanic ash reveal features never seen before
Some of the most perfectly preserved trilobite fossils ever found have revealed details of the extinct arthropod unknown until now.
The new specimens, which were killed and fossilised quickly when volcanic ash smothered them underwater more than 500 million years ago, show details never before seen in any trilobite, despite the millions of fossils gathered and studied over the past two centuries.
The trilobites, which are from the Cambrian period, have been the subject of research by an international team of scientists, led by Professor Abderrazak El Albani, geologist based at University of Poitiers and originally from Morocco. This international team include co-authors Harry Berks and Philip Donoghue from the University of Bristol’s School of Earth Sciences.
They discovered clustering of specialised leg pairs around the mouth giving a clearer picture of how trilobites fed.
The head and body appendages had an inward-facing battery of dense spines like those of horseshoe crabs, manipulating and tearing prey or scavenged carcasses as they were moved forwards to the mouth. The mouth, a narrow slit behind a fleshy lobe called a labrum, known in living arthropods, has never been so clearly seen in a trilobite before.
Harry O. Berks, co-author
Bristol Palaeobiology Group
School of Earth Sciences
University of Bristol, Bristol, UK.
The appendages at the edge of the mouth have curved bases like spoons and are so small that they went undetected in less perfectly preserved fossils.
It was widely thought that trilobites had three pairs of head appendages behind their long antennae but both Moroccan species show that there were four pairs.
The Moroccan trilobites date to the Cambrian Period, about 515 million years ago. The fossils are found in rock composed of volcanic ash, deposited on the shallow seafloor on which the trilobites lived. The trilobites, and even tiny ‘lamp shells’ (brachiopods) that attached to them via a delicate stalk in life, were killed by the hot, suffocating ash and were fossilised very quickly when the ash that encased them transformed to rock. The outer surface of the trilobites, all of their legs and the lamp shells hitching a ride on them were molded as impressions in the volcanic rock, while the trilobites’ digestive tract was preserved after it filled with ash.
To see how these impressions in the rock looked just after the trilobites died, the team used a high-resolution X-ray micro-tomography (XRµCT). X-rays detect the difference in density between the rock in which a trilobite was molded and the empty (air) space where the body was before it was obliterated. Co-author, Harry Berks, used computer modelling of X-ray slices through the fossils to study the anatomy of the entire body of the trilobites in 3-dimensions, freed from the surrounding rock.
The computer work is pains-taking but it’s definitely been worth it. These trilobites look so alive, it’s almost as though they could crawl out of the rock.
Harry O. Berks.
The ‘Pompei’ trilobites are so remarkable because they are not flattened or deformed like many fossils and every leg is arranged as it was in life, with even small spines and sensory bristles along the joints of the legs preserved.
I’ve been studying trilobites for nearly 40 years, but I never felt like I was looking at live animals as much as I have with these ones.
Gregory D. Edgecombe, co-author
The Natural History Museum, London, UK.
The study sheds new light on the anatomy and biology of the long-vanished trilobites but also signals the enormous potential for volcanic ash deposited in shallow marine settings as a setting to search for exceptionally preserved fossils.
Trilobites are a completely extinct kind of arthropod, the group of jointed-legged animals that includes more than a million species of insects, crabs, spiders, and centipedes alive today. They are one of the most abundant and diverse lifeforms in fossil deposits of the Palaeozoic Era, surviving from 521 million years ago to 250 million years ago. Palaeontologists have described more than 20,000 species of trilobites, ranging in body length from less than two millimetres to more than 90 centimetres. Most trilobite species are only known from their hard exoskeleton (like a lobster’s shell), but only about 30 species preserve a pair of antennae and/or pairs of two-branched legs under the head shield and each segment of the body.No one expects to find fossils in volcanic rocks but our study shows that volcanic ash deposits are definitely worth a look. Who knows what secrets remains to be discovered in these understudied rocks?
Philip C. J. Donoghue, co-author
Bristol Palaeobiology Group
School of Earth Sciences
University of Bristol, Bristol, UK.
The paper:
'Rapid volcanic ash entombment reveals the 3D anatomy of Cambrian trilobites' by El Albani A, Donoghue P.C.J, Berks, H.O et al in Science.
Sadly, the team's paper in Science is behind a paywall, so we only have the abstract:
AbstractThis evidence, backed up by the irrefutable evidence of the 515 million year geochronology of the volcanic ash, is just something else for creationists to dismiss on the basis that if it doesn't agree with their preconception, the science must be wrong because a bunch of Bronze Age myth-makers were infallible - because they agreed with creationists.
Knowledge of Cambrian animal anatomy is limited by preservational processes that result in compaction, size bias, and incompleteness. We documented pristine three-dimensional (3D) anatomy of trilobites fossilized through rapid ash burial from a pyroclastic flow entering a shallow marine environment. Cambrian ellipsocephaloid trilobites from Morocco are articulated and undistorted, revealing exquisite details of the appendages and digestive system. Previously unknown anatomy includes a soft-tissue labrum attached to the hypostome, a slit-like mouth, and distinctive cephalic feeding appendages. Our findings resolve controversy over whether the trilobite hypostome is the labrum or incorporates it and establish crown-group euarthropod homologies in trilobites. This occurrence of moldic fossils with 3D soft parts highlights volcanic ash deposits in marine settings as an underexplored source for exceptionally preserved organisms.
And so, their dismissal of it will be yet more evidence of the arrogance and intellectual bankruptcy that hides behind religion of the creation cult and the frauds who lead it.
What Makes You So Special? From The Big Bang To You
How did you come to be here, now? This books takes you from the Big Bang to the evolution of modern humans and the history of human cultures, showing that science is an adventure of discovery and a source of limitless wonder, giving us richer and more rewarding appreciation of the phenomenal privilege of merely being alive and able to begin to understand it all.
Available in Hardcover, Paperback or ebook for Kindle
Ten Reasons To Lose Faith: And Why You Are Better Off Without It
This book explains why faith is a fallacy and serves no useful purpose other than providing an excuse for pretending to know things that are unknown. It also explains how losing faith liberates former sufferers from fear, delusion and the control of others, freeing them to see the world in a different light, to recognise the injustices that religions cause and to accept people for who they are, not which group they happened to be born in. A society based on atheist, Humanist principles would be a less divided, more inclusive, more peaceful society and one more appreciative of the one opportunity that life gives us to enjoy and wonder at the world we live in.
Available in Hardcover, Paperback or ebook for Kindle
No comments:
Post a Comment
Obscene, threatening or obnoxious messages, preaching, abuse and spam will be removed, as will anything by known Internet trolls and stalkers, by known sock-puppet accounts and anything not connected with the post,
A claim made without evidence can be dismissed without evidence. Remember: your opinion is not an established fact unless corroborated.