In a 520 myo arthropod fossil from the Cambrian. Up until now just brains have been found. No precursors:-https://www.sciencedaily.com/releases/2016/02/160229153517.htm-"The animal, called Chengjiangocaris kunmingensis, lived during the Cambrian ‘explosion', a period of rapid evolutionary development about half a billion years ago when most major animal groups first appear in the fossil record. C. kunmingensis belongs to a group of animals called fuxianhuiids, and was an early ancestor of modern arthropods - the diverse group that includes insects, spiders and crustaceans.-***-"Like modern arthropods, C. kunmingensis had a nerve cord - which is analogous to a spinal cord in vertebrates - running throughout its body, with each one of the bead-like ganglia controlling a single pair of walking legs.-"Closer examination of the exceptionally preserved ganglia revealed dozens of spindly fibres, each measuring about five thousandths of a millimetre in length. “These delicate fibres displayed a highly regular distribution pattern, and so we wanted to figure out if they were made of the same material as the ganglia that form the nerve cord,” said Ortega-Hernández. “Using fluorescence microscopy, we confirmed that the fibres were in fact individual nerves, fossilised as carbon films, offering an unprecedented level of detail. These fossils greatly improve our understanding of how the nervous system evolved.”-"For Ortega-Hernández and his colleagues, a key question is what this discovery tells us about the evolution of early animals, since the nervous system contains so much information. Further analysis revealed that some aspects of the nervous system in C. kunmingensis appear to be structured similar to that of modern priapulids (penis worms) and onychophorans (velvet worms), with regularly-spaced nerves coming out from the ventral nerve cord.-"In contrast, these dozens of nerves have been lost independently in the tardigrades (water bears) and modern arthropods, suggesting that simplification played an important role in the evolution of the nervous system."-Comment: Following Denton, he would assume his 'Types' appeared in the Cambrian and then were later modified, but traceable to the original. Note our spinal cord is dorsal in comparison.

Found quite definitively in another Cambrian animal:

https://www.livescience.com/new-athropod-fossil-brains-found.html

"Scientists discovered these splotchy marks in fossils of the arthropod Alalcomenaeus, an animal which shares its phylum with modern insects, spiders and crustaceans. The animals lived during the Cambrian period, which took place between about 543 million and 490 million years ago, and sported a tough exoskeleton that fossilized well. But the soft tissues of the creature's brain and nerves often decayed and therefore disappeared from the fossil record.

***

"Besides Ortega-Hernández and his team, only a handful of researchers have reported finding fossilized nervous tissue in Cambrian-period arthropods. In a 2012 paper, scientists described the first evidence of a fossilized arthropod brain, in a tiny creature called Fuxianhuia protensa. Although widely covered in the media, the report attracted critics.

***

"In their study, Ortega-Hernández and his co-authors uncovered a new Alalcomenaeus fossil buried in Utah within a region of geological depressions known as the American Great Basin. The authors noted symmetrical stains along the creature's midline that resembled nervous system structures found in some modern arthropods, including horseshoe crabs, spiders and scorpions. "The nervous system and the gut kind of cross each other, which is really funky but common in arthropods nowadays," Ortega-Hernández told Live Science.

***

"The stains also contained detectable levels of carbon, a key element in nervous tissue. The dark splotches also plugged into the animal's four eyes, as would be expected for nervous system tissue. Having checked all these criteria, Ortega-Hernández said that he could confidently report finding fossilized nervous tissue in the newfound specimen.

"But to double-check their findings, the authors also examined a second Alalcomenaeus fossil from the American Great Basin. Originally dug up in the 1990s, the specimen sported similar stains and carbon traces to the newfound fossil. What's more, both Great Basin fossils matched descriptions of another specimen that Strausfeld found in China. All three fossils had been found buried in similar deposits, indicating that a unique preservation process allowed all their brain matter to fossilize, Ortega-Hernández said.

***

"More work must be done to clarify the role of sediment in fossil preservation, but as of now, ample evidence suggests that arthropod remains placed under intense pressure solidify over time, Strausfeld said. The brain and nerves within the animal flatten out in the process, and because nervous tissue contains lots of fat, the structures repel water and "have some resistance against decay," he said.

"Despite the evidence in their favor, Ortega-Hernández, Strausfeld and their colleagues may need to dig up a lot more arthropod brain bits to convince naysayers that ancient brains can fossilize."

Comment: Some scientists may be doubtful, but logic tells us if eyes are present and limbs that must have moved are found, there was a nervous system to run the show. And this means, most significantly, a complete nervous system appeared with no precursors. Darwin's cAmbrian gap strikes again!!

In a very early worm from 525 million years ago:

https://phys.org/news/2022-11-million-year-old-fossil-defies-textbook-explanation.html

"A study published in Science—led by Nicholas Strausfeld, a Regents Professor in the University of Arizona Department of Neuroscience, and Frank Hirth, a reader of evolutionary neuroscience at King's College London—provides the first detailed description of Cardiodictyon catenulum, a wormlike animal preserved in rocks in China's southern Yunnan province. Measuring barely half an inch (less than 1.5 centimeters) long and initially discovered in 1984, the fossil had hidden a crucial secret until now: a delicately preserved nervous system, including a brain.

"To our knowledge, this is the oldest fossilized brain we know of, so far," Strausfeld said.

"Cardiodictyon belonged to an extinct group of animals known as armored lobopodians, which were abundant early during a period known as the Cambrian, when virtually all major animal lineages appeared over an extremely short time between 540 million and 500 million years ago. Lobopodians likely moved about on the sea floor using multiple pairs of soft, stubby legs that lacked the joints of their descendants, the euarthropods—Greek for "real jointed foot." Today's closest living relatives of lobopodians are velvet worms that live mainly in Australia, New Zealand and South America.

***

"'From the 1880s, biologists noted the clearly segmented appearance of the trunk typical for arthropods, and basically extrapolated that to the head," Hirth said. "That is how the field arrived at supposing the head is an anterior extension of a segmented trunk."

"'But Cardiodictyon shows that the early head wasn't segmented, nor was its brain, which suggests the brain and the trunk nervous system likely evolved separately," Strausfeld said.

"Cardiodictyon was part of the Chengjiang fauna, a famous deposit of fossils in the Yunnan Province discovered by paleontologist Xianguang Hou. The soft, delicate bodies of lobopodians have preserved well in the fossil record, but other than Cardiodictyon none have been scrutinized for their head and brain, possibly because lobopodians are generally small. The most prominent parts of Cardiodictyon were a series of triangular, saddle-shaped structures that defined each segment and served as attachment points for pairs of legs. Those had been found in even older rocks dating back to the advent of the Cambrian.

"'That tells us that armored lobopodians might have been the earliest arthropods," Strausfeld said, predating even trilobites, an iconic and diverse group of marine arthropods that went extinct around 250 million years ago.

***

"In their new study, the authors not only identified the brain of Cardiodictyon but also compared it with those of known fossils and of living arthropods, including spiders and centipedes. Combining detailed anatomical studies of the lobopodian fossils with analyses of gene expression patterns in their living descendants, they conclude that a shared blueprint of brain organization has been maintained from the Cambrian until today.

"'By comparing known gene expression patterns in living species," Hirth said, "we identified a common signature of all brains and how they are formed."

***

"'At a time when major geological and climatic events were reshaping the planet, simple marine animals such as Cardiodictyon gave rise to the world's most diverse group of organisms—the euarthropods—that eventually spread to every emergent habitat on Earth, but which are now being threatened by our own ephemeral species.'"

Comment: A brain is so complex, how did the first ones evolve? Design explains all.

The abstract of this articles makes a blatant attempt to get rid of the gap, but what does it really tell us? Not much:

https://www.nature.com/articles/s41559-019-0821-6

"Abstract

The ‘Cambrian Explosion’ describes the rapid increase in animal diversity and abundance, as manifest in the fossil record, between ~540 and 520 million years ago (Ma). This event, however, is nested within a far more ancient record of macrofossils extending at least into the late Ediacaran at ~571 Ma. The evolutionary events documented during the Ediacaran–Cambrian interval coincide with geochemical evidence for the modernisation of Earth’s biogeochemical cycles. Holistic integration of fossil and geochemical records leads us to challenge the notion that the Ediacaran and Cambrian worlds were markedly distinct, and places biotic and environmental change within a longer-term narrative. We propose that the evolution of metazoans may have been facilitated by a series of dynamic and global changes in redox conditions and nutrient supply, which, potentially together with biotic feedbacks, enabled turnover events that sustained multiple phases of radiation. We argue that early metazoan diversification should be recast as a series of successive, transitional radiations that extended from the late Ediacaran and continued through the early Palaeozoic. We conclude that while the Cambrian Explosion represents a radiation of crown-group bilaterians, it was simply one phase amongst several metazoan radiations, some older and some younger."

Comment: This glosses over the gap which still exists. Yes, there were bilatarians before the Cambrian and yes, the Cambrians were bilateral, but only the Cambrians had a full set of differently functioning organs, styles of motility, eyes, etc. This is another example of having to carefully interpreting the blatant PR as atheist scientists try any way they can to obliterate the gap.

I didn't offer the title of the article:

"Integrated records of environmental change and evolution challenge the Cambrian Explosion"

The article does not challenge the gap, but makes a big hubbub about the activity in the Ediacaran period when many soft-bodied forms did appear. The 'gap' is in the magnitude of the differences in the biologic forms within the two periods of time. The magnitude of evolutionary change in the Ediacaran is obvious but this article uses a sleight-of-hand writing to make it seem activity alone can hide the gap. Ridiculous propaganda.

Another transparent attempt:

https://cosmosmagazine.com/palaeontology/inside-out-ediacaran-fossils-might-represent-i...

"The Ediacarans are weird-looking things. Estimated to be over 560 million years old, they offer the best answer to Darwin’s dilemma: what preceded the Cambrian explosion which spawned the prototypes of most modern animals 541 million year ago?

"But Ediacaran organisms, the ancient fossils of which have been found worldwide, throw up their own dilemmas. For one, what exactly were they? Some resemble plants but aren’t because they lived in seas too deep to access light; others have a trifold symmetry that doesn’t exist anymore. But some were bilaterally symmetrical and these are the best candidates for prototypes of today’s animals.

"But beyond Darwin’s dilemma lies another one – more mundane, but no less pressing to scientists.

"Ediciacarans were soft bodied, evidenced by the fact that fossils depict them folded over or with bits torn off. How then did they fossilise? They aren’t like trilobites or dinosaur bones.
Rather than petrified 3D replicas of the original, they are impressions stamped into sandstone.

***

"Now palaeontologist Ilya Bobrovskiy from the Australian National University (ANU) and colleagues have come up with a new explanation. No death masks are required, they say. Rather, they propose in an article in the journal Nature Ecology and Evolution, the flow properties, or rheology, of different sediments could explain the imprints.

“'It’s a welcome addition,” says Guy Narbonne, a palaeontologist from Queens University in Canada, who works on Ediacaran sites in Newfoundland, “but it does not necessarily do away with other models.”

"The death mask theory to explain Ediacaran impression fossils holds up well for places such as Australia’s Flinders Ranges – where the fossils were first discovered in 1947 at a site called Ediacara Hills – and Mistaken Point in Newfoundland.

***

"When it comes to the mechanism of preservation at the White Sea, “it’s been a blank”, says Narbonne, “I think this paper is important, arguing that the prevailing preservation mechanisms are not part of the equation.”

"He adds, though: “It doesn’t eliminate other possibilities. Like all good science, it raises nearly as many questions as it answers.”

"For Jim Gehling, a palaeontologist at the South Australian Museum and expert on the Flinders Ranges Ediacarans, the theory “fails to explain the vast array of photographed and cast specimens of Dickinsonia fossils that include evidence of torn specimens, folded over specimens and serial ‘resting traces’ — regarded as evidence of staged movement.”

"Palaeontologist Alex Liu from Cambridge University, UK, sees a middle path. “I think that the most likely scenario is that both early cementation and the effects of rheology acted in combination to preserve Ediacaran fossils in the Flinders and elsewhere,” he says."

Comment: The Ediacaran fossils that are found do not show internal organs and this study blames that on the methods of fossilization. The approach seems to be: If there were organs, perhaps the Cambrian gap isn't so big? That ignores the vast phenotypic changes in the Cambrian. Among Darwinists hope springs eternal.