Amazing fossils recently discovered from the Cambrian

Amazing fossils recently discovered from the Cambrian

https://reasonandscience.catsboard.com/t3179-recently-discovered-fossils-of-species-from-the-cambrian

Evolutionary biologists cannot offer an explanation for the sudden appearance in the fossil record of diverse life-forms with no discernible ancestral forms.


Royal Ontario Museum Burgess Shale Expeditions (1975-ongoing)
https://burgess-shale.rom.on.ca/en/history/discoveries/05-rom.php

Royal Ontario Museum: Massive new animal species discovered in half-billion-year-old Burgess Shale Sept 8, 2021
Palaeontologists at the Royal Ontario Museum (ROM) have uncovered the remains of a huge new fossil species belonging to an extinct animal group in half-a-billion-year-old Cambrian rocks from Kootenay National Park in the Canadian Rockies. The findings were announced on September 8, 2021, in a study published in Royal Society Open Science.

Named Titanokorys gainesi, this new species is remarkable for its size. With an estimated total length of half a meter, Titanokorys was a giant compared to most animals that lived in the seas at that time, most of which barely reached the size of a pinky finger.

“The sheer size of this animal is absolutely mind-boggling, this is one of the biggest animals from the Cambrian period ever found,” says Jean-Bernard Caron, ROM's Richard M. Ivey Curator of Invertebrate Palaeontology.

Titanokorys belongs to a group of primitive arthropods called radiodonts. The most iconic representative of this group is the streamlined predator Anomalocaris, which may itself have approached a metre in length. Like all radiodonts, Titanokorys had multifaceted eyes, a pineapple slice-shaped, tooth-lined mouth, a pair of spiny claws below its head to capture prey and a body with a series of flaps for swimming. Within this group, some species also possessed large, conspicuous head carapaces, with Titanokorys being one of the largest ever known.

Titanokorys is part of a subgroup of radiodonts, called hurdiids, characterized by an incredibly long head covered by a three-part carapace that took on myriad shapes. The head is so long relative to the body that these animals are really little more than swimming heads.

Why some radiodonts have such a bewildering array of head carapace shapes and sizes is still poorly understood and was likely driven by a variety of factors, but the broad flattened carapace form in Titanokorys suggests this species was adapted to life near the seafloor.

These enigmatic animals certainly had a big impact on Cambrian seafloor ecosystems. Their limbs at the front looked like multiple stacked rakes and would have been very efficient at bringing anything they captured in their tiny spines towards the mouth. The huge dorsal carapace might have functioned like a plough.

All fossils in this study were collected around Marble Canyon in northern Kootenay National Park by successive ROM expeditions. Discovered less than a decade ago, this area has yielded a great variety of Burgess Shale animals dating back to the Cambrian period, including a smaller, more abundant relative of Titanokorys named Cambroraster falcatus in reference to its Millennium Falcon-shaped head carapace. According to the authors, the two species might have competed for similar bottom-dwelling prey.

The Burgess Shale fossil sites are located within Yoho and Kootenay National Parks and are managed by Parks Canada. Parks Canada is proud to work with leading scientific researchers to expand knowledge and understanding of this key period of earth history and to share these sites with the world through award-winning guided hikes. The Burgess Shale was designated a UNESCO World Heritage Site in 1980 due to its outstanding universal value and is now part of the larger Canadian Rocky Mountain Parks World Heritage Site.


Reuters: Meet Titanokorys gainesi, one of Earth’s largest predators 500 million years ago September 9, 2021
The name Titanokorys means "titanic helmet," and for good reason. This creature's head carapace represented about two-thirds of its body length of roughly 50 cm.

( Supposedly ) about 506 million years ago, a strange marine creature whose body so resembled a science-fiction spacecraft that it has been dubbed ‘the mothership’ thrived in tropical seas, menacing prey on the ocean floor in what is now Canada as one of Earth’s largest predators to that point in time. Scientists announced the discovery of fossils of a Cambrian Period arthropod named Titanokorys gainesi in Kootenay National Park in the Canadian Rockies, within a vast rock formation called the Burgess Shale.

The name Titanokorys means “titanic helmet,” and for good reason. This creature’s head carapace represented about two-thirds of its body length of roughly 20 inches (50 cm). While that may not sound big by modern standards, during the Cambrian Period – a pivotal juncture in the history of life on Earth – it was a giant.
https://indianexpress.com/article/technology/science/meet-titanokorys-gainesi-earths-largest-predators-500-million-years-ago-7498506/

J.-B. Caron A giant nektobenthic radiodont from the Burgess Shale and the significance of hurdiid carapace diversity 08 September 2021
https://royalsocietypublishing.org/doi/10.1098/rsos.210664






https://www.youtube.com/watch?v=dgSb2njfJ5Y


The discovery of Titanokorys gainesi was profiled in the CBC’s The Nature of Things episode “First Animals”. These and other Burgess Shale specimens will be showcased in a new gallery at ROM, the Willner Madge Gallery, Dawn of Life, opening in December 2021.
https://www.rom.on.ca/en/about-us/newsroom/press-releases/massive-new-animal-species-discovered-in-half-billion-year-old

Royal Ontario Museum: A Voracious Cambrian Predator, Cambroraster, is a New Species from the Burgess Shale Discovered by ROM Palaeontologists July 31, 2019
Palaeontologists at the Royal Ontario Museum and University of Toronto have uncovered fossils of a large new predatory species in half-a-billion-year-old rocks from Kootenay National Park in the Canadian Rockies. This new species has rake-like claws and a pineapple-slice-shaped mouth at the front of an enormous head, and it sheds light on the diversity of the earliest relatives of insects, crabs, spiders, and their kin. The findings were announced July 31, 2019, in a study published in Proceedings of the Royal Society B.



Cambroraster: New Species from the Burgess Shale Discovered by ROM Palaeontologists
https://www.youtube.com/watch?v=m7zGEITBc9E&t=4s


https://www.rom.on.ca/en/about-us/newsroom/press-releases/a-voracious-cambrian-predator-cambroraster-is-a-new-species-from

A new hurdiid radiodont from the Burgess Shale evinces the exploitation of Cambrian infaunal food sources Proceedings of the Royal Society B
http://dx.doi.org/10.1098/rspb.2019.1079

Royal Ontario Museum: A 508 Million-year-old Sea Predator with a “Jackknife” Head December 21, 2017

Oldest close parent of spiders, scorpions and horseshoe crabs evolved sophisticated head to hunt and eat small shelly animals

TORONTO, December 21, 2017— Paleontologists from the Royal Ontario Museum (ROM) and University of Toronto (U of T) have entirely revisited a tiny yet exceptionally fierce ancient sea creature called Habelia optata that has confounded scientists since it was first discovered more than a century ago. The research by lead author Cédric Aria, recent graduate of the PhD program in the department of ecology & evolutionary biology in the Faculty of Arts & Science at U of T, and co-author Jean-Bernard Caron, senior curator of invertebrate palaeontology at the ROM and an associate professor in the departments of ecology & evolutionary biology and earth sciences at U of T, is published today in BMC Evolutionary Biology a tail as long as the rest of its body, the long-extinct Habelia optata belongs to the group of invertebrate animals called arthropods, which also includes such familiar creatures as spiders, insects, lobsters and crabs. It lived during the middle Cambrian period approximately 508 million years ago and comes from the renowned Burgess Shale fossil deposit in British Columbia. Habelia optata was part of the “Cambrian explosion,” a period of rapid evolutionary change when most major animal groups first emerged in the fossil record.


Like all arthropods, Habelia optata features a segmented body with external skeleton and jointed limbs. What remained unclear for decades, however, was the main sub-group of arthropods to which Habelia belonged. Early studies had mentioned mandibulates — a hyperdiverse lineage whose members possess antennae and a pair of specialized appendages known as mandibles, usually used to grasp, squeeze and crush their food. But Habelia was later left as one of the typically unresolved arthropods of the Burgess Shale.
The new analysis by the U of T and ROM researchers suggests that Habelia optata was instead a close relative of the ancestor of all chelicerates, the other sub-group of arthropods living today, named for the presence of appendages called chelicerae in front of the mouth and used to cut food. This is mostly due to the overall anatomy of the head in Habelia, and the presence of two small chelicerae-like appendages revealed in these fossils.
“Habelia now shows in great detail the body architecture from which chelicerates emerged, which allows us to solve some long-standing questions," said Aria, who is now a post-doctoral researcher at the Nanjing Institute of Geology and Palaeontology, in China. "We can now explain why, for instance, horseshoe crabs have a reduced pair of limbs – the chilaria – at the back of their heads. Those are relics of fully-formed appendages, as chelicerates seem to originally have had heads with no less than seven pairs of limbs."
Aria and Caron analyzed 41 specimens in total, the majority of which are new specimens acquired by ROM-led fieldwork parties to the Burgess Shale.
The research illustrates that the well-armoured body of Habelia optata, covered in a multitude of different spines, was divided into head, thorax and post-thorax, all bearing different types of appendages. The thorax displays five pairs of walking legs, while the post-thorax houses rounded appendages likely used in respiration.
“Scorpions and the now-extinct sea scorpions are also chelicerates with bodies divided into three distinct regions,” Aria explained. “We think that these regions broadly correspond to those of Habelia. But a major difference is that scorpions and sea scorpions, like all chelicerates, literally ‘walk on their heads,’ while Habelia still had walking appendages in its thorax.”
The researchers argue that this difference in anatomy allowed Habelia to evolve an especially complex head that makes this fossil species even more peculiar compared to known chelicerates. The head of Habelia contained a series of five appendages made of a large plate with teeth for mastication, a leg-like branch with stiff bristle-like spines for grasping, and an elongate, slender branch modified as a sensory or tactile appendage.
"This complex apparatus of appendages and jaws made Habelia an exceptionally fierce predator for its size," said Aria. “It was likely both very mobile and efficient in tearing apart its prey.”
The surprising outcome of this study, despite the evolutionary relationship of Habelia with chelicerates, is that these unusual characteristics led instead the researchers to compare the head of Habelia with that of mandibulates from a functional perspective. Thus, the peculiar sensory branches may have been used in a similar fashion as mandibulates use antennae. Also, the overlapping plate-like appendages in the middle series of five are shown to open and close parallel to the underside of the head — much as they do in mandibulates, especially those that feed on animals with hardened carapaces.
Lastly, a seventh pair of appendages at the back of the head seems to have fulfilled a function similar to that of “maxillipeds” — appendages in mandibulates that assist with the other head limbs in the processing of food. This broad correspondence in function rather than in evolutionary origin is called “convergence.”
"From an evolutionary point of view, Habelia is close to the point of divergence between chelicerates and mandibulates," Aria said. "But its similarities with mandibulates are secondary modifications of features that were in part already chelicerate in nature. This suggests that chelicerates originated from species with a high structural variability."
The researchers conclude from the outstanding head structure, as well as from well-developed walking legs, that Habelia optata and its relatives were active predators of the Cambrian sea floors, hunting for small shelly sea creatures, such as small trilobites—arthropods with hard, mineralized exoskeletons that were already very diverse and abundant during Cambrian times.
“This builds onto the importance of carapaces and shells for evolutionary change during the Cambrian explosion, and expands our understanding of ecosystems at this time, showing another level of predator-prey relationship and its determining impact on the rise of arthropods as we know them today,” said Caron, who was Aria’s PhD supervisor when the bulk of this research was completed.
"The appearance and spread of animals with shells are considered to be one of the defining characteristics of the Cambrian explosion, and Habelia contributes to illustrate how important this ecological factor was for the early diversification of chelicerates and arthropods in general.”
The findings are described in the study “Mandibulate convergence in an armoured Cambrian stem chelicerate,” where Habelia optata is brought to life by visual artist and scientific illustrator Joanna Liang with animations depicting the spectacular body architecture and complex feeding mechanism of this fossil. Liang collaborated with Aria and Caron to produce the animations as part of her master of science thesis in biomedical communications at U of T under supervisor Dave Mazierski.



https://www.rom.on.ca/en/about-us/newsroom/press-releases/a-508-million-year-old-sea-predator-with-a-jackknife-head-1


Cédric Aria Mandibulate convergence in an armoured Cambrian stem chelicerate   21 December 2017
https://bmcecolevol.biomedcentral.com/articles/10.1186/s12862-017-1088-7

Royal Ontario Museum: Scientists Identify New Prehistoric Sea Predator with Spines to Spare  Aug. 3, 2017

Royal Ontario Museum and Yale University researchers name new species of arrow worm from the Cambrian Period

TORONTO, Aug. 3, 2017 – Scientists have identified a small marine predator that once patrolled the ocean floor and grabbed its prey with 50 spines that it deployed from its head.
Named Capinatator praetermissus, this ancient creature is roughly ten centimeters long and represents a new genus and species. It is related to species that are found in present-day plankton. Scientists from the Royal Ontario Museum and Yale University made the identification based on 50 specimens from the fossil-rich Burgess Shale in British Columbia.

This is the most significant fossil discovery about the chaetognath group of animals to date,” says Derek Briggs, Yale’s G. Evelyn Hutchinson Professor of Geology and Geophysics and curator at the Yale Peabody Museum of Natural History. Briggs is lead author along with co-author Dr. Jean-Bernard Caron of a study published in Current Biology about this discovery.
Jean-Bernard Caron, Senior Curator of Invertebrate Palaeontology at the Royal Ontario Museum and an Associate Professor in the Departments of Ecology & Evolutionary Biology and Earth Sciences at University of Toronto, says: “This new species would have been an efficient predator and a terrifying sight to many of the smallest marine creatures that lived during that time.”
Chaetognaths are small, swimming marine carnivores that are also known as arrow worms. They are known from about 120 species today and represent a separate phylum of animals. Capinatator is one of the largest chaetognaths known, living or fossil. At more than 500 million years old, Capinatator is thought to be a forerunner of the smaller chaetognaths that are abundant in today’s oceans, where they make up a large portion of the world’s plankton and the ocean food chain.
According to the researchers, Capinatator’s head configuration is unique. With about 25 spines in each side of its head, the species has nearly double the maximum number of spines found in today’s chaetognaths. This enabled Capinatator to capture prey by closing the two halves of its grasping spines toward each other as it swam.
Briggs and Caron also determined  that while it is fairly common to find evidence of chaetognath spines, fossilized chaetognath bodies are extraordinarily rare. Many of the Capinatator specimens in this study included evidence of soft tissues.
“These Burgess Shale fossil specimens preserve evidence of features such as the gut and muscles, which normally decay away, as well as the more decay-resistant grasping spines,” says Briggs. “They show that chaetognath predators evolved during the explosion of marine diversity during the Cambrian Period, and were an important component of some of the earliest marine ecosystems.”
The species name “praetermissus” means “overlooked”. The name Capinatator is derived from “capio,” which means “to grasp,” and “natator,” which means “swimmer.”










https://www.youtube.com/watch?v=exi1s-9K4vY



https://www.rom.on.ca/en/about-us/newsroom/press-releases/scientists-identify-new-prehistoric-sea-predator-with-spines-to


A large Cambrian chaetognath with supernumerary grasping spines
Derek E.G. Briggs, G. Evelyn Hutchinson Professor of Geology and Geophysics Curator, Yale Peabody Museum of Natural History, and Jean-Bernard Caron Senior Curator of Invertebrate Palaeontology, Royal Ontario Museum, Current Biology
DOI# 10.1016/j.cub.2017.07.003

Tokummia, a new fossil species from the Burgess Shale traces origin of ants, millipedes and lobsters. April 26, 2017


Science is now commonly seen as an arrow of progress. More and more, through books, through the media, the scientific creature is shown marching forward, devouring discoveries after discoveries keeping it healthy and moving. But science can be a slow beast that sometimes takes a different direction and wanders, even if it may occasionally fall back near its former path.
As a cradle of both the familiar and the bizarre, the half-a-billion-year-old marine fauna of the Burgess Shale has long been illustrating such intellectual wanderings, sometimes at the highest levels of animal classification—take Hallucigenia, Nectocaris, or Haplophrentis. However, the arthropods (this hyperdiverse group of invertebrate animals with articulated limbs), and apart from the classic and ancestral “weird wonders” with unarticulated bodies such as Opabinia or Anomalocaris, have in general been the subject of less dramatic switchbacks, but more of “small adjustments.”
Now, it seems that the iconic “bivalved arthropods,” which are among the very first fossils discovered by Charles Walcott from the Burgess Shale—and sketched in his 1909 field notebook—have a story with more “potential energy” to tell.
The culprit’s name is Tokummia katalepsis, just published with Jean-Bernard Caron, my former Ph.D. supervisor and senior curator of invertebrate palaeontology at the ROM, in the scientific journal Nature (read paper). Tokummia was first found near Marble Canyon in Kootenay National Park, British Columbia in 2012 by a Royal Ontario Museum(ROM)-led team of researchers, students and volunteers. I had just started my Ph.D. at the time so this was a most opportune moment to join on a fieldwork trip to the Rockies. Marble Canyon is shaped by Tokumm Creek, visible from the fossil quarry across the valley and after which we named the genus of the new arthropod.
It took that seminal field season in 2012, another hefty one of quarry work in 2014, and research at the ROM—where the Burgess Shale and Marble Canyon collections are stored and where I had an office—over two more years to finally produce a manuscript ready for submission. You could say that Tokummia had remained my alluring companion through all my degree, which I completed only a few months ago, before moving to Nanjing, China, where I now work as a post-doctoral researcher.
Although the fossil specimen found in 2012 had stood out already, we had not found enough material at that time to go very far, or even to think that it would. But in 2014, Tokummia quickly became a “shining star” around the quarry. As we would split open those large slabs of shale with road-construction-type jackhammers, hand-sized Tokummia specimens would glitter as the sunlight reached the surface of the rock, stealing the fame from Yawunik and Sidneyia. It became clear that this animal had a lot more to offer, and we knew that a lot was at stake with bivalved arthropods—but, in the end, Tokummia surpassed our expectations.


In front of its two valves, the most immediately distinguishing features of Tokummia are its large pincers, an invitation to call the species “katalepsis,” meaning “grasping, seizing” in Greek. These claws are also quite specialized, with one article (the fixed one, called pollex) bearing two terminal teeth, and the other (the movable one, called dactyl) with a sharp edge and curved-in tip. The first image that came to me when I started looking at these appendages was that of an old can opener. In spite of their shape, these pincers were likely not robust enough to deal with the hardest shells or shields, such as those of trilobites. I rather see Tokummia feeding on smaller soft-bodied arthropods or on Oesia worms, which are abundant at Marble Canyon.



The most critical trait was hidden under the carapace, however, and stayed that way long after we had collected the specimens and started trying to understand the significance of that species. Even after intense days of fossil preparation during which every new appendage revealed was cause for thrills and original theories, we still did not know (at least for sure) that it was there. I am talking about the mandibles, which were eventually found in a molt, along with the seemingly cryptic but quite important projections on the limbs called “endites.”


Why did mandibles matter? They are simply the one clearest diagnostic character giving its name to a gigantic group of arthropods called the “mandibulates,” encompassing centipedes, shrimps, barnacles, pill bugs, and millions of insects. Mandibles are arthropod “jaws,” if you will, and can take various forms, such as serrated plates or protruding dentate blades, as you might know them in certain insects. But we think that they all originate from a single ancestor and were decisive in the unmatched success of mandibulates. As for “endites,” they would be typically found today in crustacean larvae, but Tokummia suggests they are remnants of limb bases divided into several sub-segments—this condition would also be typical of mandibulates, and would have facilitated the diversification of leg morphologies in this group, as well as the appearance of the mandibles themselves.
When Walcott first described the large bivalved arthropods from the Burgess Shale, he considered them to be crustaceans—by today’s standards, that made them mandibulates, but that concept was ethereal at that time, and other characters than the mandibles were put forward (carapace type, body shape, supposed limb morphology), although not necessarily with great accuracy or consistency with the requirements of crustacean taxonomists.
During a major wave of redescriptions of the Burgess Shale animals in the 70s, led by Harry Whittington from the University of Cambridge, Derek Briggs had identified such inconsistencies, and the bivalved arthropods were shown to fit both inside and outside of our modern conception of crustaceans. With difficulties to find typical crustacean “heads” and notably mandibles, they could but eventually drift away from such classification.
This migration reached a paroxysm with the publication of a paper in the early 2000s presenting these bivalved species as some of the earliest “true arthropods” (with appendages and bodies both articulated), based on a strict interpretation of their known heads as having one or two pairs of appendages. They would have therefore represented very ancestral (a better word for “primitive”) arthropods, a significant leap (down their tree of life) from being representatives of a modern group such as crustaceans. This view was then largely declined by other authors, to the point of becoming a recurrent assumption in the elaboration of new theories about the evolution of arthropods.
Tokummia throws a pebble (or a carapace) in this pond of ideas (called a paradigm in philosophy of science), and the little waves are bringing back some old leaves to the shore. Not that these mandibles and spinose limbs make a crustacean out of Tokummia, but we think that this animal, along with its bivalved relatives, are among the earliest of mandibulates—and certainly the best known of these early forms. They do tell us about the origin of modern species, and cannot be the earliest of arthropods.


https://www.rom.on.ca/en/blog/tokummia-a-new-fossil-species-from-the-burgess-shale-traces-origin-of-ants-millipedes-and

Mighty Burgess Shale fossil site discovered in Kootenay National Park  February 11, 2014

Today we are proud to report the extraordinary discovery of a new fossil deposit in Kootenay National Park that will be announced formally in the Feb 11th 2014 issue of Nature Communications.
This new fossil assemblage is about the same age as the famous Burgess Shale deposit in Yoho National Park, and has the potential to become at least as significant. Since it was discovered by Charles Walcott in 1909, the Burgess Shale has remained the main source of information about Cambrian marine life – animals that lived about 505 million years ago.
The new Kootenay site is comparable to the Walcott Quarry in its exceptional diversity and abundance of fossils, and especially for the quality of preservation of soft-bodied animals – animals usually too fragile to fossilize well or at all. It contains many new fossil species not known to science.
We were surprised at the high diversity of organisms and the number of new species we found at the Kootenay site because we only spent about 15 days working there. We have only scratched the surface, so to speak, at this site.  The possibilities for future discoveries at this site are huge, especially when we contrast this short visit with the more than 600 days of quarrying operations that together span a century of research at the Walcott Quarry. 


https://www.rom.on.ca/en/blog/mighty-burgess-shale-fossil-site-discovered-in-kootenay-national-park

Paleontologists trace origin of millipedes, crabs and insects to new 508 million-year-old sea creature with “can opener”-like pincers

Paleontologists at the Royal Ontario Museum (ROM) and the University of Toronto (U of T) have uncovered a new fossil species that sheds light on the origin of mandibulates, the most abundant and diverse group of organisms on Earth, to which belong familiar animals such as flies, ants, crayfish and centipedes. The finding was announced in a study published today in Nature.

3D reconstruction of Tokummia katalepsisThe creature, named Tokummia katalepsis by the researchers, is a new and exceptionally well-preserved fossilized arthropod – a ubiquitous group of invertebrate animals with segmented limbs and hardened exoskeletons. documents for the first time in detail the anatomy of early “mandibulates”, a hyperdiverse sub-group of arthropods which possess a pair of specialized appendages known as mandibles, used to grasp, crush and cut their food. Mandibulates include millions of species and represent one of the greatest evolutionary and ecological success stories of life on Earth.

“In spite of their colossal diversity today, the origin of mandibulates had largely remained a mystery,” said Cédric Aria, lead author of the study and recent graduate of the PhD program in the Department of Ecology & Evolutionary Biology at U of T, now working as a post-doctoral researcher at the Nanjing Institute for Geology and Palaeontology, in China. “Before now we’ve had only sparse hints at what the first arthropods with mandibles could have looked like, and no idea of what could have been the other key characteristics that triggered the unrivalled diversification of that group.”

Tokummia lived in a tropical sea teeming with life and was among the largest Cambrian predators, exceeding 10 cm in length fully extended. An occasional swimmer, the researchers conclude its robust anterior legs made it a preferred bottom-dweller, as lobsters or mantis shrimps today. Specimens come from 508 million-year-old sedimentary rocks near Marble Canyon in Kootenay National Park, British Columbia. Most specimens at the basis of this study were collected during extensive ROM-led fieldwork activities in 2014.

“This spectacular new predator, one of the largest and best preserved soft-bodied arthropods from Marble Canyon, joins the ranks of many unusual marine creatures that lived during the Cambrian Explosion, a period of rapid evolutionary change starting about half a billion years ago when most major animal groups first emerged in the fossil record,” said co-author Jean-Bernard Caron, senior curator of invertebrate paleontology at the ROM and an associate professor in the Departments of Ecology & Evolutionary Biology and Earth Sciences at U of T.

Analysis of several fossil specimens, following careful mechanical preparation and photographic work at the ROM, showed that Tokummia sported broad serrated mandibles as well as large but specialized anterior claws, called maxillipeds, which are typical features of modern mandibulates.

“The pincers of Tokummia are large, yet also delicate and complex, reminding us of the shape of a can opener, with their couple of terminal teeth on one claw, and the other being curved towards them,” said Aria. “But we think they might have been too fragile to be handling shelly animals, and might have been better adapted to the capture of sizable soft prey items, perhaps hiding away in mud. Once torn apart by the spiny limb bases under the trunk, the mandibles would have served as a revolutionary tool to cut the flesh into small, easily digestible pieces.”

The body of Tokummia is made of more than 50 small segments covered by a broad two-piece shell-like structure called a bivalved carapace. Importantly, the animal bears subdivided limb bases with tiny projections called endites, which can be found in the larvae of certain crustaceans and are now thought to have been critical innovations for the evolution of the various legs of mandibulates, and even for the mandibles themselves.

The many-segmented body is otherwise reminiscent of myriapods, a group that includes centipedes, millipedes, and their relatives. “Tokummia also lacks the typical second antenna found in crustaceans, which illustrates a very surprising convergence with such terrestrial mandibulates,” said Aria.

The study also resolves the affinities of other emblematic fossils from Canada’s Burgess Shale more than a hundred years after their discovery. “Our study suggests that a number of other Burgess Shale fossils such as Branchiocaris, Canadaspis and Odaraia form with Tokummia a group of crustacean-like arthropods that we can now place at the base of all mandibulates,” said Aria.

The animal was named after Tokumm Creek, which flows through Marble Canyon in northern Kootenay National Park, and the Greek for “seizing”. The Marble Canyon fossil deposit was first discovered in 2012 during prospection work led by the Royal Ontario Museum and is part of the Burgess Shale fossil deposit, which extends to the north into Yoho National Park in the Canadian Rockies. All specimens are held in the collections of the Royal Ontario Museum on behalf of Parks Canada.

The Burgess Shale fossil sites are located within Yoho and Kootenay National Parks in British Columbia. The Burgess Shale was designated a UNESCO World Heritage Site in 1980. Parks Canada is proud to protect these globally significant palaeontological sites, and to work with leading scientific researchers to expand knowledge and understanding of this key period of earth history. New information from ongoing scientific research is continually incorporated into Parks Canada's Burgess Shale education and interpretation programs, which include guided hikes to these outstanding fossil sites.



https://www.rom.on.ca/en/about-us/newsroom/press-releases/paleontologists-trace-origin-of-millipedes-crabs-and-insects-to-new

The findings are described in the paper “'Burgess Shale fossils illustrate the origin of the mandibulate body plan”. Doi:10.1038/nature22080  Funding for the research was provided primarily by a Natural Sciences and Engineering Research Council of Canada Discovery Grant (#341944) to Caron, and Royal Ontario Museum fieldwork grants.

Cédric Aria Burgess Shale fossils illustrate the origin of the mandibulate body plan 2017
https://sci-hub.ren/10.1038/nature22080

Royal Ontario Museum: Mystery of conical fossils solved, after 175 years  January 11, 2017

Adding a new branch to the tree of life

For the past year and a half, I have had the opportunity to collaborate with Dr. Martin R. Smith of Durham University and Dr. Jean Bernard Caron of the ROM. The subject of our research was an extinct group of cone-shaped marine organisms called hyoliths. Hyoliths were some of the first animals to evolve a mineralized external skeleton – comprised of upper and lower shells and curving spines – during the Cambrian Explosion (starting about 542 million years ago). Fossilized skeletal remains of hyoliths are abundant around the world, and demonstrate that these animals existed for about 280 million years during the Palaeozoic Era, but they became extinct around 20 million years before the appearance of the first dinosaurs. Despite their excellent fossil record, little was previously known about where hyoliths fit in the tree of life – a palaeontological mystery that persisted for over 175 years since their discovery. In our paper, my coauthors and I present exceptionally preserved hyolith fossils from the Burgess Shale, complete with their internal soft anatomy preserved. Newly described features, in particular a band of feeding tentacles, reveal a surprising evolutionary relationship between hyoliths and a group of animals called lophophorates (whose living representatives include brachiopods and phoronid worms). For more information about hyoliths and our research, see our press release.


https://www.rom.on.ca/en/blog/mystery-of-conical-fossils-solved-after-175-years

Royal Ontario Museum: New lobster-like predator found in 508 million-year-old fossil-rich site March 27, 2015

First new species from Marble Canyon site within Burgess Shale
What do butterflies, spiders and lobsters have in common? They are all surviving relatives of a newly identified species called Yawunik kootenayi, a marine creature with two pairs of eyes and prominent grasping appendages that lived as much as 508 million years ago – more than 250 million years before the first dinosaur.
The fossil was identified by an international team led by palaeontologists at the University of Toronto (U of T) and the Royal Ontario Museum (ROM) in Toronto, as well as Pomona College in California. It is the first new species to be described from the Marble Canyon site, part of the renowned Canadian Burgess Shale fossil deposit.
Yawunik had evolved long frontal appendages that resemble the antennae of modern beetles or shrimps, though these appendages were composed of three long claws, two of which bore opposing rows of teeth that helped the animal catch its prey.
“This creature is expanding our perspective on the anatomy and predatory habits of the first arthropods, the group to which spiders and lobsters belong,” said Cédric Aria, a PhD candidate in U of T’s Department of Ecology & Evolutionary Biology and lead author of the resulting study published this week in Palaeontology. “It has the signature features of an arthropod with its external skeleton, segmented body and jointed appendages, but lacks certain advanced traits present in groups that survived until the present day. We say that it belongs to the ‘stem’ of arthropods.”
The study presents evidence that Yawunik was capable of moving its frontal appendages backward and forward, spreading them out during an attack and then retracting them under its body when swimming. Coupled with the long, sensing whip-like flagella extending from the tip of the claws, this makes the frontal appendages of the animal some of the most versatile and complex in all known arthropods.
“Unlike insects or crustaceans, Yawunik did not possess additional appendages in the head that were specifically modified to process food,” said Aria. “Evolution resulted here in a combination of adaptations onto the frontal-most appendage of this creature, maybe because such modifications were easier to acquire.
“We know that the larvae of certain crustaceans can use their antennae to both swim and gather food. But a large active predator such as a mantis shrimp has its sensory and grasping functions split up between appendages. Yawunik and its relatives tell us about the condition existing before such a division of tasks among parts of the organism took place.”
The Marble Canyon site is located in British Columbia’s Kootenay National Park, 40 kilometres south from the original Burgess Shale in Yoho National Park. Aria was part of the team that discovered the site in 2012, led by Jean-Bernard Caron, an associate professor at U of T’s Departments of Earth Sciences and Ecology & Evolutionary Biology and curator of invertebrate palaeontology at the ROM, and Robert Gaines, associate professor at the Department of Geology at Pomona College in California, both co-authors of the study.
“Yawunik is the most abundant of the large new species of the Marble Canyon site, and so, as a predator, it held a key position in the food network and had an important impact on this past ecosystem,” said Caron. “This animal is therefore important for the study of Marble Canyon, and shows how the site increases the significance of the Burgess Shale in understanding the dawn of animals.”
The study benefited from cutting-edge techniques of fossil imagery, including so-called “elemental mapping,” which consists in detecting the atomic composition of the fossil and the sediment surrounding it.
“Our understanding of these organisms rests upon interpreting their fossil remains,” said Gaines. “These fossils are a composed of a mosaic of delicate original organic material and minerals that replicate parts of fossil anatomy.
“The scanning electron microscope allows us to make maps of the fossils that reveal their composition. This gives us a remarkable perspective on the fossils, allowing anatomical structures to be visualized more precisely. This technique also provides insight into the unusual fossilization process that was at work here.”
The new creature is named in tribute to the Ktunaxa People who have long inhabited the Kootenay area where the Marble Canyon locality was found. It owes its name to “Yawu?ni’”, a mythological figure described as a huge and fierce marine creature, killing and causing such mayhem that it triggered an epic hunt by other animals to bring the threat down.
“We wanted to acknowledge the Ktunaxa culture, and given the profile of Yawunik, it looked like a natural choice of name,” Aria said.
“Yawu?nik’ is a central figure in the Ktunaxa creation story, and, as such, is a vital part of Ktunaxa oral history,” said Donald Sam, Ktunaxa Nation Council Director of Traditional Knowledge and Language. “I am ecstatic that the research team recognizes how important our history is in our territory, and chose to honour the Ktunaxa through this amazing discovery.”
Parks Canada, which holds jurisdiction over the site as it is located in Kootenay National Park, celebrated the discovery as another chapter in the ongoing and unfolding story of secrets given up by the Burgess Shale about the evolution of the animal kingdom since the Cambrian Explosion.
The research appears in a study titled “A large new leanchoiliid from the Burgess Shale and the influence of inapplicable states on stem arthropod phylogeny,” published in Palaeontology. The material under study was collected in 2012 and fieldwork was mainly supported by the Royal Ontario Museum, Uppsala University and Pomona College. Aria’s doctoral research is supported by a Natural Sciences and Engineering Research Council of Canada discovery grant to Jean-Bernard Caron and University of Toronto fellowships.









[url=Yawunik kootenayi - lobster-like predator from 508 million years ago]Yawunik kootenayi - lobster-like predator from 508 million years ago[/url]


https://www.rom.on.ca/en/about-us/newsroom/press-releases/new-lobster-like-predator-found-in-508-million-year-old-fossil-rich

Royal Ontario Museum: The life cycle of a new fossil: Meet the ancient cousin of the earthworm January 19, 2018

Have you ever wondered how a new fossil is described? Or picked up an earthworm on a rainy day and thought to yourself “where do animals like these come from?” In this ROMblog post, I’ll walk you through the process of describing an exceptionally well-preserved new fossil species from the half-a-billion year old Burgess Shale and give you an inside look into some of the tools and techniques that we use in our work when studying fossils from this famous site. This “life cycle” in the discovery and description of a new fossil species will take us from the Rocky Mountains of British Columbia to a special display case at the Royal Ontario Museum where you can admire this new species.
My name is Karma Nanglu and I’m a PhD candidate at the University of Toronto and Royal Ontario Museum. Along with my supervisor, Senior Curator of Invertebrate Palaeontology Dr. Jean-Bernard Caron, we have described a new species of ancient marine worm from the half-a-billion year old Burgess Shale in the Canadian Rockies which is now published in and featured on the cover of the journal Current Biology. Despite being an oceanic animal, this new fossil species is an ancient cousin to the earthworms you can find in your garden. This worm possesses a unique anatomy which tells the story of how the head of these animals evolved (you can read more about the significance of this new study here ).
Our new fossil species was discovered from the Marble Canyon fossil site located in Kootenay National Park, British Columbia. It was discovered in 2012 by a ROM research team led by Dr. Caron, and is part of the famous Burgess Shale site in the Canadian Rockies. The fossils of the Burgess Shale critically document a phenomenon called the Cambrian Explosion, the first indisputable evidence of most modern animal groups in the fossil record. In 2014 and 2016, Dr. Caron led two further ROM research expeditions to the Marble Canyon totaling approximately 3 months of field work, which I was fortunate enough to be a part of.
 In total, we have collected over 20,000 observations of fossil animals at Marble Canyon, with over 500 of them being the new species described today. This new worm is a particularly crucial find, as fossil worms are far less common than animals with hard parts like bones (vertebrates such as dinosaurs), exoskeletons (arthropods such as insects and crustaceans) or shells (mollusks such as snails). The result is that the evolutionary history of many soft bodied animal groups is not very well documented due to a lack of information regarding what they looked like near their origins and how they changed over geological time. The stunning abundance of this new worm and other soft bodied fossils at Marble Canyon underscores the exceptional nature of the Burgess Shale. My PhD thesis is concerned with analyzing all of these observations together, including this new species we've described, to give us a window into how the community of animals that lived at Marble Canyon 508 million years ago would have lived.









https://www.rom.on.ca/en/about-us/newsroom/press-releases/new-lobster-like-predator-found-in-508-million-year-old-fossil-rich

New research published today in the journal Nature describes a newly-discovered 'ring of teeth' in an otherworldly creature from half a billion years ago. 

Researchers from the University of Cambridge, the Royal Ontario Museum and the University of Toronto have found that the creature, known as Hallucigenia due to its strange appearance, had a throat lined with needle-like teeth, a previously unidentified feature which could help connect the dots between it, modern velvet worms and arthropods – the group which contains modern insects, spiders and crustaceans. Read the full press reslease.

Hallucigenia was just one of the weird creatures that lived during the Cambrian Explosion, a period of rapid evolutionary development starting about half a billion years ago, when most major animal groups first emerge in the fossil record. Visit The Burgess Shale website to learn more about one of the world’s first complex marine ecosystems.
Reference: Smith, Martin R. and Caron, Jean-Bernard, Hallucigenia’s  head and pharyngeal armature of early ecdysozoans, Nature (2015), http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14573.html


https://www.rom.on.ca/en/blog/common-ancestor-of-moulting-animals-discovered

Palaeontologists solve mystery of 500 million-year-old squid-like carnivore August 29, 2012 

A study by Martin Smith of the University of Toronto and Jean-Bernard Caron of the Royal Ontario Museum sheds new light on a previously unclassifiable 500 million-year-old squid-like carnivore known as Nectocaris pteryx. The new interpretation became possible with the discovery of 91 new fossils that were collected from the Burgess Shale site in the UNESCO World Heritage Canadian Rocky Mountain Parks, BC.

The findings are presented in ""Primitive soft-bodied cephalopods from the Cambrian"", published in Nature(May 27, 2010).

Martin R. Smith Primitive soft-bodied cephalopods from the Cambrian 2010
The exquisite preservation of soft-bodied animals in Burgess Shale-type deposits provides important clues into the early evolution of body plans that emerged during the Cambrian explosion1 . Until now, such deposits have remained silent regarding the early evolution of extant molluscan lineages—in particular the cephalopods. Nautiloids, traditionally considered basal within the cephalopods, are generally depicted as evolving from a creeping Cambrian ancestor whose dorsal shell afforded protection and buoyancy2 . Although nautiloid-like shells occur from the Late Cambrian onwards, the fossil record provides little constraint on this model, or indeed on the early evolution of cephalopods. Here, we reinterpret the problematic Middle Cambrian animal Nectocaris pteryx3,4 as a primitive (that is, stem-group), nonmineralized cephalopod, based on new material from the Burgess Shale. Together with Nectocaris, the problematic Lower Cambrian taxa Petalilium5 and (probably) Vetustovermis6,7 form a distinctive clade, Nectocarididae, characterized by an open axial cavity with paired gills, wide lateral fins, a single pair of long, prehensile tentacles, a pair of non-faceted eyes on short stalks, and a large, flexible anterior funnel. This clade extends the cephalopods’ fossil record2 by over 30 million years, and indicates that primitive cephalopods lacked a mineralized shell, were hyperbenthic, and were presumably carnivorous. The presence of a funnel suggests that jet propulsion evolved in cephalopods before the acquisition of a shell. The explosive diversification of mineralized cephalopods in the Ordovician may have an understated Cambrian ‘fuse’. 
https://sci-hub.ren/10.1038/nature09068

Royal Ontario Museum: A new mid-Silurian aquatic scorpion – one step closer to land? January 15, 2015

Rocks of the 430 million year old Eramosa Formation Konservat-Lagerstätte on the Bruce Peninsula have produced an amazing new species of aquatic fossil scorpions, Eramoscorpius brucensis, which contributes to our understanding of how scorpions may eventually have moved from the sea onto land. 
Their legs, intriguingly similar to those of a modern scorpion, end in a short foot that could have been placed flat on the ground, providing a weight-bearing surface which, combined with the legs’ sturdy attachment to the body, would have allowed the animal to support its own weight without using the buoyancy of water. This demonstrates that a key prerequisite for living on land – the ability to walk unsupported by water – appeared surprisingly early in the fossil record
The presence in the same rocks of other fossils of animals that lived only in the sea, and a lack of any other evidence of dry land, indicate that these new scorpions must have spent most of their time under water; however the fossils occur alone on rock surfaces that show ripples suggestive of brief exposure to air.  A possible explanation is that the scorpions took advantage of their leg structure to venture briefly into a temporarily exposed area in order to moult and then returned to deeper water.  A scorpion sheds its old exoskeleton (shell) by spreading its legs and pincers and then pulling itself out through the front of its old shell. Picture trying to get out of a turtle neck onesie through the neck, without undoing it, by pulling it down over your arms, body and legs. Oh – and it has built in mitts and booties, doesn’t crumple up very well, and you can’t turn it inside out. Having difficulty? For a while you are totally immobilized. Scorpions do this several times in their lifetime. If it could get away from deep water, the vulnerable, and probably tasty, scorpion would have been safe from predators such as large cephalopods and eurypterids, whose remains are also found in the Eramosa Formation. Our scorpions are preserved in a splayed posture suggesting that they represent empty moulted exoskeletons – the discarded, too small shells they left behind - rather than actual carcasses of an animal that died. 

The Eramosa scorpions range in size from about 29 to 165 mm long, representing several different age classes. These Ontario specimens are the oldest known scorpions from North America and among the oldest in the world.
Our specimens all hail from the Bruce Peninsula, where the Eramosa Formation Konservat-Lagerstätte has been likened to “Ontario’s Burgess Shale” because of its rich assemblage of superbly preserved remains of soft-bodied organisms normally poorly represented in the fossil record (see also https://www.rom.on.ca/en/blog/a-silurian’shark’tale). The Eramosa is quarried extensively for building and dimension stone, but our fossils have arrived at the ROM in a variety of ways: while several were spotted by quarry workers, one was found in a quarry spoil heap by a young fossil hunter, and others were discovered in quarried stone delivered to landscaping projects far from their origin, destined for patios and garden walls.
The enthusiasm and generosity of amateur fossil collectors brings important specimens to our attention and allows us to study and publish these findings, which are vital to the ROM's collections and research.





https://www.rom.on.ca/en/blog/a-new-mid-silurian-aquatic-scorpion-one-step-closer-to-land


Andrew J. Wendruff A Silurian ancestral scorpion with fossilised internal anatomy illustrating a pathway to arachnid terrestrialisation : 16 January 2020
https://www.nature.com/articles/s41598-019-56010-z?sf229075860=1

Joanna Thompson This trilobite was equipped with a 'hyper-eye' never seen before in the animal kingdom 08 October 2021

The humble trilobite, a helmet-headed creature that swam the seas hundreds of millions of years ago, was hiding an extraordinary secret — a "hyper-eye" never seen before in the animal kingdom.
By poring over X-ray images,  researchers found that certain species of trilobite — extinct arthropods distantly related to horseshoe crabs — had "hyper compound eyes," complete with hundreds of lenses, their own neural network to process and send signals and multiple optic nerves, according to new research published Sept. 30 in the journal Scientific Reports. 

B. Schoeneman A 390 million-year-old hyper-compound eye in Devonian phacopid trilobites 30 September 2021
Trilobites, extinct arthropods that dominated the faunas of the Palaeozoic, since their appearance c 523 million years ago, were equipped with elaborate compound eyes. While most of them possessed apposition compound eyes (in trilobites called holochroal eyes), comparable to the compound eyes of many diurnal crustaceans and insects living today, trilobites of the suborder Phacopina developed atypical large eyes with wide lenses and wide interspaces in between (schizochroal eyes). Here, we show that these compound eyes are highly sophisticated systems—hyper-compound eyes hiding an individual compound eye below each of the big lenses. Thus, each of the phacopid compound eyes comprises several tens, in cases even hundreds of small compound eye systems composing a single visual surface. We discuss their development, phylogenetic position of this hyper-compound eye, and its neuronal infrastructure. A hyper-compound eye in this form is unique in the animal realm.


Filaments at the visual units of phacopid trilobites. (a) Chotecops (Phacops) ferdinandi (Kayser, 1880), [WS 2617]. (b) Right eye of a. ‘fibers' originating below the facets, converging towards interior of the cephalon. (c) Left eye of a, with (indistinct) ‘fibers', converging to plate of spheres and pyramidal element. (d) Schematic drawing of ‘fibers'. (e) typical ommatidium (apposition eye). (f) Lehmann’s specimen of Asteropyge6 (Rhenops) sp., [WS 2882]. (g) Left eye of f, showing ‘fibers'. h) C. ferdinandi, [WS 822]. (i) Appendage with gill-filaments, tapering distally. (j) i with endopodite (en) and exopodite (ex) of the appendage explained. (k) Eye of C. ferdinandi, each ‘fiber' connected to one visual unit [WS 4.1/503]. (l) Section of k, there as red circle. (m) Eye of C. ferdinandi [not numbered, XRCB], ‘fibers' converging to a centre. (n) C. ferdinandi, ‘fibers', converging to a supposed neuropile, [WS 295]. (o) C. ferdinandi, 1:1 relation between visual units; [WS 609(3)]. (p) C. ferdinandi, indistinct ‘fibers', converging to pyramidal element [WS 1832]. (q) C. ferdinandi, indistinct ‘fibers', converging to plate of spheres and pyramidal element [WS 1832]. (r) Thin-section of the eye of Phacops tafilatelensis Alberti 1983, showing lens, capsule that contains the receptors, foamy structure below (supposed neuropil), and ‘fibers', c capsule containing receptor cells, cc crystalline cone, ce compound eye, f ‘fiber', L lens, n neuropile, rc receptor cells, r rhabdom, (g–k) no scales given. XRCB Stürmer’s x-radiographs in the Steinmann Institute, Bonn. blue arrows: ‘fibers'; red arrows: pyramidal element; yellow arrow: underlying appendage; pink arrows: neural plate; white arrow: neuropil. Figure 1a–c are taken from Stürmer et al.22, pl. iV, Fig 15a and Fig. 1 c,n from Stürmer and Bergström7, plate 21b,c.

https://www.nature.com/articles/s41598-021-98740-z?utm_medium=affiliate&utm_source=commission_junction&utm_campaign=3_nsn6445_deeplink_PID100052172&utm_content=deeplink