Trace fossils or ichnofossils are burrows, footprints, tracks or even faeces left behind by plants and animals that lived long ago.
Animals may have scurried across a muddy exposure or sea bottom, perhaps eaten a tasty meal then pooped it out — leaving behind clues to how they lived, what they ate and what the environment was like at the time. These are wonderfully informative clues to our ancient world.
These marine arthropods flourished from 505 million years ago to 487 million years ago.
Charles Doolittle Walcott found nine partially complete fossils of Opabinia regalis and a few of what he classified as Opabinia media, that he published in 1912.
The bizarre arthropod's name is derived from the Opabin pass between Mount Hungabee and Mount Biddle, southeast of Lake O'Hara, British Columbia, Canada.
In 1966–1967, Harry B. Whittington found a rather good specimen which he published in 1975. He provided a detailed description based on a very thorough dissection of some specimens and photographs of these specimens lit from a variety of angles. Harry was a very thorough fellow.
But he was still ridiculed. Opabinia looked so strange that the audience at the first presentation of Whittington's analysis laughed.
Earth's ancient seas teemed with new life 541 - 485 Million Years Ago. The Cambrian Explosion had arrived. Weird and wonderful life forms like Hallucigenia and Anomalocaris are found in the fossil record giving us a peek at ancient life half a billion years ago.
Calymene blumenbachii, sometimes erroneously spelled blumenbachi, is a species of trilobite found in the limestone quarries of the Wren's Nest in Dudley, England.
Nicknamed the Dudley Bug or Dudley Locust by an 18th-century quarryman, it became a symbol of the town and featured on the Dudley County Borough Council coat-of-arms. Calymene blumenbachii is commonly found in Silurian rocks (422.5-427.5 million years ago) and is thought to have lived in the shallow waters of the Silurian, in low energy reefs.
This particular species of Calymene — a fairly common genus in the Ordovician-Silurian — is unique to the Wenlock series in England and comes from the Wenlock Limestone Formation in Much Wenlock and the Wren's Nest in Dudley. These sites seem to yield trilobites more readily than any other areas on the Wenlock Edge, and the rock here is dark grey as opposed to yellowish or whitish as it appears on other parts of the Edge, just a few miles away, in Church Stretton and elsewhere. This suggests local changes in the environment in which the rock was deposited. The Wenlock Edge quarry is closed now to further collecting but may be open to future research projects. We shall have to see.
These lovelies swam by moving their bodies in a series of zigzag curves similar to the movement of eels, all the while filtering particles from the water.
Although primitive, Pikaia shows the essential prerequisites for vertebrates. When alive, Pikaia was a compressed, leaf-shaped animal with an expanded tail fin; the flattened body is divided into pairs of segmented muscle blocks, seen as faint vertical lines.
The muscles lie on either side of a flexible structure resembling a rod that runs from the tip of the head to the tip of the tail. It swam by throwing its body into a series of S-shaped undulating movements that mimicked the movement of eels. Fish inherited this same swimming movement, but they generally have stiffer backbones so it does not quite have the same visual effect.
Pikaia was likely a slow swimmer since it lacked the fast-twitch fibres that we associate with rapid swimming in modern chordates. Still, even that form of movement in the Middle Cambrian is impressive in terms of mobility and design.
Conway Morris and Caron (2012) published an exhaustive description based on more than one hundred known fossil specimens. Through their deeper look at this primitive marine mystery, they discovered new and unexpected characteristics that they recognized as primitive features of the first chordate animals. On the basis of these findings, they constructed a new scenario for chordate evolution.
Subsequently, Mallatt and Holland reconsidered Conway Morris and Caron's description and concluded that many of the newly recognized characters are unique, already-divergent specializations that would not be helpful for establishing Pikaia as a basal chordate.
They soared our skies during most of the Mesozoic — from the late Triassic to the end of the Cretaceous (228 to 66 million years ago).
By the end of the Cretaceous, they had grown to giants and one of their brethren, Quetzalcoatlus, a member of the family Azhdarchidae, boasts being the largest known flying animal that ever lived.
They were the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the ankles to a dramatically lengthened fourth finger.
The Iberian Peninsula is the westernmost of the three major southern European peninsulas — the Iberian, Italian, and Balkan. It is bordered on the southeast and east by the Mediterranean Sea, and on the north, west, and southwest by the Atlantic Ocean. The Pyrenees mountains are situated along the northeast edge of the peninsula, where it adjoins the rest of Europe. Its southern tip is very close to the northwest coast of Africa, separated from it by the Strait of Gibraltar and the Mediterranean Sea.
The Iberian Peninsula contains rocks of every geological period from the Ediacaran to the recent, and almost every kind of rock is represented. To date, there are 127 localities of theropod fossil finds ranging from the Callovian-Oxfordian — Middle-Upper Jurassic — to the Maastrichtian (Upper Cretaceous), with most of the localities concentrated in the Kimmeridgian-Tithonian interval and the Barremian and Campanian stages. The stratigraphic distribution is interesting and suggests the existence of ecological and/or taphonomic biases and palaeogeographical events that warrant additional time and attention.
As well as theropods, we also find their plant-eating brethren. This was the part of the world where the last of the hadrosaurs, the duck-billed dinosaurs, lived then disappeared in the Latest Cretaceous K/T extinction event 65.5 million years ago.
The core of the Iberian Peninsula is made up of a Hercynian cratonic block known as the Iberian Massif. On the northeast, this is bounded by the Pyrenean fold belt, and on the southeast, it is bounded by the Baetic System. These twofold chains are part of the Alpine belt. To the west, the peninsula is delimited by the continental boundary formed by the magma-poor opening of the Atlantic Ocean. The Hercynian Foldbelt is mostly buried by Mesozoic and Tertiary cover rocks to the east but nevertheless outcrops through the Sistema Ibérico and the Catalan Mediterranean System. The photo you see here is care of the awesome Pedro Marrecas from Lisbon, Portugal. Hola, Pista de baile jurásica!
Pereda-Suberbiola, Xabier; Canudo, José Ignacio; Company, Julio; Cruzado-Caballero, Penélope; Ruiz-Omenaca, José Ignacio. "Hadrosauroid dinosaurs from the latest Cretaceous of the Iberian Peninsula" Journal of Vertebrate Paleontology 29(3): 946-951, 12 de septiembre de 2009.
Pereda-Suberbiola, Xabier; Canudo, José Ignacio; Cruzado-Caballero, Penélope; Barco, José Luis; López-Martínez, Nieves; Oms, Oriol; Ruíz-Omenaca, José Ignacio. Comptes Rendus Palevol 8(6): 559-572 septiembre de 2009.
About 250 million years ago, our once silent world became a cacophony of diverse animal sounds.
One of the most lyrical of those voices to join the Earth's chorus were the true crickets. We can count them as some of the earliest musicians on the planet.
This group evolved and contributed to the nocturnal circumambience of our planet a full 150 million years before our human ancestors would have heard them for the very first time. It is their long lineage that I am mindful of when I am out for an evening stroll and hear their pleasing serenade.
If you find yourself out in the woods and are wondering what the temperature might be, you need only slip closer to the nearest stand of deciduous trees to follow the musical sounds of the wee Snowy Tree Cricket, Oecanthus Fultoni, part of the order orthoptera.Snowy Tree Crickets and their cousins double as thermometers and wee garden predators, dining on aphids and other wee beasties. Weather conditions, both hot and cold, alter the speed at which they rub the base of their wings together and consequently regulate their rate of chirping.
Listen closely for their tell-tale high pitch triple chirp sound in the early evening. Being in Canada, our crickets chirp in Celsius. To figure out the temperature, we simply count the number of chirps over a seven-second period and add five to learn the local temperature.
If did not happen to bring your calculator and you are still operating in old-school Fahrenheit, you can use this handy conversion — double the temperature in Celsius, add 32 you'll get the approximate temperature in Fahrenheit. And if you are not all that interested in the temperature, enjoy their pleasing serenade as you take your early evening stroll. They've been working on this number for millions of years.
Daniel Otte from the Academy of Natural Sciences in Philadelphia did up a wonderful piece on the evolution of cricket songs. If you’re a keen bean & want to learn more, I'll attach the journal article for you. https://doi.org/10.2307/3503559. https://www.jstor.org/stable/3503559
Mary's specimen was acquired by William Buckland and reported in a meeting of the Geological Society on 5 February 1829. Six years later, in 1835, William Clift and William John Broderip built upon the work by Buckland to publish in the Transactions of the Geological Society, describing and naming the fossil as a new species.
As was the case with most early pterosaur finds, Buckland classified the remains in the genus Pterodactylus, coining the new species Pterodactylus macronyx. The specific name is derived from Greek makros, "large" and onyx, "claw", in reference to the large claws of the hand. The specimen, presently NHMUK PV R 1034, consisted of a partial and disarticulated skeleton on a slab — notably lacking the skull. Buckland in 1835 also assigned a piece of the jaw from the collection of Elizabeth Philpot to P. macronyx.
Later, the many putative species assigned to Pterodactylus had become so anatomically diverse that they began to be broken into separate genera.
In 1858, Richard Owen reported finding two new specimens, NHMUK PV OR 41212 and NHMUK PV R 1035, again partial skeletons but this time including the skulls. Having found the skull to be very different from that of Pterodactylus, Owen assigned Pterodactylus macronyx its own genus, which he named Dimorphodon.
His first report contained no description and the name remained a nomen nudum. In 1859, however, a subsequent publication by Owen provided a description. After several studies highlighting aspects of Dimorphodon's anatomy, Owen finally made NHMUK PV R 1034 the holotype in 1874 — 185 million years after cruising our skies the Dimorphodon had finally fully arrived.
Mammoths have a wonderful display of mammoth teeth, the diagnostic flat enamel plates and the equally distinct pointy cusped molars of the mastodons. He was a true elephant, unlike his less robust cousins, the mastodons. Mammoths were bigger — both in girth and height — weighing in at a max of 13 tonnes.
They are closely related to Asian elephants and were about the size of the African elephants you see roaming the grasslands of Africa today.
If you stood beside him and reached way up, you might be able to touch his tusks but likely not reach up to his mouth or even his eyes. He would have had a shaggy coat of light or dark coloured hair with long outer hair strands covering a dense thick undercoat. His oil glands would have worked overtime to secrete oils, giving him natural waterproofing.
Some of the hair strands we have recovered are more than a meter in length. These behemoth proboscideans boasted long, curved tusks, little ears, short tails and grazed on leaves, shrubs and grasses that would have been work to get at as much of the northern hemisphere was covered in ice and snow during his reign. It is often the teeth of mammoths like those you see in the photo here that we see displayed.
Their molar teeth were large and have always struck me as looking like ink plates from a printing press. If they are allowed to dry out in collection, they fall apart into discreet plates that can be mistaken for mineralized or calcified rock and not the bits and pieces of mammoth molars that they indeed are. Their large surface area was perfect for grinding down the low nutrient, but for the most part, plentiful grasses that sustained them.
 |
| Mammoth Tusk, Wrangel Island, Chukotka Okrug, Russia |
It's a genius design, really. A bit like having a plough on the front of your skull. In the photo here you can see a tusk washed clean in a creek bed on Wrangel Island.
Their size offered protection against other predators once the mammoth was full grown. Sadly for the juveniles, they offered tasty prey to big cats like Homotherium who roamed those ancient grasslands alongside them.
They roamed widely in the Pliocene to Holocene, roaming much of Africa, Europe, Asia and North America. We see them first some 150,000 years ago from remains in Russia then expanding out from Spain to Alaska. They enjoyed a very long lifespan of 60-80 — up to 20 years longer than a mastodon and longer than modern elephants.
They enjoyed the prime position as the Apex predator of the megafauna, then declined — partially because of the environment and food resources and partially because of their co-existence with humans. In places where the fossil record shows a preference for hunting smaller prey, humans and megafauna do better together. We see this in places like the Indian Subcontinent where primates and rodents made the menu more often than the large megafauna who roamed there. We also see this in present-day Africa, where the last of the large and lovely megafauna show remarkable resilience in the face of human co-existence.
The woolly mammoths from the Ukrainian-Russian plains died out 15,000 years ago. This population was followed by woolly mammoths from St. Paul Island in Alaska who died out 5,600 years ago — and quite surprisingly, at least to me, the last mammoth died just 4,000 years ago in the frosty ice on the small island of Wrangel in the Arctic Ocean — their final days spent scratching out a dwindling existence of genetic mutations, howling winds, rain-darkened hills and subsistence on tough grasses grown in thin soil.
Further reading: Laura Arppe, Juha A. Karhu, Sergey Vartanyan, Dorothée G. Drucker, Heli Etu-Sihvola, Hervé Bocherens. Thriving or surviving? The isotopic record of the Wrangel Island woolly mammoth population. Quaternary Science Reviews, 2019; 222: 105884 DOI: 10.1016/j.quascirev.2019.105884
The name originates from the Permian genus Coelacanthus, which means hollow spine and was published by Swiss-born American biologist and geologist Jean Louis Rodolphe Agassiz in 1839.
The type species Coelacanthus granulatus was described from the Late Permian, Wuchiapingian of Kupferschiefer of Germany and England. Coelacanthus is primarily known from Late Permian and Early Triassic deposits in Europe and Canada, although the referred species C. welleri, known from Iowa, is of Late Devonian, Famennian age. They survived the Permian–Triassic extinction event, and one species, C. banffensis, is known from the Early Triassic.
Coelacanths belong to the subclass Actinistia, a group of lobed-finned fish related to lungfish and certain extinct Devonian fish such as osteolepiforms, porolepiforms, rhizodonts, and Panderichthys. The oldest known coelacanth fossils are over 410 million years old. Coelacanths were thought to have become extinct in the Late Cretaceous, around 66 million years ago, but were rediscovered in 1938 off the coast of South Africa.
Coelacanths follow the oldest-known living lineage of Sarcopterygii, lobe-finned fish and tetrapods, which makes them are more closely related to lungfish and tetrapods — which includes amphibians, reptiles, birds and mammals — than to ray-finned fish. They are found along the coastline of Indonesia and in the Indian Ocean. The West Indian Ocean coelacanth is a critically endangered species.
The coelacanth was long considered a living fossil because scientists thought it was the sole remaining member of a taxon otherwise known only from fossils, with no close relations alive, and that it evolved into roughly its current form approximately 400 million years ago. Several more recent studies have shown that coelacanth body shapes are much more diverse than previously thought.
 |
| Sanctacaris uncata |
We first see them emerge in our ancient oceans in the Middle Cambrian, some 508 million years ago, as the arthropod Sanctacaris uncata (Briggs & Collins, 1988) known from the Glossopleura Zone, Stephen Formation of Mount Stephen in the Burgess Shale, British Columbia, Canada.
Sanctacaris is proof positive that chelicerates, although rare, were present in the Middle Cambrian sea. Even at this early stage of evolution, Sanctacaris had the number and type of head appendages found in modified form in the eurypterids and xiphosurids, the major Palaeozoic groups that succeeded it. Even more interesting is that Sanctacaris had all the characteristics of later chelicerates except chelicerae — placing this early arthropod in a primitive sister group of all other chelicerates.
Although harvestmen can digest solid food it is more akin to a mashed pulp by the time they do. The guts of most modern chelicerates are too narrow to digest solid food, instead, they generally liquidize their chosen meal by grinding it with their chelicerae and pedipalps then flooding it with digestive enzymes.
To conserve water, air-breathing chelicerates excrete waste as solids that are removed from their blood by Malpighian tubules, structures that also evolved independently in insects — another case of convergent evolution.
The evolutionary origins of chelicerates from the early arthropods have been debated for decades. And although there is considerable agreement about the relationships between most chelicerate sub-groups, the inclusion of the Pycnogonida in this taxon has recently been questioned and the exact position of scorpions is still controversial, though they were long considered the most primitive or basal of the arachnids.
We still have much to explore to sort out their evolutionary origins and placement within the various lineages but we will get there with time.
Image One: Reconstruction of Sanctacaris uncata, a Cambrian Habeliidan arthropod (stem-Chelicerata: Habeliida). by Junnn11 @ni075; Image Two: Chelicerata by Fossil Huntress
Aria C, Caron JB (December 2017). "Mandibulate convergence in an armoured Cambrian stem chelicerate". BMC Evolutionary Biology. 17 (1): 261. doi:10.1186/s12862-017-1088-7. PMC 5738823. PMID 29262772.
Legg DA (December 2014). "Sanctacaris uncata: the oldest chelicerate (Arthropoda)". Die Naturwissenschaften. 101 (12): 1065–73. doi:10.1007/s00114-014-1245-4. PMID 25296691.
Briggs DE, Collins D (August 1988). "A Middle Cambrian chelicerate from Mount Stephen, British Columbia" (PDF). Palaeontology. 31 (3): 779–798. Archived from the original (PDF) on July 16, 2011. Retrieved April 4, 2010.
Briggs DE, Erwin DH, Collier FJ (1995). Fossils of the Burgess Shale. Washington: Smithsonian Institution Press. ISBN 1-56098-659-X. OCLC 231793738.
Much like (slow) Water Striders (Aquarius remigis), (relatively sluggish) Coelacanth (Latimeria chalumnae) and (the current winner on really slow evolution) Elephant Sharks (Callorhinchus milii), these fellows have a long history in the fossil record with very few anatomical changes.
But slow change provides loads of great information. It makes our new friend, Yunnanolimulus luoingensis, an especially interesting and excellent reference point for how this group evolved.
We can examine their genome today and make comparisons all the way back to the Middle Triassic (with this new find) and other specimens from further back in the Ordovician — 445 million years ago.
These living fossils have survived all five mass extinction events. They are generalists who can live in shallow or deep water and will eat pretty much anything they can find on the seafloor.
The oldest horseshoe crab fossil, Lunataspis aurora, is found in outcrops in Manitoba, Canada. Charmingly, the name means crescent moon shield of the dawn. It was palaeontologist Dave Rudkin and team who chose that romantic name. Finding them as fossils is quite remarkable as their shells are made of protein which does not mineralized like typical fossils.
Even so, the evolution of their exoskeleton is well-documented by fossils, but appendage and soft-tissue preservation are extremely rare.
A new study analyzes details of the appendage and soft-tissue preservation in Yunnanolimulus luoingensis, a Middle Triassic (ca. 244 million years old) horseshoe crab from Yunnan Province, SW China. The remarkable anatomical preservation includes the chelicerae, five pairs of walking appendages, opisthosomal appendages with book gills, muscles, and fine setae permits comparison with extant horseshoe crabs.
 |
The occurrence of Carcinoscorpius-type claspers on the first and second walking legs in male individuals of Y. luoingensis tells us that simple chelate claspers in males are plesiomorphic for horseshoe crabs, and the bulbous claspers in Tachypleus and Limulus are derived.
As an aside, if you hadn't seen an elephant shark before and were shown a photo, you would likely say, "that's no freaking shark." You would be wrong, of course, but it would be a very clever observation.
Callorhinchus milii look nothing like our Great White friends and they are not true sharks at all. Rather, they are ghost sharks that belong to the subclass Holocephali (chimaera), a group lovingly known as ratfish. They diverged from the shark lineage about 400 million years ago.
If you have a moment, do a search for Callorhinchus milii. The odd-looking fellow with the ironic name, kallos, which means beautiful in Greek, sports black blotches on a pale silver elongate body. And their special feature? It is the fishy equivalent of business in the front, party in the back, with a dangling trunk-like projection at the tip of their snout and well-developed rectal glands near the tail.
As another small point of interest with regards to horseshoe crabs, John McAllister collected several of these while working on his MSc to see if they had microstructures similar to trilobites (they do) and whether their cuticles were likewise calcified. He found no real calcification in their cuticles, in fact, he had a rather frustrating time getting anything measurable to dissolve in acid in his hunt for trace elements.
Likewise, when looking at oxygen isotopes (16/18) to get a handle on water salinity and temperature, his contacts at the University of Waterloo had tons of fun getting anything at all to analyze. It made for some interesting findings. Sadly, for a number of reasons, he abandoned the work, but you can read his very interesting thesis here: https://dr.library.brocku.ca/handle/10464/1959
Ref: Hu, Shixue & Zhang, Qiyue & Feldmann, Rodney & Benton, Michael & Schweitzer, Carrie & Huang, Jinyuan & Wen, Wen & Zhou, Changyong & Xie, Tao & Lü, Tao & Hong, Shuigen. (2017). Exceptional appendage and soft-tissue preservation in a Middle Triassic horseshoe crab from SW China. Scientific Reports. 7. 10.1038/s41598-017-13319-x.
 |
| Trilobite and Sea Scorpion Fossil Trackways |
It shows a nice combination of Cruziana fossil trilobite trackway and eurypterid (sea scorpion) or horseshoe crab trackway on the same matrix.
When we use the term Cruziana, we are not referring to the trilobite species, but to the particular shape and form of the trackway.
In this case, elongate, bilaterally symmetrical burrows preserved along the bedding plane with repeated striations that are mostly oblique to the long dimension. I like to picture a teeny, tiny painter or sculpture with a small putty knife making angled cuts along a line or a wave motion to create a small curved line. Very showy skate skiing is another good visual. Sadly, neither is the case. While a Cruziana trace fossil is most often associated with trilobites, it can be made by other arthropods.
When we see trace fossils — preserved tracks or other signs of behaviour from our marine friends living on the seafloor — they are generally from their furrowing, resting, emerging, walking or striding. They provide a glimpse of how these ancient sea creatures moved about to make a living.
 |
| Trilobite and Sea Scorpion Fossil Trackways |
The Tar Springs Formation is recognized on the surface from southwestern Orange County to the Ohio River and is known in the subsurface from central Martin County southwestward (Gray, 1970, 1986).
In Indiana, the Tar Springs Formation is primarily shale, but it also contains scattered thin beds of limestone and massive local lenses of sandstone that on outcrop are differentiated as the Tick Ridge Sandstone Member (Gray, 1986). The formation ranges in thickness from about 70 ft (21 m) to more than 150 ft (46 m) in central Posey County and in southwestern Gibson County (Droste and Keller, 1995). Commonly sandstone predominates in those areas where the Tar Springs is as much as 150 ft (46 m) thick (Droste and Keller, 1995).
They left many beautifully preserved examples of their three-lobed exoskeletons in the fossil record.
Trilobites — in all their many wonderful forms — lived in our ancient oceans for more than 270 million years. The last of their lineage went extinct at the end of the Permian, 252 million years ago.
We saw the first of their brethren during the Ordovician and the last of them during the End-Permian Mass Extinction Event.
In between, they thrived and irradiated out to every niche within our ancient seas and many later forms survived and thrived in both brackish and freshwater.
The group Arthropoda includes invertebrate animals with exoskeletons, segmented bodies, and paired joint appendages. Eurypterids had six sets of appendages. You can clearly see the segmented body on this cutie, which is one of the defining characteristics of arthropods. The first set was modified into pinchers which are used for feeding. The largest appendage visible in this fossil is a broad paddle that E. tetragonophthalmus used to swim.
This first eurypterid, Eurypterus remipes, was discovered in New York in 1818. It is an iconic fossil for this region and was chosen as the state's official fossil in 1984. An excellent choice as most of the productive eurypterid-bearing outcrops are within the state's boundaries. Most of the fossils we find from them, whether body fossils or trace fossils are from fossil sites in North America and Europe This is because the group lived primarily in the waters around and within the ancient supercontinent of Euramerica.
Only a handful of eurypterid groups spread beyond the confines of Euramerica and a few genera, such as Adelophthalmus — the longest-lived of all known eurypterid genera — and the giant predatory Pterygotus, achieved a cosmopolitan distribution so we find their fossil remains worldwide today.
Interestingly, the type species, Pterygotus anglicus, was first through to be the remains of a massive fish by Swiss naturalist Louis Agassiz who described it in 1839 — hence the poorly chosen name Pterygotus, which translates to winged fish. He did catch that embarrassing error five years later, but the name remains for all time.
Pirania is named after Mount St. Piran, near the Bow River Valley, Banff National Park, Alberta, Canada. It was first described by Charles Doolittle Walcott in 1920 from 128 fossil specimens found within the Greater Phyllopod bed, the most famous fossil-bearing member of the 508 million-year-old Burgess Shale Fossil Lagerstätte in the Canadian Rockies of British Columbia. The type locality has exceptional preservation of soft-bodied animals from the Middle Cambrian.
They were particularly abundant in the later Triassic and early Jurassic periods before being replaced as the premier aquatic predator by another marine reptilian group, the Plesiosauria, in the later Jurassic and Cretaceous periods.
They thrived during much of the Mesozoic era; based on fossil evidence, they first appeared around 250 million years ago and at least one species survived until about 90 million years ago into the Late Cretaceous.
While they resembled fish and dolphins, ichthyosaurs were large marine reptiles belonging to the order known as Ichthyosauria or Ichthyopterygia. In 2018, Benjamin Kear and his team were able to study ichthyosaur remains at the molecular level, Their findings suggest ichthyosaurs had skin and blubber quite similar to our modern dolphins.
While ichthyosaurs evolved from land-dwelling, lung-breathing reptiles, they returned to our ancient seas and evolved into the fish-shaped creatures we find in the fossil record today.
Their limbs fully transformed into flippers, sometimes containing a very large number of digits and phalanges. Their flippers tell us they were entirely aquatic as they were not well-designed for use on land. And it was their flippers that first gave us the clue that they gave birth to live young; a find later confirmed by fossil embryo and wee baby ichy finds.
During his high school years, which he finished in Saratov in 1932, he developed an active interest in Mesozoic stratigraphy and palaeontology while visiting the classical Upper Jurassic sections along the Volga River.
You will undoubtedly recall that the Volga is that region that offers up the spectacular oil-in-water coloured ammonite specimens like Quenstedtoceras (Lamberticeras) lamberti, Eboraciceras, Peltoceras, Kosmoceras, Grossouvria, Proriceras, Cadoceras and Rursiceras — inspirational indeed.
He graduated with honours from the Geological and Geophysical Faculty of the State University at Kyiv in 1938 and completed graduate studies in palaeontology and stratigraphy at the Institute of Geological Sciences of the Ukrainian Academy of Sciences, Kyiv, in 1941. His Candidate of Geological Sciences (equivalent to a PhD) thesis was devoted to the stratigraphy and belemnite fauna of the Boreal Upper Cretaceous of northern Eurasia.
On June 22, 1941, the day Germany invaded the USSR, he married a physician, Tamara Fedorovna, the daughter of the distinguished professor F. P. Bohatirchuk and had four children together — Alex, Olga, Theodore, and Halina.
Throughout those difficult years, in which he worked as a librarian and finally as a translator in the U .S.-occupied zone of Germany, Jurij managed to keep his family together and to save some of his personal belongings. In 1948, he moved to Canada, where he became a research scientist for the Geological Survey of Canada. He held that title until 1982 when he was awarded emeritus status.
Jurij’s first paper, published in 1938, dealt with Pleistocene gastropods, but the bulk of the nearly 150 papers published in his lifetime were devoted to Mesozoic palaeontology and stratigraphy, especially from western and northern Canada; Cretaceous stratigraphy and belemnite faunas of northern Eurasia; as well as palaeogeography and paleobiogeography.
He worked on Vancouver Island initially, producing geologic maps and structural and stratigraphic reports, and this work was followed up with studies of correlative strata in southern British Columbia. His second major area of study was the northern Yukon where he elucidated the stratigraphy, structure, and palaeontology of Mesozoic rocks. His outstanding contribution to the work of the Geological Survey of Canada was sustained research on the Cretaceous stratigraphy and fossils of Canada.
He was a great champion of the role that fossils play in biochronology and the development of the Phanerozoic time scale. George had broad interests that impacted many aspects of geology, including palaeogeography, tectonics, and eustacy.
In 1955, on completion of stratigraphic studies on Vancouver Island, Jurij began a long-range project in the Mackenzie District of northwestern Canada. He said he was searching “for the most nearly continuous and largely or entirely open-marine section of Upper Jurassic-Low er Cretaceous rocks.”
He believed that such a section was badly needed to correlate and order sequentially what were then the scattered Early Cretaceous and Late Jurassic marine invertebrate faunas from western and Arctic Canada. His extensive field research, which began by canoe and on foot in the company of an Indigenous guide and a cook in inaccessible and unpopulated areas of the northern Yukon, was conducted between 1955 and 1975. Numerous publications and shelves of detailed field notebooks document the complete Upper Jurassic-Lower Cretaceous sequence for which he searched.
In that work, as in most others related to boreal biostratigraphy, a thorough analysis of the subject was facilitated by his Russian background and his knowledge of several other Slavic languages, as well as German and French.
In the 1960s, Jurij became coordinator and principal author of the Coleoidea volume of the Treatise on Invertebrate Paleontology, after the editors had agreed that the usual compilation of the volume should be preceded by a thorough revision of morphology, taxonomy, and phylogeny. This implied the reappraisal of all principal morphologic features of the Belemnitida and included the study of all type collections available worldwide.
Only an individual with Jurij’s determination and intellectual and working capacity could have faced such a staggering enterprise. He thus amassed an enormous amount of information and became the world’s leading authority on the subject.
A number of papers were published, including his extensively documented work on the comparative morphology, phylogeny, and classification of the fossil Coleoidea (1966, University of Kansas Paleontological Contribution No. 7). Meanwhile, he tended to his official duties for the Survey with his habitual thoroughness. This work included the study of large collections made by other geologists, as well as provincial surveys and research by oil and mining companies, and resulted in a large number of papers and unpublished reports.
However, it slowed the preparation of the Treatise final manuscript. He could have shortened some parts and compiled others, but Jurij felt that as a conscientious scientist he could not agree to publish any results that he considered either wrong or substandard.
Thus, several papers remain unpublished, including a 331-page manuscript, finished in 1978, on early and middle Liassic Belemnite faunas of England in relation to coeval faunas of northern Eurasia.
Jurij was a Fellow of the Geological Society of America and of the Royal Society of Canada. He received the Willet G. Miller Medal of the Royal Society of Canada in 1969 for outstanding basic research in geology (palaeontology and stratigraphy), and the Elkanah Billings Medal of the Geological Association of Canada (1978) for his research on Canadian palaeontology. He was also honoured, together with Ralph Imlay of the U.S.
Geological Survey, with a Special Symposium on the Jurassic-Cretaceous biochronology and palaeogeography of North America, during the Third North American Paleontological Convention in Montreal in 1982 (see Westermann, G., ed., 1984, Geological Association of Canada Special Paper 27).
Jurij Jeletzky worked for many years to the limit of his physical endurance, although he realized the danger to his health. From 1984 until his death in 1988, suffering from cancer, he worked to the limit of his failing strength to publish an important monograph on ammonites of the boreal regions, and to finish the Coleoidea volume of the Treatise and a large synthesis on the Yukon area.
At his death, the first paper (co-written with E. Kemper, Geological Survey of Canada Bulletin 377) was already published; Jurij was still correcting the last version of the Yukon manuscript, and the Treatise manuscript was 80 to 90 per cent complete. In the last week of his life, he forced himself to correct, in his hospital bed, the proof pages of a paper on the relation of the Neuburg Formation of Germany to the sub-boreal Volgian of the Russian platform, thus completing the circle that brought him to geology during his high school years.
A true earth scientist, Jurij based all his interpretations and theoretical discussions on facts, and as a committed, responsible, and independent-minded researcher, he challenged any hypothesis, even the most popular one, if it did not fit his data. Thus, in 1962 (Royal Society of Canada Transactions, v. 56), he opposed the prevailing views on the Cordilleran geosyncline in relation to northern Yukon, and in 1984 (Geological Survey of Canada Special Paper 27), he rejected the existence of large-scale north-south movements of “ allochthonous terranes” in western North America and Alaska after the Middle Jurassic.
Instead, he adhered to the expanding Earth hypothesis rather than to orthodox plate tectonics. He held that palaeontology was the only basis for practical geochronology (1956, American Association of Petroleum Geologists Bulletin, v. 40), discussed the abuse of quantification in palaeontology and biochronological correlation (1965, Journal of Paleontology, v. 39), and the overestimation of eustatic compared to vertical tectonic movements in controlling large-scale transgressions and regressions (1978, Geological Survey of Canada Paper 77-18), and he vindicated the value of molluscs with respect to foraminifers for age and depositional interpretation of Tertiary rocks in British Columbia (1973, Canadian Journal of Earth Sciences, v. 10).
He also thought that his data from extensive collections of Late Jurassic-Early Cretaceous Buchia and Late Cretaceous Inoceramus were in conflict with the “punctuated equilibrium” hypothesis. Whenever he became involved in scientific controversy, it was based on his deep belief that a scientist’s duty is to express openly his doubts whenever his data are challenged. Thus, he was always ready to stand up for his beliefs without being pompous; on the contrary, he was a very modest man.
Jurij never refused to give advice, when asked, especially to a junior colleague, or to write a detailed review of a thesis or manuscript. Even in the last weeks of his life, he completed a review, knowing that time was short and precious. He was extremely loyal to his profession—his love—and to the institution for which he worked.
He loved life, every hour of it. In his private life, he was a kind and generous person, always ready to give help to a colleague or friend. He never showed the strains of a personal life full of hardships.
Jura (George) Jeletzky will be missed by all those who believe that personal freedom, independence of thought, respect for facts, and a straightforward attitude in upholding fundamental principles as the hallmarks of a valuable human and scientific life.
A.C. Riccardi, Museum de Ciencias Naturalas, Universidad Nactional de La Plata, Argentina wrote a wonderful memorial to Jeletzky as did Godfrey Nowland, Chief Paleontologist, Geological Survey of Canada. Much of what they shared is included here.
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/BF4C5A14713639CE54B473408D4406E6/S0022336000019776a.pdf/div-class-title-j-a-jeletzky-1915-1988-div.pdf
 |
| Dan Bowen, Chair, VIPS, Trent River |
The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. And it is massive. At 103 million km2 (40 million sq mi), it is the largest tectonic plate and continues to grow fed by volcanic eruptions that piggyback onto its trailing edge.
This relentless expansion pushes the Pacific Plate into the North American Plate. The pressure subducts it beneath our continent where it then melts back into the earth. Plate tectonics are slow but powerful forces.
The island chains that rode the plates across the Pacific smashed into our coastline and slowly built the province of British Columbia. And because each of those islands had a different origin, they create pockets of interesting and diverse geology.
It is these islands that make up the Insular Belt — a physio-geological region on the northwestern North American coast. It consists of three major island groups — and many smaller islands — that stretches from southern British Columbia up into Alaska and the Yukon. These bits of islands on the move arrived from the Late Cretaceous through the Eocene — and continues to this day.
The rocks that form the Insular Superterrane are allochthonous, meaning they are not related to the rest of the North American continent. The rocks we walk over along the Trent River are distinct from those we find throughout the rest of Vancouver Island, Haida Gwaii, the rest of the province of British Columbia and completely foreign to those we find next door in Alberta.
To discover what we do find on the Trent takes only a wee stroll, a bit of digging and time to put all the pieces of the puzzle together. The first geological forays to Vancouver Island were to look for coal deposits, the profitable remains of ancient forests that could be burned to the power industry.
We know from their work that by 85 million years ago, the Insular Superterrane had made its way to what is now British Columbia.
The lands were forested much as they are now but by extinct genera and families. The fossil remains of trees similar to oak, poplar, maple and ash can be found along the Trent and Vancouver Island. We also see the lovely remains of flowering plants such as Cupanities crenularis, figs and breadfruit.
Heading up the river, you come to a delineation zone that clearly marks the contact between the dark grey marine shales and mudstones of the Haslam Formation where they meet the sandstones of the Comox Formation. Fossilized material is less abundant in the Comox sandstones but still contains some interesting specimens. Here you begin to see fossilized wood and identifiable fossil plant material.
Further upstream, there is a small tributary, Idle Creek, where you can find more of this terrestrial material in the sandy shales. As you walk up, you see identifiable fossil plants beneath your feet and jungle-like, overgrown moss-covered, snarly trees all around you.
Walking west from the Trent River Falls at the bottom, you pass the infamous Ammonite Alley, where you can find Mesopuzosia sp. and Kitchinites sp. of the Upper Cretaceous (Santonian), Haslam Formation. Minding the slippery green algae covering some of the river rocks, you can see the first of the Polytychoceras vancouverense zone.
Continuing west, you reach the first of two fossil turtle sites on the river — amazingly, one terrestrial and one marine. If you continue, you come to the Inland Island Highway.
The Trent River has yielded some very interesting marine specimens, and significant terrestrial finds. We have found a wonderful terrestrial helochelydrid turtle, Naomichelys speciosa, and the caudal vertebrae of a Hadrosauroid dinosaur. Walking down from the Hadrosaur site you come to the site of the fossil ratfish find — one of the ocean's oddest fish.
This robust fellow had exceptionally large eyes and sex organs that dangled enticingly between them. You mock, but there are many ratfish who would differ. While inherently sexy by ratfish standards, this fellow was not particularly tasty to their ancient marine brethren (or humans today) — so not hugely sought after as a food source or prey.
A little further again from the ratfish site we reach the contact of the two Formations. The rocks here have travelled a long way to their current location. With them, we peel away the layers of the geologic history of both the Comox Valley and the province of British Columbia.
The Trent River is not far from the Puntledge, a river whose banks have also revealed many wonderful fossil specimens. The Puntledge is also the name used by the K'ómoks First Nation to describe themselves. They have lived here since time immemorial. Along with Puntledge, they refer to themselves as Sahtloot, Sasitla and Ieeksun.
References: Note on the occurrence of the marine turtle Desmatochelys (Reptilia: Chelonioidea) from the Upper Cretaceous of Vancouver Island Elizabeth L. Nicholls Canadian Journal of Earth Sciences (1992) 29 (2): 377–380. https://doi.org/10.1139/e92-033; References: Chimaeras - The Neglected Chondrichthyans". Elasmo-research.org. Retrieved 2017-07-01.
Directions: If you're keen to explore the area, park on the side of Highway 19 about three kilometres south of Courtenay and hike up to the Trent River. Begin to look for parking about three kilometres south of the Cumberland Interchange. There is a trail that leads from the highway down beneath the bridge which will bring you to the Trent River's north side.
 |
| Figure 2: Preserved elements of RBCM P900 |
 |
| Figure 3: Pectoral Elements of Laramidian leptoceratopsids |
 |
| Collishaw Point, known locally as Boulder Point, Hornby Island |
 |
| Upper Cretaceous Nanaimo Group Fossil Concretion |
 |
| Dan Bowen, Chair, VIPS. Photo: Deanna Steptoe Graham |
