Thursday, 12 January 2023

TRACKING THROUGH THE TRIASSIC

Grambergia sp. Middle Triassic Ammonoid of  BC, Canada
In the early 1980s, Tim Tozer, Geological Survey of Canada was looking at the spread of marine invertebrate fauna in the Triassic of North America. 

In the western terranes of the Cordillera, marine faunas from southern Alaska and Yukon to Mexico are known from the parts that are obviously allochthonous with regard to the North American plates.

Lower and upper Triassic faunas of these areas, as well as some that are today up to 63 ° North, have the characteristics of the lower palaeo latitudes. 

In the western Cordillera, these faunas of the lower paleo latitudes can be found up to 3,000 km north of their counterparts on the American plate. This indicates a tectonic shift of significant magnitude. There are marine triads on the North American plate over 46 latitudes from California to Ellesmere Island. 

For some periods, two to three different faunal provinces can be distinguished. The differences in faunal species are linked, not surprisingly, to their palaeolatitude. They are called LPL, MPL, HPL (lower, middle, higher palaeolatitude).

Nevada provides the diagnostic features of the lower (LPL); northeastern British Columbia that of the middle (MPL) and Sverdrup Basin, the large igneous province on Axel Heiberg Island and Ellesmere Island, Nunavut, Canada near the rifted margin of the Arctic Ocean, that of the higher palaeolatitude (HPL).

A distinction between the provinces of the middle and the higher palaeo-situations can not be made for the lower Triassic and lower Middle Triassic (anise). However, all three provinces can be seen in the deposits of Ladin, Kam and Nor.

In the early 2000s, as part of a series of joint UBC, VIPS and VanPS fossil field trips (and then Chair of the VanPS), I explored much of the lower faunal outcrops of northeastern British Columbia. It was my first time seeing many of British Columbia's Triassic outcrops. Years later, and fueled by seeing paper after paper correlating the faunal assemblages of BC to those of Nevada, I had the very great pleasure of walking through the Nevada strata with John Fam (VanPS, Vice-Chair), Dan Bowen (VIPS, Chair) and Betty Franklin (VIPS, Goddess of Everything and BCPA, Treasurer) — and witnessing first-hand the correlation between the Nevada fauna and those from the Triassic of British Columbia, Canada.

Triassic ammonoids, West Humboldt Mountains, Nevada, USA
The Nevada faunal assemblages are a lovely match. The quality of preservation at localities like Fossil Hill in the Humboldt Mountains of Nevada, perhaps the most famous and important locality for the Middle Triassic (Anisian/Ladinian) of North America, is truly outstanding.

Aside from sheer beauty and spectacular preservation, the ammonoids and belemnites were tucked in cozily with very well preserved ichthyosaur remains.

Tozer's interest in our marine invert friends was their distribution. How and when did certain species migrate, cluster, evolve — and for those that were prolific, how could their occurrence — and therefore significance — aide in an assessment of plate and terrane movements that would help us to determine paleolatitudinal significance. 

I share a similar interest but not exclusive to our cephalopod fauna. The faunal collection of all of the invertebrates holds appeal.

Middle Triassic (Anisian/Ladinian) Fauna
This broader group held an interest for J.P. Smith who published on the marine fauna in the early 1900s based on his collecting in scree and outcrops of the West Humboldt Mountains, Nevada. He published his first monograph on North American Middle Triassic marine invertebrate fauna in 1914.

N. J. Siberling from the US Geological Survey published on these same Nevada outcrops in 1962. His work included nearly a dozen successive ammonite faunas, many of which were variants on previously described species. Both their works would inform what would become a lifelong piecing together of the Triassic puzzle for Tozer.

If one looks at the fauna and the type of sediment, the paleogeography of the Triassic can be interpreted as follows: a tectonically calm west coast of the North American plate that bordered on an open sea; in the area far from the coast, a series of volcanic archipelagos delivered sediment to the adjacent basins. 

Some were lined or temporarily covered with coral wadding and carbonate banks. Deeper pools were in between. The islands were probably within 30 degrees of the triadic equator. They moved away from the coast up to about 5000 km from the forerunner of the East Pacific Ridge. The geographical situation west of the back was probably similar.

Jurassic and later generations of the crust from near the back have brought some of the islands to the North American plate; some likely to South America; others have drifted west, to Asia. There are indications that New Guinea, New Caledonia and New Zealand were at a northern latitude of 30 ° or more during the Triassic period.

The terranes that now form the western Cordillera were probably welded together and reached the North American plate before the end of the Jurassic period.

Marine Triassic occurs on the North American Plate over a latitudinal spread of 46 degrees, from California to Ellesmere Island. At some intervals of time faunas on the Plate permit the discrimination of two or three provinces with distinctively different coeval faunas. 

The faunal differences are evidently related to paleolatitude and the provinces are designated LPL, MPL, HPL (low, mid, high paleolatitude). Nevada provides the diagnostic characters of the LPL province; northeastern British Columbia the MPL; the Sverdrup Basin the HPL. In the Lower Triassic and early Middle Triassic (Anisian), the distinction between the MPL and HPL provinces cannot be made. All three provinces are recognized in the Ladinian, Carnian and Norian deposits.

Juvavites sp. Geological Survey of Canada. Photo: John Fam
In the western tracts of the Cordillera, the part formed of suspect terranes, apparently allochthonous with respect to the North American Plate, marine faunas are known all the way from southern Alaska and Yukon to Mexico.

Lower and Upper Triassic faunas from these terranes, including some which today are at 63 degrees north, have the characters of the LPL province.

Middle Triassic faunas from the terranes, as presently known, do not contribute significant data. In the terranes of the Western Cordillera, LPL faunas were now up to 3,000 km north of their counterparts on the American Plate. Through the fossil fauna assemblages, we can see this level of tectonic displacement.

Taking into account the faunas and the nature of the rocks, the Triassic paleogeography is interpreted as a tectonically quiet west shore for the North American Plate, bordered by an open sea or ocean; then, well off-shore, a series of volcanic archipelagos shedding sediment into adjacent basins. Some were fringed or intermittently covered by coralline shoals and carbonate banks. Deeper basins were in between. The islands probably were within 30 degrees of the Triassic equator and extended offshore for about 5000 km, to the spreading ridge directly ancestral to the East Pacific Rise. The geography west of the spreading ridge was probably comparable.

Jurassic and later generation of crust at the ridge had driven some of the islands into the North American Plate; some probably to South America; others have gone west to Asia. Evidence is given that northern New Guinea, New Caledonia and New Zealand may have been at a north latitude of 30 degrees or more in the Triassic. The terranes now forming the Western Cordillera had probably amalgamated, and reached the North American Plate, before the end of the Jurassic.

At the end of the Rhaetian (part of the Triassic period), most of the ammonites had died out. These are the lovely coiled molluscs you often see in museums and gift shops that sell fossils. They are a particular favourite of mine and they are both beautiful and useful to tell us much about deep time. The Hettangian, a rather poorly understood 3 million year time interval followed the Triassic-Jurassic mass extinction event.

During the Hettangian, the new or  Neoammonites developed quite quickly. Within a million years, a fairly large, diverse selection of genera and species had risen to fill the void. The gap created by the Triassic-Jurassic extinction event was re-filled and our ability to "read the rocks' to understand their continued movement through tectonic plate shifting recommenced.

Alsatites proaries, Hettangian Ammonite
It is during the Hettangian that the smooth shelled ammonite genus Psiloceras first appears. They span the time between 201.3 ± 0.2 Ma and 199.3 ± 0.3 Ma (million years ago). For my European friends, the Hettangian is the time span in which the marine limestone, shales and clay Lias of western Europe were deposited.

This Hettangian ammonite, Alsatites proaries, is a lovely example of the cephalopods cruising our ancient oceans at that time. Alsatites is an extinct genus of cephalopod belonging to the Ammonite subclass. They lived during the Early Jurassic, Hettangian till the Sinemurian and are generally extremely evolute, many whorled with a broad keel. Or, as described by one of my very young friends, he looks like a coiled snake you make in pottery class.

The Hettangian is an interesting little period of our history. It spans the time between 201.3 ± 0.2 Ma and 199.3 ± 0.3 Ma (million years ago). For my European friends, the Hettangian is the time in which the marine limestone, shales and clay Lias of western Europe were deposited. In British Columbia, Canada, we see the most diverse middle and late Hettangian (Early Jurassic) ammonite assemblages in the Queen Charlotte Islands (Haida Gwaii), an archipelago about 50 km off British Columbia's northern Pacific coast. In total, 53 ammonite taxa are described of which Paradasyceras carteri, Franziceras kennecottense, Pleuroacanthites charlottensis, Ectocentrites pacificus and Curviceras haidae are new.

In general, North American Early Jurassic ammonites are of Tethyan affinity or endemic to the eastern Pacific. For this reason, a separate zonation for the Hettangian and Sinemurian of the Western Cordillera of North America was established. Taylor et al. (2001), wrote up and published on much of this early research though, at the time, very little Canadian information was included.

Longridge, L. M., et al. “Three New Species of the Hettangian (Early Jurassic) Ammonite Sunrisites from British Columbia, Canada.” Journal of Paleontology, vol. 82, no. 1, 2008, pp. 128–139. JSTOR, www.jstor.org/stable/20144175. Accessed 27 Jan. 2020.

Tozer, ET (Tim): Marine Triassic faunas of North America: Their significance for assessing plate and terrane movements. Geol Rundsch 71, 1077-1104 (1982). https://doi.org/10.1007/BF01821119

Danner, W. (Ted): Limestone resources of southwestern British Columbia. Montana Bur. Mines & Geol., Special publ. 74: 171-185, 1976.

Davis, G., Monger, JWH & Burchfiel, BC: Mesozoic construction of the Cordilleran “collage”, central British Columbia to central California. Pacific Coast Paleography symposium 2, Soc. Economic Paleontologists and Mineralogists, Los Angeles: 1-32, 1978.

Gibson, DW: Triassic rocks of the Rocky Mountain foothills and front ranges of northeastern British Columbia and west-central Alberta. Geol. Surv. Canada Bull. 247, 1975.

Photo of the large belemnite (Atractites sp?) and ammonites (Sunrisites & Badouxia) from the Lower Jurassic (Late Hettangian), Last Creek Formation (Castle Pass member), Taseko Lakes area, British Columbia, Canada in the collection of the deeply awesome John Fam.

Photo: A drawer of Juvavites sp. in the collections of the Geological Survey of Canada. These rarely seen Upper Triassic (Carnian to Norian) ammonoids were collected over many decades by geologists of the Geological Survey of Canada from Northeastern British Columbia. Photo care of the deeply awesome John Fam.

Photo: Grambergia sp. from the Early Anisian (Middle Triassic) ammonoid biostratigraphy of northeastern British Columbia, Canada. Collection of Fossil Huntress.

Photo: Alsatites proaries, Coll. Reiter, Neoammoniten, 30 July 2011, 19:26:10

Wednesday, 11 January 2023

CHOCOLATE CHIP SEA STAR

If you happen to be swimming in the warm, shallow waters of the Indo-Pacific region, you may encounter one of the most charming of all the sea stars, Protoeaster nodosus.

These beauties are commonly known as Horned Sea Stars or, my personal favorite, Chocolate Chip Sea Stars.

They are part of the class Asteroidea (starfish or sea stars) one of the most diverse groups within the phylum Echinodermata and have a lengthy lineage in the fossil record stretching all the way back to the Triassic. These echinoderms make a living on near-shore sandy bottoms or lurk in the seagrass meadows of some of our most beautiful waters.

Chocolate Chip Sea Stars live in the waters off the Philippine Sea, off the coast of Australia and New Guinea. Their range extends to the Marshall Islands through central and southeastern Polynesia, past Easter Island and all the way up to Hawaii. Pretty much pick any of the top contenders for a warm, tropical vacation and they've beaten you to it!

This species of sea star has black rows of "horns" or "spines" meant to scare off predators. A noble deterrent for his fishy friends but I find this signature decoration rather fetching. These fellows like to graze on choice corals and sponges. They are also happy to make a meal of snails and bitter sea urchins when these ambrosial treats are presented. And they are social, both to mate, gathering in groups to aid in fertilization and acting as a softcover for shrimp, wee brittle stars and juvenile leatherjackets or filefish, who tuck in and enjoy the protective cover of those dark nodes.

Monday, 9 January 2023

KWAGU'Ł INTO THE MIST

Kwagu'ł into the Mist by Heidi Henderson
Heidi Henderson is a Norwegian-Canadian Kwagu'ł Kwakwaka'wakw & proud citizen of the Central Council of Tlingit & Haida of Alaska living in British Columbia. 

Heidi grew up in Tsaxis, Fort Rupert, on northern Vancouver Island and is a direct blood descendant of Anisalaga, Master Chilkat Weaver and Raven of Tongass.

When she is not writing about natural history or filming it for television, she works in oil, acrylic, watercolour, Sterling Silver, wood, digital and other mixed media. Along with her visual designs, Heidi also designs clothing, jewellery and 3D sculptures. 

Sunday, 8 January 2023

FOSSILS AND FIRST NATION HISTORY OF EASTERN CANADA

Elpistostege watsoni

In the late 1930s, our understanding of the transition of fish to tetrapods — and the eventual jump to modern vertebrates — took an unexpected leap forward. The evolutionary a'ha came from a single partial fossil skull found on the shores of a riverbank in Eastern Canada. 

Meet the Stegocephalian, Elpistostege watsoni, an extinct genus of finned tetrapodomorphs that lived during the Late Givetian to Early Frasnian of the Late Devonian — 382 million years ago. 

Elpistostege watsoni — perhaps the sister taxon of all other tetrapods — was first described in 1938 by British palaeontologist and elected Fellow of the Royal Society of London, Thomas Stanley Westoll. Westoll's research interests were wide-ranging. He was a vertebrate palaeontologist and geologist best known for his innovative work on Palaeozoic fishes and their relationships with tetrapods. 

As a specialist in early fish, Westoll was asked to interpret that single partial skull roof discovered at the Escuminac Formation in Quebec, Canada. His findings and subsequent publication named Elpistostege watsoni and helped us to better understand the evolution of fishes to tetrapods — four-limbed vertebrates — one of the most important transformations in vertebrate evolution. 

Hypotheses of tetrapod origins rely heavily on the anatomy of but a few tetrapod-like fish fossils from the Middle and Late Devonian, 393–359 million years ago. These taxa — known as elpistostegalians — include Panderichthys, Elpistostege and Tiktaalik — none of which had yet to reveal the complete skeletal anatomy of the pectoral fin. 

Elpistostege watsoni
None until 2010 that is, when a complete 1.57-metre-long articulated specimen was found and described by Richard Cloutier et al. in 2020. 

The specimen helped us to understand the origin of the vertebrate hand. Stripped from its encasing stone, it revealed a set of paired fins of Elpistostege containing bones homologous to the phalanges (finger bones) of modern tetrapods and is the most basal tetrapodomorph known to possess them. 

Once the phalanges were uncovered, prep work began on the fins. The fins were covered in wee scales and lepidotrichia (fin rays). The work was tiresome, taking more than 2,700 hours of preparation but the results were thrilling. 

Origin of the Vertebrate Hand
We could now clearly see that the skeleton of the pectoral fin has four proximodistal rows of radials — two of which include branched carpals — as well as two distal rows organized as digits and putative digits. 

Despite this skeletal pattern — which represents the most tetrapod-like arrangement of bones found in a pectoral fin to date blurring the line between fish and land vertebrates — the fin retained lepidotrichia (those wee fin rays) distal to the radials. 

This arrangement confirmed an age-old question — showing us for the first time that the origin of phalanges preceded the loss of fin rays, not the other way around.

E. watsoni is very closely related to Tiktaalik roseae found in 2004 in the Canadian Arctic — a tetrapodomorpha species also known as a Choanata. These were advanced forms transitional between fish and the early labyrinthodonts playfully referred to as fishapods — half-fish, half-tetrapod in appearance and limb morphology. 

Up to that point, the relationship of limbed vertebrates (tetrapods) to lobe-finned fish (sarcopterygians) was well known, but the origin of major tetrapod features remained obscure for lack of fossils that document the sequence of evolutionary changes — until Tiktaalik. While Tiktaalik is technically a fish, this fellow is as far from fish-like you can be and still be a card-carrying member of the group. 

Tiktaalik roseae
Complete with scales and gills, this proto-fish lacked the conical head we see in modern fish but had a rather flattened triangular head more like that of a crocodile. 

Tiktaalik had scales on its back and fins with fin webbing but like early land-living animals, it had a distinctive flat head and neck. He was a brawny brute. The shape of his skull and shoulder look part fish and part amphibian.

The watershed moment came as Tiktaalik was prepped. Inside Tiktaalik's fins, we find bones that correspond to the upper arm, forearm and even parts of the wrist — all inside a fin with webbing — remarkable! 

Its fins have thin ray bones for paddling like most fish, but with brawny interior bones that gave Tiktaalik the ability to prop itself up, using his limbs for support. I picture him propped up on one paddle saying, "how you doing?" 

Six years after Tiktaalik was discovered by Neil Shubin and team in the ice-covered tundra of the Canadian Arctic on southern Ellesmere Island, a team working the outcrops at Miguasha on the Gaspé Peninsula discovered the only fully specimen of E. watsoni found to date — greatly increasing our knowledge of this finned tantalizingly transitional tetrapodomorph. 

E. watsoni fossils are rare — this was the fourth specimen collected in over 130 years of hunting. Charmingly, the specimen was right on our doorstop — extracted but a few feet away from the main stairs descending onto the beach of Miguasha National Park. 

L'nu Mi’gmaq First Nations of the Gespe’gewa’gi Region

Miguasha is nestled in the Gaspésie or Gespe’gewa’gi region of Canada — home to the Mi’gmaq First Nations who self-refer as L’nu or Lnu. The word Mi’gmaq or Mi’kmaq means the family or my allies/friends in Mi'kmaw, their native tongue (and soon to be Nova Scotia's provincial first language). They are the people of the sea and the original inhabitants of Atlantic Canada having lived here for more than 10,000 years. 

The L'nu were the first First Nation people to establish contact and trade with European explorers in the 16th and 17th centuries — and perhaps the Norse as early as the turn of the Millenium. Sailing vessels filled with French, British, Scottish, Irish and others arrived one by one to lay claim to the region — settling and fighting over the land. As each group rolled out their machinations of discovery, tensions turned to an all-out war with the British and French going head to head. I'll spare you the sordid details but for everyone caught in the crossfire, it went poorly.

North America Map 1775 (Click to Enlarge)
Cut to 1760, the British tipped the balance with their win at the Battle of the Restigouche, the last naval battle between France and England for possession of the North American continent — Turtle Island. 

The bittersweet British victory sparked the American War of Independence. 

For the next twenty years, the L'nu would witness and become embroiled in yet another war for these lands, their lands — first as bystanders, then as American allies, then intimidated into submission by the British Royal Navy with a show of force by way of a thirty-four gun man-of-war, encouraging L'nu compliance — finally culminating in an end to the hostilities with the 1783 Treaty of Paris. 

The peace accord held no provisions for the L'nu, Métis and First Nations impacted. None of these newcomers was Mi'kmaq — neither friends nor allies.

It was to this area some sixty years later that the newly formed Geological Survey of Canada (GSC) began exploring and mapping the newly formed United Province of Canada. Geologists in the New Brunswick Geology Branch traipsed through the rugged countryside that would become a Canadian province in 1867. 

It was on one of these expeditions that the Miguasha fossil outcrops were discovered. They, too, would transform in time to become Miguasha National Park or Parc de Miguasha, but at first, they were simply the promising sedimentary exposures on the hillside across the water —  a treasure trove of  Late Devonian fauna waiting to be discovered.

In the summer of 1842, Abraham Gesner, New Brunswick’s first Provincial Geologist, crossed the northern part of the region exploring for coal. Well, mostly looking for coal. Gesner also had a keen eye for fossils and his trip to the Gaspé Peninsula came fast on the heels of a jaunt along the rocky beaches of Chignecto Bay at the head of the Bay of Fundy and home to the standing fossil trees of the Joggins Fossil Cliffs. 

Passionate about geology and chemistry, he is perhaps most famous for his invention of the process to distil the combustible hydrocarbon kerosene from coal oil — a subject on which his long walks exploring a budding Canada gave him a great deal of time to consider. We have Gesner to thank for the modern petroleum industry. He filed many patents for clever ways to distil the soft tar-like coal or bitumen still in use today.

He was skilled in a broad range of scientific disciplines — being a geologist, palaeontologist, physician, chemist, anatomist and naturalist — a brass tacks geek to his core. Gesner explored the coal exposures and fossil outcrops across the famed area that witnessed the region become part of England and not France — and no longer L'nu.

Following the Restigouche River in New Brunswick through the Dalhousie region, Gesner navigated through the estuary to reach the southern coast of the Gaspé Peninsula into what would become the southeastern coast of Quebec to get a better look at the cliffs across the water. He was the first geologist to lay eyes on the Escuminac Formation and its fossils.

In his 1843 report to the Geologic Survey, he wrote, “...I found the shore lined with a coarse conglomerate. Farther eastward the rocks are light blue sandstones and shales, containing the remains of vegetables. (...) In these sandstone and shales, I found the remains of fish and a small species of tortoise with fossil foot-marks.”

We now know that this little tortoise was the famous Bothriolepis, an antiarch placoderm fish. It was also the first formal mention of the Miguasha fauna in our scientific literature. Despite the circulation of his report, Gesner’s discovery was all but ignored — the cliffs and their fossil bounty abandoned for decades to come. Geologists like Ells, Foord and Weston, and the research of Whiteaves and Dawson, would eventually follow in Gesner's footsteps.

North America Map 1866 (Click to Enlarge)
Over the past 180 years, this Devonian site has yielded a wonderfully diverse aquatic assemblage from the Age of Fishes — five of the six fossil fish groups associated with the Devonian including exceptionally well-preserved fossil specimens of the lobe-finned fishes. 

This is exciting as it is the lobe-finned fishes — the sarcopterygians — that gave rise to the first four-legged, air-breathing terrestrial vertebrates – the tetrapods. 

Fossil specimens from Miguasha include twenty species of lower vertebrates — anaspids, osteostra-cans, placoderms, acanthodians, actinopterygians and sarcopterygians — plus a limited invertebrate assemblage, along with terrestrial plants, scorpions and millipedes.

Originally interpreted as a freshwater lacustrine environment, recent paleontological, taphonomic, sedimentological and geochemical evidence corroborates a brackish estuarine setting — and definitely not the deep waters of the sea. This is important because the species that gave rise to our land-living animals began life in shallow streams and lakes. It tells us a bit about how our dear Elpistostege watsoni liked to live — preferring to lollygag in cool river waters where seawater mixed with fresh. Not fully freshwater, but a wee bit of salinity to add flavour.  

  • Photos: Elpistostege watsoni (Westoll, 1938 ), Upper Devonian (Frasnian), Escuminac formation, Parc de Miguasha, Baie des Chaleurs, Gaspé, Québec, Canada. John Fam, VanPS
  • Origin of the Vertebrate Hand Illustration, https://www.nature.com/articles/s41586-020-2100-8
  • Tiktaalik Illustration: By Obsidian Soul - Own work, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=47401797

References & further reading:

  • From Water to Land: https://www.miguasha.ca/mig-en/the_first_discoveries.php
  • UNESCO Miguasha National Park: https://whc.unesco.org/en/list/686/
  • Office of L'nu Affairs: https://novascotia.ca/abor/aboriginal-people/
  • Cloutier, R., Clement, A.M., Lee, M.S.Y. et al. Elpistostege and the origin of the vertebrate hand. Nature 579, 549–554 (2020). https://doi.org/10.1038/s41586-020-2100-8
  • Daeschler, E. B., Shubin, N. H. & Jenkins, F. A. Jr. A Devonian tetrapod-like fish and the evolution of the tetrapod body plan. Nature 440, 757–763 (2006).
  • Shubin, Neil. Your Inner Fish: A Journey into the 3.5 Billion History of the Human Body.
  • Evidence for European presence in the Americas in AD 1021: https://www.nature.com/articles/s41586-021-03972-8

Saturday, 7 January 2023

OF LAND AND SEA

Our dear penguins, seals, sea lions, walruses, whales, crocodiles and sea turtles were once entirely terrestrial. Yes, they lived mostly or entirely on land. 

Many of these once land-dwelling animals returned to the sea throughout evolutionary history. We have beautifully documented cases from amphibians, reptiles, birds and mammals from over 30 different lineages over the past 250 million years.

Some dipped a toe or two into freshwater ponds, but make no mistake, they were terrestrial. Each of these animals had ancestors that tried out the sea and decided to stay. They evolved and employed a variety of adaptations to meet their new saltwater challenges. Some adapted legs as fins, others became more streamlined, and still, others developed specialized organs to extract dissolved oxygen from the water through their skin or gills. The permutations are endless.

Returning to the sea comes with a whole host of benefits but some serious challenges as well. Life at sea is very different from life on land. Water is denser than air, impacting how an animal moves, sees and hears. More importantly, it impacts an air-breathing animal's movement on a pretty frequent basis. If you need air and haven't evolved gills, you need to surface frequently. Keeping your body temperature at a homeostatic level is also a challenge as water conducts heat much better than air. Even with all of these challenges, the lure of additional food sources and freedom of movement kept those who tried the sea in the sea and they evolved accordingly.

Most major animal groups appear for the first time in the fossil record half a billion years ago. We call this flourishing of species the Cambrian Explosion. While this was a hugely intense period of species radiation, the evolutionary origins of animals are likely to be significantly older. About 700 million years ago the Earth was covered in ice and snow. This was an ice age so intense we refer to this time in our ancient history as Snowball Earth. Once that ice receded, it exposed rocks that contained a variety of weird and wonderful fossils that speak to ancient animals that are only now being studied.

Dr Frankie Dunn, a palaeontologist and an Early Career Research Fellow at the Oxford University Museum of Natural History and Merton College is one of the folks who are examining this early history of some of our first animals. Her research focuses on the origin and early evolution of animals and particularly on the fossil record of the late Ediacaran Period (570 – 540 million years ago).  Dr Dunn's research is exploring ancient species like the long-extinct Rangeomorpha to help understand how animal body plans evolved in deep time well before the divergence of the extant (living) animal lineages.

Andy Temple (bless him) sent me a link for an online talk Dr Dunn is giving, The Chronicles of Charnia, Wed, June 17th at 7PM. She's based in Oxford so adjust your timezone accordingly. The talk is free but booking is required. Here's the link: https://event.webinarjam.com/register/59/xyy07flg 

This is an interesting article from Alicia Ault writing for the Smithsonian who interviewed Nick Pysenson and Neil Kelley about some of their research that touches on this area. They published a paper on it in the journal Science. Here's the link: https://science.sciencemag.org/content/348/6232/aaa3716

And Ault's work is definitely worth a read: https://www.smithsonianmag.com/smithsonian-institution/take-deep-dive-reasons-land-animals-moved-seas-180955007/

Wednesday, 4 January 2023

GRAY WHALES: ESCHRICHTIUS ROBUSTUS

Young Gray Whale, Eschrichtius robustus
The lovely fellow you see here is a young Gray Whale, Eschrichtius robustus, with a wee dusting of barnacles and his mouth ajar just enough to show his baleen.

Two Pacific Ocean populations are known to exist: one of about 200 individuals whose migratory route is presumed to be between the Sea of Okhotsk off Russia's south coast and southern Korea, and a larger one with a population of about 27,000 individuals in the eastern Pacific.

This second group are the ones we see off the shores of British Columbia as they travel the waters from northernmost Alaska down to Baja California. Gray whale mothers make this journey accompanied by their calves, hugging the shore in shallow kelp beds and providing rare but welcome glimpses of this beauty.

The gray whale is traditionally placed as the only living species in its genus and family, Eschrichtius and Eschrichtiidae, but an extinct species was discovered and placed in the genus in 2017 — the Akishima whale, E. akishimaensis. Some recent DNA analyses suggest that certain rorquals of the family Balaenopteridae, such as the humpback whale, Megaptera novaeangliae, and fin whale, Balaenoptera physalus, are more closely related to the gray whale than they are to some other rorquals, such as minke. Still, others place gray whales as outside the rorqual clade, a kissing cousin if you will.

John Edward Gray placed it in its own genus in 1865, naming it in honour of physician and zoologist Daniel Frederik Eschricht. The common name of the whale comes from its colouration. The subfossil remains of now-extinct gray whales from the Atlantic coasts of England and Sweden were used by Gray to make the first scientific description of a species then surviving only in Pacific waters. The living Pacific species was described by American palaeontologist, Edward Drinker Cope as Rhachianectes glaucus in 1869.

Fin Whale, Balaenoptera physalus
Skeletal comparisons showed the Pacific species to be identical to the Atlantic remains in the 1930s, and Gray's naming has been generally accepted since. Although identity between the Atlantic and Pacific populations cannot be proven by anatomical data, its skeleton is distinctive and easy to distinguish from that of all other living whales.

In 1993, a twenty-seven million-year-old specimen was discovered in deposits in Washington state that represents a new species of early baleen whale. It is especially interesting as it is from a stage in the group’s evolutionary history when baleen whales transitioned from having teeth to filtering food with baleen bristles.

Visiting researcher Carlos Mauricio Peredo studied the fossil whale remains, publishing his research to solidify Sitsqwayk cornishorum (pronounced sits-quake) in the annals of history. The earliest baleen whales clearly had teeth, and clearly still used them. Modern baleen whales have no teeth and have instead evolved baleen plates for filter feeding. Look to the rather good close-up of this young Gray Whale here to see his baleen where once there was a toothy grin.

The baleen is the comb-like strainer that sits on the upper jaw of baleen whales and is used to filter food. We have to ponder when this evolutionary change —moving from teeth to baleen — occurred and what factors might have caused it. Traditionally, we have sought answers about the evolution of baleen whales by turning to two extinct groups: the aetiocetids and the eomysticetids.

The aetiocetids are small baleen whales that still have teeth, but they are very small, and it remains uncertain whether or not they used their teeth. In contrast, the eomysticetids are about the size of an adult Minke Whale and seem to have been much more akin to modern baleen whales; though it’s not certain if they had baleen. Baleen typically does not preserve in the fossil record being soft tissue; generally, only hard tissue, bones and teeth are fossilized.

Monday, 2 January 2023

MADAGASCAR GIANT: LOBOLYTOCERAS

This big beastie is a superb specimen of the ammonite Lobolytoceras costellatum showing the intricate fractal pattern of its septa. This lovely measures to a whopping 230 mm and hails from Oxfordian outcrops near Sakara, Madagascar. Lovingly prepped by the supremely talented José Juárez Ruiz.

Ammonites were predatory, squidlike creatures that lived inside coil-shaped shells. Like other cephalopods, ammonites had sharp, beak-like jaws inside a ring of squid-like tentacles that extended from their shells. They used these tentacles to snare prey — plankton, vegetation, fish and crustaceans — similar to the way a squid or octopus hunt today.

Catching a fish with your hands is no easy feat, as I'm sure you know. Ammonites did the equivalent, catching prey in their tentacles. They were skilled and successful hunters. They caught their prey while swimming and floating in the water column. Within their shells, they had a number of chambers, called septa, filled with gas or fluid that were interconnected by a wee air tube. By pushing air in or out, they were able to control their buoyancy in the water column.

They lived in the last chamber of their shells, continuously building new shell material as they grew. As each new chamber was added, the squid-like body of the ammonite would move down to occupy the final outside chamber.

They were a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids — octopuses, squid, and cuttlefish) then they are to shelled nautiloids such as the living Nautilus species.

Ammonites have intricate and complex patterns on their shells called sutures. The suture patterns differ across species and tell us what time period the ammonite is from. If they are geometric with numerous undivided lobes and saddles and eight lobes around the conch, we refer to their pattern as goniatitic, a characteristic of Paleozoic ammonites.

Ammonites first appeared about 240 million years ago, though they descended from straight-shelled cephalopods called bacrites that date back to the Devonian, about 415 million years ago, and the last species vanished in the Cretaceous–Paleogene extinction event.

They were prolific breeders that evolved rapidly. If you could cast a fishing line into our ancient seas, it is likely that you would hook an ammonite, not a fish. They were prolific back in the day, living (and sometimes dying) in schools in oceans around the globe. We find ammonite fossils (and plenty of them) in sedimentary rock from all over the world.

In some cases, we find rock beds where we can see evidence of a new species that evolved, lived and died out in such a short time span that we can walk through time, following the course of evolution using ammonites as a window into the past.

For this reason, they make excellent index fossils. An index fossil is a species that allows us to link a particular rock formation, layered in time with a particular species or genus found there. Generally, deeper is older, so we use the sedimentary layers rock to match up to specific geologic time periods, rather the way we use tree-rings to date trees. A handy way to compare fossils and date strata across the globe.

Sunday, 1 January 2023

HUMPBACK WHALES: MEGAPTERA NOVAENGLIAE

Look deep into the knowing eye of this magnificent one. He is a Humpback whale, Megaptera novaeangliae, a species of baleen whale for whom I hold a special place in my heart. 

Baleens are toothless whales who feed on plankton and other wee oceanic tasties that they consume through their baleens, a specialised filter of flexible keratin plates that frame their mouth and fit within their robust jaws.

Baleen whales, the mysticetes, split from toothed whales, the Odontoceti, around 34 million years ago. The split allowed our toothless friends to enjoy a new feeding niche and make their way in a sea with limited food resources. There are fifteen species of baleen whales who inhabit all major oceans. Their number include our humbacks, grays, right whales and the massive blue whale. Their territory runs as a wide band running from the Antarctic ice edge to 81°N latitude. These filter feeders

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, and my cousins on my father's side, whales are known as g̱wa̱'ya̱m. Both the California grey and the Humpback whale live on the coast. Only a small number of individuals in First Nation society had the right to harpoon a whale. This is a practice from many years ago. It was generally only the Chief who was bestowed this great honour. Humpback whales like to feed close to shore and enter the local inlets. Around Vancouver Island and along the coast of British Columbia, this made them a welcome food source as the long days of winter passed into Spring.

Humpback whales are rorquals, members of the Balaenopteridae family that includes the blue, fin, Bryde's, sei and minke whales. The rorquals are believed to have diverged from the other families of the suborder Mysticeti during the middle Miocene. 

While cetaceans were historically thought to have descended from mesonychids—which would place them outside the order Artiodactyla—molecular evidence supports them as a clade of even-toed ungulates—our dear Artiodactyla. 

It is one of the larger rorqual species, with adults ranging in length from 12–16 m (39–52 ft) and weighing around 25–30 metric tons (28–33 short tons). The humpback has a distinctive body shape, with long pectoral fins and a knobbly head. It is known for breaching and other distinctive surface behaviours, making it popular with whale watchers and the lucky few who see them from the decks of our local ferries.

Both male and female humpback whales vocalize, but only males produce the long, loud, complex "song" for which the species is famous. Males produce a complex soulful song lasting 10 to 20 minutes, which they repeat for hours at a time. I imagine Gregorian Monks vocalizing their chant with each individual melody strengthening and complimenting that of their peers. All the males in a group produce the same song, which differed in each season. Its purpose is not clear, though it may help induce estrus in females and bonding amongst the males.

Humpback Whale, Megaptera novaeangliae
Found in oceans and seas around the world, humpback whales typically migrate up to 25,000 km (16,000 mi) each year. 

They feed in polar waters and migrate to tropical or subtropical waters to breed and give birth, fasting and living off their fat reserves. Their diet consists mostly of krill and small fish. 

Humpbacks have a diverse repertoire of feeding methods, including the bubble net technique.

Humpbacks are a friendly species that interact with other cetaceans such as bottlenose dolphins. They are also friendly and oddly protective of humans. You may recall hearing about an incident off the Cook Islands a few years back. Nan Hauser was snorkelling and ran into a tiger shark. Two adult humpback whales rushed to her aid, blocking the shark from reaching her and pushing her back towards the shore. We could learn a thing or two from their kindness. We have not been as good to them as they have been to us.

Like other large whales, the humpback was a tasty and profitable target for the whaling industry. My grandfather and uncle participated in that industry out of Coal Harbour on northern Vancouver Island back in the 1950s. So did many of my First Nation cousins. My cousin John Lyon has told me tales of those days and the slippery stench of that work.

Six whaling stations operated on the coast of British Columbia between 1905 and 1976. Two of these stations were located at Haida Gwaii, one at Rose Harbour and the other at Naden Harbour. Over 9,400 large whales were taken from the waters around Haida Gwaii. The catch included blue whales, fin whales, sei whales, humpback whales, sperm whales and right whales. In the early years of the century, primarily humpback whales were taken. In later years, fin whales and sperm whales dominated the catch. 

Whales were hunted off South Moresby in Haida Gwaii, on the north side of Holberg Inlet in the Quatsino Sound region. It was the norm at the time and a way to make a living, especially for those who had hoped to work in the local coal mine but lost their employment when it shut down. 

While my First Nations relatives hunted whales in small numbers and many years ago, my Norwegian relatives participated in the hunt on a scale that nearly led to their extinction before the process was banned. The Coal Harbour Whaling Station closed in 1967. Once it had closed, my grandfather Einar Eikanger, my mother's father, took to fishing and my uncle Harry lost his life the year before when he slipped and fell over the side of the boat. He was crushed between the hull and a Humpback in rough seas. 

Humpback populations have partially recovered since that time to build their population up to 80,000 animals worldwide—but entanglement in fishing gear, collisions with ships, and noise pollution continue to negatively impact the species. So be kind if you see them. Turn your engine off and see if you can hear their soulful cries echoing in the water.

I did up a video on Humpback Whales over on YouTube so you could see them in all their majesty. Here is the link: https://youtu.be/_Vbta7kQNoM

Saturday, 31 December 2022

DINOFLAGELLATES: TEENSY OCEAN STARS

This showy Christmas Cracker is a Dinoflagellate

The showy royal blue Christmas cracker looking fellow you see here is a dinoflagellate. 

Bioluminescent dinoflagellates are a type of plankton — teensy marine organisms that make the seaways shimmer as you swim through them or the tide crashes them against the shore. 

The first modern dinoflagellate was described by Baker in 1753, the first species was formally named by Muller in 1773. 

The first fossil forms were described by Ehrenberg in the 1830s from Cretaceous outcrops. More dinoflagellates have lived, died and gone extinct than there are living today. We know them mainly from fossil dinocysts dating back to the Triassic. They are one of the most primitive of the eukaryotic group with a fossil record that may extend into the Precambrian. They combine primitive characteristics of prokaryotes and advanced eukaryotic features.

The luciferase found in dinoflagellates is related to the green chemical chlorophyll found in plants. Their twinkling lights are brief, each containing about 100 million photons that shine for only a tenth of a second. While each individual flicker is here and gone in the wink of an eye, en masse they are breathtaking. I have spent several wondrous evenings scuba diving amongst these glittering denizens off our shores. What you know about light above the surface does not hold true for the light you see as bioluminescence. Its energy and luminosity come from a chemical reaction. 

In a luminescent reaction, two types of chemicals — luciferin and luciferase — combine together. Together, they produce cold light — light that generates less than 20% thermal radiation or heat. 

The light you see is produced by a compound called Luciferin. It is the shiny, showy bit in this chemical show. Luciferase acts as an enzyme, the substance that acts as a catalyst controlling the rate of chemical reactions, allowing the luciferin to release energy as it is oxidized. 

The colour of the light depends on the chemical structures of the chemicals. There are more than a dozen known chemical luminescent systems, indicating that bioluminescence evolved independently in different groups of organisms.

Coelenterazine is the type of luciferin we find in shrimp, fish and jellyfish. Dinoflagellates and krill share another class of unique luciferins, while ostracods or firefleas and some fish have a completely different luciferin — but all produce lights of various colours to great effect.  

Friday, 30 December 2022

JELLYFISH: GAGISAMA

These festive lovelies are jellyfish. Jellyfish are found all over the world, from surface waters to our deepest seas — and they are old. They are some of the oldest animals in the fossil record.

Sea jellies and jellyfish are the common names for the medusa-phase or adult phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria — more closely related to anemones and corals.

Jellyfish are not fish at all. Jellyfish evolved millions of years before true fish. 

The oldest conulariid scyphozoans — picture an ice-cream cone with fourfold symmetry — appeared between 635 and 577 million years ago in the Neoproterozoic of the Lantian Formation a 150-meter-thick sequence of rocks deposited in southern China. 

Others are found in the youngest Ediacaran rocks of the Tamengo Formation of Brazil, c. 505 mya, through to the Triassic. Cubozoans and hydrozoans appeared in the Cambrian of the Marjum Formation in Utah, USA, c. 540 mya. Like other soft-bodied organisms, ctenophores (comb jellies), sea jellies and jellyfish only produce fossils only under exceptional taphonomic conditions — think rare.

I have seen all sorts of their brethren growing up on the west coast of Canada. I have seen them in tide pools, washed up on the beach and swam amongst thousands of Moon Jellyfish while scuba diving in the Salish Sea. Their movement in the water is marvellous.  

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, jellyfish are known as ǥaǥisama.

The watercolour ǥaǥisama you see here is a bit of fancy. While I chose blue, purple and pink for these lovelies, they also come in bright yellow, orange and relatively clear — and are often luminescent.

Jellyfish such as comb jellies produce bright flashes to startle a predator, others such as siphonophores can produce a chain of light or release thousands of glowing particles into the water as a mimic of small plankton to confuse the predator.

For most jellyfish bioluminescence is used for defence against predators — and about half of all jellyfish are bioluminescent. Some produce a glowing sticky slime that clings to predators making them vulnerable to other predators. Some jellyfish can release their tentacles as glowing decoys. So you see that there are many strategies for using bioluminescence by jellyfish.

All bioluminescence comes from energy released from a chemical reaction. This is very different from other sources of light, such as from the sun or a light bulb, where the energy comes from heat. In a luminescent reaction, two types of chemicals, called luciferin and luciferase, combine together. The luciferase acts as an enzyme, allowing the luciferin to release energy as it is oxidized. The colour of the light depends on the chemical structures of the chemicals. 

There are more than a dozen known chemical luminescent systems, indicating that bioluminescence evolved independently in different groups of organisms. One type of luciferin is called coelenterazine, found in jellyfish, shrimp, and fish. Dinoflagellates and krill share another class of unique luciferins, while ostracods (firefleas) and some fish have a completely different luciferin. The occurrence of identical luciferins for different types of organisms suggests a dietary source for some groups. Organisms such as bacteria and fireflies have unique luminescent chemistries. In many other groups, the chemistry is still unknown

Some of the most amazing deep-sea jellyfish are the comb jellies, which can get as large as a basketball, and are in some cases so fragile that they are almost impossible to collect intact.

Also spectacular are the siphonophores, some of which can reach several meters in length. Siphonophores deploy many tentacles like a gill net casting for small fish.

Thursday, 29 December 2022

BIOLUMINESCENCE: CHEMICAL POETRY

Light in the oceans? It is chemistry, my friends. 

In the inky blackness of the deep sea, more than 90% of the animals are luminescent. It is quite a startling number but makes good sense when you think of the edge bioluminescence provides. 

The ability to generate light helps umpteen animals find mates, attract prey and avoid predation. Handy stuff, light. 

What you know about light above the surface does not hold true for the light you see as bioluminescence. Its energy and luminosity come from a chemical reaction. 

In a luminescent reaction, two types of chemicals — luciferin and luciferase — combine together. Together, they produce cold light — light that generates less than 20% thermal radiation or heat. 

The light you see is produced by a compound called Luciferin. It is the shiny, showy bit in this chemical show. Luciferase acts as an enzyme, the substance that acts as a catalyst controlling the rate of chemical reactions, allowing the luciferin to release energy as it is oxidized. The colour of the light depends on the chemical structures of the chemicals. There are more than a dozen known chemical luminescent systems, meaning that bioluminescence evolved independently in different groups of organisms.

Coelenterazine is the type of luciferin we find in shrimp, fish and jellyfish. Dinoflagellates and krill share another class of unique luciferins, while ostracods or firefleas and some fish have a completely different luciferin. 

The luciferase found in dinoflagellates is related to the green chemical chlorophyll found in plants. Bioluminescent dinoflagellates are a type of plankton — teensy marine organisms that make the seaways shimmer like the Milky Way as you swim through them. 

Their twinkling lights are brief, each containing about 100 million photons that shine for a tenth of a second. While each individual flicker is here and gone in the wink of an eye, en masse they are awe-inspiring. I have spent many wondrous evenings scuba diving amongst these glittering denizens off our shores. 

Cotylorhiza Tuberculata Jellyfish
In this close up of a Cotylorhiza Tuberculata Jellyfish, you can see the luminosity of her blue and white tentacles. The occurrence of identical luciferins for different types of organisms may suggest a dietary source for some groups strengthening the adage, you are what you eat, or perhaps you glow how you eat

Bacteria and fireflies have unique luminescent chemistries. Fireflies light up when oxygen combines with calcium, adenosine triphosphate (ATP) and luciferin in the presence of luciferase. 

For bacteria, the world stage of luminosity is quite small — and a bit gormless. Just how much light they emit and when is a free-for-all. Not so for the rest of our bioluminescent friends who have very precise control over when they shine and just how bright. 

Bioluminescence comes in a variety of colours, from blue through red. The colour is based on the chemistry, which involves a substrate molecule called luciferin, the source of energy that goes into light, and an enzyme called luciferase or photoprotein. 

Most of this lighting up of our world happens on land or in saltwater. There are almost no bioluminescent organisms native to freshwater.

In terrestrial plants and animals — fireflies, beetles and fungi like this Ghost Fungus, Omphalotus nidiformis, a gilled basidiomycete mushroom — we commonly find green, yellow, and sometimes red. 

In the ocean, bioluminescence is mostly blue-green or green. You would think that blues and green would not show up all that well in our seas but, surprisingly, they do. While sound travels better through saltwater than air, it is the reverse for light. 

Various colours of light do not transmit equally through saltwater. Once we move deeper than the top layer of the ocean warmed by the sun and brimming with nutrients, the epipelagic zone, and move deeper through the mesopelagic, deeper and deeper still to the bathypelagic, frigid abyssalpelagic and finally the deep trenches of the icy pressure and all but inhospitable hadalpelagic, less and less light — until no light — gets through.

It is the twilight of the mesopelagic, 200 - 1000 metres below the surface, that is the sweet spot for most of our bioluminescent friends. Here, only very faint sunlight gets through. The water pressure is higher than at the surface but still lacks the crushing intensity of the lower zones. It is here that bioluminescence becomes a real advantage — good real estate and the showmanship of light pays gold.

We know that the deeper you go in our oceans, less and less sunlight gets through, so if the purpose of bioluminescence is to provide a signal that is noticed by prey, potential mates and predators alike, it is important that the light moves through the seawater, and not be absorbed or scattered — and this plays out in the colours evolved to be seen here. 

If you have spent any time underwater, you will know that blue-green light transmits best through seawater. The deeper you go, the colours fade. Gone are the reds and yellows until everything looks brown or blue-green. Because of this, it is no surprise that blue-green is the most common colouring of bioluminescence in our oceans. 

There are some exceptions to the blue-green/green colour rule — minuscule planktonic polychaete worms, Tomopteris helgolandica, emit yellow light, and deep-sea fish Malacosteus niger in the family Stomiidae, the barbeled dragonfishes, produce both red and blue. 

Malacosteus niger's unique adaptation of producing red bioluminescence is only found in two other deep-sea dwelling creatures, Aristostomias and Pachystomias

This rare form of bioluminescence can reach up to 700 nm in the deep-sea and cannot be perceived by green and blue bioluminescent organisms — granting M. niger a considerable advantage while hunting at depth.

The red light may function as an invisible searchlight of sorts because most animals in the ocean cannot see red light, while the eyes of M. niger are red-sensitive. It is much easier to find and eat something that cannot see you, particularly if it is lit up like a tasty red holiday snack.

Reference: https://latzlab.ucsd.edu/bioluminescence/

Wednesday, 28 December 2022

SEA ANEMONES: CNIDARIA

These colourful beauties are sea anemones. They are familiar inhabitants of rocky shores and coral reefs around the world — with some of their brethren found at very low depths in our oceans. They are one of the wonderful examples of the diversity that radiated out of the Cambrian Explosion.

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, sea anemones are known as 'mis'ma̱t̕sa. 

These beautiful predatory animals are a common site in tide pools all along the Pacific Coast. They form a large part of many special memories of exploring the tide pools along Storey's Beach on the east side of Vancouver Island as a child. 

Touching their soft tentacles is hypnotic and highly entertaining but our human skin is coated in oils and bacteria that may damage these delicate organisms. 

We sometimes see them turn up in First Nation's art — particularly in association with Kumugwe' or the Copper-Maker, Chief of the undersea world and the one to thank for the rising and ebbing of the tides.

At first glance, they look like beautiful and delicate marine flowers. If you have discovered them in tidepools, you will know that they retract or pull into themselves with the lightest touch. These would-be flowers are predatory marine animals of the order Actiniaria that have graced our oceans for over half a billion years. 

They are named after anemones — Anemonastrum, a genus of flowering plants in the family Ranunculaceae — because of their colourful flower-like appearance. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. 

As cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and Hydra. Jellyfish have a complex life cycle that includes both sexual and asexual phases, with the medusa being the sexual stage in most instances. 

A typical sea anemone is a single polyp attached to a hard surface by its base, but some species live in soft sediment and a few float near the surface of the water. The polyp has a columnar trunk topped by an oral disc with a ring of sticky tentacles that fold in towards its central mouth. If they have stung and paralyzed a tasty snack, it is pulled towards the gaping mouth to be consumed. 

The tentacles can be retracted or pulled back inside the body cavity or stretched out and expanded to catch passing prey. They are armed with cnidocytes or stinging cells. In many species, nourishment comes from a symbiotic relationship with single-celled dinoflagellates — zooxanthellae or with green algae, zoochlorellae, that live within the cells. Some species of sea anemone live in association with hermit crabs, small fish or other animals to their mutual benefit.

Most actinarians are sessile — that is, they live attached to rocks or other substrates and do not move, or move only very slowly by contractions of the pedal disk. 

A number of anemones burrow into sand, and a few can even swim short distances, by bending the column back and forth or by "flapping" their tentacles. In all, there are about 1000 species of sea anemone in the world's oceans — including those who live amongst the mythic sea lions that form the posts and beams of Kumugwe''s undersea home.

Sea anemones breed by releasing sperm and eggs through their mouth into the surrounding ocean. The fertilized eggs develop into wee planula larvae that live as tiny planktonic bits floating in the sea. Eventually, they settle on the seafloor and develop directly into juvenile polyps. Sea anemones can also breed asexually. They do this by breaking in half or into smaller pieces that regenerate into polyps.

We sometimes see these beauties kept in saltwater aquariums. I can understand the appeal but it comes with a price. The global trade in marine ornamentals threatens our lovely sea anemone populations. 

Most Actiniaria do not form hard parts that can be recognized as fossils, but a few fossils of sea anemones have been found. The bag-like — almost sea cucumber-like — Mackenzia, from the Middle Cambrian, Stephen Formation in the Canadian Rockies of British Columbia and Alberta, is the oldest fossil identified as a sea anemone. These ancient sea anemones attached themselves to hard surfaces, such as brachiopod shells in a similar fashion to their modern sessile cousins. 

Mackenzia costalis, Walcott 1911
Fourteen specimens of Mackenzia costalis are known from the Greater Phyllopod bed, where they make up less than <0.1% of the fossil community. Mackenzia was originally described by Charles Walcott in 1911 — but as a holothurian echinoderm, which was a reasonable assumption at the time. Once additional specimens had been found and studied, Mackenzia costalis was reclassified as a cnidarian and the great grandparent of our modern sea anemones.

Some fossil sea anemones have also been found from the Lower Cambrian of China. The new find lends support to genetic data that suggests anthozoans — anemones, corals, octocorals and their kin — were one the first Cnidarian groups to diversify. We will likely find more of these rare fossils over time and perhaps get a better view of their long lineage.

Photo: Charles Doolittle Walcott - Charles D. Walcott: Middle Cambrian Holothurians and Medusae. Smithsonian Miscellaneous Collections Volume 57, Number 3 (Publication 2011). City of Washington. Published by the Smithsonian Institution. June 13, 1911. 

References:  

Caron, Jean-Bernard; Jackson, Donald A. (October 2006). "Taphonomy of the Greater Phyllopod Bed community, Burgess Shale". PALAIOS. 21 (5): 451–65. doi:10.2110/palo.2003.P05-070R. JSTOR 20173022.

 Durham, J. W. (1974). "Systematic Position of Eldonia ludwigi Walcott". Journal of Paleontology. 48 (4): 750–755. JSTOR 1303225.

Conway Morris, S. (1993). "Ediacaran-like fossils in Cambrian Burgess Shale–type faunas of North America". Palaeontology. 36 (31–0239): 593–635.


Tuesday, 27 December 2022

ANCIENT SNOW PLOW: WOOLLY MAMMOTHS

Woolly Mammoths, Mammuthus primigenius,  have always held wonder for me. These massive, hairy — and likely very smelly beasts — lived alongside us for a time. 

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 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 hard work to get at as much of his world was covered in ice and snow during his reign.

We first see Woolly Mammoths in northeastern Siberia dating back 700,000 years. We find them in East Asia as far back as 800,000 years ago. They arose from the massive steppe mammoths, Mammuthus trogontherii, slowly evolving traits we see in this older species to the mammoths we think of today. 

Over time, their body size shrank and their teeth and tusks evolved to take advantage of the tough vegetation available to those few animals who could chew their way through ice and snow and work these tundra grasses into a digestible form. 

The enamel plates of their cheek teeth multiplied while the enamel itself became thinner. Tusks slowly took on more of a curved to act as ploughs for the snow. 

Those smaller than their predecessors, they were still formidable. Their size offered protection against predators once full grown. Sadly for the juveniles, they offered tasty prey to big cats like Homotherium who roamed these ancient grasslands alongside them.

The Mammoths of the Steppe spread to the northern areas of Eurasia, down through Europe, into the British Isles to Spain and crossed over to populate North America via the Bering Isthmus. It was the lowered sea levels during the last Ice Age that exposed dry land between Asia and the Americas. Here in this flat, grassy treeless plain known as the Bering Land Bridge or Isthmus, animals, including humans, could migrate from Europe west into North America.

The woolly mammoth coexisted with our ancestors who made good use of their bones and tusks for tools, housing, art and food. The last of their lineage died out relatively recently on Wrangel Island until 4,000 years ago — a time when we were making our first harps and flutes in Egypt, dams, canals and stone sculptures in Sumer, using numbers for the first time and using tin to make tools.

Monday, 26 December 2022

KAZAKHSTAN ANAHOPLITES

This tasty block of Semenovites (Anahoplites) cf. michalskii ammonites hails from Cretaceous, Albian deposits that outcrop on the Tupqaraghan — Mangyshlak Peninsula on the eastern coast of the Caspian Sea, Kazakhstan. 

Present-day Kazakhstan is made up of several micro continental blocks that were broken up in the Cambrian and then crushed back together then smashed up against Siberia and came to rest where we find them today. 

Mangyshlak or Mangghyshlaq Peninsula is a large peninsula located in western Kazakhstan. It borders on the Caspian Sea in the west and with the Buzachi Peninsula, a marshy sub-feature of the main peninsula, in the northeast. The Tyuleniy Archipelago lies off the northern shores of the peninsula.

Lowlands make up one-third of Kazakhstan’s huge expanse, hilly plateaus and plains account for nearly half, and low mountainous regions about one-fifth. Kazakhstan’s highest point, Mount Khan-Tengri (Han-t’eng-ko-li Peak) at 22,949 feet (6,995 metres), in the Tien Shan range on the border between Kazakhstan, Kyrgyzstan, and China, contrasts with the flat or rolling terrain of most of the republic. 

The western and southwestern parts of Kazakhstan are dominated by the low-lying Caspian Depression, which at its lowest point lies some 95 feet below sea level. South of the Caspian Depression are the Ustyurt Plateau and the Tupqaraghan (formerly Mangyshlak) Peninsula jutting into the Caspian Sea. 

Vast amounts of sand formed the Greater Barsuki and Aral Karakum deserts near the Aral Sea, the broad Betpaqdala Desert of the interior, and the Muyunkum and Kyzylkum deserts in the south. Most of these desert regions have slight vegetative cover eeking out a slim existence fed by subterranean groundwater.

Depressions filled by salt lakes — whose water has largely evaporated — dot the undulating uplands of central Kazakhstan. 

In the north, the mountains reach about 5,000 feet, and there are similar high areas among the Ulutau Mountains in the west and the Chingiz-Tau Range in the east. In the east and southeast, massifs — enormous blocks of crystalline rock — are furrowed by valleys. 

The Altai mountain complex to the east sends three ridges into the republic, and, farther south, the Tarbagatay Range is an offshoot of the Naryn-Kolbin complex. Another range, the Dzungarian Alatau, penetrates the country to the south of the depression containing the icy waters of Lake Balkhash. The beautiful Tien Shan peaks rise along the southern frontier with Kyrgyzstan. 

As well as lovely ammonite outcrops, dinosaurian material and pterosaur remains are also found in Kazakhstan. The ammonites you see here are in the collections of the deeply awesome Emil Black.

Paleo Coordinates: 44 ° 35'46 ″ 51 ° 52'53″