Thursday, 9 September 2021

CANADOCERAS YOKOYAMAI: HASLAM FORMATION

A lovely chunky slate grey handful of an ammonite is Canadoceras yokoyamai from Upper Cretaceous (Early Campanian) outcrops in the Haslam Formation of Vancouver Island, British Columbia, Canada. 

This gorgeous ammonite was found by Tim O'Bear and is now in the collections of the Vancouver Island Palaeontological Society (VIPS), a regional paleontological society based in Courtenay.

This meaty cephalopod swam and hunted in our ancient oceans 80-84 million years ago and was once a leading candidate as the provincial fossil of British Columbia — an honour won by Shonisaurus sikanniensis.

The species is named for Matajirō Yokoyama, Professor of Geology and Palaeontology at the Imperial University of Tokyo, Japan. 

Yokoyama was born in the Nagasaki Prefecture on the 14th of June 1860 — the day slavery was abolished in the Neth Indies and the year Abraham Lincoln was elected president of the United States — a move that would lead to the beginning of the US Civil War the following year.

During his early life, the Meiji Restoration would begin the process of transforming Japan into a global imperial power. During the Restoration, Japan rapidly industrialized, adopting Western ideas and production methods. This shift in the cultural focus of his nation allowed him to pursue his studies in science — something encouraged in an emerging nation.

Matajirō Yokoyama (1860-1942)
Yokoyama did some wonderful work on the Cretaceous of Japan and opened up our understanding of the species on Vancouver Island. 

Through his research, we learned of the Japanese fauna and the extent of their occurrence. The range of Canadoceras yokoyamai extended from Alaska, the eastern coast of Vancouver Island, California to Santonian outcrops in the Yezo Group of Hokkaido in Japan’s northern islands. 

Within the Yezo Group, we find Canadoceras yokoyami amongst other ammonites, bivalves — and some wonderful marine reptiles — both mosasaurs and marine turtles.

Given that Canadoceras yokoyami arose, lived and died in a relatively short time frame — geologically speaking — they make excellent Index fossils. They can act as guides as to the age of the rocks in which they are preserved. This is helpful in the field. 

If you were to find a fossil in a rock of unknown age, you can look at the species and guess with relative certainty what age that rock likely is. 

References:

Matsumoto, T., 1954a [for 1953]: The Cretaceous system in the Japanese islands., pp. i–xiv + 1–324, pls. 1–20. The Japanese Society for the Promotion of Scientific Research, Ueno, Tokyo. (Reference No. 0219)

Tanabe, K., Ito, Y., Moriya, K. and Sasaki, T., 2000: Database of Cretaceous ammonite specimens registered in the Department of Historical Geology and Paleontology of the University Museum, University of Tokyo. The University Museum, The University of Tokyo, Material Reports, no. 37, pp. i–iv + 1–509. (Reference No. 0879)

Photo: Matajirō Yokoyama, Professor of Geology, Palaeontology and Mineralogy. 日本語: 横山又次郎 地質学古生物学及鉱物学教授 Tokyo Teikoku Daigaku (Imperial University of Tokyo). Ogawa Shashin Seihanjo, 1900 (reprint, Ryūkei Shosha, 2004).

Wednesday, 8 September 2021

OCEAN SUNFISH: MOLA MOLA

Mola mola (Linnaeus, 1758)
The massive docile ocean sunfish or common mola, Mola mola (Linnaeus, 1758) is one of the two heaviest known bony fish in the world — the other being the southern sunfish of the same genus. 

As a family, Molidae emerged between 45 million and 35 million years ago, well after the dinosaurs disappeared and at a time when whales still had legs. 

A group of pufferfishes — the kissing cousins to the Mola we know today and built like little tanks — left the safety of the coral reefs for the open ocean. 

They evolved and gave rise to Mola about 23 – 20.4 million years ago. These were followed by their still extant cousins, the Ranzania, 16 – 13.8 million years ago. The third genus of extant sunfish, Masturus, has not been identified in the fossil record (Carnevale et al. 2020) though we will keep looking and put that puzzle piece in its place in time.

When they are born, dozens would fit in the palm of your hand — each roughly the size of a pea. When they are youngsters, they are very curious and will swim up to you to take a wee nibble to figure out what you are. My mother had such a harmless bite when she was travelling as a girl. The bite left a tooth embedded in her leg that worked its way out a few weeks later. Not in any way perturbed, she speaks of her encounter fondly. 

As they grow, Mola take on a very roundish look and grow to a massive 247 to 1,000 kg (544 to 2,204 lbs) — that's one and a half times the size of a typical cow and bigger than a Grizzly Bear. The heaviest specimen on record is a bump-head sunfish, Mola alexandrini, caught off Kamogawa, Chiba, Japan, in 1996. It weighed 2,300 kilograms (5,070 pounds) and measured 2.72 metres (8 feet 11 inches) long.

The sheer size and thick skin of an adult of the species deter many smaller predators, but younger fish are vulnerable to predation by bluefin tuna and mahi-mahi. 

Adults are often consumed as tasty snacks by orca, sharks and sea lions — and sadly, by humans, particularly those from Japan, Korea and Taiwan. Fortunately, the EU has banned the sale of common mola and others within the family Molidae. 

Of all the fish we have in our oceans, the common mola or sunfish has the most names I have ever come across. 

Many of the sunfish's various names allude to its round, flattened, moonish or millstone shape. Its scientific name, mola, is Latin for millstone. It is a rather good choice as the fish resembles a millstone you might use for grinding grain, in part because of its grey colour, rough texture, and rounded body. 

Its English name, sunfish, refers to the animal's habit of enjoying the sun's rays as it basks near the surface. Its common names in Dutch, Portuguese, French, Spanish, Catalan, Italian, Russian, Greek, Norwegian, and German — maanvis, peixe lua, Poisson lune, pez luna, peix lluna, Pesce luna, рыба-луна, φεγγαρόψαρο, månefisk and Mondfisch, respectively — mean moonfish, in reference to its round moonish shape. 

In German or auf Deutsch, the common mola is also known as Schwimmender Kopf or swimming head. In Polish, it is named samogłów, meaning head alone or only head, because it lacks a true tail. In Swedish, Danish and Norwegian it is known rather unflatteringly as klumpfisk, in Dutch klompvis, in Finnish möhkäkala — all of which mean lump fish

The Chinese translation of its name is fān chē yú 翻車魚, meaning toppled wheel fish — perhaps as a wee homage to the original Latin mola or millstone. 

By any name, we find these gentle giants cruising through tropical and temperate waters around the world where they have thrived for many millions of years.

Tuesday, 7 September 2021

PHRAGMOTEUTHIS CONOCAUDA

Phragmoteuthis conocauda
A superb specimen of Phragmoteuthis conocauda, (Quenstedt, 1846-49). These ancient marine lovelies had an internal phragmocone and ten arms.

Phragmoteuthis is a genus of extinct coleoid cephalopod known from the late Triassic to the Lower Jurassic. Its soft tissue has been preserved wonderfully. Some rare specimens contain intact ink sacs, arm hooks, and others, gills.

There are some wonderful specimens from the Carnian, Late Triassic outcrops near Lunz, in Lower Austria with wee arm hooks and ink sacs, though the ink now looks like an agglomerate of grains. 

In Toarcian deposits in Southwestern Germany, we find fragments of Phracmoteuthis concocauda with bits of gill preserved. They look remarkably like the gills of octopod and vampyromorph colcoids.

Palaeontologist Jurji (Jura) Jeletzky characterized phragmoteuthids as having a large tripartite, fanlike pro-ostracum forming the longest portion of the shell, attached to about three-quarters of the circumference of a comparatively small breviconic phragmocone with short camerae and superficially belemnitid-like siphuncle.

Add that to an absent or much-reduced rostrum at the apical part of the phragmocone, belemnite-like arm hooks, an ink sack, beaks resembling those of recent teuthids, and a muscular mantle.

Think early squid. These are their great great grandparents. 

This specimen is in the collections of the University of Oslo Natural History Museum, Norway's oldest and largest museum of natural history in the lovely neighbourhood of Tøyen near Grünerløkka in Oslo. If you visit, check out the nearby Munch Museum to see some of Edvard Munch's work.

Monday, 6 September 2021

Sunday, 5 September 2021

FIRST NATION POLES IN STANLEY PARK

Totem, Welcome & Mortuary Poles at Stanley Park
If you visit Brockton Point in Stanley Park, there are many carved red cedar First Nation poles for you to admire.  

What you are viewing are replicas of First Nation welcome and totem poles that once stood in the park but have been returned to their homes within the province's diverse First Nation communities — or held within museum collections. 

Some of the original totems came from Alert Bay on Cormorant Island, near the Port McNeill on the north coast of Vancouver Island. Others came from communities in Haida Gwaii — and still more from the Wuikinuxv First Nations at Rivers Inlet on British Columbia's central west coast — home of the Great Bear Rainforest with her Spirit Bears.

The exception is the most recent addition carved by Robert Yelton in 2009. Robert is a First Nation carver from the Squamish Nation and his original welcome pole graces Brockton Point, the original settlement site of a group of Squamish-Portuguese settlers.  

If you look at the photo above, the lovely chocolate, red and turquoise pole on the right is a replica of the mortuary pole raised to honour the Raven Chief of Skedans or Gida'nsta, the Haida phrase for from his daughter, the title of respect used when addressing a person of high rank. Early fur traders often took the name of the local Chief and used it synonymously as the place names for the sites they visited — hence Skedans from Gida'nsta.

Chief Skedans Mortuary Pole
Chief Skedans, or Qa'gials qe'gawa-i, to his children, lived in Ḵ’uuna Llnagaay, or village at the edge, in Xaayda Kil — a village on the exposed coast of Louise Island — now a Haida Heritage Site.  

There are some paintings you may have seen by Emily Carr of her visits to the site in 1912, She used the phonetic Q'una from Q:o'na to describe both the place name and title of her work. 

Carr's paintings of the totems have always looked to me to be a mash-up — imagine if painter Tamara de Lempicka and photographer Edward Curtis had a baby — not pretty, but interesting.

Some called this area, Huadju-lanas or Xu'adji la'nas, which means Grizzly-Bear-Town, in reference to resident grizzly bear population and their adornment of many totems and artwork by the local artists.

Upon Chief Skedan's death, the mortuary pole was carved both to honour him and provide his final resting place. Dates are a bit fuzzy, but local accounts have this as sometime between 1870-1878 — and at a cost of 290 blankets or roughly $600 in today's currency. 

The great artistry of the pole was much admired by those in the community and those organizing the celebrations for the 1936 Vancouver Golden Jubilee — witnessed by  350,000 newly arrived residents.

Negotiations were pursued and the pole made its way down from Haida Gwaii to Stanley Park in time for the celebrations. The original totem graced Stanley Park for a little over twenty years before eventually making its way back to Haida Gwaii. It was returned to the community with bits of plaster and shoddy paint marring the original. These bits were scraped off and the pole welcomed back with due ceremony. 

In 1964, respected and renowned Northwest Coast master carver, Bill Reid, from the Kaadaas gaah Kiiguwaay, Raven/Wolf Clan of T'anuu, Haida Gwaii and Scottish-German descent, was asked to carve this colourful replica. 

Mountain Goat Detail, Skedans Mortuary Pole
Reid carved the totem onsite in Stanley Park with the help of German carver Werner True. Interestingly, though I looked at length for information on Werner True, all I can find is that he aided Bill Reid on the carving for a payment of $1000.

Don Yeomans, Haida master carver, meticulously recarved the moon crest in 1998. If you have admired the totem pole in the Vancouver Airport, you will have seen some of Yeoman's incredible work. 

The crest is Moon with the face, wings, legs and claws of a mighty and proud Thunderbird with a fairly smallish hooked beak in a split design. We have Moon to thank for the tides and illuminating our darkest nights. As a crest, Moon is associated with transformation and acting as both guardian and protector.

The original pole had a mortuary box that held the Chief's remains. The crest sits atop a very charming mountain goat. I have included a nice close-up here of the replica for you to enjoy. 

Mountain Goats live in the high peaks of British Columbia and being so close to the sky, they have the supernatural ability to cross over to the sky world. They are also credited as being spirit guardians and guides to First Nation shamans.

I love his horns and tucked in cloven hooves. There is another pole being carved on Vancouver Island that I hope to see during its creation that also depicts a Mountain Goat. With permission and in time, I hope to share some of those photos with you. 

Mountain Goat is sitting atop Grizzly Bear or Huaji or Xhuwaji’ with little human figures placed in his ears to represent the Chief's daughter and son-in-law, who raised the pole and held a potlatch in his honour. 

Beneath the great bear is Seal or Killer Whale in his grasp. The inscription in the park says it is a Killer Whale but I am not sure about that interpretation — both the look and lore make Seal more likely. Perhaps if Killer Whale were within Thunderbird's grasp — maybe

Though it is always a pleasure to see Killer Whale carved in red cedar, as the first whales came into being when they were carved in wood by a human — or by Raven — then magically infused with the gift of life.

Siwash Rock on the northern end of Third Beach, Stanley Park
The ground these totems sit upon is composed of plutonic, volcanic and sedimentary layers of rock and exhibits the profound influences of glaciation and glacial retreat from the last ice age. 

Glacial deposits sit atop as a mix of clay, sand, cobbles and larger boulders of glacial till. 

There are a few areas of exposed volcanics within the park that speak to the scraping of the glaciers as they retreated about 12,500 years ago. 

The iconic moss and lichen coated Siwash Rock on the northern end of Third Beach is one of the more picturesque of these. It is a basaltic and andesitic volcanic rock — a blend of black phenocrysts of augite cemented together with plagioclase, hornblende and volcanic glass.

Images not shown: 

Do check out the work of Emily Carr and her paintings of Q:o'na from the 1940s. I'll share a link here but do not have permission to post her works. http://www.emilycarr.org/totems/exhibit/haida/ssintro.htm

Saturday, 4 September 2021

STANLEY PARK: HIDDEN HISTORY

Anavitrinella pampinaria / Dan Bowden Photography
A Common grey moth of the family Geometridae. We begin to see them in the fossil record some 200 million years ago. 

These lovelies live in North America from Mexico to Alaska and do a wonderful job at camouflage. 

While not a perfect hiding spot, this fellow has chosen to settle in for the evening on a young yellow cedar tree, Chamaecyparis nootkatensis, in Vancouver's Stanley Park — a 405-hectare urban forest in Vancouver, B.C. that became a provincial park in 1887. 

This area was once the exclusive domain of the Coast Salish First Nations —  xʷmə?kʷəyəm (Musqueam), Skwxwú7mesh (Squamish), and səlilwətaɬ (Tsleil-Waututh) Nations until the early 1800s. 

Blending into that mix in the mid-1800s was a group of mixed Portuguese-Squamish settlers who called the eastern shores of the park at Brockton Point home from the mid-1800s to the 1930s. 

Brockton Point. City of Vancouver Archives, CVA 677-228
On the park's northern shores, there were well established Squamish First Nations villages — Whoi Whoi known today as Lumberman's Arch and Chaythos, which we now call Prospect Point. 

There was also a well-established Hawaiian settlement at Kanaka Ranch closer to the park's entrance near Coal Harbour. 

Many individuals from Vancouver's growing Chinese population lived peacefully alongside squirrels, coyotes, racoons and other wildlife within the natural beauty of the park. Enticed to British Columbia by the lure of gold but finding the riches far less than expected, they took to the forest in Stanley Park to make out of the way homes for themselves. That, of course, did not last. All of the residents in and around the newly minted park were ousted with ill regard for their welfare. 

You may know of one of the families, Khatsahlano, from whence my community of Kitsilano gets its name. August Jack Khatsahlano (July 16, 1877 – June 5, 1971), lived in Whoi Whoi alongside eleven other families. August Jack Khatsahlano or X̱ats'alanexw, was born in the village of Xwayxway on the peninsula that is now Stanley Park, Vancouver/Chaythoos, British Columbia.

He was the son of Supple Jack "Khay- Tulk" of Chaythoos and Sally "Owhaywat" from the Yekwaupsum Reserve north of Squamish, British Columbia. His grandfather was Chief Khahtsahlano of Senakw (Snauq or Sun'ahk) who migrated from his home at Toktakanmic on the Squamish River to Chaythoos, from whence he inherited his name. The suffix lan-ogh means man. In an interview with Vancouver's first archivist, Khatsahlano recounts:

Stanley Park, Vancouver, BC
“When they make [the] Stanley Park road, we were eating [breakfast] in our house. Someone make noise outside; chop our house. We were inside the house when the surveyors came along, and they chop the corner of our house while we were eating inside.”

You can imagine taking just what you can carry and walking into the unknown of where you will sleep that night and make a home in the future. It saddens me that we treat people so poorly, historically and now. 

We also treat our wildlife poorly. There are plans to capture and kill the coyotes in Stanley Park today as they are a nuisance to those visiting the park. We might consider that we are a nuisance to them. 

The only real winners in Stanley Park are the trees, birds and insects, including lovelies like this grey moth. In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest and part of my heritage, yellow cedar is dixw, and a moth is ma̱stła̱ḵ̕wa or ma̱stła̱ḵ̕wani

The thin, greyish-brown and scaly bark provides a pretty good cover. He was caught unawares and photographed beautifully by the hugely talented, Dan Bowden on a visit to the city.

Friday, 3 September 2021

HETEROMORPH AMMONITE: AINOCERAS

A wee baby deep chocolate Ainoceras sp. heteromorph ammonite from Vancouver Island. This adorable corkscrew-shaped ammonite is an extinct marine mollusc related to squid and octopus.  

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. These little cuties were predators who hunted in Cretaceous seas.

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. 

Not all ammonites have this whacky corkscrew design. Most are coiled and some are even shaped like massive paperclips. This one is so remarkable, so joyously perfect my internal thesaurus can’t keep up.

Thursday, 2 September 2021

ABALONE: GWA'LIT'SA

Abalone is the common name for a group of large marine snails — gastropod molluscs in the genus Haliotis, family Haliotidae.

Haliotis once contained six subgenera but these are now grouped together as alternate representations of Haliotis

In the Pacific Northwest, our rocky shores are home to the Northern or Pinto abalone, Haliotis kamtschatkana

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

They range from Mexico to Alaska and are the only abalone species found in Washington state, British Columbia and Alaska. Abalone prefer to live amongst the cold waters and high surf of rocky reef habitats. They are easily harvested as their sweet spot is water between 3-18 meters or 10-60 feet deep.  

The shells of abalones have a low, open spiral structure, and are characterized by several open respiratory pores in a row near the shell's outer edge. The thick inner layer of the shell is composed of nacre or mother-of-pearl. Their iridescent nacre is gorgeous and runs from white to blue to green. Both their meat and their shells are highly prized. 

The Northern or Pinto abalone is protected today. Those looking to use the shell for decorative purposes must now look to California or New Zealand. The California abalone is more colourful than its northern cousin and has long been preferred by First Nations artists, particularly for the large earrings favoured by women of rank amongst First Nation clans.

Tuesday, 31 August 2021

AIOLOCERAS BESAIRIEI: VIPS COLLECTION

Aioloceras besairiei (Collingnon, 1949)
Beauty is a stimulant that is administered through the eyes.

And just look at this beauty. This gorgeous burnt orange and creamy visual feast is the ammonite Aioloceras besairiei (Collingnon, 1949) from the Upper Cretaceous (Lower Albian) Boeny region of Madagascar. 

This is specimen #00783B in the collections of the Vancouver Palaeontological Society, (VIPS). The chambers have a wonderful calcite filling best viewed by carefully slicing these specimens in two. 

There is a small imperfection near the centre that renders this ammonite its signature mark of perfection. This lovely is in my care as a study specimen. 

Madagascar is an island country is about 400 kilometres off the coast of East Africa in the Indian Ocean and a wonderful place to explore off the beaten track. Exotic, beautiful and geologically interesting — it remains high on my bucket list to explore. 

Madagascar has some of the most pleasing of all the fossil specimens I have ever seen. This beauty is no exception. The shell has a generally small umbilicus, arched to acute centre and falcoid ribs that spring in pairs from the umbilical tubercles then disappear on the outer whorls. Take that magical body plan with its pleasing symmetry and add an infilling with spectacular calcite — spectacular! 

It is rightfully Aioloceras besairiei — and correctly labelled as such by the VIPS — but some specimens I have looked at earlier were marked as a Cleoniceras besairiei. This is impossible, of course, as Cleoniceras and Grycia are not present in Madagascar. This lovely, seen in cross-section, is now far from home and in my collection to enjoy for a time before returning to Courtenay on Vancouver Island. 

Aioloceras besairiei are within beudanticeratinae. Cleoniceras and Grycia are the boreal genera. If you would like to see — or argue — the rationale on the name, consider reading Riccardi and Medina's riveting work from back in 2002, or Collingnon from 1949.

The beauty you see here measures in at a whopping 23 cm. It hails from the youngest or uppermost subdivision of the Lower Cretaceous. I had originally thought this locality was older, but dating reveals it to be from the Lower Albian, approximately 113.0 ± 1.0 Ma to 100.5 ± 0.9 Ma. This locality produces ammonites that are beyond measure in their singular beauty. 

Aioloceras are found in the Cretaceous of Madagascar at geo coordinates 16.5° S, 45.9° E: paleo-coordinates 40.5° S, 29.3° E.; and in four localities in South Africa: at locality 36, near the Mzinene River at 28.0° S, 32.3° E: paleo-coordinates 48.6° S, 7.6° E. 

We find them near the Mziene River, at a second locality north of Hluhluwe where the Mzinene Formation overlies the Aptian-Albian Makatini Formation at 28.0° S, 32.3° E: paleo-coordinates 48.6° S, 7.6° E; and at Haughton Z18, on the Pongola River in the Albian III, Tegoceras mosense beds at 27.3° S, 32.2° E: paleo-coordinates 48.0° S, 7.8° E.

If you happen to be trekking to Madagascar, know that it's big. It is 592,800 square kilometres (or  226,917 square miles), making it the fourth-largest island on the planet — bigger than Spain, Thailand, Sweden and Germany. So, enjoy your time and wear comfortable shoes. 

If you are interested in learning more about this species, check out the Treatise on Invertebrate Paleontology, Part L (Ammonoidea). R.C. Moore (ed). Geological Soc of America and Univ. Kansas Press (1957), p L394. Or head over to look at the 2002 paper from Riccardi and Medina. 2002. Riccardi, A., C. & Medina, F., A. The Beudanticeratinae and Cleoniceratinae (Ammonitina) from the Lower Albian of Patagonia in Revue de Paléobiologie - 21(1) - Muséum d’Histoire Naturelle de la ville de Genève, p 313-314 (=Aioloceras besairiei (COLLIGNON, 1949). You have Bertrand Matrion to thank for the naming correction. Good to have friends in geeky places!

Collignon, M., 1933, Fossiles cenomaniens d’Antmahavelona (Province d’ Analalave, Madagascar), Ann. Geol. Serv. Min. Madagascar, III, 1934 Les Cephalopods du Trias inferieur de Madagascar, Ann. Paleont. XXII 3 and 4, XXII 1.

Besairie, H., 1971, Geologie de Madagascar, 1. Les terrains sedimentaires, Ann. Geol. Madagascar, 35, p. 463.

J. Boast A. and E. M. Nairn collaborated on a chapter in An Outline of the Geology of Madagascar, that is very readable and cites most of the available geologic research papers. It is an excellent place to begin a paleo exploration of the island.

If you happen to parle français, check out: Madagascar ammonites: http://www.ammonites.fr/Geo/Madagascar.htm

Sunday, 29 August 2021

BLUE DRAGON SEA SLUG

This otherwordly fellow, straight out of a novel, is Glaucus atlanticus — the Blue Dragon Sea Slug. And what an amazing wee little dragon this is. Folk sometimes refer to them as sea swallow, blue angel, blue glaucus, dragon slug, blue dragon, blue sea slug and blue ocean slug. 

By any name, they are a very pleasing addition to our planet. Glaucus atlanticus are a species of small, blue sea slug, a pelagic aeolid nudibranch — a shell-less gastropod mollusc in the family Glaucidae.

Nudibranchs likely date back as far as the Early Jurassic, some180 million years ago. This was around the time that the supercontinent of Pangea was breaking apart to form the modern continents and the Atlantic and Indian Oceans. The date is an estimate built upon the evolutionary lineages of their closest relatives, in part because the soft-bodied nature of nudibranchs means they do not fossilize well.

These sea slugs are pelagic — they float upside down by using the surface tension of the water to stay up near the surface where they drift along, carried by the winds and ocean currents. Glaucus atlanticus makes use of countershading: the blue side of their body faces upwards, blending in with the blue of the water. The silver/grey side of the sea slugs faces downwards, blending in with the sunlight reflecting on the ocean's surface when viewed facing upwards underwater, helping them avoid becoming a tasty snack.

Glaucus atlanticus feed on other pelagic creatures, including the Portuguese man o' war and other venomous siphonophores. This sea slug stores stinging nematocysts from the siphonophores within its own tissues as a defence against predators. Humans handling the slug may receive a very painful and potentially dangerous sting. Good on you little Dragon!

Saturday, 28 August 2021

SERENE SIRENIA

This adorable aquatic vacuum is a dugong. I had always grouped the dugongs and manatees together. There are slight differences between these two but both belong to the order Sirenia. 

They shared a cousin in the Steller's sea cow, Hydrodamalis gigas, but that piece of their lineage was hunted to extinction by our species in the 18th century. 

Dugongs have tail flukes with pointed tips — similar to whales — and manatees have paddle-shaped tails, similar to a Canadian Beaver.

Both of these lovelies from the order Sirenia went from terrestrial to marine, taking to the water in search of more prosperous pastures, as it were. 

We find dugongs today in waters near northern Australia and parts of the Indian and Pacific Oceans. 

They inhabit rivers and shallow coastal waters, making the best use of their fusiform bodies that lack dorsal fins and hind limbs. I have been thinking about them in the context of some of the primitive armoured fish we find in the Chengjiang biota of China, specifically those primitive species that were also fusiform.

They favour locations where seagrass, their food of choice, grows plentiful and they eat it roots and all. While seagrass low in fibre, high in nitrogen, and easily digestible is preferred, dugongs will also dine on lower grade seagrass, algae, and invertebrates should the opportunity arise. They have been known to eat jellyfish, sea squirts, and shellfish over the course of their long lives. 

Some of the oldest dugongs have been known to live 70+ years, which is another statistic I find surprising. They are large, passive, have poor eyesight, and look pretty tasty floating in the water; a defenceless floating buffet. Their population is in decline and yet they live on.

Friday, 27 August 2021

ICE AGE MANATEES

Manatees do not live year-round in Texas, but these gentle sea cows are known to occasionally visit, swimming in for a summer vacation and returning to warmer waters for the winter. 

Interestingly, we have recently found fossil evidence for manatees along the Texas coast dating back to the most recent ice age. 

The discovery raises questions about whether manatees have been visiting for thousands of years, or if an ancient population of ice age manatees once called Texas home.

The findings were published in Palaeontologia Electronica by lead author Christopher Bell, a professor at the UT Jackson School of Geosciences with co-authors Sam Houston State University Natural History Collections curator William Godwin and SHSU alumna Kelsey Jenkins — now a graduate student at Yale University — and SHSU Professor Patrick Lewis.

The eight fossils described in the paper include manatee jawbones and rib fragments from the Pleistocene, the geological epoch of the last ice age. Most of the bones were collected from McFaddin Beach near Port Arthur and Caplen Beach near Galveston during the past 50 years by amateur fossil collectors who donated their finds to the SHSU collections.

The Jackson Museum of Earth History at UT holds two of the specimens. A lower jawbone fossil, which was donated to the SHSU collections by amateur collector Joe Liggio, jumpstarted the research.

Manatee jawbones have a distinct S-shaped curve that immediately caught Godwin's eye. But Godwin said he was met with scepticism when he sought other manatee fossils for comparison. He recalls reaching out to a local fossil enthusiast who told him point-blank, "there are no Pleistocene manatees in Texas."

But an examination of the fossils by Bell and Lewis proved otherwise. The bones belonged to the same species of manatee that visits the Texas coast today, Trichechus manatus. An upper jawbone donated by U.S. Rep. Brian Babin was found to belong to an extinct form of the manatee, Trichechus manatus bakerorum.

The age of the manatee fossils is based on their association with better-known ice age fossils and paleo-Indian artefacts that have been found on the same beaches.

It is assumed that the cooler ice age climate would have made Texas waters even less hospitable to manatees than they are today. But the fact that manatees were in Texas — whether as visitors or residents — raises questions about the ancient environment and ancient manatees. The Texas coast stretched much farther into the Gulf of Mexico and hosted wider river outlets during the ice age than it does today. Either the coastal climate was warmer than is generally thought, or ice age manatees were more resilient to cooler temperatures than manatees of today.

Subsurface imaging of the now flooded modern continental shelf reveals both a greater number of coastal embayments and the presence of significantly wider channels during ice age times.

If there was a population of ice age manatees in Texas, it is entirely plausible that they would have ridden out winters in these warmer river outlets similar to how they do today in Florida and Mexico.

Reference: Christopher Bell, William Godwin, Kelsey Jenkins, Patrick Lewis. First fossil manatees in Texas: Trichechus manatus bakerorum in the Pleistocene fauna from beach deposits along the Texas Coast of the Gulf of Mexico. Palaeontologia Electronica, 2020; DOI: 10.26879/1006

Wednesday, 25 August 2021

SHORE CRAB: CARCINUS MAENAS / KU'MIS

European Green Shore Crab / Carcinus maenas
The adaptable European Green Shore Crab, Carcinus maenas, lives in a wide range of environments from fully marine to brackish estuaries.

In the Kwak'wala language of the Kwakiutl First Nations of the Pacific Northwest, this brave fellow is ḵ̓u'mis — and in Norwegian, he is called krabbe.

They make a living off the seafloor, dining on worms, molluscs, small crustaceans and any number of bits and pieces that fall their way.

Shore Crabs are euryhaline, meaning they can tolerate a wide range of salinities (4 to 52 %), and survive in temperatures of zero to 30 °C (32 to 86 °F). This adaptability gives them a very wide range and competitive edge. This fellow is from the chilly waters of central Norway. The ability to eat pretty near anything and survive in extremely cold climates means he'll do quite well beneath the ice this winter.