Monday, 13 March 2023

AMMONOIDS AND ICHTHYOSAURS: NEVADA PALAEONTOLOGY

Time Slows at Berlin-Ichthyosaur State Park
Around half past five, as the first flush of dawn appears, our group was up and ready to visit a site that has been on my bucket list for some time.

High on the hillside up a long entry road sits the entrance to Berlin-Ichthyosaur State Park in central Nevada. It is a short 2-hour drive from our lodgings through orange-hued grasslands and low sloping hills.

A worn American flag and sun-bleached outbuildings greet you on your way to the outcrops. Away from the hustle and bustle that defines the rest of Nevada this place feels remarkably serene. Your eyes squint against the sun as you search for ammonoids and other marine fossil fauna while your nose tends to the assault from the bracing smell of sagebrush.

This site holds many stories. The interpretive centre displays wonderful marine reptiles, ichthyosaurs in situ, as you might expect from the name of the park — but it also showcases years of history lovingly tended. This stretch of dry golden low hills dappled with the yellow of creosote and desert grasses is an important locality for our understanding of the Carnian-Norian boundary (CNB) in North America.

The area is known worldwide as one of the most important ichthyosaur Fossil-Lagerstätte because of the sheer volume of remarkably well-preserved, fully articulated (all the sweet bones laid out all in a row...) specimens of Shonisaurus popularis.

Rich ammonoid faunas outcrop in the barren hills of the Upper Triassic (Early Norian, Kerri zone), Luning Formation, West Union Canyon, Nevada. They were studied by N. J. Silberling (1959) and provide support for the definition of the Schucherti and Macrolobatus zones of the latest Carnian — which are here overlain by well-preserved faunas of the earliest Norian Kerri Zone. 

The genus Gonionotites, very common in the Tethys and British Columbia, is for the moment, unknown in Nevada. The Upper Carnian faunas are dominated by Tropitidae, while Juvavitidae are conspicuously lacking. 

Middle Triassic Ammonoids
Despite its importance, no further investigations had been done at this site for a good 50 years. That changed in 2010 when Jim Haggart, Mike Orchard and Paul Smith — all local Vancouverites — collaborated on a project that took them down to Nevada to look at the conodonts and ammonoids. They did a bed-by-bed sampling of ammonoids and conodonts in West Union Canyon during October of that year.

October is an ideal time to do fieldwork in this area. There are a few good weeks between screaming hot and frigid cold. It is also tarantula breeding season so keep your eyes peeled. Those sweet little burrows you see are not from rodents but rather largish arachnids. 

The eastern side of the canyon provides the best record of the Macrolobatus Zone, which is represented by several beds yielding ammonoids of the Tropites group, together with Anatropites div. sp. 

Conodont faunas from both these and higher beds are dominated by ornate metapolygnthids that would formerly have been collectively referred to Metapolygnathus primitius, a species long known to straddle the CNB. Within this lower part of the section, they resemble forms that have been separated as Metapolygnathus mersinensis. Slightly higher, forms close to Epigondolella' orchardi and a single Orchardella n. sp. occur. This association can be correlated with the latest Carnian in British Columbia.

Higher in the section, the ammonoid fauna shows a sudden change and is dominated by Tropithisbites. Few tens of metres above, but slightly below the first occurrence of Norian ammonoids Guembelites jandianus and Stikinoceras, two new species of conodonts (Gen et sp. nov. A and B) appear that also occur close to the favoured Carnian/Norian boundary at Black Bear Ridge, British Columbia. Stratigraphically higher collections continue to be dominated by forms close to M. mersinensis and E. orchardi after BC's own Mike Orchard.

The best exposure of the Kerri Zone is on the western side of the West Union Canyon. Ammonoids, dominated by Guembelites and Stikinoceras div. sp., have been collected from several fossil-bearing levels. Conodont faunas replicate those of the east section. The collected ammonoids fit perfectly well with the faunas described by Silberling in 1959, but they differ somewhat from coeval faunas of the Tethys and Canada. 

The ammonoid fauna paints a compelling picture of Tethyan influence with a series of smoking guns. We see an abundance of Tropitidae in the Carnian, a lack of Pterosirenites in the Norian, copious Guembelites, the Tethyan species G. philostrati, the stratigraphic position of G. clavatus and the rare occurrence of Gonionotites. Their hallelujah moment was likely finding an undescribed species of the thin-shelled bivalve Halobia similar to Halobia beyrichi — the clincher that perhaps seals this deal on Tethyan influence. 

I'll take a boo to see what Christopher McRoberts published on the find. A jolly good idea to have him on this expedition as it would have been easy to overlook if the focus remained solely on the conodonts and ammonoids. McRoberts has published on the much-studied Pardonet Formation up in the Willison Lake Area of Northeastern, British Columbia. He knows a thing or two about Upper Triassic Bivalvia and the correlation to coeval faunas elsewhere in the North American Cordillera, and to the Boreal, Panthalassan and Tethyan faunal realms. 

If you fancy a read, they published a paper: "Towards the definition of the Carnian/Norian Boundary: New data on Ammonoids and Conodonts from central Nevada," which you can find in the proceedings of the 21st Canadian Paleontology Conference; by Haggart, J W (ed.); Smith, P L (ed.); Canadian Paleontology Conference Proceedings no. 9, 2011 p. 9-10.

Fig. 1. Location map of Berlin-Ichthyosaur State Park

Marco Balini, James Jenks, Riccardo Martin, Christopher McRoberts, along with Mike Orchard and Norman Siberling, did a bed by bed sampling in 2013 and published on The Carnian/Norian boundary succession at Berlin-Ichthyosaur State Park (Upper Triassic, central Nevada, USA) and published in January 2014 in Paläontologische Zeitschrift 89:399–433. That work is available for download from ResearchGate. The original is in German, but there is a translation available.

After years of reading about the correlation between British Columbia and Nevada, I had the very great pleasure of walking through these same sections in October 2019 with members of the Vancouver Paleontological Society and Vancouver Island Palaeontological Society. It was with that same crew that I'd originally explored fossil sites in the Canadian Rockies in the early 2000s. Those early trips led to paper after paper and the exciting revelations that inspired our Nevada adventure.

If you plan your own adventure, you'll want to keep an eye out for some of the other modern fauna — mountain lions, snakes, lizards, scorpions, wolves, coyotes, foxes, ground squirrels, rabbits, falcons, hawks, eagles, bobcats, sheep, deer and pronghorns.

Figure One: Location map of Berlin-Ichthyosaur State Park. A detailed road log with access information for this locality is provided in Lucas et al. (2007).

Sunday, 12 March 2023

HERMIT CRAB: REAL ESTATE TYCOONS

This little cutie is a hermit crab and he is wearing a temporary home borrowed from one of our mollusc friends. 

His body is a soft, squishy spiral that he eases into the perfect size shell time and time again as he grows. 

His first choice is always the empty shell of a marine snail but will get inventive in a pinch — nuts, wood, serpulid worm tubes, aluminium cans or wee plastic caps. 

They are inventive, polite and patient. 

You see, a hermit crabs' desire for the perfect bit of real estate will have them queueing beside larger shells — shells too large for them — to wait upon a big hermit crab to come along, discard the perfect home and slip into their new curved abode. This is all done in an orderly fashion with the hermit crabs all lined up, biggest to smallest to see who best fits the newly available shell. 

There are over 800 species of hermit crab — decapod crustaceans of the superfamily Paguroidea. Their lineage dates back to the Jurassic, 200 million years ago. Their soft squishy, weakly calcified bodies do not fossilize all that often but when they do the specimens are spectacular. Think of all the species of molluscs these lovelies have had a chance to try on — including ammonites — and all the shells that were never buried in sediment to become fossils because they were harvested as homes.  

On the shores of British Columbia, Canada, the hermit crab I come across most often is the Grainyhand hermit crab, Pagurus granosimanus

These wee fellows have tell-tale orange-brown antennae and olive green legs speckled with blue or white dots. 

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, a shell is known as x̱ala̱'is and gugwis means house on the beach. 

I do not know the Kwak’wala word for a hermit crab, so I will think of these cuties as x̱ala̱'is gugwis — envisioning them finding the perfect sized shell on the surf worn shores of Tsax̱is, Fort Rupert, Vancouver Island. 

MEET ACICULOLENUS ASKEWI AFTER DON ASKEW

A new species of trilobite from the upper Cambrian McKay Group was introduced in March of 2020: Aciculolenus askewi.  The species is named after Don Askew, an avid fossil hunter of Upper Cambrian trilobites from Cranbrook, British Columbia, Canada, who has discovered several new species in the East Kootenays. 

Don was the first to brave the treacherous cliffs up the waterfall on the west side of the ravine below Tanglefoot mountain. That climb led to his discovery of one of the most prolific outcrops in the McKay Group with some of the most exciting and best-preserved trilobites from the region. 

The faunal set are similar to those found at site one — the first of the trilobite outcrops discovered by Chris New and Chris Jenkins — an hours hike through grizzly bear country.

The specimens found at the top of the waterfall are not in calcite wafers, as they are elsewhere, instead, these exceptionally preserved specimens are found complete with a thin coating of matrix that must be prepped down to the shell beneath. 

Askew was also the skill preparator called upon to tease out the details from the 'gut trilobite' recently published from the region. In all, this area has produced more than 60 new species — many found by Askew — and not all of which have been published yet.

I caught up with Don last summer on a trip to the region. He was gracious in openly sharing his knowledge and a complete mountain goat in the field — a good man that Askew. Not surprising then that Brian Chatterton would do him the honour of naming this new species after him. 

Chatterton, Professor Emeritus at the University of Alberta, is an invertebrate palaeontologist with a great sense of humour and a particular love of trilobites. Even so, his published works span a myriad of groups including conodonts, machaeridians, sponges, brachiopods, corals, cephalopods, bivalves, trace fossils — to fishes, birds and dinosaurs.

Brian Chatterton has been visiting the East Kootenay region for many years. In 1998, he and Rolf Ludvigsen published the pivotal work on the "calcified trilobites" we had begun hearing about in the late 1990s. There were tales of blue trilobites in calcified layers guarded by a resident Grizzly. This was years before logging roads had reached this pocket of paleontological goodness and hiking in — bear or no bear — was a daunting task. 

In his Cambridge University Press paper, Chatterton describes the well-preserved fauna of largely articulated trilobites from three new localities in the Bull River Valley. 

The Dream Team at Fossil Site #15, East Kootenays
All the trilobites from these localities are from the lower or middle part of the Wujiajiania lyndasmithae Subzone of the Elvinia Zone, lower Jiangshanian, in the McKay Group. 

Access is via a bumpy ride on logging roads 20 km northeast of Fort Steele that includes fording a river (for those blessed with large tires and a high wheelbase) and culminating in a hot, dusty hike and death-defying traipse down 35-degree slopes to the localities.

Two new species were proposed with types from these localities: Aciculolenus askewi and Cliffia nicoleae. The trilobite (and agnostid) fauna from these localities includes at least 20 species that read like a who's who of East Kootenay palaeontology: 

Aciculolenus askewi n. sp., Agnostotes orientalis (Kobayashi, 1935), Cernuolimbus ludvigseni Chatterton and Gibb, 2016, Cliffia nicoleae n. sp., Elvinia roemeri (Shumard, 1861), Grandagnostus? species 1 of Chatterton and Gibb, 2016, Eugonocare? phillipi Chatterton and Gibb, 2016, Eugonocare? sp. A, Housia vacuna (Walcott, 1912), Irvingella convexa (Kobayashi, 1935), Irvingella flohri Resser, 1942, Irvingella species B Chatterton and Gibb, 2016, Olenaspella chrisnewi Chatterton and Gibb, 2016, Proceratopyge canadensis (Chatterton and Ludvigsen, 1998), Proceratopyge rectispinata (Troedsson, 1937), Pseudagnostus cf. P. josepha (Hall, 1863), Pseudagnostus securiger (Lake, 1906), Pseudeugonocare bispinatum (Kobayashi, 1962), Pterocephalia sp., and Wujiajiania lyndasmithae Chatterton and Gibb, 2016.

Chris New, pleased as punch atop Upper Cambrian Exposures
It has been the collaborative efforts of Guy Santucci, Chris New, Chris Jenkins, Don Askew and Stacey Gibb that has helped open up the region — including finding and identifying many new species or firsts including Pseudagnostus securiger, a widespread early Jiangshanian species not been previously recorded from southeastern British Columbia. 

Other interesting invertebrate fossils from these localities include brachiopods, rare trace fossils, a complete silica sponge (Hyalospongea), and a dendroid graptolite. 

The species we find here are more diverse than those from other localities of the same age in the region — and enjoy much better preservation. 

The birth of new species into our scientific nomenclature takes time and the gathering of enough material to justify a new species name. Fortunately for Labiostria gibbae, specimens had been found of this rare species had been documented from the upper part of Wujiajiania lyndasmithae Subzone — slightly younger in age. 

Combined with an earlier discovery, they provided adequate type material to propose the new species — Labiostria gibbae — a species that honours Stacey Gibb and which will likely prove useful for biostratigraphy.

Reference: https://www.cambridge.org/core/journals/journal-of-paleontology/article/abs/midfurongian-trilobites-and-agnostids-from-the-wujiajiania-lyndasmithae-subzone-of-the-elvinia-zone-mckay-group-southeastern-british-columbia-canada/E8DBC8BD635863E840715122C05BB14A#

Photo One: Aciculolenus askewi by Chris Jenkins, Cranbrook, British Columbia
Photo Two: L to R: Dan Bowden, Guy Santucci, Chris Jenkins, Dan Askew and John Fam at Fossil Site #15, East Kootenay Region, British Columbia, Canada, August 2, 2020.
Photo Three: Chris New pleased as punch atop of Upper Cambrian Exposures in the East Kootenay Region, British Columbia, Canada

Saturday, 11 March 2023

OLENELLUS OF THE EAGER: CRANBROOK, BRITISH COLUMBIA

The partial specimen you see here is an Olenellus trilobite from the Eager Formation near Cranbrook, British Columbia.

It was exciting to crack open the rock and find a specimen, many specimens, more than half a billion years old. It is something we so rarely do but the opportunity is all around us in the many sedimentary rocks that outcrop near the surface around the globe. 

Near Cranbrook, the Eager Formation outcrops at several locations just outside of town. This particular lovely is from the Rifle Range locality and is in my collection at 98-CR-EF042 — meaning it was collected in 1998 and the 42nd find of the day. This is a prolific site and with diligent collecting, you can find many wonderful specimens of scientific and aesthetic value in the course of a day.

The Rifle Range locality sits on the Silhouette Rifle Range — which is literally on a rifle range where folks go to shoot at things.

The fossils we find here are just a shade older than those found at the Burgess Shale. Burgess is Middle Cambrian and the species match the Eager fauna one for one but the Eager fauna are much less varied. 

Olenellus is an extinct genus of redlichiid trilobites, early arthropods, that litter this glorious Cambrian site. Olenellus is the only genus currently recognised in the subfamily Olenellinae. The sister group called the Mesonacinae consists of the genera Mesonacis and Mesolenellus.

Olenellus range in size but are about 5 centimetres or 2.0 inches long on average. They lived during the Botomian and Toyonian stages, Olenellus-zone, 522 to 510 million years ago, in what is currently North America in what was part of the paleocontinent of Laurentia.

Olenellus are both common in and restricted to Early Cambrian rocks — 542 million to 521 million years old — and thus a useful Index Fossil for the Early Cambrian. 

Olenellus had a well-developed head, large and crescentic eyes, and a poorly developed, small tail. The fellow you see had a bit of his tail crushed as he turned to stone.

Trilobites were amongst the earliest fossils with hard skeletons. While they are extinct today, they were the dominant life form at the beginning of the Cambrian and it is what we find as the primary fossil in the fauna of the Eager Formation. 

A slightly crushed lingulida brachiopod
The Eager Formation has produced many beautifully preserved Wanneria, abundant Olellenus and a handful of rare and treasured Tuzoia and Anomalocaris claws. The shale matrix lends itself to amazing preservation. 

The specimens of Wanneria from here are impressively large. Some are up to thirteen centimetres long and ten centimetres wide. You find a mixture of complete specimens and head impressions from years of perfectly preserved moults.

From July 21 to 31, 2015, the Royal Ontario Museum (ROM), under the direction of Dr. Jean-Bernard Caron carried out a palaeontological dig at an exposure of the Eager Formation that outcrops between Cranbrook and  Fort Steele in the East Kootenay Region of British Columbia. 

The team included David George (APS), Dr. Bob Gaines (Pomona College), Dr. Jean-Bernard Caron (ROM), Dr. Gabriela Mangano (University of Saskatchewan), Maryam Akrami (ROM), Darrell Nordby (APS), Joe Moysiuk (University of Toronto), and local, Guy Santucci (APS and project field co-ordinator), and Dr. Mark Webster (University of Chicago).

Dr. Caron was interested in the fauna of the Eager Formation as there is an overlap with the Burgess Shale species — the Eager is a window into time 513 million years ago — 8 million years earlier than the Burgess. 

Lower Cambrian Brachiopod
They found the usual suspects, including multiple specimens of Wanneria dunnae and Olenellus ricei along with the rarer genus Mesonacis, in addition to specimens of the elusive Tuzoia

They also found a block with at least 112 individual trilobites (mostly moulted cephalons) of Olenellus ricei and Wanneria dunnae

The most exciting of their finds included a sponge, Anomalocaris, Morania (a cyanobacterial growth), and a hyolithid similar to the Burgess Haplophrentis.

They also found many trace fossils. There was a particularly fetching 30 cm trace fossil, likely from a large Wanneria, that I hope Dr. Mángano or one of her graduate students lend their gaze — Gabriela is a particularly good writer. 

She is co-editor of Palaios, in addition to being a member of the editorial board of a number of journals, including Journal of Paleontology, Paleontologia Electronica, Palaeogeography Palaeoclimatology Palaeoecology, Ameghiniana, and Revista Brasilera de Paleontologia. Gabriela is a member of the Scientific Board of the UNESCO International Geoscience Program (IGCP), member of the SEPM Board, and Treasurer of the International Ichnological Association. Add all that to extensive fieldwork and supervising over fifteen graduate students and postdoctoral fellows — she's an amazing woman.

Their excavation of the site was thorough — reducing all of the potentially fossil-bearing strata to pieces the size or smaller than a dinner plate. The 2015 team used a backhoe to take off the weathered top layer and get down to the bedrock below.

It has been six years since their visit and we will hopefully see some worthy publications from their efforts. There had been talk of multiple publications stemming from the spectrum of species, a comparison to the Burgess fauna and papers on the trace fossils. I checked in with Joe Moysuik from the University of Toronto who had been on the dig in 2015. To his knowledge, no new papers have yet to be published — though, Caron has been a busy bee on a sexy new nektobenthic suspension feeder from the Burgess material. I am rather hoping their team sorts out the naming of some of the species and gets them to publication so we can finally put them to bed.

Days after my correspondence with Moysuik, Chris Jenkins, a Cranbrook local and huge contributor to our knowledge of Upper Cambrian trilobites, shared an exciting find. 

He and Don Askew had ventured out together for their first fossil field trip of 2021 — and made a rather auspicious start to the year. 

The two had met some 10 years previous when Don, an avid outdoorsman and Jenkins' neighbour, had wandered over to see what all the rocks were about in Jenkins' yard. 

Tales of trilobites and a lifelong friendship ensued. It was also the beginnings of shared fieldwork. This time, it was to outcrops of the Eager Formation just outside of Cranbrook. Together, the two unearthed a three-foot-wide band of Eager Formation bedrock. Not unusual in and of itself — but instead of the usual trilobites — this rock revealed several varieties of Lower Cambrian brachiopods. 

Jenkins shared photos of at least three different types of brachiopods — potentially new fauna for the Eager. Although they superficially resemble the molluscs that make modern seashells, they are not related. Brachiopods were the most abundant and diverse fossil invertebrates of the Paleozoic — over 4500 genera known; the number of species is far greater. So, naturally, we had expected to find brachiopods in the Eager Formation as they were abundant in Lower Cambrian seas — but so far they had eluded us.

And, interestingly, the rock containing the brachiopods is devoid of any trilobite specimens — not a one. Have they found a wee slip of the Eager Formation that records a nearshore environment or have they stumbled across a segment that records another time period altogether?

The brachiopods you see in the photos above are roughly 1/4 inch to 3/4 inches. Should Caron and team return to the site, these new brachiopods will be of great interest as they look to rewrite the geology and palaeontology of the site and region. 

Friday, 10 March 2023

FOSSIL FISHAPODS OF CANADA'S FAR NORTH

Qikiqtania wakei, a fishapod & relative to tetrapods
You will likely recall the amazing tetrapodomorpha fossil found on Ellesmere Island in the Canadian Arctic in 2004, Tiktaalik roseae

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 significant tetrapod features remained obscure for the 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 as you can be and still be a card-carrying member of the group. 

Interestingly, while Neil Shubin and crew were combing the icy tundra for Tiktaalik, another group was trying their luck just a few kilometres away. 

A week before the eureka moment of Tiktaalik's discovery, Tom Stewart and Justin Lemberg unearthed material that we now know to be a relative of Tiktaalik's. 

Meet Qikiqtania wakei, a fishapod and close relative to our dear tetrapods — and cousin to Tiktaalik — who shares features in the flattened triangular skull, shoulders and elbows in the fin. 

Qikiqtania (pronounced kick-kick-TAN-ee-ya)
But, and here’s the amazing part, its upper arm bone (humerus) is specialised for open water swimming, not walking. 

The story gets wilder when we look at Qikiqtania’s position on the evolutionary tree— all the features for this type of swimming are newly evolved, not primitive. 

This means that Qikiqtania secondarily reentered open water habitats from ancestors that had already had some aspect of walking behaviour. 

And, this whole story was playing out 365 million years ago — the transition from water to land was going both ways in the Devonian.

Why is this exciting? You and I descend from those early tetrapods. We share the legacy of their water-to-land transition and the wee bony bits in their wrists and paddles that evolved to become our hands. I know, mindblowing!

Thomas Stewart and Justin Lemberg put in thousands of hours bringing Qikiqtania to life. 

The analysis consisted of a long path of wild events— from a haphazard moment when it was first spotted, a random collection of a block that ended up containing an articulated fin, to a serendipitous discovery three days before Covid lockdowns in March 2020.

Both teams acknowledge the profound debt owed to the individuals, organizations and indigenous communities where they had the privilege to work — Grise Fiord and Resolute Bay— Ellesmere Island in Nunavut, the largest and northernmost territory of Canada. 

Part of that debt is honoured in the name chosen for this new miraculous species. 

Aerial View of Ellesmere Island
The generic name, Qikiqtania (pronounced kick-kick-TAN-ee-ya), is derived from the Inuktitut words Qikiqtaaluk and Qikiqtani which are the traditional place name of the region where the fossil was discovered. 

The specific name, wakei, is in memory of the evolutionary biologist David Wake — colleague, mentor and friend. 

He was a professor of integrative biology and Director and curator of herpetology at the Museum of Vertebrate Zoology at the University of California, Berkeley who passed away in April 2021. 

Wake is known for his work on the biology and evolution of salamanders and vertebrate evolutionary biology. 

If you look at the photo on the left you can imagine visiting these fossil localities in Canada's far north.

Qikiqtania was found on Inuit land and belongs to the community. Thomas Stewart and his colleagues were able to conduct this research because of the generosity and support of individuals in the hamlets of Resolute Bay and Grise Fiord, the Iviq Hunters and Trappers of Grise Fiord, and the Department of Heritage and Culture, Nunavut.

To them, on behalf of the larger scientific community — Nakurmiik. Thank you! 

Here is the link to Tom Stewart's article in The Conversation & paper in Nature that dropped yesterday:

  1. Stewart, Thomas A.; Lemberg, Justin B.; Daly, Ailis; Daeschler, Edward B.; Shubin, Neil H. (2022-07-20). "A new elpistostegalian from the Late Devonian of the Canadian Arctic". Naturedoi:10.1038/s41586-022-04990-wISSN 0028-0836.
  2. Stewart, Thomas. "Meet Qikiqtania, a fossil fish with the good sense to stay in the water while others ventured onto land" The Conversation. Retrieved 2022-07-20.

Image One: An artist’s vision of Qikiqtania enjoying its fully aquatic, free-swimming lifestyle. Alex Boersma, CC BY-ND

Image Two: A new elpistostegalian from the Late Devonian of the Canadian Arctic, T. A. Stewart, J. B. Lemberg, A. Daly, E. B. Daeschler, & N. H. Shubin.

A huge shout out to the deeply awesome Neil Shubin who shared that the paper had been published and offered his insights on what played out behind the scenes!

Thursday, 9 March 2023

ARTURIA BEAUTY FOR SHELLIE

This lovely Lower Miocene nautiloid is Aturia angustata collected on the foreshore near Clallam Bay, Olympic Peninsula, northwestern Washington. 

I have been exploring Washington State for many years. It is rugged, windswept and has amazing fossil exposures all along its northern edge. The area goes by the name of the Olympic Peninsula and it is a wilderness playground. The sites I usually visit are Majestic Beach for its rare but prized fossil whale bone.

Further west are the beach exposures that have fossil echinoids in matrix and Ghost shrimp claws in concretion. There is a clay mine that holds wonderful nautiloids like the creamy Aturia you see here. Sometimes they are cemented together and come out whole. Sometimes calcified and show yellow, brown and white when you hold them to the light. Further up are the beach exposures along Clallam Bay.

Aturia is an extinct genus of Paleocene to Miocene nautilids within Aturiidae, a monotypic family, established by Campman in 1857 for Aturia Bronn, 1838, and is included in the superfamily Nautilaceae in Kümmel, 1964.

Aturia is characterized by a smooth, highly involute, discoidal shell with a complex suture and subdorsal siphuncle. 

Their shells are rounded ventrally and flattened laterally; the dorsum is deeply impressed. The suture is one of the most complex within Nautiloidea. It has a broad flattened ventral saddle, narrow pointed lateral lobes, broad rounded lateral saddles, broad lobes on the dorso-umbilical slopes, and a broad dorsal saddle divided by a deep, narrow median lobe. 

The siphuncle is moderate in size and located subdorsally in the adapical dorsal flexure of the septum. Based on the feeding and hunting behaviours of living nautiluses, Aturia most likely preyed upon small fish and crustaceans. It is well worth exploring the exposures at Clallam Bay. The local clay quarry is on private land so you would need to seek permission. I have also seen calcified beauties of this species collected from river sites within the Olympic Peninsula range, though I have not explored these myself.

ART OF THE PORTAGE: BOWRON LAKE CIRCUIT

A cool morning breeze keeps the mosquitoes down as we pack our kayaks and gear for today’s paddling journey. 

It is day four of our holiday, with two days driving up from Vancouver to Cache Creek, past the Eocene insect and plant site at McAbee, the well-bedded Permian limestone near Marble Canyon and onto Bowron Provincial Park, a geologic gem near the gold rush town of Barkerville.

The initial draw for me, given that collecting in a provincial park is forbidden and all collecting close at hand outside the park appears to amount to a handful of crushed crinoid bits and a few conodonts, was the gorgeous natural scenery and a broad range of species extant. It was also the proposition of padding the Bowron Canoe Circuit, a 149,207-hectare geologic wonderland, where a fortuitous combination of plate tectonics and glacial erosion have carved an unusual 116-kilometre near-continuous rectangular circuit of lakes, streams and rivers bound on all sides by snowcapped mountains. From all descriptions, something like heaven.

The east and south sides of the route are bound by the imposing white peaks of the Cariboo Mountains, the northern boundary of the Interior wet belt, rising up across the Rocky Mountain Trench, and the Isaac Formation, the oldest of seven formations that make up the Cariboo Group (Struik, 1988). 

Some 270 million-plus years ago, had one wanted to buy waterfront property in what is now British Columbia, you’d be looking somewhere between Prince George and the Alberta border. The rest of the province had yet to arrive but would be made up of over twenty major terranes from around the Pacific. The rock that would eventually become the Cariboo Mountains and form the lakes and valleys of Bowron was far out in the Pacific Ocean, down near the equator.

With tectonic shifting, these rocks drifted north-eastward, riding their continental plate, until they collided with and joined the Cordillera in what is now British Columbia. Continued pressure and volcanic activity helped create the tremendous slopes of the Cariboo Range we see today with repeated bouts of glaciation during the Pleistocene carving their final shape.

We brace our way into a headwind along the east side of the fjord-like Isaac Lake. Paddling in time to the wind, I soak up the view of this vast, deep green, ocean-like expanse that runs L-shape for nearly 38 kilometres, forming nearly half of the total circuit. The rock we paddle past is primarily calcareous phyllite, limestone and quartzite, typical of the type locality for this group and considered upper Proterozoic (Young, 1969), the time in our geologic history between the first algae and the first multicellular animals. It is striking how much this lake fits exactly how you might picture pristine wilderness paddling in your mind’s eye. No powerboats, no city hum, just pure silence, broken only by the sound of my paddle pulling through the water and the occasional burst of glee from one of the park’s many songbirds.

We’ve chosen kayaks over the more-popular canoes for this journey, as I got to experience my first taste of the handling capabilities of a canoe last year in Valhalla Provincial Park. The raised sides acted like sails and kept us off course in all but the lightest conditions. This year, Philip Torrens, Leanne Sylvest, and I were making our trek in low profile, Kevlar style. One single & one double kayak would be our faithful companions and mode of transport. They would also be briefly conscripted into service as a bear shield later in the trip.

Versatile those kayaks.

The area is home to a variety of plant life. Large sections of the forest floor are carpeted in the green and white of dogwood, a prolific ground cover we are lucky enough to see in full bloom. Moss, mushrooms and small wildflowers grow on every available surface. Yellow Lily line pathways and float in the cold, clear lake water. Somewhere I read a suggestion to bring a bathing suit to the park, but at the moment, I cannot imagine lowering anything more than my paddle into these icy waters. To reach the west side of the paddling route, we must first face several kilometres portaging muddy trails to meet up with the Isaac River and then paddle rapids to grade two.

At the launch site, we meet up with two fellow kayakers, Adele and Mary of Victoria, and take advantage of their preceding us to watch the path they choose through the rapids. It has been raining in the area for forty plus days, so the water they run is high and fast. Hot on their heels, our short, thrilling ride along the Isaac River, is a flurry of paddle spray and playing around amid all the stumps, silt and conglomerate. 

The accommodation gods smile kindly on us as we are pushed out from Isaac River and settle into McLeary Lake. An old trapper cabin built by local Freddie Becker back in the 1930s, sits vacant and inviting, providing a welcome place to hang our hats and dry out. From here we can see several moose, large, lumbering, peaceful animals, the largest members of the deer family, feeding on the grass-like sedge on the far shore. The next morning, we paddle leisurely down the slower, silt-laden Cariboo River, avoiding the occasional deadhead, and make our way into the milky, glacier-fed Lanezi Lake.

Like most mountainous areas, Bowron makes its own weather system and it appears you get everything in a 24-hour period. In fact, whatever weather you are enjoying seems to change 40 minutes later; good for rain, bad for sun. 

Wisps of cloud that seemed light and airy only hours early have become dark. Careful to hug the shore, we are ready for a quick escape from lightning as thundershowers break.

Paddling in the rain, I notice bits of mica in the water, playing in the light and the rock here changes to greywacke, argillite, phyllite and schist. Past Lanezi, we continue onto Sandy Lake, where old-growth cedars line the south-facing slopes to our left and grey limestone, shale and dolostone line the shore. 

Mottled in with the rock, we sneak up on very convincing stumps posing as large mammals. Picking up the Cariboo River again, we follow it as it flows into Babcock Lake, an area edged with Lower Cambrian limestone, shale and argillite. At the time these rocks were laid down, the Earth was seeing our earliest relatives, the first chordates entering the geologic scene.

As we reach the end of Babcock Lake and prepare for our next portage I get my camera out to take advantage of the angle of the sun and the eroded rounded hilltops of the Quesnel Highlands that stand as a backdrop.

Leanne remarks that she can see a moose a little ways off and that it appeared to be heading our way. Yes, heading our way quickly with a baby moose in tow. I lift my lens to immortalize the moment and we three realized the moose are heading our way in double time because they are being chased by a grizzly — at top speed. 

A full-grown moose can run up to fifty-six kilometres per hour, slightly faster than a Grizzly. They are also strong swimmers. Had she been alone, Mamma moose would likely have tried to outswim the bear. Currently, however, this is not the case. From where we stand we can see the water turned to white foam at their feet as they fly towards us.

We freeze — bear spray in hand.

In seconds the three were upon us. Mamma moose, using home-field advantage, runs straight for us and just reaching our boats, turned 90 degrees, bolting for the woods, baby moose fast on her heels.

The Grizzly, caught up in the froth of running and thrill of the kill, doesn’t notice the deke, hits the brakes at the boats and stands up, confused. Her eyes give her away. This was not what she had planned and the whole moose-suddenly-transformed-into-human thing is giving her pause. Her head tilts back as she gets a good smell of us.

Suddenly, a crack in the woods catches her attention. Her head snaps around and she drops back on all fours, beginning her chase anew. Somewhere there is a terrified mother moose and calf hoping the distance gained is enough to keep them from being lunch. I choose to believe both moose got away with the unwitting distraction we provided, but I’m certainly grateful we did.

The Lakes are at an elevation of over 900 m (3000 ft) and both grizzly and black bear sightings are common. Both bear families descend from a common ancestor, Ursavus, a bear-dog the size of a raccoon who lived more than 20 million years ago. Seems an implausible lineage having just met one of the larger descendants. While we’d grumbled only hours earlier about how tired we were feeling, we now feel quite motivated and do the next two portages and lakes in good time. 

Aside from the gripping fear that another bear encounter is imminent, we enjoy the park-like setting, careful to scan the stands of birch trees for dark shapes now posing as stumps. Fortunately, the only wildlife we see are a few wily chipmunks, various reticent warblers and some equally shy spruce grouse.

The wind favours us now as we paddle Skoi and Spectacle Lake, even giving us a chance to use the sails we’ve rigged to add an extra knot of oomph to our efforts. Reaching the golden land of safety-in-numbers, we leap from our kayaks, happy to see the smiling faces of Mary and Adele.

Making it here is doubly thrilling because it means I am sleeping indoors tonight and I can tell the bear story with adrenaline still pumping through my veins. Tonight is all about camaraderie and the warmth of a campfire. Gobbling down Philip’s famous pizza, Leanne impresses everyone further by telling of his adventures in the arctic and surviving a polar bear attack.

This is our first starlit night without rain, a luxury everyone comments on, but quietly, not wanting to jinx it. We share a good laugh at the expense of the local common loons — both Homeo sapien sapien and Gavia immer. The marshy areas of the circuit provide a wonderful habitat for the regions many birds including a host of sleek, almost regal black and white common loons.

Their cool demeanour by day is reduced to surprisingly loud, maniacal hoots and yelps with undignified flapping and flailing by night. It seems hardly possible that these awful noises could be coming from the same birds and that this has been going for nearly 65 million years, since the end of the age of dinosaurs, as loons are one of the oldest bird families in the fossil record.

A guitar is pulled out to liven the quiet night while small offerings, sacred and scare this late in our journey, are passed around. Tonight is a celebration that we have all, both separately and together, made our way around this immense mountain-edged circuit.

Wednesday, 8 March 2023

MAJESTIC BEACH FOSSIL WHALE BONE

Oligocene Fossil Whale Vertebrae, Olympic Peninsula
These lovely water-worn specimens are difficult to ID to species with certainty but they likely hail from an early baleen whale.

Found amongst the beach pebbles on the Olympic Peninsula, they are definitely cetacean and very likely baleen as this area is home to some of the earliest baleen whales in the Pacific Northwest.

In 1993, a twenty-seven million-year-old specimen was discovered in deposits nearby 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.

Baby Gray Whale, Eschrichtius robustus
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. I've included a rather good close-up of a baby Gray Whale here that shows the baleen to good effect.

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 & teeth, are fossilized.

Photo: Oligocene Fossil Whale vertebrae from Majestic Beach, Olympic Peninsula, Washington State, USA.

Tuesday, 7 March 2023

ZEACINITIES MAGNOLIAEFORMIS

This lovely specimen is Zeacrinites magnoliaeformis, an Upper Mississippian-Chesterian crinoid found by Keith Metts in the Glen Dean Formation, Grayson County, Kentucky, USA.

Crinoids are unusually beautiful and graceful members of the phylum Echinodermata. They resemble an underwater flower swaying in an ocean current. But make no mistake they are marine animals. Picture a flower with a mouth on the top surface that is surrounded by feeding arms. Awkwardly, add an anus right beside that mouth. That's him!

Crinoids with root-like anchors are called Sea Lilies. They have graceful stalks that grip the ocean floor. Those in deeper water have longish stalks up to 3.3 ft or a meter in length.

Then there are other varieties that are free-swimming with only vestigial stalks. They make up the majority of this group and are commonly known as feather stars or comatulids. Unlike the sea lilies, the feather stars can move about on tiny hook-like structures called cirri. It is these same cirri that allows crinoids to latch to surfaces on the seafloor. Like other echinoderms, crinoids have pentaradial symmetry. The aboral surface of the body is studded with plates of calcium carbonate, forming an endoskeleton similar to that in starfish and sea urchins.

These make the calyx somewhat cup-shaped, and there are few, if any, ossicles in the oral (upper) surface called a tegmen. It is divided into five ambulacral areas, including a deep groove from which the tube feet project, and five interambulacral areas between them. The anus, unusually for echinoderms, is found on the same surface as the mouth, at the edge of the tegmen.

Crinoids are alive and well today. They are also some of the oldest fossils on the planet. We have lovely fossil specimens dating back to the Ordovician.

Monday, 6 March 2023

GOOSE: NAXAK

What's good for the goose is good for the gander. A goose is a bird of any of several waterfowl species in the family Anatidae. 

They can fly 40 mph and you'll notice that in the sky they choose the highly efficient V form as it gives them a 71% increased flight range. Smart those geese. 

A male goose is called a gander and a group of geese are charmingly called a gaggle. We use geese for the plural of male, female or a mix of both. The females are referred to as goose, as in Mother Goose from your childhood stories.

These social birds are very loyal and will follow you around like puppies if you happen to raise one from a wee gosling. And no matter which of the many geese you see as wee goslings, they are all charmingly fluffy and cute.

Geese fossils have been found ranging from 10 to 12 million years ago, so a relatively recent addition to our species list. We have found proto-geese fossils in Gargano, one of the most scenic but overlooked parts of the southern Italian region of Puglia in central Italy. This massive relative of our modern geese stood one and a half metres tall and was likely flightless, unlike modern geese.

The family Anatidae comprises the genera Anser — the grey geese and white geese — and Branta —the black geese. Some other birds, mostly related to the shelducks, have goose as part of their names which can muddle things a bit. More distantly related members of the family Anatidae are swans, most of which are larger than true geese, and ducks, which are significantly smaller.

The word goose is a direct descendant of the Proto-Indo-European root, ghans. In the Germanic languages, the root gave Old English gōs with the plural gēs and gandres — becoming our Modern English goose, geese, gander, and gosling, respectively. The Frisian's use goes, gies and guoske. In New High German, Gans, Gänse, and Ganter, and Old Norse gās.

In the Kwak̓wala language of the or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, we use na̱x̱aḵ as the word for goose. 

Around the world, we refer to these birds as: Lithuanian: žąsìs, Irish: gé (goose, from Old Irish géiss), Latin: anser, Spanish: ganso, Ancient Greek: χήν (khēn), Dutch: gans, Albanian: gatë (heron), Sanskrit haṃsa and haṃsī ("gander" and "goose", also the words for male and female swans), Finnish: hanhi, Avestan zāō, Polish: gęś, Romanian: gâscă / gânsac, Ukrainian: гуска / гусак (huska / husak), Russian: гусыня / гусь (gusyna / gus), Czech: husa, and Persian: غاز‎ (ghāz). 

By any name, geese are majestic birds. They are long lived at around 20 years for some species and spend their days eating seeds, nuts, plants and berries. Once fattened up, they have been on our menu for a very long time. They grace the wilderness around the globe and are fond of our parks, golf courses and are surprisingly comfortable in major cities. And while they are social and friendly, a threatened goose will chase you and take wee nips of your bottom if they take issue with your presence. You go, goose!

Sunday, 5 March 2023

KI'A'PALANO: STONE, BONE AND WATER

Cretaceous Plant Material / Three Brothers Formation
Vancouver has a spectacular mix of mountains, forests, lowlands, inlets and rivers all wrapped lovingly by the deep blue of the Salish Sea. 

When we look to the North Shore, the backdrop is made more spectacular by the Coast Mountains with a wee bit of the Cascades tucked in behind.

If you were standing on the top of the Lion's Gate Bridge looking north you would see the Capilano Reservoir is tucked in between the Lions to the west and Mount Seymour to the east on the North Shore. 

The bounty of that reservoir flows directly into your cup. If you look down from the reservoir you see the Capilano River as it makes its way to the sea and enters Burrard Inlet.

The Capilano River on Vancouver's North Shore flows through the Coast Mountains and our coastal rainforest down to the Capilano watershed enroute to Burrard Inlet. The headwaters are at the top of Capilano up near Furry Creek. They flow down through the valley, adding in rainwater, snowmelt and many tributaries before flowing into Capilano Lake. The lake in turn flows through Capilano Canyon and feeds into the Capilano River.

Today, for many, the Capilano River is the clear, cold water with which we fill our cups. But not so long ago, this Kia’palano, this beautiful river, was the entry point to Homulchesan, traditionally called X̱wemelch'stn, whose name means fast-moving water of fish and the domain of Douglas fir trees and the wild sacred salmon who spawn here.

Capilano Watershed & Reservoir
Sacred First Nations Land

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. 

The Musqueam First Nation are traditional hən̓q̓əmin̓əm̓ speaking people who number a strong and thriving 1,300. Many live today on a wee slip of their traditional territory just south of Marine Drive near the mouth of the Fraser River. 

The Secwepemc or Shuswap First Nations are a collective of 17 bands occupying the south-central part of British Columbia. Their ancestors have lived in the interior of BC, the Secwepemc territories, for at least 10,000 years.

The Coast Salish First Nations have lived in this region for thousands of years — from the mouth of the Columbia River in Oregon to north of Bute Inlet. They ancestors of those who live here today braved the cold, following the receding of the ice to forge new roots, build villages and strengthen their connections to this land.   
It is to the Squamish Nation that we owe the name of Capilano which is an anglicized version of Kia'palano. 

In Sḵwx̱wú7mesh snichim or Skwxwú7mesh, their spoken language, Kia'palano/Capilano means beautiful river

Chief Kia'palano (c. 1854-1910) was the Chief of the Squamish Nation from 1895-1910 — and Chief of the territory where this beautiful river flows — Sa7plek.
 
The Cleveland Dam — Capilano River Regional Park

Many things have changed since then, including the Capilano River's path, water levels and sediment deposition. For the salmon who used this path to return home and those who depended on them, life has been forever altered by our hands. The Capilano River still runs with Summer Coho, Spring & Summer Steelhead and Autumn Chinook. The small numbers of Spring/Summer Steelhead are maintained through catch and release and may one day reach their former levels of plenty along Vancouver’s North Shore. Elsewhere, we are beginning to see a rewilding of Vancouver with the return of the salmon to our rivers these past few years. 

It is a hopeful recovery from an amazing creature and their will to not just survive but thrive. Marina Dodis, a local film maker has done a wonderful job of recording that rewilding in her film, The Return. I'll pop a link below for you to watch it. I'm sure you'll enjoy it as much as I did.

We have Ernest Albert Cleveland to thank for the loss of that salmon but can credit him with much of our drinking water as it is caught and stored by the dam that bears his name. It was his vision to capture the bounty from the watershed and ensure it made its way into our cups and not the sea. 

Both the water and a good deal of sediment from the Capilano would flow into Burrard Inlet if not held back by the 91-metre concrete walls of the Cleveland Dam. While it was not Ernest's intention, his vision and dam had a secondary impact. In moving the mouth of the Capilano River he altered the erosion pattern of the North Shore and unveiled a Cretaceous Plant Fossil outcrop that is part of the Three Brothers Formation.

Capilano River Canyon & Regional Park
Know Before You Go

The fossil site is easily accessible from Vancouver and best visited in the summer months when water levels are low. 

The level of preservation of the fossils is quite good. The state in which they were fossilized, however, was not ideal. They look to have been preserved as debris that gathered in eddies in a stream or delta.

There are Cretaceous fossils found only in the sandstone. You will see exposed shale in the area but it does not contain fossil material. 

Interesting, but again not fossiliferous, are the many granitic and limestone boulders that look to have been brought down by glaciers from as far away as Texada Island. Cretaceous plant material (and modern material) found here include Poplar (cottonwood)  Populus sp. Bigleaf Maple, Acer machphyllum, Alder, Alnus rubra, Buttercup  Ranvuculus sp., Epilobrium, Red cedar, Blackberry and Sword fern.

Capilano Fossil Field Trip:

From downtown Vancouver, drive north through Stanley Park and over the Lion’s Gate Bridge. Take the North Vancouver exit toward the ferries. Turn right onto Taylor Way and then right again at Clyde Avenue. Look for the Park Royal Hotel. Park anywhere along Clyde Avenue.

From Clyde Avenue walk down the path to your left towards the Capilano River. Watch the water level and tread cautiously as it can be slippery if there has been any recent rain. Look for beds of sandstone about 200 meters north of the private bridge and just south of the Highway bridge. The fossil beds are just below the Whytecliff Apartment high rises. Be mindful of high water and slippery rocks.

Visiting the Capilano Watershed and Reservoir:

Visitors can see the reservoir from Cleveland Dam at the north end of Capilano River Regional Park. You can also visit the Capilano River Hatchery, operated below Cleveland Dam since 1971.

IN THE HEART OF THE CITY, A WILD MIRACLE AWAITS — THE RETURN, a film by the supremely talented Marina Dodis

There is something astonishing happening in the city of Vancouver. Largely unnoticed amidst vehicle traffic, industrial sites and construction, wild salmon are returning to their ancient spawning grounds.

Once an important salmon bearing area, this watershed became severely degraded as the city grew. The run collapsed and was declared “dead”. As salmon are iconic for people in British Columbia, concerned citizens became engaged. The rewilding has begun to pay off. After disappearing for 80 years, people can now witness the autumn spectacle of these powerful swimmers fighting to reach the streams they hatched in. To have a salmon run taking place within city limits is almost completely unique in a metropolis of this size.

Filmed with a quiet, observing lens over many years, "The Return" takes us into hidden enclaves of wilderness within the city, where tiny salmon smolts shimmer beneath the water's surface. Now that they have come back, their future is in our hands.

Link: https://madodis.wixsite.com/the-return?fbclid=IwAR349gFSZtmb3FN4iZRP6AGLyTH0O7MQnQbY-Prup6Qa0ICUzdhaw3vCkSk

Saturday, 4 March 2023

LEMURS OF MADAGASCAR

These lovelies are lemurs. They are very social and like to live in groups of half a dozen to up to 30 individuals. A female leads the group, or troop, and will likely have mated with the stinkiest — think sexiest — male. 

Once they breed, mamma will give birth to one to a half dozen pups after a gestation period of about 100 to 107 days. The wee pups cling to mamma's belly for the first few weeks of life then crawl up to live on her back for the next few months. By three to six months, the wee ones are weaned and a year to three years later, this pup will be mature and ready to mate. If all goes well, some species can live up to 30 years — rather a long life in the wild.

Lemurs are mammals of the order Primates, divided into 8 families and consisting of 15 genera and around 100 highly diverse species — 105 to be exact. They are native only to the island of Madagascar.

Most lemurs are relatively small, have a pointed snout, large eyes, and a long tail. They are arboreal, living primarily in trees and nocturnal, preferring to be active at night, snacking on leaves, shoots, fruit, flowers, tree bark, nectar and sap.

Phylogenetic, genetic, and anatomical evidence all suggest that lemurs split from other primates on Africa around 62 million years ago and that the ancestral lemur lineage had dispersed to Madagascar by around 54 million years ago. They must have come over to the island clinging to floating vegetation.

Once on the island, the lemur lineage diversified. Now there are at least 105 species of lemur, all endemic to Madagascar. They range in size from just an ounce and just 9 to 11 cm in the case of the Madame Berthe's mouse lemurs to up to 15 to 22 lbs or 7 to 10 kilograms, in the case of the Indri.

The evolutionary and biogeographic processes experienced by the lemurs are not unusual. Madagascar is home to many groups of endemic organisms with close within-group relationships. The simplest — or most parsimonious — explanation for this pattern is that, like the lemurs, the groups first arrived on the island by dispersal as a single lineage and then rapidly diversified. This diversification was likely spurred on by other geologic and geographic characteristics of Madagascar.

The east coast of the island is lined with a mountain range — and this causes different parts of the island to get drastically different amounts of rain. Hence, the island is made of many different habitat types — from deserts to rainforests — that have shifted and changed over the past 88 million years. This likely provided many opportunities for subpopulations to become isolated and evolve traits for specializing in different niches. And that likely encouraged lineages to diversify.

Today, Madagascar is one of the most diverse places on Earth. Understanding where that diversity comes from requires understanding, not just the living world, but the geologic, geographic, and climactic histories that have shaped the evolution of lineages on the island. Now, human history in the making threatens to undo tens of millions of years of evolution in just a few years of political turmoil — unless safeguards can be put in place to protect Madagascar's unique biota from the instabilities of human institutions.

Cooper, A., Lalueza-Fox, C., Anderson, S., Rambaut, A., Austin, J., and Ward, R. (2001). Complete mitochondrial genome sequences of two extinct moas clarify ratite evolution. Nature 409:704-707.

Goodman, S. M., and Benstead, J. P. (2005). Updated estimates of biotic diversity and endemism for Madagascar. Oryx 39(1):73-77.

Evolution Berkeley: https://evolution.berkeley.edu/evolibrary/news/091001_madagascar

Vences, M., Wollenberg, K. C., Vieites, D. R., and Lees, D. C. (2009). Madagascar as a model region of species diversification. Trends in Ecology and Evolution 24(8):456-465.

Friday, 3 March 2023

AIOLOCERAS OF MADAGASCAR

Aioloceras besairiei (Collingnon, 1949)
A stunning example of the internal suturing with calcite infill in this sliced Aioloceras besairiei (Collingnon, 1949) ammonite from the Upper Cretaceous (Lower Albian) Boeny region of Madagascar. 

This island country is 400 kilometres off the coast of East Africa in the Indian Ocean and a wonderful place to explore off the beaten track.

Madagascar has some of the most spectacular of all the fossil specimens I have ever seen. This beauty is no exception. The shell has a generally small umbilicus, arched to acute venter, and typically at some growth stage, falcoid ribs that spring in pairs from umbilical tubercles, usually disappearing on the outer whorls. I had originally had this specimen marked as a Cleoniceras besairiei, except Cleoniceras and Grycia are not present in Madagascar. 

This lovely, seen in cross-section, is now far from home and in the collection of a wonderful friend. It is an especially lovely example of the ammonite, Aioloceras besairiei, making it a beudanticeratinae. Cleoniceras and Grycia are the boreal genera. If you'd 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 22 cm, so quite a handful. This specimen is from the youngest or uppermost subdivision of the Lower Cretaceous. I'd originally thought this locality was older, but dating reveals it to be from the Lower Albian, so approximately 113.0 ± 1.0 Ma to 100.5 ± 0.9 Ma.

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’s 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. The island has an interesting geologic history.

Although there has been a geological survey, which was active extending back well into French colonial times, in the non-French-speaking world our geological understanding of the island is still a bit of a mystery. 

Plate tectonic theory had its beginnings in 1915 when Alfred Wegener proposed his theory of "continental drift." 

Wegener proposed that the continents ploughed through the crust of ocean basins, which would explain why the outlines of many coastlines (like South America and Africa) look like they fit together like a puzzle. Half a century after Wegener there is still no agreement as to whether in continental reconstructions Madagascar should be placed adjacent to the Tanzanian coast to the north (e.g., McElhinny and Embleton,1976), against the Mozambique-Natal coast (Flores 1970), or basically left where it is (Kent 1974, Nairn 1978).

There have been few attempts apart from McKinley’s (1960) comparison of the Karoo succession of southwestern Tanzania with that of Madagascar to follow the famous geological precept of “going to sea.” One critical reason is that although there may be a bibliography of several thousand items dealing with Madagascan geology as Besairie (1971) claims, they are items not generally available to the general public. The vital information gained of the geology of the offshore area by post-World War II petroleum exploration has remained largely proprietary. 

Without this data to draw upon, our understanding remains incomplete. I don't actually mind a bit of a mystery here. It is interesting to speculate on how these geologic puzzle pieces fit together and wait for the big reveal. Still, we have good old Besairie from his 1971, Geologie de Madagascar, and a later précis (Besairie, 1973).

We do know that Madagascar was carved off from the African-South American landmass early on. The prehistoric breakup of the supercontinent Gondwana separated the Madagascar–Antarctica–India landmass from the Africa–South America landmass around 135 million years ago. Madagascar later split from India about 88 million years ago, during the Late Cretaceous, so the native plants and animals on the island evolved in relative isolation. 

It is a green and lush island country with more than its fair share of excellent fossil exposures. Along the length of the eastern coast runs a narrow and steep escarpment containing much of the island's remaining tropical lowland forest. If you could look beneath this lush canopy, you'd see rocks of the Precambrian age stretching from the east coast all the way to the centre of the island. The western edge is made up of sedimentary rock from the Carboniferous to the Quaternary.

Red-Tailed Lemurs, Waiwai & Hedgehog
Madagascar is a biodiversity hotspot. Just as Darwin's finches on the Galápagos were isolated, evolving into distinct species (hello, adaptive radiation), over 90% of the wildlife from Madagascar is found nowhere else. 

The island's diverse ecosystems, like so many on this planet, are threatened by Earth's most deadly species, homo sapien sapiens. 

We arrived back in 490 CE and have been chopping down trees and eating our way through the island's tastier populations ever since. Still, they have cuties like this Red-Tailed Lemur. Awe, right?

Today, beautiful outcrops of wonderfully preserved fossil marine fauna hold appeal for me. The material you see from Madagascar is distinctive — and prolific.

Culturally, you'll see a French influence permeating the language, architecture and legal process. There is a part of me that pictures these lovely Lemurs chatting away in French. "Ah, la vache! Regarde le beau fossile, Hérissonne!"

We see the French influence because good 'ol France invaded sleepy Madagascar back in 1883, during the first Franco-Hova War. Malagasy (the local Madagascarian residents) were enlisted as troops, fighting for France in World War I.  During the Second World War, the island was the site of the Battle of Madagascar between the Vichy government and the British. By then, the Malagasy had had quite enough of colonization and after many hiccuping attempts, reached full independence in 1960. Colonization had ended but the tourist barrage had just begun. You can't stop progress.

If you're 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