Showing posts with label art. Show all posts
Showing posts with label art. Show all posts

Monday, February 26, 2024

FOSSIL FISHAPODS OF NUNAVUT

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!

Monday, January 24, 2022

CRINOIDS — UNDERWATER FLOWERS OR LIVING ANIMALS?

Agaricocrinus splendens
This lovely is Agaricocrinus splendens, an aptly named and wonderfully preserved fossil crinoid. 

Crinoids are one of my favourite echinoderms. It is magical when all the elements come together to preserve a particularly lovely specimen in such glorious detail. 

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. 

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 allow 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, an area we call the tegmen. It is divided into five ambulacral areas, including a deep groove from which the tube feet project, and five interambulacral areas between them. 

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 — if one ignores the enigmatic Echmatocrinus of the Burgess Shale. And they can be quite plentiful. Crinoid fossils, and in particular disarticulated crinoid columnals, can be so abundant that they at times serve as the primary supporting clasts in sedimentary rocks.

Friday, October 1, 2021

URSIDAE: URSAVUS

Hiking in BC, both grizzly and black bear sightings are common. These majestic beasts live up to 28 years and nearly half the world's population, some 25,000 grizzlies, roam the Canadian wilderness.

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 given the size of their very large descendants.

An average Grizzly weighs in around 800 lbs (363 kg), but a recent find in Alaska tops the charts at 1600 lbs (726 kg). 

This mighty beast stood 12' 6' high at the shoulder, 14' to the top of his head and is one of the largest grizzlies ever recorded. This past September, the King of the forest was seen once again in the Washington Cascades -- the first sighting in over 50 years.

Grizzly Bears in First Nation Lore and Language

In the Kwak'wala language of the Kwakiutl First Nations of the Pacific Northwest — or Kwakwaka'wakw, speakers of Kwak'wala — a grizzly bear is known as na̱n and the ornamental grizzly bear headdress worn by the comic Dluwalakha grizzly bear dancers in the Grizzly Bear Dance, Gaga̱lalał, is known as na̱ng̱a̱mł

There is another grizzly bear who features in the Hamatsa dance, known as Nanes Bakbakwalanooksiwae, a high-ranking figure who has no mask — instead, the dancers paint their faces dark red to symbolize a hungry bear mouth and dance in costumes made of bearskin with terrifying long wooden claws.