DUGONG: SEA COW

One of the most delightful creatures to ever grace this planet is the dugong — a species of sea cow found throughout the warm latitudes of the Indian and western Pacific Oceans. 

It is one of four living species of the order Sirenia, which also includes three species of manatees — their large, fully aquatic, mostly herbivorous marine mammal cousins.

The closest living relatives of sirenians are elephants. Manatees evolved from the same land animals as elephants over 50 million years ago. 

If not for natural selection, we might have a much more diverse showing of the Sirenia as their fossil lineage shows a much more diverse group of sirenians back in the Eocene than we have today. It is the only living representative of the once-diverse family Dugongidae; its closest modern relative, Steller's sea cow, was hunted to extinction in the 18th century. 

While only one species of the dugong is alive today – a second, the Steller's sea cow only left this Earth a few years ago. Sadly, it was hunted to extinction within 27 years of its discovery – about 30 species have been recovered in the fossil record

The first appearance of sirenians in the fossil record was during the early Eocene, and by the late Eocene, sirenians had significantly diversified. Inhabitants of rivers, estuaries, and nearshore marine waters, they were able to spread rapidly.

The most primitive sirenian known to date, Prorastomus, was found in Jamaica, not the Old World; however, more recently the contemporary Sobrarbesiren has been recovered from Spain. The first known quadrupedal sirenian was Pezosiren from the early Eocene. 

The earliest known sea cows, of the families Prorastomidae and Protosirenidae, are both confined to the Eocene and were about the size of a pig, four-legged amphibious creatures. 

By the time the Eocene drew to a close, the Dugongidae had arrived; sirenians had acquired their familiar fully aquatic streamlined body with flipper-like front legs with no hind limbs, powerful tail with horizontal caudal fin, with up and down movements which move them through the water, like cetaceans.

The last of the sirenian families to appear, Trichechidae, apparently arose from early dugongids in the late Eocene or early Oligocene. The current fossil record documents all major stages in hindlimb and pelvic reduction to the extreme reduction in the modern manatee pelvis, providing an example of dramatic morphological change among fossil vertebrates.

Since sirenians first evolved, they have been herbivores, depending on seagrasses and aquatic angiosperms, tasty flowering plants of the sea, for food. To the present, almost all have remained tropical — with the notable exception of Steller's Sea Cow — marine, and angiosperm consumers. Sea cows are shallow divers with large lungs. They have heavy skeletons to help them stay submerged; the bones are pachyostotic (swollen) and osteosclerotic (dense), especially the ribs which are often found as fossils.

Eocene sirenians, like Mesozoic mammals but in contrast to other Cenozoic ones, have five instead of four premolars, giving them a 3.1.5.3 dental formula. Whether this condition is truly primitive retention in sirenians is still under debate.

Although cheek teeth are relied on for identifying species in other mammals, they do not vary to a significant degree among sirenians in their morphology but are almost always low-crowned —brachyodont — with two rows of large, rounded cusps — bunobilophodont. The most easily identifiable parts of sirenian skeletons are the skull and mandible, especially the frontal and other skull bones. With the exception of a pair of tusk-like first upper incisors present in most species, front teeth — incisors and canines — are lacking in all, except the earliest sirenians.

TITANITES: THE FERNIE AMMONITE

Titanites occidentalis, Fernie Ammonite

The Fernie ammonite, Titanites occidentalis, from outcrops on Coal Mountain near Fernie, British Columbia, Canada. 

This beauty is the remains of a carnivorous cephalopod within the family Dorsoplanitidae that lived and died in a shallow sea some 150 million years ago.

If you would like to get off the beaten track and hike up to see this ancient beauty, you will want to head to the town of Fernie in British Columbia close to the Alberta border. 

There was some active logging along the hillside in 2021, so if you are looking at older directions on how to get to the site be mindful that many of the trailheads have been altered and a fair bit of bushwhacking will be necessary to get to the fossil site proper. That being said, the loggers did give the ammonite a wide berth and have left it intact.

Driving to the trail base is along an easy access road just east of town along Fernie Coal Road. There are some nice exposures of Cretaceous plant material on the north side (left-hand side) of the road as you head from Fernie towards Coal Creek. I recently drove up to Fernie to look at Cretaceous plant material and locate the access point to the now infamous Late Jurassic (Tithonian) Titanites (S.S. Buckman, 1921) site. While the drive out of town is on an easy, well-maintained road, the slog up to the ammonite site is a steep 3-hour push.

Fernie, British Columbia, Canada

The first Titanites occidentalis was about one-third the size and was incorrectly identified as Lytoceras, a fast-moving nektonic carnivore. The specimen you see here is significantly larger at 1.4 metres (about four and a half feet) and rare in North America. 

Titanites occidentalis, the Western Giant, is the second known specimen of this extinct fossil species. The first was discovered in 1947 in nearby Coal Creek by a British Columbia Geophysical Society mapping team. When they first discovered this marine fossil high up on the hillside, they could not believe their eyes — both because it is clearly marine at the top of a mountain and the sheer size of this ancient beauty.

In the summer of 1947, a field crew was mapping coal outcrops for the BC Geological Survey east of Fernie. One of the students reported finding “a fossil truck tire.” Fair enough. The similarity of size and optics are pretty close to your average Goodridge. 

A few years later, GSC Paleontologist Hans Frebold described and named the fossil Titanites occidentalis after the large Jurassic ammonites from Dorset, England. The name comes from Greek mythology. Tithonus, as you may recall, was the Prince of Troy. He fell in love with Eos, the Greek Goddess of the Dawn. Eos begged Zeus to make her mortal lover immortal. Zeus granted her wish but did not grant Tithonus eternal youth. He did indeed live forever — ageing hideously. Ah, Zeus, you old trickster. It is a clever play on time placement. Dawn is the beginning of the day and the Tithonian being the latest age of the Late Jurassic. Clever Hans!

HIKING TO THE FERNIE AMMONITE

From the town of Fernie, British Columbia, head east along Coal Creek Road towards Coal Creek. The site is 3.81 km from the base of Coal Creek Road to the trailhead as the crow flies. I have mapped it here for you in yellow and added the wee purple GPS marker for the ammonite site proper. There is a nice, dark grey to black roadcut exposure of Cretaceous plants on the north side of the dirt road that is your cue to pull over and park.  

You access what is left of the trailhead on the south side of the road. You will need to cross the creek to begin your ascent. There is no easy way across the creek and you'll want to tackle this one with a friend when the water level is low. 

The beginning of the trail is not clear but a bit of searching will reveal the trailhead with its telltale signs of previous hikers. This is a 1-2 hour moderate 6.3-kilometre hike up & back bushwhacking through scrub and fallen trees. Heading up, you will make about a 246-metre elevation gain. You will likely not have a cellular signal up here but if you download the Google Map to your mobile, you will have GPS to guide you. The area has been recently logged so much of the original trail has been destroyed. There may now be easier vehicle access up the logging roads but I have not driven them since the logging and new road construction.

If you are coming in from out of town, the closest airport is Cranbrook. Then it is about an hour and change to Fernie and another 15-minutes or so to park near the site.

You will want to leave your hammers with your vehicle (no need to carry the weight) as this site is best enjoyed with a camera. 

This is a site you will want to wear hiking boots to access. Know that these will get wet as you cross the creek. 

If you would like to see the ammonite but are not keen on the hike, a cast has been made by fossil preparator Rod Bartlett is on display at the Courtenay Museum in Courtenay, Vancouver Island, Canada. 

As your feet move up the hillside, you can imagine this land 10,000 years ago, rising above great glaciers. Where footfalls trace the steps of those that came before you. This land has been home to the Ktunaxa or Kukin ʔamakis First Nations whose oral history have them living here since time immemorial. Like them, take only what you need and no more than the land offers — packing out anything that you packed in. 

Fernie Ammonite Palaeo Coordinates: 49°29'04"N 115°00'49"W

AMMONITE: INDEX FOSSILS AS TIME KEEPERS

Argonauticeras besairei, José Juárez Ruiz

An exceptional example of the fractal building of an ammonite septum, in this clytoceratid Argonauticeras besairei from the awesome José Juárez Ruiz.

Ammonites were predatory, squidlike creatures that lived inside coil-shaped shells.

Like other cephalopods, ammonites had sharp, beak-like jaws inside a ring of squid-like tentacles that extended from their shells. 

They used these tentacles to snare prey, — plankton, vegetation, fish and crustaceans — similar to the way a squid or octopus hunt today.

Catching a fish with your hands is no easy feat, as I am sure you know. But the Ammonites were skilled and successful hunters. They caught their prey while swimming and floating in the water column. 

Within their shells, they had a number of chambers, called septa, filled with gas or fluid that were interconnected by a wee air tube. By pushing air in or out, they were able to control their buoyancy in the water column.

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

They were a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. 

These molluscs, commonly referred to as ammonites, are more closely related to living coleoids — octopuses, squid, and cuttlefish) than they are to shelled nautiloids such as the living Nautilus species.

The Ammonoidea can be divided into six orders:

• Agoniatitida, Lower Devonian - Middle Devonian
• Clymeniida, Upper Devonian
• Goniatitida, Middle Devonian - Upper Permian
• Prolecanitida, Upper Devonian - Upper Triassic
• Ceratitida, Upper Permian - Upper Triassic
• Ammonitida, Lower Jurassic - Upper Cretaceous

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

If they are ceratitic with lobes that have subdivided tips; giving them a saw-toothed appearance and rounded undivided saddles, they are likely Triassic. For some lovely Triassic ammonites, take a look at the specimens that come out of Hallstatt, Austria and from the outcrops in the Humboldt Mountains of Nevada.

Hoplites bennettiana (Sowby, 1826) Christophe Marot

If they have lobes and saddles that are fluted, with rounded subdivisions instead of saw-toothed, they are likely Jurassic or Cretaceous. If you'd like to see a particularly beautiful Lower Jurassic ammonite, take a peek at Apodoceras. Wonderful ridging in that species.

One of my favourite Cretaceous ammonites is the ammonite, Hoplites bennettiana (Sowby, 1826). This beauty is from Albian deposits near Carrière de Courcelles, Villemoyenne, near la région de Troyes (Aube) Champagne in northeastern France.

At the time that this fellow was swimming in our oceans, ankylosaurs were strolling about Mongolia and stomping through the foliage in Utah, Kansas and Texas. Bony fish were swimming over what would become the strata making up Canada, the Czech Republic and Australia. Cartilaginous fish were prowling the western interior seaway of North America and a strange extinct herbivorous mammal, Eobaatar, was snuffling through Mongolia, Spain and England.

In some classifications, these are left as suborders, included in only three orders: Goniatitida, Ceratitida, and Ammonitida. Once you get to know them, ammonites in their various shapes and suturing patterns make it much easier to date an ammonite and the rock formation where it is found.

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

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

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

For this reason, they make excellent index fossils. An index fossil is a species that allows us to link a particular rock formation, layered in time with a particular species or genus found there. 

Generally, deeper is older, so we use the sedimentary layers of rock to match up to specific geologic time periods, rather like the way we use tree rings to date trees. A handy way to compare fossils and date strata across the globe.

References: Inoue, S., Kondo, S. Suture pattern formation in ammonites and the unknown rear mantle structure. Sci Rep 6, 33689 (2016). https://doi.org/10.1038/srep33689

https://www.nature.com/articles/srep33689?fbclid=IwAR1BhBrDqhv8LDjqF60EXdfLR7wPE4zDivwGORTUEgCd2GghD5W7KOfg6Co#citeas

Photos: Argonauticeras besairei from the awesome José Juárez Ruiz.

Photo: Hoplites bennettiana from near Troyes, France. Collection de Christophe Marot

PSEUDOTHURMANNIA PICTETI

Pseudothurmannia is a genus of extinct cephalopods belonging to the subclass Ammonoidea and included in the family Crioceratitidae of the ammonitid superfamily Ancylocerataceae.

Ammonites have intricate and complex patterns on their shells called sutures. The suture patterns differ across species and tell us what time period the ammonite is from.

We can see from the suture patterns shown here and by comparing it to others that are similar that this fast-moving nektonic carnivore lived in the Cretaceous, from the Hauterivian to the Barremian.

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

Catching a fish with your hands is no easy feat, as I'm sure you know. Ammonites were skilled and successful hunters. They caught their prey while swimming and floating in the water column. 

Within their shells, they had a number of chambers, called septa, filled with gas or fluid that were interconnected by a wee air tube. By pushing air in or out, they were able to control their buoyancy in the water column. They lived in the last chamber of their shells, continuously building new shell material as they grew. As each new chamber was added, the squid-like body of the ammonite would move down to occupy the final outside chamber.

Shells of Pseudothurmannia can reach a diameter of about 4–12 centimetres (1.6–4.7 in). They show flat or slightly convex sides, with dense ribs and a subquadrate whorl section.

We find fossils of Pseudothurmannia in Cretaceous outcrops in Antarctica, Czechoslovakia, France, Hungary, Italy, Japan, Morocco, Spain, Russia and the United States. The specimen you see here is in the collection of the deeply awesome Manuel Peña Nieto from Córdoba, Spain and is from the Lower Cretaceous of Mallorca.

SEA ANEMONES: CNIDARIA

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Mackenzia costalis, Walcott 1911

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

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

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

References:  

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

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

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

THE CALL OF THE WILD: ANTARCTIC FUR SEALS

This little cutie is an Antarctic fur seal pup. He and his Mamma belong to the species Arctocephalus gazella — pinnipeds that live in dense colonies alongside King Penguins. 

These two call the South Georgia islands home, as do 95% of the world's fur seal population.  

Though a wee pup, he can already recognize her voice from all the other lovely Mammas in his busy, noisy colony. Little ones left on the rocky shores while their mother is out hunting will raise their heads and listen for their mother's voice. They can distinguish its vocal pitch over the loud calls of all the other busy Mammas and penguins of the colony. If you look closely, you can see his wee little ears. Antarctic fur seals, unlike some other seal species, have visible ears.  

Seal pups stay with their mother, relying on her lactation milk to help them fatten up and grow healthy and strong. For the first four months of their lives, their mother will feed them on her rich milk, then head out to sea to forage for food. 

Once she is back, she will call out to him and then give him a good sniff upon their reunion, the final confirmation for both parties that the right match has been made. The interaction between mother and pup is tender and heartbreakingly sweet to watch. She only gives birth to one pup (two is rare) each October to December. Pups are born with a sheen of fur and grow their waterproof fur during their first months of life. 

When this little fellow grows up, he will dine on fish, birds (including his penguin pals), squid and krill. Krill are small crustaceans of the order Euphausiacea that look like tiny shrimp. They look similar and are both crustaceans but shrimp hail from the suborder Natantia, order Decapoda and their hearts are located in their heads.

Krill live in all the world's oceans and sadly for them, they make a handy and tasty snack. They form an important part of the oceanic food chain. The krill feed on phytoplankton and zooplankton and then larger animals feed on the krill. 

Krill is Norwegian for small fry of fish. And they are small, indeed — but also tasty, nutritious and easy to catch. Once this little pinniped pup is out hunting on his own, krill will make up the majority of his adult diet. He will need our help to make sure he gets a steady supply. Krill are one of the casualties of ocean acidification from climate change. Hopefully, we will do better so they can, too.

PLAYFUL WATERBABIES: PORPOISE

Dall's Porpoise

These delightfully friendly and super smart fellows are Dall's porpoise. 

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, a blowhole is known as a ka̱'was, whether on a dolphin (porpoise) or whale and a porpoise is known as a k̓ulut̕a. 

In the Pacific Northwest, we see many of their kind — the shy, blunt-nosed harbour porpoise, the social and herd-minded Pacific white-sided dolphin and the showy and social Dall's porpoise.  

Of these, the Dall's porpoise is a particular favourite. These speedy muscular black and white showboats like to ride the bow waves of passing boats — something they clearly enjoy and a thrill for everyone on board the vessel. If you slow down, they will often whisk away, but give them a chance to race you and they may stay with you all afternoon. 

Harbour porpoises are the complete opposite. You are much more likely to see their solid black bodies and wee fin skimming through the waves across the bay as they try to avoid you entirely. Harbour porpoise prefer quiet sheltered shorelines, often exploring solo or in small groups of two or three. 

We sometimes see these lovely marine mammals represented in the art of the First Nations in the Pacific Northwest, particularly along the coast of British Columbia. You will know them from their rather rectangular artistic depiction with a pronounced snout and lacking teeth (though they have them) used to portray killer whales or orca. 

As a group, even considering the shy Harbour porpoise, these marine mammals are social and playful. Humpback whales are fond of them and you will sometimes see them hanging out altogether in the bays and inlets or near the shore. 

They are quite vocal, making lots of distinctive and interesting noises in the water. They squeak, squawk and use body language — leaping from the water while snapping their jaws and slapping their tails on the surface. They love to blow bubbles, will swim right up to you for a kiss and cuddle. 

Each individual has a signature sound, a whistle that is uniquely their own. They use these whistles to tell one of their friends and family members from another.

Porpoise are marine mammals that live in our world's oceans. If it is salty and cold, you can be pretty sure they are there. They breathe air at the surface, similar to humans, using their lungs and inhaling and exhaling through a blowhole at the top of their heads instead of through their snouts. 

TRACKING WHALES WITH BARNACLES

We can trace the lineage of barnacles back to the Middle Cambrian. That is half a billion years of data to sift through. 

If you divide that timeline in half yet again, we begin to understand barnacles and their relationship to other sea-dwelling creatures — with a lens that reveals ancient migration patterns.

Barnacles are in the infraclass Cirripedia in the class Maxillopoda. They are marine arthropods related to crabs and lobsters. 

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, barnacles are known as k̕wit̕a̱'a and broken barnacle shells are known as t̕sut̕su'ma. Unless scraped off, barnacles live on one single sturdy object for their entire lives — 8 to 20 years — while chowing down on tasty snacks like plankton and algae they absorb from the surrounding water.

One of the most interesting aha moments in palaeontology came from the study of 270,000 million-year-old k̕wit̕a̱'as. These sticky wee crustaceans have enabled us to trace the course of ancient whale migration. 

University of California Berkeley doctoral student Larry Taylor published some clever findings on how fossil barnacles hitched a ride on the backs of humpback and grey whales millions of years ago and used this data to reconstruct the migrations of ancient whale populations.

The barnacles record details about the whales’ yearly travels in the fossil record. By following this barnacle trail, Taylor et al. were able to reconstruct migration routes of whales from millions of years in the past.

Today, Humpback whales come from both the Southern Hemisphere (July to October with over 2,000 whales) and the Northern Hemisphere (December to March about 450 whales along with Central America) to Panama (and Costa Rica). They undertake annual migrations from polar summer feeding grounds to winter calving and nursery grounds in subtropical and tropical coastal waters.

One surprise find is that the coast of Panama has been a meeting ground for humpback whales going back at least 270,000 years. To see how the barnacles have travelled through the migration routes of ancient whales, the team used oxygen isotope ratios in barnacle shells and measured how they changed over time with ocean conditions. 

Did the whale migrate to warmer breeding grounds or colder feeding grounds? Barnacles retain this information even after they fall off the whale, sink to the ocean bottom, and become fossils. As a result, the travels of fossilized barnacles can serve as a proxy for the journeys of whales in the distant past.

Barnacles can play an important role in estimating paleo-water depths. The degree of disarticulation of fossils suggests the distance they have been transported, and since many species have narrow ranges of water depths, it can be assumed that the animals lived in shallow water and broke up as they were washed down-slope. 

Barnacles have few predators. Their one nemesis is the whelk. It seems that catching a lifetime's ride on a passing whale would have extended their ability to feed on plankton in a variety of settings whelk-free and likely live longer than they might have cemented to something closer to the seafloor.

HUMPBACK WHALES: MEGAPTERA NOVAENGLIAE

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

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

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

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

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

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

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

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

Humpback Whale, Megaptera novaeangliae

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

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

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

Humpbacks are a friendly species that interact with other cetaceans such as bottlenose dolphins. They are also friendly and oddly protective of humans. You may recall hearing about an incident off the Cook Islands a few years back. In September of 2017, Nan Hauser was snorkeling and ran into a tiger shark. Two adult humpback whales rushed to her aid, blocking the shark from reaching her and pushing her back towards the shore. We could learn a thing or two from their kindness. We have not been as good to them as they have been to us.

Like other large whales, the humpback was a tasty and profitable target for the whaling industry. My grandfather and uncle participated in that industry out of Coal Harbour on northern Vancouver Island back in the 1950s. 

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

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

While my First Nations relatives hunted whales in small numbers, my Norwegian relatives participated in the hunt on such a scale that it nearly led to the extinction of our lovely Humpbacks before the process was banned back in the 1960s. The Coal Harbour Whaling Station closed in 1967. Once it had closed, my grandfather Einar Eikanger took to fishing and my uncle Harry lost his life when he slipped and fell over the side of the boat. He was crushed between the hull and a Humpback in rough seas. The Gods will have their sacrifice.

Humpback populations have partially recovered to build their population up to 80,000 animals worldwide since the 1960s but entanglement in fishing gear, collisions with ships, and noise pollution continue to negatively impact the species. So be kind if you see them. Turn your engine off and see if you can hear their soulful cries echoing in the water.

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

CONLINOCERAS TARRANTENSE

Previously Calycoceras Tarrantense, this ammonite is now called Conlinoceras tarrantense after J.P. Conlin, a famous early 20th-century fossil collector from Texas, USA.

Ammonite expert Bill Cobban used this collection to describe many Texas Cretaceous ammonites species including this species from Tarrant County, Arlington, Texas.

He was a surveyor by training and kept incredibly detailed notes on the context of his fossils.

Conlin donated his collection to the USGS and we have learned much by studying it along with other specimens from the Lone Star State. Almost a quarter of Texas is covered by Cretaceous strata, much of it fossiliferous. If we stepped back 95 million years, the world and what we now call Texas was a very different place.

95 million years ago, during the Late Cretaceous, a shallow seaway separated North America into separate eastern and western landmasses. We have a pretty complete picture in the fossil record of the western groups of species but relatively little in comparison to their cohorts in the east.

At the time this fellow was swimming our ancient seas, he was sharing the Earth with carnivorous dinosaurs, duck-billed dinosaurs, mammals, crocodilians, turtles, a variety of amphibians, prehistoric bony fish, oddly prolific sea cucumbers, various invertebrates and plants. Many of these sites are just being written up now and contain new species just being discovered.

During the Late Cretaceous Period, a shallow seaway separated North America into separate eastern and western landmasses. The Woodbine Formation in Texas preserves a rare fossil record of this time for the east, but many of these fossils are isolated and incomplete, making interpretations more difficult. Preliminary excavations at the Arlington Archosaur Site (AAS) are providing hints at a more complete ecosystem, preserving similar patterns of change to what we see in the west.

The Arlington Archosaur site contains an extraordinary diversity, abundance, and quality of fossil material, preserving one of the most complete terrestrial ecosystems known for this time period and area.

These outcrops and the fossils they contain have a lot to tell us about Late Cretaceous life in the east. Over 2200 individual specimens have been found belonging to numerous groups including carnivorous dinosaurs, duck-billed dinosaurs, crocodilians, turtles, mammals, amphibians, sharks, bony fish, invertebrates, and plants.

Many of the fossils found here represent brand new species and studying these fossils will help to establish the geographic and environmental forces that shaped Cretaceous ecosystems in North America by providing a necessary comparison to the fossil record of the west.

VOAY ROBUSTUS

This big beastie is Voay robustus. You likely met him first as Crocodylus‭ (‬C.‭ ‬robustus‭) from his original naming by Grandidier and Vaillant in‭ 1872. 

Looking more closely at his remains revealed that he is nearer in design to the dwarf crocodile Osteolaemus. 

The type series cannot be identified, but the original description includes details consistent with known specimens that almost certainly pertain to the same species. 

It had a prominent triangular ‘horn’ on the posterolateral corner of each squamosal; near-exclusion of the nasals from the external naris; constricted supratemporal fenestral rims; a dorsoventrally deep snout; a constricted external mandibular fenestra in which the surangular–angular suture emerges from the posterior rather than posteroventral margin; and robust limb and limb-girdle elements. 

It shares with Osteolaemus, and with several extinct crocodylids from the Neogene of Africa, a depressed surface of the pterygoid around the internal choana forming a choanal ‘neck’. It cannot be referred to as Crocodylus and a new praenomen, Voay, was established for its reception. 

In 2007, Christopher‭ ‬A.‭ ‬Brochu created a new genus, Voay, and this fellow became Voay robustus. Christopher published his work in the Zoological Journal of the Linnean Society in Volume 150, Issue 4, August 2007, Pages 835-863. Voay lived into the Holocene of Madagasgar, perhaps meeting some of our relatives 2,000 years ago. Voay was replaced by Crocodylus niloticus in Madagascar as they moved into the niche left by Voay's ultimate demise. 

https://doi.org/10.1111/j.1096-3642.2007.00315.x

WHALER

 

INKY BEAUTY: AMMONITE OF PONGO DE MANSERICHE

This inky beauty is Prolyelliceras ulrichi (Knechtel, 1947) a fast-moving nektonic carnivorous ammonite from Cretaceous lithified, black, carbonaceous limestone outcrops in the Pongo de Manseriche gorge in northwest Peru. 

If you look closely, you can see that this specimen shows a pathology, a slight deviation to the side of the siphonal of the ammonite. We see Prolyelliceras from the Albian to Middle Albian from five localities in Peru.

The canyons of the Amazon River system in the eastern ranges of the Andes of Peru are known by the Indian name pongo. 

The most famous of these is the Pongo de Manseriche, cut by the Marañon River through the eastern range of the Andes, where it emerges from the cordillera into the flat terrane of the Amazon Basin. The fossil exposures here are best explored by boat. The reality of the collecting is similar to the imagined. I was chatting with Betty Franklin, VIPS, about this. They float along and pick up amazing specimen after amazing specimen. When the water rises, the ammonites are aided in their erosion out of the cliffs.  

The Pongo de Manseriche lies nearly 500 miles upstream from Iquitos, and consequently nearly 3,000 miles above the mouth of the Amazon River. It is situated in the heart of the montaña, in a vast region the ownership of which has long been in dispute between Peru and Ecuador, but over which neither country exercises any police or other governmental control. There is an ancient tradition of the indigenous people of the vicinity that one of their gods descended the Marañón and another ascended the Amazon to communicate with him. Together they opened the pass called the Pongo de Manseriche.

Reference: M. M. Knechtel. 1947. Cephalopoda. In: Mesozoic fossils of the Peruvian Andes, Johns Hopkins University Studies in Geology 15:81-139

W. J. Kennedy and H. C. Klinger. 2008. Cretaceous faunas from Zululand and Natal, South Africa. The ammonite subfamily Lyelliceratinae Spath, 1921. African Natural History 4:57-111. The beauty you see here is in the collection of the deeply awesome José Juárez Ruiz.

FOSSILIZED SEA URCHIN: AM'DA'MA

This lovely little biscuit is a Holectypus sea urchin from 120 million-year-old deposits from the Lagniro Formation of Madagascar.

The specimen you see here is in the collections of my beautiful friend Ileana. She and I were blessed to meet in China many years ago and formed an unbreakable bond that happens so few times in one's life. 

Holectypus are a genus of extinct echinoids related to modern sea urchins and sand dollars. They were abundant from the Jurassic to the Cretaceous (between 200 million and 65.5 million years ago).

This specimen is typical of Holectypus with his delicate five-star pattern adorning a slightly rounded test and flattened bottom. The specimen has been polished and was harvested both for its scientific and aesthetic value. 

I have many wonderful memories of collecting their modern cousins that live on the north end of Vancouver Island and along the beaches of Balaklava Island. In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, sea urchins are known as a̱m'da̱'ma and it is this name that I hear in my head when I think of them.

In echinoids, the skeleton is almost always made up of tightly interlocking plates that form a rigid structure or test — in contrast with the more flexible skeletal arrangements of starfish, brittle stars, and sea cucumbers. Test shapes range from nearly globular, as in some sea urchins, to highly flattened, as in sand dollars. 

Sea Urchin Detail

Living echinoids are covered with spines, which are movable and anchored in sockets in the test. These spines may be long and prominent, as in typical sea urchins and most have lovely raised patterns on their surface. 

In sand dollars and heart urchins, however, the spines are very short and form an almost felt-like covering. The mouth of most echinoids is provided with five hard teeth arranged in a circle, forming an apparatus known as Aristotle’s lantern.

Echinoids are classified by the symmetry of the test, the number and arrangement of plate rows making up the test, and the number and arrangement of respiratory pore rows called petals. Echinoids are divided into two subgroups: regular echinoids, with nearly perfect pentameral (five-part) symmetry; and irregular echinoids with altered symmetry.

Because most echinoids have rigid tests, their ability to fossilize is greater than that of more delicate echinoderms such as starfish, and they are common fossils in many deposits. The oldest echinoids belong to an extinct regular taxon called the Echinocystitoidea. 

They first appeared in the fossil record in the Late Ordovician. Cidaroids or pencil urchins appear in the Mississippian (Early Carboniferous) and were the only echinoids to survive the mass extinction at the Permo-Triassic boundary. Echinoids did not become particularly diverse until well after the Permo-Triassic mass extinction event, evolving the diverse forms we find them in today. 

True sea urchins first appear in the Late Triassic, cassiduloids in the Jurassic, and spatangoids or heart urchins in the Cretaceous. Sand dollars, a common and diverse group today, do not make an appearance in the fossil record until the Paleocene. They remain one of my favourite echinoderms and stand tall amongst the most pleasing of the invertebrates.

AMMONITE TRACE FOSSIL

This is a particularly fetching trace fossil of an ammonite.

Trace fossils or ichnofossils are burrows, footprints, tracks or even faeces left behind by plants and animals that lived long ago. 

Animals may have scurried across a muddy exposure or sea bottom, perhaps eaten a tasty meal then pooped it out — leaving behind clues to how they lived, what they ate and what the environment was like at the time. These are wonderfully informative clues to our ancient world.

OPABINIA REGALIS

Opabinia regalis is an extinct stem-group arthropod found in the Greater Phyllopod Bed, Middle Cambrian Burgess Shale Lagerstätte of British Columbia, Canada. 

These marine arthropods flourished from 505 million years ago to 487 million years ago.

Charles Doolittle Walcott found nine partially complete fossils of Opabinia regalis and a few of what he classified as Opabinia media, that he published in 1912. 

The bizarre arthropod's name is derived from the Opabin pass between Mount Hungabee and Mount Biddle, southeast of Lake O'Hara, British Columbia, Canada. 

In 1966–1967, Harry B. Whittington found a rather good specimen which he published in 1975. He provided a detailed description based on a very thorough dissection of some specimens and photographs of these specimens lit from a variety of angles. Harry was a very thorough fellow.

But he was still ridiculed. Opabinia looked so strange that the audience at the first presentation of Whittington's analysis laughed.

Earth's ancient seas teemed with new life 541 - 485 Million Years Ago. The Cambrian Explosion had arrived. Weird and wonderful life forms like Hallucigenia and Anomalocaris are found in the fossil record giving us a peek at ancient life half a billion years ago.

THE DUDLEY BUG: CALYMENE BLUMENBACHII

A lovely rolled trilobite, Calymene blumenbachii,  from outcrops in the UK. This wee beauty is in the collections of the deeply awesome Theresa Paul Spink Dunn — or perhaps in her daughter Layla's collections as she is quite the budding palaeontologist. This Silurian beauty is from the Homerian, Wenlock Series, Wrens Nest, Dudley, UK.

Calymene blumenbachii, sometimes erroneously spelled blumenbachi, is a species of trilobite found in the limestone quarries of the Wren's Nest in Dudley, England.

Nicknamed the Dudley Bug or Dudley Locust by an 18th-century quarryman, it became a symbol of the town and featured on the Dudley County Borough Council coat-of-arms. Calymene blumenbachii is commonly found in Silurian rocks (422.5-427.5 million years ago) and is thought to have lived in the shallow waters of the Silurian, in low energy reefs.

This particular species of Calymene — a fairly common genus in the Ordovician-Silurian — is unique to the Wenlock series in England and comes from the Wenlock Limestone Formation in Much Wenlock and the Wren's Nest in Dudley. These sites seem to yield trilobites more readily than any other areas on the Wenlock Edge, and the rock here is dark grey as opposed to yellowish or whitish as it appears on other parts of the Edge, just a few miles away, in Church Stretton and elsewhere. This suggests local changes in the environment in which the rock was deposited. The Wenlock Edge quarry is closed now to further collecting but may be open to future research projects. We shall have to see.

PIKAIA GRACILIENS: MIDDLE CAMBRIAN GRACE

Pikaia graciliens is an extinct, primative chordate animals from the Middle Cambrian Burgess Shale Lagerstätte of British Columbia, Canada. 

These lovelies swam by moving their bodies in a series of zigzag curves similar to the movement of eels, all the while filtering particles from the water.

Although primitive, Pikaia shows the essential prerequisites for vertebrates. When alive, Pikaia was a compressed, leaf-shaped animal with an expanded tail fin; the flattened body is divided into pairs of segmented muscle blocks, seen as faint vertical lines. 

The muscles lie on either side of a flexible structure resembling a rod that runs from the tip of the head to the tip of the tail. It swam by throwing its body into a series of S-shaped undulating movements that mimicked the movement of eels. Fish inherited this same swimming movement, but they generally have stiffer backbones so it does not quite have the same visual effect. 

Pikaia was likely a slow swimmer since it lacked the fast-twitch fibres that we associate with rapid swimming in modern chordates. Still, even that form of movement in the Middle Cambrian is impressive in terms of mobility and design.

Conway Morris and Caron (2012) published an exhaustive description based on more than one hundred known fossil specimens. Through their deeper look at this primitive marine mystery, they discovered new and unexpected characteristics that they recognized as primitive features of the first chordate animals. On the basis of these findings, they constructed a new scenario for chordate evolution. 

Subsequently, Mallatt and Holland reconsidered Conway Morris and Caron's description and concluded that many of the newly recognized characters are unique, already-divergent specializations that would not be helpful for establishing Pikaia as a basal chordate.

PTEROSAURS: SOARING ANCIENT SKIES

If you could travel through time and go back to observe our ancient skies, you would see massive pterosaurs — huge, winged flying reptiles of the extinct order Pterosauria — cruising along with you. 

They soared our skies during most of the Mesozoic — from the late Triassic to the end of the Cretaceous (228 to 66 million years ago). 

By the end of the Cretaceous, they had grown to giants and one of their brethren, Quetzalcoatlus, a member of the family Azhdarchidae, boasts being the largest known flying animal that ever lived. 

They were the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the ankles to a dramatically lengthened fourth finger.

PISTA DE BAILE JURÁSICA

This busy slate grey dinosaur trackway from the Iberian Peninsula looks more like a dance floor than the thoroughfare it is. 

The numerous theropod dinosaur tracks — with a few enormous sauropod tracks thrown in for good measure — cover the entire surface. 

The local soil has a bit of rusty iron ore in it that highlights each print nicely when the soil is blown into the depressions the tracks left. 

The dinosaurs crossed this muddy area en masse sometime back in the Jurassic.

The Iberian Peninsula is the westernmost of the three major southern European peninsulas — the Iberian, Italian, and Balkan. It is bordered on the southeast and east by the Mediterranean Sea, and on the north, west, and southwest by the Atlantic Ocean. The Pyrenees mountains are situated along the northeast edge of the peninsula, where it adjoins the rest of Europe. Its southern tip is very close to the northwest coast of Africa, separated from it by the Strait of Gibraltar and the Mediterranean Sea.

The Iberian Peninsula contains rocks of every geological period from the Ediacaran to the recent, and almost every kind of rock is represented. To date, there are 127 localities of theropod fossil finds ranging from the Callovian-Oxfordian — Middle-Upper Jurassic — to the Maastrichtian (Upper Cretaceous), with most of the localities concentrated in the Kimmeridgian-Tithonian interval and the Barremian and Campanian stages. The stratigraphic distribution is interesting and suggests the existence of ecological and/or taphonomic biases and palaeogeographical events that warrant additional time and attention.

As well as theropods, we also find their plant-eating brethren. This was the part of the world where the last of the hadrosaurs, the duck-billed dinosaurs, lived then disappeared in the Latest Cretaceous K/T extinction event 65.5 million years ago.

The core of the Iberian Peninsula is made up of a Hercynian cratonic block known as the Iberian Massif. On the northeast, this is bounded by the Pyrenean fold belt, and on the southeast, it is bounded by the Baetic System. These twofold chains are part of the Alpine belt. To the west, the peninsula is delimited by the continental boundary formed by the magma-poor opening of the Atlantic Ocean. The Hercynian Foldbelt is mostly buried by Mesozoic and Tertiary cover rocks to the east but nevertheless outcrops through the Sistema Ibérico and the Catalan Mediterranean System. The photo you see here is care of the awesome Pedro Marrecas from Lisbon, Portugal. Hola, Pista de baile jurásica!

Pereda-Suberbiola, Xabier; Canudo, José Ignacio; Company, Julio; Cruzado-Caballero, Penélope; Ruiz-Omenaca, José Ignacio. "Hadrosauroid dinosaurs from the latest Cretaceous of the Iberian Peninsula" Journal of Vertebrate Paleontology 29(3): 946-951, 12 de septiembre de 2009.

Pereda-Suberbiola, Xabier; Canudo, José Ignacio; Cruzado-Caballero, Penélope; Barco, José Luis; López-Martínez, Nieves; Oms, Oriol; Ruíz-Omenaca, José Ignacio. Comptes Rendus Palevol 8(6): 559-572 septiembre de 2009.

SNOWY TREE CRICKET: CHIRPING THERMOMETERS

About 250 million years ago, our once silent world became a cacophony of diverse animal sounds. 

One of the most lyrical of those voices to join the Earth's chorus were the true crickets. We can count them as some of the earliest musicians on the planet. 

This group evolved and contributed to the nocturnal circumambience of our planet a full 150 million years before our human ancestors would have heard them for the very first time. It is their long lineage that I am mindful of when I am out for an evening stroll and hear their pleasing serenade.

If you find yourself out in the woods and are wondering what the temperature might be, you need only slip closer to the nearest stand of deciduous trees to follow the musical sounds of the wee Snowy Tree Cricket, Oecanthus Fultoni, part of the order orthoptera.

Snowy Tree Crickets and their cousins double as thermometers and wee garden predators, dining on aphids and other wee beasties. Weather conditions, both hot and cold, alter the speed at which they rub the base of their wings together and consequently regulate their rate of chirping.

Listen closely for their tell-tale high pitch triple chirp sound in the early evening. Being in Canada, our crickets chirp in Celsius. To figure out the temperature, we simply count the number of chirps over a seven-second period and add five to learn the local temperature.

If did not happen to bring your calculator and you are still operating in old-school Fahrenheit, you can use this handy conversion — double the temperature in Celsius, add 32 you'll get the approximate temperature in Fahrenheit. And if you are not all that interested in the temperature, enjoy their pleasing serenade as you take your early evening stroll. They've been working on this number for millions of years. 

Daniel Otte from the Academy of Natural Sciences in Philadelphia did up a wonderful piece on the evolution of cricket songs. If you’re a keen bean & want to learn more, I'll attach the journal article for you. https://doi.org/10.2307/3503559. https://www.jstor.org/stable/3503559

DIMORPHODON: TWO TOOTH PTERODACTYLUS

This remarkable fellow is Dimorphodon — a genus of medium-sized pterosaur from the Early Jurassic. He is another favourite of mine for his charming awkwardness.

You can see this fellow's interesting teeth within his big, bulky skull. Dimorphodon had two distinct types of teeth in their jaws — an oddity amongst reptiles — and also proportionally short wings for their overall size. 

Just look at him. What an amazing beast. We understand their anatomy quite well today, but can you imagine being the first to study their fossils and try to make sense of them. 

The first fossil remains now attributed to Dimorphodon were found in England by fossil collector Mary Anning, at Lyme Regis in Dorset, United Kingdom in December 1828. While she faced many challenges in her life, she was blessed to live in one of the richest areas in Britain for finding fossils. 

She walked the beaches way back in the early 1800s of what would become the Jurassic Coast UNESCO World Heritage Site. The Jurassic Coast holds some of the most interesting fossils ever found — particularly within the strata of the Blue Lias which date back to the Hettangian-Sinemurian. It is one of the world’s most famous fossil sites. Millions come to explore the eroding coastline looking for treasures that provide delight and inspiration to young and old.

 

These fossil treasures provide us with tremendous insights into our world 185 million years ago when amazing animals like Dimorphodon ruled the skies. 

Mary's specimen was acquired by William Buckland and reported in a meeting of the Geological Society on 5 February 1829. Six years later, in 1835, William Clift and William John Broderip built upon the work by Buckland to publish in the Transactions of the Geological Society, describing and naming the fossil as a new species. 

As was the case with most early pterosaur finds, Buckland classified the remains in the genus Pterodactylus, coining the new species Pterodactylus macronyx. The specific name is derived from Greek makros, "large" and onyx, "claw", in reference to the large claws of the hand. The specimen, presently NHMUK PV R 1034, consisted of a partial and disarticulated skeleton on a slab — notably lacking the skull. Buckland in 1835 also assigned a piece of the jaw from the collection of Elizabeth Philpot to P. macronyx. 

Later, the many putative species assigned to Pterodactylus had become so anatomically diverse that they began to be broken into separate genera.

In 1858, Richard Owen reported finding two new specimens, NHMUK PV OR 41212 and NHMUK PV R 1035, again partial skeletons but this time including the skulls. Having found the skull to be very different from that of Pterodactylus, Owen assigned Pterodactylus macronyx its own genus, which he named Dimorphodon. 

His first report contained no description and the name remained a nomen nudum. In 1859, however, a subsequent publication by Owen provided a description. After several studies highlighting aspects of Dimorphodon's anatomy, Owen finally made NHMUK PV R 1034 the holotype in 1874  — 185 million years after cruising our skies the Dimorphodon had finally fully arrived.

MAMMUTUS PRIMIGENIUS: WOOLLY MAMMOTH

This fellow is Mammutus primigenius a Woolly Mammoth from the Pleistocene of Siberia, Russia. 

Mammoths have a wonderful display of mammoth teeth, the diagnostic flat enamel plates and the equally distinct pointy cusped molars of the mastodons. He was a true elephant, unlike his less robust cousins, the mastodons. Mammoths were bigger — both in girth and height — weighing in at a max of 13 tonnes. 

They are closely related to Asian elephants and were about the size of the African elephants you see roaming the grasslands of Africa today.

If you stood beside him and reached way up, you might be able to touch his tusks but likely not reach up to his mouth or even his eyes. He would have had a shaggy coat of light or dark coloured hair with long outer hair strands covering a dense thick undercoat. His oil glands would have worked overtime to secrete oils, giving him natural waterproofing.

Some of the hair strands we have recovered are more than a meter in length. These behemoth proboscideans boasted long, curved tusks, little ears, short tails and grazed on leaves, shrubs and grasses that would have been work to get at as much of the northern hemisphere was covered in ice and snow during his reign. It is often the teeth of mammoths like those you see in the photo here that we see displayed. 

Their molar teeth were large and have always struck me as looking like ink plates from a printing press. If they are allowed to dry out in collection, they fall apart into discreet plates that can be mistaken for mineralized or calcified rock and not the bits and pieces of mammoth molars that they indeed are. Their large surface area was perfect for grinding down the low nutrient, but for the most part, plentiful grasses that sustained them.

Mammoth Tusk, Wrangel Island, Chukotka Okrug, Russia

How did they use their tusks? Likely for displays of strength, protecting their delicate trunks, digging up ground vegetation and in dry riverbeds, digging holes to get at the precious life-giving water. 

It's a genius design, really. A bit like having a plough on the front of your skull. In the photo here you can see a tusk washed clean in a creek bed on Wrangel Island.

Their size offered protection against other predators once the mammoth was full grown. Sadly for the juveniles, they offered tasty prey to big cats like Homotherium who roamed those ancient grasslands alongside them.

They roamed widely in the Pliocene to Holocene, roaming much of Africa, Europe, Asia and North America. We see them first some 150,000 years ago from remains in Russia then expanding out from Spain to Alaska. They enjoyed a very long lifespan of 60-80 — up to 20 years longer than a mastodon and longer than modern elephants. 

They enjoyed the prime position as the Apex predator of the megafauna, then declined — partially because of the environment and food resources and partially because of their co-existence with humans. In places where the fossil record shows a preference for hunting smaller prey, humans and megafauna do better together. We see this in places like the Indian Subcontinent where primates and rodents made the menu more often than the large megafauna who roamed there. We also see this in present-day Africa, where the last of the large and lovely megafauna show remarkable resilience in the face of human co-existence.  

The woolly mammoths from the Ukrainian-Russian plains died out 15,000 years ago. This population was followed by woolly mammoths from St. Paul Island in Alaska who died out 5,600 years ago — and quite surprisingly, at least to me, the last mammoth died just 4,000 years ago in the frosty ice on the small island of Wrangel in the Arctic Ocean — their final days spent scratching out a dwindling existence of genetic mutations, howling winds, rain-darkened hills and subsistence on tough grasses grown in thin soil. 

Further reading: Laura Arppe, Juha A. Karhu, Sergey Vartanyan, Dorothée G. Drucker, Heli Etu-Sihvola, Hervé Bocherens. Thriving or surviving? The isotopic record of the Wrangel Island woolly mammoth population. Quaternary Science Reviews, 2019; 222: 105884 DOI: 10.1016/j.quascirev.2019.105884

COELACANTHS: LIVING FOSSILS

Coelacanths are members of a now-rare order of fish, the Coelacanthiformes, that includes two extant species in the genus Latimeria: the West Indian Ocean coelacanth — Latimeria chalumnae — primarily found near the Comoro Islands off the east coast of Africa and the Indonesian coelacanth — Latimeria menadoensis. 

The name originates from the Permian genus Coelacanthus, which means hollow spine and was published by Swiss-born American biologist and geologist Jean Louis Rodolphe Agassiz in 1839. 

The type species Coelacanthus granulatus was described from the Late Permian, Wuchiapingian of Kupferschiefer of Germany and England. Coelacanthus is primarily known from Late Permian and Early Triassic deposits in Europe and Canada, although the referred species C. welleri, known from Iowa, is of Late Devonian, Famennian age. They survived the Permian–Triassic extinction event, and one species, C. banffensis, is known from the Early Triassic.

Coelacanths belong to the subclass Actinistia, a group of lobed-finned fish related to lungfish and certain extinct Devonian fish such as osteolepiforms, porolepiforms, rhizodonts, and Panderichthys. The oldest known coelacanth fossils are over 410 million years old. Coelacanths were thought to have become extinct in the Late Cretaceous, around 66 million years ago, but were rediscovered in 1938 off the coast of South Africa.

Coelacanths follow the oldest-known living lineage of Sarcopterygii, lobe-finned fish and tetrapods, which makes them are more closely related to lungfish and tetrapods — which includes amphibians, reptiles, birds and mammals — than to ray-finned fish. They are found along the coastline of Indonesia and in the Indian Ocean. The West Indian Ocean coelacanth is a critically endangered species.

The coelacanth was long considered a living fossil because scientists thought it was the sole remaining member of a taxon otherwise known only from fossils, with no close relations alive, and that it evolved into roughly its current form approximately 400 million years ago. Several more recent studies have shown that coelacanth body shapes are much more diverse than previously thought.

CHELICERATA: EURYPTERIDS, SPIDERS AND HORSESHOE CRABS

Sanctacaris uncata

This lovely is Sanctacaris uncata — a wonderful example of Chelicerata.

We first see them emerge in our ancient oceans in the Middle Cambrian, some 508 million years ago, as the arthropod Sanctacaris uncata (Briggs & Collins, 1988) known from the Glossopleura Zone, Stephen Formation of Mount Stephen in the Burgess Shale, British Columbia, Canada. 

Sanctacaris is proof positive that chelicerates, although rare, were present in the Middle Cambrian sea. Even at this early stage of evolution, Sanctacaris had the number and type of head appendages found in modified form in the eurypterids and xiphosurids, the major Palaeozoic groups that succeeded it. Even more interesting is that Sanctacaris had all the characteristics of later chelicerates except chelicerae — placing this early arthropod in a primitive sister group of all other chelicerates.

An extinct marine creature half a billion years old may sound otherworldly, but you know some of their more well-known marine brethren — sea spiders, the sexy eurypterids, chasmataspidids and horseshoe crabs — and some of their terrestrial cousins — spiders, scorpions, harvestmen, mites and ticks. 

They are grouped together because, like all arthropods, they have a segmented body and segmented limbs and a thick chitinous cuticle called an exoskeleton. Add those characteristics to a body system with two body segments — a cephalothorax and an abdomen. 

Like all arthropods, chelicerates' bodies and appendages are covered with a tough cuticle made mainly of chitin and chemically hardened proteins. 

Since this cannot stretch, the animals must moult to grow. In other words, they grow new but still soft cuticles, then cast off the old one and wait for the new one to harden. 

Until the new cuticle hardens the animals are defenceless and almost immobilized.  This also helps to explain why you find so many cephalons or moulted head shields — or whatever else our good arthropod friends shed and regrow — in the field and far fewer body fossils of the whole animal.

Some chelicerate are predatory animals that patrol the warm waters near thermal vents. They can be found feeding upon other predators and fish. Although the group were originally solely predatory, they have diversified to use all sorts of feeding strategies: predation, parasitism, herbivory, scavenging and dining on bits of decaying organic matter. 

Although harvestmen can digest solid food it is more akin to a mashed pulp by the time they do. The guts of most modern chelicerates are too narrow to digest solid food, instead, they generally liquidize their chosen meal by grinding it with their chelicerae and pedipalps then flooding it with digestive enzymes. 

To conserve water, air-breathing chelicerates excrete waste as solids that are removed from their blood by Malpighian tubules, structures that also evolved independently in insects — another case of convergent evolution.

The evolutionary origins of chelicerates from the early arthropods have been debated for decades. And although there is considerable agreement about the relationships between most chelicerate sub-groups, the inclusion of the Pycnogonida in this taxon has recently been questioned and the exact position of scorpions is still controversial, though they were long considered the most primitive or basal of the arachnids. 

We still have much to explore to sort out their evolutionary origins and placement within the various lineages but we will get there with time.

Image One: Reconstruction of Sanctacaris uncata, a Cambrian Habeliidan arthropod (stem-Chelicerata: Habeliida). by Junnn11 @ni075; Image Two: Chelicerata by Fossil Huntress

Aria C, Caron JB (December 2017). "Mandibulate convergence in an armoured Cambrian stem chelicerate". BMC Evolutionary Biology. 17 (1): 261. doi:10.1186/s12862-017-1088-7. PMC 5738823. PMID 29262772.

Legg DA (December 2014). "Sanctacaris uncata: the oldest chelicerate (Arthropoda)". Die Naturwissenschaften. 101 (12): 1065–73. doi:10.1007/s00114-014-1245-4. PMID 25296691.

Briggs DE, Collins D (August 1988). "A Middle Cambrian chelicerate from Mount Stephen, British Columbia" (PDF). Palaeontology. 31 (3): 779–798. Archived from the original (PDF) on July 16, 2011. Retrieved April 4, 2010.

Briggs DE, Erwin DH, Collier FJ (1995). Fossils of the Burgess Shale. Washington: Smithsonian Institution Press. ISBN 1-56098-659-X. OCLC 231793738.