CETACEANS OF WASHINGTON STATE

Fossil Whale Bone

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

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 showing his baleen

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.

UNLIKELY RHINOCEROS

The Miocene pillow basalts from the Lake Roosevelt National Recreation Area of central Washington hold an unlikely fossil mould of a small rhinoceros, preserved by sheer chance as it's bloated carcass sunk to the bottom of a shallow lake just prior to a volcanic explosion.

We've known about this gem for a long while now. The fossil was discovered by hikers back in 1935 and later cast by the University of California paleontologists in 1948. These were the Dirty Thirties and those living in Washington state were experiencing the Great Depression along with the rest of the country and the world. Franklin D. Roosevelt was President of the United States, navigating the States away from laissez-faire economics. Charmingly, Roosevelt would have his good name honoured by this same park in April of 1946, a few years before researchers at Berkeley would rekindle interest in the site.

Both hiking and fossil collecting was a fine answer to these hard economic times and came with all the delights of discovery with no cost for natural entertainment. And so it was that two fossil enthusiast couples were out looking for petrified wood just south of Dry Falls on Blue Lake in Washington State. While searching the pillow basalt, the Frieles and Peabodys came across a large hole high up in a cave that had the distinctive shape of an upside-down rhinoceros.

This fossil is interesting in all sorts of ways. First, we so rarely see fossils in igneous rocks. As you might suspect, both magma and lava are very hot. Magma, or molten rock, glows a bright red/orange as it simmers at a toasty 700 °C to 1300 °C (or 1300 °F to 2400 °F) in hot chambers beneath the Earth's surface.

During the late Miocene and early Pliocene, repeated basaltic lava floods engulfed about 63,000 square miles of the Pacific Northwest over a period of ten to fifteen million years. After these repeated bathings the residual lava accumulated to more than 6,000 feet.

As the magma pushes up to the surface becoming lava, it cools to a nice deep black. In the case of our rhino friend, this is how this unlikely fellow became a fossil. Instead of vaporizing his remains, the lava cooled relatively quickly preserving his outline as a trace fossil and remarkably, a few of his teeth, jaw and bones. The lava was eventually buried then waters from the Spokane Floods eroded enough of the overburden to reveal the remains once more.

Diceratherium tridactylum (Marsh, 1875)

Diceratherium (Marsh, 1875) is known from over a hundred paleontological occurrences from eighty-seven collections.

While there are likely many more, we've found fossil remains of Diceratherium, an extinct genus of rhinoceros, in the Miocene of Canada in Saskatchewan, China, France, Portugal, Switzerland, and multiple sites in the United States.

He's also been found in the Oligocene of Canada in Saskatchewan, and twenty-five localities in the US, specifically in Arizona, Colorado, Florida, Nebraska, North Dakota, Oregon,  South Dakota, Washington and Wyoming. We know a bit about him. He roamed a much warmer, wetter Washington state some 15 million years ago. By then, the Cascades had arrived and we'd yet to see the volcanic eruptions that would entomb whole forests up near Vantage in the Takama Canyon of Washington state. Diceratherium was a scansorial insectivore with two horns and a fair bit of girth. He was a chunky fellow, weighing in at about one tonne (or 2,200 lbs).

You are welcome to go see his final resting site beside the lake but it is difficult to reach and comes with its own risks. Head to the north end of Blue Lake in Washington. Take a boat and search for openings in the cliff face. You'll know you're in the right place if you see a white "R" a couple hundred feed up inside the cliff. Inside the cave, look for a cache left by those who've explored here before you. Once you find the cache, look straight up. That hole above you is the outline of the rhino.

If you don't relish the thought of basalt caving, you can visit a cast of the rhino at the Burke Museum in Seattle, Washington. They have a great museum and are pretty sporting as they've built the cast hardy enough to let folk climb inside. The Burke Museum recently underwent a rather massive facelift and has re-opened its doors to the public. You can now explore their collections in the New Burke, a 113,000 sq.ft. building at 4300 15th Ave NE, Seattle, WA 98105, United States. Or visit them virtually, at https://www.burkemuseum.org/

Photo: Robert Bruce Horsfall - https://archive.org/details/ahistorylandmam00scotgoog, Public Domain, https://commons.wikimedia.org/w/index.php?curid=12805514

Reference: Prothero, Donald R. (2005). The Evolution of North American Rhinoceroses. Cambridge University Press. p. 228. ISBN 9780521832403.

Reference: O. C. Marsh. 1875. Notice of new Tertiary mammals, IV. American Journal of Science 9(51):239-250

FOSSIL FAUNAS OF THE PACIFIC NORTHWEST

Some water-worn samples of the fossil bivalve Vertipecten fucanus from Lower Miocene deposits in the Clallam Formation.

These were collected on the foreshore near Clallam Bay, Olympic Peninsula, northwestern Washington. Range zones of pectinid bivalves provide a principal means of age determination and correlation of shallow-water, inshore facies for Washington state. Until Addicott's study from 1976, the area was considered middle Miocene. The new Lower Miocene designation can be credited in large part to the restricted stratigraphic range of Vertipecten fucanus (Dall) and the restricted and overlapping ranges of several other fossil mollusks collected from Alaska to California.

Neogene marine sediments of the West Coast of North America were deposited in a series of widely spaced basins that extended geographically from the western and northern Gulf of Alaska (60°N) to southern California (33°N). Rich molluscan faunas occur extensively throughout these deposits and form the basis for biostratigraphic schemes that are useful for correlating within and between individual basins.

Early biostratigraphic work was concerned with faunas from particular horizons and with the stratigraphic range of diverse taxa, such as Pecten and Turritella, without reference to other fossil groups. Succeeding work increasingly dealt with the relationships of molluscan zones to benthic and, later, planktonic foraminiferal stages. In recent years the age limits of Neogene molluscan stages have become better documented by reference to planktonic microfossils from dated DSDP cores and onshore faunas.

Neogene molluscan faunas from California, the Pacific Northwest states (Oregon and Washington), and southern Alaska have been treated separately due to differences in faunal composition and geographic isolation. As a result, a different biostratigraphic sequence has been described for each region.

Pacific Northwest stages have been formally named and defined, and their names are also used informally for Alaskan faunas. California Neogene stages were proposed early in this century, are in need of redescription, and their usage is informal. Precise correlations between the three regional sequences have not yet been achieved, due to the low number of co-occurring species and the general lack of planktonic microfossils in these largely shallow-water faunas. The objectives of ongoing research include the documentation of the faunas of California and Pacific Northwest stages; formal description of California stages; an improved correlation between regional stage sequences; refinement of age estimates for stage boundaries; and, the establishment of Neogene stages for Alaskan faunas.

PANOPEA ABRUPTA OF CLALLAM

This lovely large fossil bivalve is Panopea abrupta (Conrad) an extinct species of marine mollusc in the family Hiatellidae, subclass Heterodonta.

This specimen was collected from lower Miocene deposits in the Clallam Formation on the foreshore bordering the Strait of Juan de Fuca near Clallam Bay, Olympic Peninsula, northwestern Washington.

Clallam Bay is a sleepy little town on the northwestern edge of the Olympic Peninsula. It was founded back in the 1880s as a steamboat stop and later served as a Mill town. If you are planning to visit the fossil exposures, head to the edge of town where it meets the sea.

Once at the water's edge, head east along the shore until you can go no further. You'll find marine fossils in the sandstone on the shore and cliffs. Mind the tide as access to the fossil site is only possible at low or mid-tide. You'll have to swim for it if you time it poorly. Clallam Bay: 48°15′17″N 124°15′30″W. Near this site, there are many additional fossil localities to explore. In Sequim Bay, you can find Pleistocene vertebrates as well as Miocene cetacean bones near Slip Point. Near the Twin Post Office, you can find Oligocene nautiloids and bivalves (2.5km west in the bluff); You can find crabs including, Branchioplax in the Eocene limestone concretions from Neah Bay.

References: Addicott, Warren. Molluscan paleontology of the lower Miocene Clallam Formation, northwestern Washington, Geological Survey Paper 976.

EXPLORING THE OLYMPIC PENINSULA

One of the most beautiful in the Pacific Northwest is the Olympic Peninsula from Port Angeles to Neah Bay.

This stretch of coastline is home to the Clallam Formation, a thick, mainly marine sequence of sandstones and siltstones that line the northwestern margin of western Washington. These beachfront exposures offer plentiful fossils for those keen to make the trek.

The beautifully preserved clams, scallops and gastropods found here are mostly shallow-water marine from the late Eocene to Miocene. Time, tide and weather permitting, a site well worth visiting is the south flank of a syncline at Slip Point, near Clallam Bay. Head to the most Northwestern tip of the lower 48, visiting Cape Flattery on the Makah Reservation located 75 miles NW of PA on Hwy 112. Cape Flattery is located approx 7 miles from Neah Bay. The newly constructed wooden walkway takes you to some of the most gorgeous, rugged and wild scenery on the Pacific Coast.

Be sure to take time to explore the internationally known Makah Museum. The museum is open every day during the summer months and closed Mondays and Tuesdays from Sept. 16 through May 31. The hours are 10AM-5PM. The Makah Museum is the nation's sole repository for archaeological discoveries at the Makah Coastal village of Ozette. The centuries-old village was located 15 miles south of present-day Neah Bay. Ozette served the Makah people as a year-around home well into the 20th century.

In 1970, tidal erosion exposed a group of 500-year-old Ozette homes that have been perfectly preserved in an ancient mudslide. The thousands of artifacts subsequently discovered have helped recreate Makahs' rich and exciting history as whalers, fishermen, hunters, gatherers, craftspeople, basket weavers, and warriors. Lake Ozette is located off of Hwy 112 on the Hoko-Ozette Road and follows the road 21 miles to the Ozette Ranger Station.

Three miles of planked trail leads you to Sand Point, one of the most beautiful and primitive beaches on the coast. Continuing north along the beach you will find dozens of Indian petroglyphs at Wedding Rocks, ask for the interpretive handout at the ranger station. The northern point of this 9-mile triangular trail is Cape Alava, with a rocky shore and reefs to explore at low tide. Cape Alava is also the site of an ancient Makah village. The site is now closed and marked with a small sign. Be sure to check a tide table and carry the 10 essentials - and lots of film as seals, deer, eagles and perhaps osprey, otters and whales may be there, rain or shine! Hike north to Cape Alava along the beach to keep the ocean breeze at your back, and avoid Vibram-soled shoes as the cedar plank walkway can be slick!

Salt Creek County Park located on the Strait of Juan de Fuca west of Port Angeles offers fascinating tidal pools, (ask your hosts regarding tide tables). The Dungeness Spit and Wildlife Refuge offers great beach hiking and wildlife. The Olympic Game Farm in Sequim is great for children of all ages. Ediz Hook in Port Angeles provides great views of the Olympic and Cascade mountains. Ediz Hook is part of the 5.5 miles of Waterfront Trail; perfect for jogging, walking, biking, or rollerblading.
The Elwha Valley west of Port Angeles is a beautiful drive along the rushing Elwha River. Madison Falls is an easy hike. Further up the valley beyond Lake Mills is the trailhead to the Olympic Hot Springs.

Port Townsend, known as "Washington's Victorian Seaport" is less than an hour east of Sequim. Victorian homes and commercial buildings erected during the late 1800s are still the city's trademark, along with Fort Worden State Park.

Park fee: A pass is required to enter the Olympic National Park. The fee is $10.00 per carload and is good for 7 days. It can be attained at any of the Park entrances. No pass is required during the winter months for the Elwha Valley or the Sol Duc Valley. Phone # for Olympic National Park Visitors Center in Port Angeles is 360-452-2713.

Getting here…

Directions: From Vancouver, it is a 5-6 hour drive to the Olympic Peninsula. Head South on Oak or Knight to connect up with Hwy 99 to the US border and continue South on Hwy 5, past Bellingham, take Hwy 20 to Anacortes.Head South on Hwy 20 until you get to the Keystone Jetty. Take the ferry from Keystone to Port Townsend. From Port Townsend take Hwy 20 until it connects with Hwy 101. Turn right onto Hwy 101 and head West.

You will pass through Port Angeles. This is an excellent place for you to top up your food stores and fill up with gas. Just after Port Angeles, look for a sign for Hwy 112 (towards Joyce, Neah Bay & Seiqu). Turn right and head West. It is about another 30 km from Port Angeles to Whiskey Creek. From the turn-off, it is about 10 miles to Joyce.

This little town has restaurants and gas stations. From Joyce, it is another 3 miles to the campsite at Whiskey Creek where Joe or Ronee can help direct you to your cabin or campsite.

UPTHRUSTING PLATES: WASHINGTON GEOLOGY

Two hundred million years ago, Washington was two large islands, bits of the continent on the move westward, eventually bumping up against the North American continent and calling it home. The shifting continues, subtly changing the landscape like a breath. We only notice when pockets of resistance manifest as earthquakes, some newsworthy, some all but unnoticed. For now, the more extreme movement has subsided laterally and continues vertically, pushing California towards the North Pole. Hello Baja-BC.

The upthrusting of plates move our mountain ranges skyward – the path of least resistance. And it is this dynamic movement that's created the landscape we see today.

The 3,000 meters of the stratigraphic section of the Chuckanut Formation along Chuckanut Drive span an age range of just a few million years. The lower part is late Paleocene with a radiometric age of around 56 million years. The upper part of the section is early Eocene. The fossils found here lived and died very close to where they are now but in a much warmer, wetter, swampy setting. The exposures of the Chuckanut Formation were once part of a vast river delta; imagine, if you will, the bayou country of the Lower Mississippi. The siltstones, sandstones, mudstones and conglomerates of this formation were laid down during a time of luxuriant plant growth in the subtropical flood plain that covered much of the Pacific Northwest.

This ancient wetland provided ideal conditions to preserve the many trees, shrubs and plants that thrived here giving us a lot of information about climate, temperature, the water cycle and humidity of the region. The Chuckanut flora is made up predominantly of plants whose modern relatives live in tropical areas such as Mexico and Central America. While less abundant, evidence of the animals that called this ancient swamp home are also found here. Rare bird, reptile, and mammal tracks have been immortalized in the outcrops of the Chuckanut Formation.

Sumas Eocene Shorebird Trackway

Tracks of a type of archaic mammal of the Orders Pantodonta or Dinocerata (blunt foot herbivores), footprints from a small shorebird, and tracks from an early equid or webbed bird track give evidence to the vertebrates that inhabited the swamps, lakes and riverways of the Pacific Northwest 50 million years ago.

Fossil mammals and bird trackways from Washington State have caused great excitement over the past few years. Many new trackways have been discovered since the 2009 slides near Sumas. George Mustoe and team collected these important finds, bringing them to the Burke Museum in Washington State to study and make available for display.

The movement of these vertebrates was captured in the soft mud on the banks of an ancient river, one of the only depositional environments favourable for track preservation. The terrestrial paleontological record of Washington State at sites like Chuckanut and Racehorse Creek (U-Pb 53 Ma.) is primarily made up of plant material with some wonderfully enticing mammal, shorebird (seen here) and large Diatryma bird tracks on rare occasions.

BREWERICERAS OF HAIDA GWAII

Brewericeras hulenense (Anderson 1938) a fast-moving, nektonic (no idle floating here!) carnivorous ammonite from the Lower Cretaceous (Albian) of Haida Gwaii (Queen Charlotte Islands), British Columbia, Canada.

This specimen is just over 12cm in length, a little under the average of 13.4cm. There are several localities in the islands of Haida Gwaii where Brewericeras can be found (six that I know of and likely plenty more!)

Brewericeras can also be found in Albian deposits in Svedenborgfjellet, Ulladalen, Norway (Cretaceous of Svalbard and Jan Mayen - så fin!) (77.7° N, 15.2° E: paleo-coordinates 66.6° N, 13.6° E) and Matanuska-Susitna County, Alaska, 62.0° N, 147.7° W: paleo-coordinates 57.3° N, 85.6° W (112.6 to 109.0 Ma.)

JURASSIC COAST BEAUTIES

Charmouth Nodule; Photo and prep: Lizzie Hingley

The talented Lizzie Hingley of Stonebarrow Fossils found this beautiful chock-a-block nodule on Charmouth beach last year.

The nodule contains a couple of Caenisites turneri, along with some Promicroceras and Cymbites ammonites, but there was also a wee surprise just outside the nodule proper. Look closely and you'll see a very well preserved fish!

When she began to prep this nodule, Lizzie had no idea there was going to be a lovely little fish associated with it. Luckily, she caught a glimpse of it when her pen was just millimetres away. The fish is incredibly fragile but looks complete. I'm not sure which species this little fellow is but he shows nice detail in his preservation. A little over fifty fossil fish species are known from the area, including some early teleost fish— a group that includes over 23,000 living species.

The coast and the cliffs around Charmouth and Lyme Regis are famous for their fossils around the world. These are the same beaches that the famous Mary Anning explored as a youngster years ago and Lizzie and many of the locals walk today, all hunting for fabulous Jurassic finds. The most common fossils along the Jurassic coastline in this area are ammonites and belemnites.

Ammonites were predatory, squid-like creatures that lived inside coil-shaped shells. Like other cephalopods, ammonites had sharp, beaklike jaws inside a ring of tentacles that extended from their shells to snare prey such as small fish and crustaceans. We see and collect their beautiful coiled shells but often forget the squid-like fellow who was living inside.

Some ammonites grew more than three feet (one meter) across — tasty snacks for the giant marine reptiles of the day. Most, though not all, ammonites have coiled shells. The chambered part of the shell is called a phragmocone.  It contains a series of progressively layered chambers called camerae, which were divided by thin walls called septae. The last chamber is the body chamber. As the ammonite grew, it added new and larger chambers to the opened end of the shell. A thin living tube called a siphuncle passed through the septa, extending from the body to the empty shell chambers.

Fish detail, Photo: Lizzie Hingley

Beautiful ammonites can be found along the coast at Charmouth and Lyme Regis in southwestern England. Some are in nodules on the beach, brought in as erratics or washed down from the cliffs. Sometimes the tides do all the work and you find the fossils perfectly prepped out, loose in the beach gravels.

Other Jurassic fossils found here include occasional partial or complete marine reptiles — such as Ichthyosaurus and Plesiosaurus. Fossilized fish, as you see here, also pop up on occasion.

As you travel to Charmouth from the east the coastline changes, from the chalk cliffs west of Poole, through the unique rock formations of Lulworth and Durdle Door, to the 28 kilometres (18 miles) and 180 billion pebbles of Chesil Beach and the Fleet Lagoon. The cliffs at West Bay will be particularly familiar to fans of the television series Broadchurch. To the west of Charmouth there is the Lyme Regis ‘ammonite pavement’ on Monmouth beach, with many exposed ammonites in the rocks. And further west you move into the Triassic red cliffs of Devon and the historic pretty coastal villages of Beer and Branscombe.

Photo and fossil preparation: Lizzie Hingley, Stonebarrow Fossils. She has workshops in Dorset and Oxfordshire. Check out more of her work here: https://www.stonebarrowfossils.co.uk/

If you're looking to head to Charmouth, check out the Charmouth Heritage Coast Centre. They also have a well-designed website with the local weather and tide tables.  You can visit it here: https://charmouth.org/chcc/fish/

PLIENSBACHIAN: APODEROCERAS

This stunning specimen with her regal ridges — and small anomaly — is an Apoderoceras ammonite. Apoderoceras are an extinct genus of cephalopod, an active predatory mollusk belonging to the subclass Ammonoidea.

Apoderoceras is, in fact, a wonderful example of sexual dimorphism within ammonites as the macroconch (putative female) shell grew to diameters in excess of 40 cm – many times larger than the diameters of the microconch (putative male) shell. Apoderoceras has been found in the Lower Jurassic of Argentina, Hungary, Italy, Portugal, and most of North-West and central Europe, including as this one is, the United Kingdom. She was found on the beaches of Charmouth in West Dorset, in South West England, then prepped expertly by the lovely and talented Lizzie Hingley.

Neither Apoderoceras nor Bifericeras donovani are strictly index fossils for the Taylori subzone, the index being Phricodoceras taylori. Note that Bifericeras is typical of the earlier Oxynotum Zone, and ‘Bifericeras’ donovani is doubtfully attributable to the genus.

The International Commission on Stratigraphy (ICS) has assigned the First Appearance Datum of genus Apoderocerasas and of Bifericeras donovani the defining biological marker for the start of the Pliensbachian Stage of the Jurassic, 190.8 ± 1.0 million years ago.  As the brilliant Murray Edmunds points out, this lovely large specimen (macroconch) of Apoderoceras is likely a female. Her larger body perfected for egg production.

Cat's Paw Sutures of Apoderoceras. Simon Guscott Photo

Apoderoceras (Family Coeloceratidae) appears out of nowhere in the basal Pliensbachian and dominates the ammonite faunas of NW Europe. It is superficially similar to the earlier Eteoderoceras (Family Eoderoceratidae, of the Raricostatum Zone), but on closer inspection can be seen to be quite different.  It is, therefore, an invader species and its ancestry is somewhat cryptic.

The Pacific ammonite Andicoeloceras, known from Chile, appears quite closely related and may be ancestral, but the time correlation of Pacific and NW European ammonite faunas is challenging. Even if Andicoeloceras is ancestral to Apoderoceras, no other preceding ammonites attributable to Coeloceratidae are known.

Perhaps there are clues in the Pliensbachian of Canada. We shall have to see. Apoderoceras remains present in NW Europe throughout the Taylori Subzone, showing endemic evolution. It becomes progressively more inflated during this interval of time, the adult ribs more distant, and there is evidence that the diameter of the macroconch evolved to become larger. At the end of the Taylori Subzone, Apoderoceras disappeared as suddenly as it appeared in the region, and ammonite faunas of the remaining Jamesoni Zone are dominated by the Platypleuroceras–Uptonia lineage, generally assigned — but erroneously, IMO!— to the Family Polymorphitidae.

In the NW European Taylori Subzone, Apoderoceras is accompanied — as well as by the Eoderoceratid, B. donovani, which is only documented from the Yorkshire coast, although I know of examples from Northern Ireland — by the oxycones Radstockiceras (quite common) and Oxynoticeras (very rare), the late Schlotheimid, Phricoderoceras (uncommon: note P. taylori is a microconch, and P. lamellosum the macroconch), and the Eoderoceratid, Tetraspidoceras (very rare).

Thank you to Murray Edmunds for his advice and insights on Apoderoceras and the ammonite faunas of the Pacific and NW Europe. You are deeply awesome, my friend! Check out Murray’s Research Gate site for more interesting tidbits.

https://www.researchgate.net/profile/Murray_Edmunds; the photo above of the Cat's Paw Sutures of an Apoderoceras from Dorset are from the lovely Simon Guscott. Look at the wee belemnite that has been washed into the body chamber. Appreciate you!

LOWER ALBIAN AMMONITE

Lovely defined sutures on this rather involute, high-whorled ammonite from the middle part of the Lower Albian in the Mahajanga Province, northwestern Madagascar. This specimen of Phylloceras velledae (Michelin) has a shell with a small umbilicus, arched, acute venter, and at some growth stage, falcoid ribs that spring in pairs from umbilical tubercles, disappearing on the outer whorls.

While this large island off the southeast coast of Africa is known more for exotic lemurs, rainforests & beaches, it also boasts some of the world's loveliest fossils.

This specimen is from a quarry near the top of an escarpment, 3 km to the west of the village of Ambatolafia (coordinates: Lat. 16.330 23.600 S, Long. 46.120 10.20 E). Judging from plate tectonic reconstruction (Stampfli & Borel, 2002), the area was located in middle latitudes within the tropical-subtropical climatic zone at palaeo-latitudes of 40E45.S in the late Early Cretaceous of the early Albian.

ARMOURED AGNATHA

This lovely specimen is an armoured agnatha jawless bony fish, Victoraspis longicornualis, from Lower Devonian deposits of Podolia, Ukraine.

Victoraspis longicornualis was named by Anders Carlsson and Henning Bloom back in 2008. The new osteostracan genus and species were described based on material from Rakovets' present-day Ukraine. This new taxon shares characteristics with the two genera Stensiopelta (Denison, 1951) and Zychaspis (Javier, 1985).

Agnatha is a superclass of vertebrates. This fellow looks quite different from our modern Agnatha, which includes lamprey and hagfish. Ironically, hagfish are vertebrates who do not have vertebrae. Sometime in their evolution, they lost them as they adapted to their environment. Photo: Fossilero Fisherman

Ref: Carlsson, A. & Blom, H. Paläont. Z. (2008) 82: 314. https://doi.org/10.1007/BF02988898

SUTURES, RIDGES AND LOBES

Ammonitic Suture Detail

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

Like other cephalopods, ammonites had sharp, beak-like jaws inside a ring of squid-like tentacles that extended from their shells. They used these tentacles to snare prey, — plankton, vegetation, fish and crustaceans — similar to the way a squid or octopus hunt today. Catching a fish with your hands is no easy feat, as I'm sure you know. 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.

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.

Ammonites were prolific breeders that evolved rapidly. If you could cast a fishing line into our ancient seas, it is likely that you would hook an ammonite, not a fish. They were prolific back in the day, living (and sometimes dying) in schools in oceans around the globe.  We find ammonite fossils (and plenty of them) in sedimentary rock from all over the world. In some cases, we find rock beds where we can see evidence of a new species that evolved, lived and died out in such a short time span that we can walk through time, following the course of evolution using ammonites as a window into the past. For this reason, they make excellent index fossils. An index fossil is a species that allows us to link a particular rock formation, layered in time with a particular species or genus found there. Generally, deeper is older, so we use the sedimentary layers rock to match up to specific geologic time periods, rather the way we use tree-rings to date trees.

Ammonites have intricate patterns on their shells called sutures. The different suture patterns 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. If they have lobes and saddles that are fluted, with rounded subdivisions instead of saw-toothed, they are likely Jurassic or Cretaceous.

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

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 a rock formation at a glance.

Their fossil shells are pleasing to the eye, usually taking on a planispiral form— although there are some helically spiralled and fully crazy spiralled forms — known as heteromorphs.

Heteromorphs come in a variety of shapes and sizes. They must have intrigued and mystified those who were first to find them as they do not have an intuitive shape at all for a marine predator.

The beautiful plate you see on the upper left here showing two ammonites is from Sowerby (1837) and is one of the very first scientifically accurate studies of heteromorph ammonites. We see similar species to the heteromorph on the right of the plate in the Nanaimo Group of Vancouver Island, British Columbia.

The beautiful plate to the right shows some of the heteromorph ammonites from Pictet's Paleontology in its second edition (1853-57). Some of the figures are copied from Astier or d'Orbigny works, not included in the first edition.

Ammonite shells have been collected for millennia. During medieval times they were believed to be snakes that had been turned into stone and were sold to people going on pilgrimages. They have been found in archaeological sites in many parts of the world. We find them in archaeological remains spanning human history, across cultures and civilizations.

Ammonites are prized for their scientific and aesthetic value and have been used as building materials, jewellery, amulets, charms to aid in the hunt, religious totems amongst other things. The original discus used by the ancient Greeks in their Olympics was a fossilized ammonite.

A great temple to the god Amon was built at Karnak in Upper Egypt around c. 1785. It is from Amon that we get his cephalopod namesake, the ammonites and also the name origin for the compound ammonia or NH3.

GRAPTOLITES

Graptolites — Graptolita — are colonial animals. The biological affinities of the graptolites have always been debatable. Originally regarded as being related to the hydrozoans, graptolites are now considered to be related to the pterobranchs, a rare group of modern marine animals.

The graptolites are now classed as hemichordates (phylum Hemichordata), a primitive group that probably shares a common ancestry with the vertebrates.

In life, many graptolites appear to have been planktonic, drifting freely on the surface of ancient seas or attached to floating seaweed by means of a slender thread. Some forms of graptolite lived attached to the sea-floor by a root-like base. Graptolite fossils are often found in shales and slates. The deceased planktonic graptolites would sink down to and settle on the seafloor, eventually becoming entombed in the sediment and are thus well preserved.

Graptolite fossils are found flattened along the bedding plane of the rocks in which they occur. They vary in shape, but are most commonly dendritic or branching (such as Dictoyonema), saw-blade like, or "tuning fork" shaped, such as Didymograptus murchisoni.

An excellent resource on graptolites is Old as the Hills. You can find them at:

https://www.asoldasthehills.org/Graptolites.html