Thursday, 31 December 2020

BACK IN THE USSR: BEADANTICERAS

This lovely oil in water coloured ammonite is the beauty Beudanticeras sp. from the Lower Cretaceous (Upper Aptian), Krasnodar region, Northern Caucasus, southern Russia. 

This area of the world has beautiful fossil specimens with their distinct colouring. The geology and paleontological history of the region are fascinating as is its more recent history. 

The territory of present Krasnodar Krai was inhabited as early as the Paleolithic, about 2 million years ago. It was inhabited by various tribes and peoples since ancient times. There were several Greek colonies on the Black Sea coast, which later became part of the Kingdom of the Bosporus. In 631, the Great Bulgaria state was founded in the Kuban. In the 8th-10th centuries, the territory was part of Khazaria.

In 965, the Kievan Prince Svyatoslav defeated the Khazar Khanate and this region came under the power of Kievan Rus, Tmutarakan principality was formed. At the end of the 11th century, in connection with the strengthening of the Polovtsy and claims of Byzantium, Tmutarakan principality came under the authority of the Byzantine emperors (until 1204).

In 1243-1438, this land was part of the Golden Horde. After its collapse, Kuban was divided between the Crimean Khanate, Circassia, and the Ottoman Empire, which dominated in the region. Russia began to challenge the protectorate over the territory during the Russian-Turkish wars.

In 1783, by decree of Catherine II, the right-bank Kuban and Taman Peninsula became part of the Russian Empire after the liquidation of the Crimean Khanate. In 1792-1793, Zaporozhye (Black Sea) Cossacks resettled here to protect new borders of the country along the Kuban River. 

During the military campaign to establish control over the North Caucasus (Caucasian War of 1763-1864), in the 1830s, the Ottoman Empire for forced out of the region and Russia gained access to the Black Sea coast.

Prior to the revolutionary events of 1917, most of the territory of present Krasnodar Krai was occupied by the Kuban region, founded in 1860. In 1900, the population of the region was about 2 million people. In 1913, it ranked 2nd by the gross harvest of grain, 1st place for the production of bread in the Russian Empire.

The Kuban was one of the centres of resistance after the Bolshevik revolution of 1917. In 1918-1920, there was a non-Bolshevik Kuban People’s Republic. In 1924, North-Caucasian krai was founded with the centre in Rostov-on-Don. In 1934, it was divided into Azov-Black Sea krai (Rostov-on-Don) and North Caucasus krai (Stavropol).

September 13, 1937, the Azov-Black Sea region was divided into the Rostov region and Krasnodar Krai that included Adygei autonomous oblast. During the Second World War, the region was captured by the Germans. After the battle for the Caucasus, it was liberated. There are about 1,500 monuments and memorials commemorating heroes of the war on the territory of Krasnodar Krai.

The lovely block you see here is in the collections of the awesome John Fam, Vice-Chair of the Vancouver Paleontological Society in British Columbia, Canada.

Wednesday, 30 December 2020

MIDDLE TRIASSIC PAPER CLAMS & AMMONOIDS

Paper clams or "flat clams" were widespread in the Triassic. They often dominate the rocks in which they are found, as in these specimens from the Daonella dubia zone of the West Humboldt Range and the Desatoya Range of Nevada where they are associated with Ceratities trinodosus, Nevadites Whitney, Daonella lindstomi, D. moussoni and other species.

This designation was coined by J. P. Smith in the early 1900s for specific localities in the Humboldt Mountain Range. Because of their widespread distribution and very high species turnover rates, they make for excellent biochronological macrofossils, helping us to correlate biological events through time.

We see the "cousins" of these Nevada specimens up in  Pine Pass near Chetwynd, British Columbia.

Pine Pass is part of the Pardonet Formation. Just a short hike from the road we were able to easily find the abundant outcroppings of the paper clam Monotis subcircularis, perfectly preserved and cemented in this strata from the Late Triassic.

Monday, 28 December 2020

BACK IN THE USSR: KEPPLERITES

This glorious chocolate block contains the creamy grey ammonite Kepplerites gowerianus (Sowerby 1827) with a few invertebrate friends, including two brachiopods: Ivanoviella sp., Zeilleria sp. and the deep brown gastropod Bathrotomaria sp. There is also a wee bit of petrified wood on the backside.

These beauties hail from Jurassic, Lower Callovian outcrops in the Quarry of Kursk Magnetic Anomaly (51.25361,37.66944), Kursk region, Russia. Diameter ammonite 70мм. 

Back in the USSR — in the mid-1980s — during the expansion and development of one of the quarries, an unusual geological formation was found. This area had been part of the seafloor around an ancient island surrounded by Jurassic Seas. 

The outcrops of this geological formation turned out to be very rich in marine fossils. This ammonite block was found there years ago by the deeply awesome Emil Black. Sadly, he has not been able to collect there for some time. In more recent years, the site has been closed to fossil collecting and is in use solely for the processing and extraction of iron ore deposits.

Sunday, 27 December 2020

MEGALODON: APEX PREDATOR OF THE DEEP

Otodos megalodon with Cam Muskelly in scuba for scale
23-million-years ago to just over 3-million-years ago, the apex predator of the seas was the hulking cousin to today's Great White Shark. Otodus megalodon was the largest shark ever to grace our oceans and the largest fish as well. 

This big boy swam in at a whopping fifty-tonnes and grew to 18 metres or 60 feet in length — twice the size of an ankylosaur or triceratops and larger than a Tyrannosaurs rex but a wee bit smaller than a brontosaurus. 

From our modern oceans and their modern cousins, that is a full three times larger Deep Blue, the 2.5 tonne, 6-metre long shark found off Oahu's south shore in 2019. Deep Blue weighed the equivalent of two Stonehenge Sarsen stones or half a house. Picture your house, now add another half and that is the size of Otodus megalodon. It truly puts their size in perspective. 

We often estimate the size of animals and what they ate by the size and shape of their teeth. Megalodon had large serrated teeth up to 18 centimetres long — perfect for dining on dolphins and humpback whales — and they had loads of them. Their mouths were lined with up to 276 teeth and these packed a punch with one of the most powerful bites on record. We have a rather paltry bite force of around 1,317 Newtons (N) when we chomp down with gusto. 

In 2012, we learned that the most powerful bite recorded from a living animal belongs to the saltwater crocodile. Gregory Erickson of Florida State University in Tallahassee compared 23 crocodilian species and discovered that the largest saltwater crocodiles can bite with an impressive 16,414N. That is more than 3.5 times the crushing force of the previous record-holder, the spotted hyena. Still, our aquatic friends beat that, if only slightly. A great white shark does indeed have a mightier bite than a crocodile.

We have known the estimated bite force of a great white a while longer. In 2008, Stephen Wroe of the University of New England in Australia and his colleagues used computer simulations to estimate the chomping pressure of a great white. Not surprisingly, great white sharks chomp in at an impressive 18,216N — greater than a saltwater crocodile but a full ten times less than Otodus

But all those bites pale in comparison to Otodus megalodon — this beastie takes the cake — or the whale — with a bite force of 182,201N.  

It is amazing to think of something as large and majestic as a whale being on any creatures menu but feast they did. Megalodon could open their toothy jaws 3.4 metres wide — that is wide enough to make a meal of a whale or swallow you and a friend whole. 

I added a brave and deeply awesome human, Cam Muskelly, award-winning Avocational Paleontologist & Geologist in Georgia, USA, Science Writer, Fossil Hunter, ASD in the image above to give you a sense of scale. Cam is five feet, five inches tall or 1.65 metres tall. Our dear Otodus megalodon is more than ten times longer. Now, Cam is a brave man and reached his hand out as an act of solidarity, but fortunately for him, there is 20-million-years separating his hand and those chompers.

Otodus megalodon was a bit blunt-nosed in comparison to a great white. They hail from a different lineage that broke off deeper in their hereditary history around 55-million-years ago. We now know that Otodus megalodon was the last of their lineage and the great grandbaby of Otodus obliquus and possibly Cretalamina appendiculata, who cruised our ancient seas 105 million years ago.           

We sometimes see Otodus megalodon referred to as Carcharodon or Carcharocles megalodon, particularly in the labels from older fossil collections but those names have fallen out of favour. 

If you would like to check out a talk by the award-winning Cam Muskelly, visit: https://youtu.be/I-pXdzeLAMI

Cameron Muskelly is an award-winning avocational palaeontologist from Georgia who is a fantastic science communicator. Join him for a fun, short chat about two important Permian fossils from his personal collection, which he uses for education and outreach across his home state. He shared this talk as part of the Discovery Day: National Fossil Day for the KU Natural History Museum.

Cam Muskelly Paleo 101 YouTube: https://www.youtube.com/channel/UCq-68CrGM398gd3NFXfX87w

Cam Muskelly on Twitter: @PaleoCameron. He's a good man that Cam. You should follow him. I do and love his posts!

Scuba vs Shark Image: Fossil Huntress. Scuba Model: Cam Muskelly, Georgia, USA 


Saturday, 26 December 2020

AMMONITE OF THE RHÔNE

An exquisite specimen of the delicately ridged ammonite, Porpoceras verticosum, from Middle Toarcian outcrops adjacent the Rhône in southeastern France.

Porpoceras (Buchman, 1911) is a genus of ammonite that lived during the early and middle Toarcian stage of the Early Jurassic. We see members of this genus from the uppermost part of Serpentinum Zone to Variabilis Subzone. These beauties are found in Europe, Asia, North America and South America.

Ammonites belonging to this genus have evolute shells, with compressed to depressed whorl section. Flanks were slightly convex and venter has been low. The whorl section is sub-rectangular. 

The rib is pronounced and somewhat fibulate on the inner whorls — just wee nodes here — and tuberculate to spined on the ventrolateral shoulder. It differs from Peronoceras by not having a compressed whorl section and regular nodes or fibulation. Catacoeloceras is also similar, but it has regular ventrolateral tubercules and is missing the classic nodes or fibulation of his cousins.

This specimen hails from southern France near the Rhône, one of the major rivers of Europe. It has twice the average water level of the Loire and is fed by the Rhône Glacier in the Swiss Alps at the far eastern end of the Swiss canton of Valais then passes through Lake Geneva before running through southeastern France. This 10 cm specimen was prepared by the supremely talented José Juárez Ruiz

Friday, 25 December 2020

GOD JUL / MERRY HO HO

God Jul & the Very Best of the Holiday Season to You & Yours. 

However you celebrate, sending you love and light for a wonderful holiday season with family and friends. Merry Ho Ho. Joyeux Noël. Chag Urim Sameach. Seku Kulu. Vrolijk Kerstfeest. Prettige Kerst. Wesołych Świąt. Nadelik Lowen. Glædelig Jul. Hyvää joulua. Bon Natale. Feliz Natal. Frohe Weihnachten. Mele Kalikimaka. Gleðileg jól. Christmas MobArak. Buon Natale. Meri Kuri. Felicem Diem Nativitatis.  Среќен Божик. Quvianagli Anaiyyuniqpaliqsi. Gledelig Jul. Maligayang Pasko. Crăciun Fericit. Blithe Yule. Veselé Vianoce. Hanukkah Sameach. Nollaig Chridheil. Счастливого рождества. Cualli netlācatilizpan. חג מולד שמח. Nollaig Shona Dhuit. Śubh krisamas (शुभ क्रिसमस). Prabhu Ka Naya Din Aapko Mubarak Ho. And Ho Ho Ho!

Thursday, 24 December 2020

ALCIDS AUKS

Puffins are any of three small species of alcids or auks in the bird genus Fratercula with a brightly coloured beak during the breeding season.

Their sexy orange beaks shift from a dull grey to bright orange when it is time to attract a mate. While not strictly monogamous, most Puffins choose the same mate year upon year producing adorable chicks or pufflings (awe) from their mating efforts.

Female Puffins produce one single white egg which the parents take turns to incubate over a course of about six weeks. Their dutiful parents share the honour of feeding the wee pufflings five to eight times a day until the chick is ready to fly. Towards the end of July, the fledgeling Puffins begin to venture from the safety of their parents and dry land. Once they take to the seas, mom and dad are released from duty and the newest members of the colony are left to hunt and survive on their own.

These are pelagic seabirds that feed primarily by diving in the water. They breed in large colonies on coastal cliffs or offshore islands, nesting in crevices among rocks or in burrows in the soil. Two species, the tufted puffin and horned puffin are found in the North Pacific Ocean, while the Atlantic puffin is found in the North Atlantic Ocean. This lovely fellow, with his distinctive colouring, is an Atlantic Puffin or "Sea Parrot" from Skomer Island near Pembrokeshire in the southwest of Wales. Wales is bordered by Camarthenshire to the east and Ceredigion to the northeast with the sea bordering everything else. It is a fine place to do some birding if it's seabirds you're after.

These Atlantic Puffins are one of the most famous of all the seabirds and form the largest colony in Southern Britain. They live about 25 years making a living in our cold seas dining on herring, hake and sand eels. Some have been known to live to almost 40 years of age. They are good little swimmers as you might expect, but surprisingly they are great flyers, too! They are hindered by short wings, which makes flight challenging but still possible with effort. Once they get some speed on board, they can fly up to 88 km an hour.

The oldest alcid fossil is Hydrotherikornis from Oregon dating to the Late Eocene while fossils of Aethia and Uria go back to the Late Miocene. Molecular clocks have been used to suggest an origin in the Pacific in the Paleocene. Fossils from North Carolina were originally thought to have been of two Fratercula species but were later reassigned to one Fratercula, the tufted puffin, and a Cerorhinca species. Another extinct species, Dow's puffin, Fratercula dowi,  was found on the Channel Islands of California until the Late Pleistocene or early Holocene.

The Fraterculini are thought to have originated in the Pacific primarily because of their greater diversity in the region. There is only one extant species in the Atlantic, compared to two in the Pacific. The Fraterculini fossil record in the Pacific extends at least as far back as the middle Miocene, with three fossil species of Cerorhinca, and material tentatively referred to that genus, in the middle Miocene to late Pliocene of southern California and northern Mexico.

Although there no records from the Miocene in the Atlantic, a re-examination of the North Carolina material indicated that the diversity of puffins in the early Pliocene was as great in the Atlantic as it is in the Pacific today. This diversity was achieved through influxes of puffins from the Pacific; the later loss of species was due to major oceanographic changes in the late Pliocene due to closure of the Panamanian Seaway and the onset of severe glacial cycles in the North Atlantic.

Wednesday, 23 December 2020

KAZAKHSTAN ANAHOPLITES

This tasty block of Semenovites (Anahoplites) cf. michalskii ammonites hails from Cretaceous, Albian deposits that outcrop on the Tupqaraghan — Mangyshlak Peninsula on the eastern coast of the Caspian Sea, Kazakhstan. 

Present-day Kazakhstan is made up of several micro continental blocks that were broken up in the Cambrian and then crushed back together then smashed up against Siberia and came to rest where we find them today. 

Mangyshlak or Mangghyshlaq Peninsula is a large peninsula located in western Kazakhstan. It borders on the Caspian Sea in the west and with the Buzachi Peninsula, a marshy sub-feature of the main peninsula, in the northeast. The Tyuleniy Archipelago lies off the northern shores of the peninsula.

Lowlands make up one-third of Kazakhstan’s huge expanse, hilly plateaus and plains account for nearly half, and low mountainous regions about one-fifth. Kazakhstan’s highest point, Mount Khan-Tengri (Han-t’eng-ko-li Peak) at 22,949 feet (6,995 metres), in the Tien Shan range on the border between Kazakhstan, Kyrgyzstan, and China, contrasts with the flat or rolling terrain of most of the republic. 

The western and southwestern parts of Kazakhstan are dominated by the low-lying Caspian Depression, which at its lowest point lies some 95 feet below sea level. South of the Caspian Depression are the Ustyurt Plateau and the Tupqaraghan (formerly Mangyshlak) Peninsula jutting into the Caspian Sea. 

Vast amounts of sand formed the Greater Barsuki and Aral Karakum deserts near the Aral Sea, the broad Betpaqdala Desert of the interior, and the Muyunkum and Kyzylkum deserts in the south. Most of these desert regions have slight vegetative cover eeking out a slim existence fed by subterranean groundwater.

Depressions filled by salt lakes — whose water has largely evaporated — dot the undulating uplands of central Kazakhstan. 

In the north, the mountains reach about 5,000 feet, and there are similar high areas among the Ulutau Mountains in the west and the Chingiz-Tau Range in the east. In the east and southeast, massifs — enormous blocks of crystalline rock — are furrowed by valleys. 

The Altai mountain complex to the east sends three ridges into the republic, and, farther south, the Tarbagatay Range is an offshoot of the Naryn-Kolbin complex. Another range, the Dzungarian Alatau, penetrates the country to the south of the depression containing the icy waters of Lake Balkhash. The beautiful Tien Shan peaks rise along the southern frontier with Kyrgyzstan. 

As well as lovely ammonite outcrops, dinosaurian material and pterosaur remains are also found in Kazakhstan. The ammonites you see here are in the collections of the deeply awesome Emil Black.

Paleo Coordinates: 44 ° 35'46 ″ 51 ° 52'53″ 

Tuesday, 22 December 2020

AMMONITES IN PYRITE

We sometimes find fossils preserved by pyrite. They are prized as much for their pleasing gold colouring as they are for their scientific value as windows into the past. 

Sometimes folk add a coating of brass to increase the aesthetic appeal — a practice is frowned upon in paleontological communities.

Pyrite, sometimes called Fool's Gold, is a brass-yellow mineral with a bright metallic lustre. I popped a photo of some pyrite below so you can see the characteristic shape of its cubic crystal system.

Fool's Gold has a chemical composition of iron sulfide (FeS2) and is the most common sulfide mineral. It forms at high and low temperatures usually in small quantities, in igneous, metamorphic, and sedimentary rocks. If these sulfide minerals are close at hand when a fossil is forming, they can infuse specimens, replacing their mineral content to beautiful effect.

When we find a fossil preserved with pyrite, it tells us a lot about the conditions on the seabed where the organism died. Pyrite forms when there is a lot of organic carbon and not much oxygen in the vicinity. 

The reason for this is that bacteria in sediment usually respire aerobically (using oxygen), however, when there is no oxygen, they respire without oxygen (anaerobic) typically using sulphate. 

Sulphate is a polyatomic anion with the empirical formula SO2−4. It is generally highly soluble in water. Sulfate-reducing bacteria, some anaerobic microorganisms, such as those living in sediment or near deep-sea thermal vents, use the reduction of sulfates coupled with the oxidation of organic compounds or hydrogen as an energy source for chemosynthesis.

The sulfide mineral Pyrite, FeS2
High quantities of organic carbon in the sediment form a barrier to oxygen in the water. This also works to encourage anaerobic respiration. Anaerobic respiration using sulphate releases hydrogen sulphide, which is one of the major components in pyrite. 

So, when we find a fossil preserved in pyrite, we know that it died and was buried in sediment with low quantities of oxygen and high quantities of organic carbon. 

If you have pyrite specimens and want to stop them from decaying, you can give them a 'quick' soak in water (hour max) then wash them off, dry thoroughly in a warm oven. 

Cool, then soak in pure acetone for a couple of days. Then soak in paraloid, a thermoplastic resin surface coating or acetone for a couple of days. Keep in a sealed container with a desiccant pack afterwards to keep them dry — or leave them out on display to enjoy knowing that the decay will come in time. We do this with cut flowers so why not fossils sometimes.

I have a friend who gives her pyrite fossils on display a quick thumb wipe with vasoline or petroleum jelly. I'm not sure if the hydrocarbons there will play nice over time but it will act as a protective barrier.  

Monday, 21 December 2020

BALEARITES OF MOROCCO

This beautifully prepped specimen of a Balearites cf. balearis (Nolan, 1984) ammonite is from Upper Hauterivian deposits near Tamri, a small seaside town and rural commune in Agadir-Ida Ou Tanane Prefecture, Souss-Massa, Morocco. Aside from wonderful fossil localities, this area of Morocco has some of the most amazing surfing and banana plantations.

Balearites, with their planispiral shell or conch and compressed whorls, is an extinct ancyloceratin genus ammonite in the family Crioceratitidae, suborder Ancyloceratina.

We find fossils of this genera in Romania, Slovakia, Austria, France, Spain, Switzerland, Hungary, Italy, Russia, Bulgaria and Morocco. 

This specimen is in the collection of José Juárez Ruiz and is roughly 202 mm. If you find this lovely interesting, you'll enjoy reading more on this genus and others in Arkell, W. J. et al., 1957. Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology Part L, Mollusca 4. 1957.

Sunday, 20 December 2020

AMMONOIDS, BIVALVES AND POLAR BEARS OF SVALBARD

 This marvellous block is filled with Aristoptychites (syn=Arctoptychites) euglyphus (Mojsisovics, 1886) and Daonella sp., oyster-like saltwater clams or bivalves from the Middle Triassic (Ladinian) outcrops in the Botneheia Formation of Spitzbergen, in Edgeøya and Barentsøya, eastern Svalbard, Norway. 

Daonella and Monotis are important species for our understanding of biostratigraphy in the Triassic and are useful as an index fossil. Daonellids preferred soft, soupy substrates and we tend to find them in massive shell beds.

Svalbard is a Norwegian archipelago between mainland Norway and the North Pole. One of the world’s northernmost inhabited areas, it's known for its rugged, remote terrain of glaciers and frozen tundra sheltering polar bears, reindeer and Arctic fox. The Northern Lights are visible during winter, and summer brings the “midnight sun”—sunlight 24 hours a day.

The Botneheia Formation is made up of dark grey, laminated shales coarsening upwards to laminated siltstones and sandstones. South of the type area, the formation shows several (up to four) coarsening-upward units. 

The formation is named for Botneheia Mountain, a mountain in Nordenskiöld Land at Spitsbergen, Svalbard. It has a height of 522 m.a.s.l., and is located south of Sassenfjorden, east of the valley of De Geerdalen. 

Polar Bears, Ursus maritimus
As well as lovely ammonoids and bivalves, we've found ichthyosaur remains here. We had been expecting too, but it was not until the early 2000s that the first bones were found.

Two specimens have of ichthyosaur have been recovered. They comprise part of the trunk and the caudal vertebral column respectively. 

Some features, such as the very high and narrow caudal and posterior thoracic neural spines, the relatively elongate posterior thoracic vertebrae and the long and slender haemapophyses indicate that they probably represent a member of the family Toretocnemidae. 

Numerous ichthyosaur finds are known from the underlying Lower Triassic Vikinghøgda Formation and the overlying Middle to Upper Triassic Tschermakfjellet Formation, the new specimens help to close a huge gap in the fossil record of the Triassic ichthyosaurs from Svalbard.

There is a resident research group working on the Triassic ichthyosaur fauna, the Spitsbergen Mesozoic Research Group. Lucky for them, they often find the fossil remains fully articulated — the bones having retained their spacial relationship to one another. Most of their finds are of the tail sections of primitive Triassic ichthyosaurs. In later ichthyosaurs, the tail vertebrae bend steeply downwards and have more of a fish-like look. In these primitive ancestors, the tail looks more eel-like — bending slightly so that the spines on the vertebrae form more of the tail.

Maisch, Michael W. and Blomeier, Dierk published on these finds back in 2009: Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen Band 254 Heft 3 (2009), p. 379 - 384. Nov 1, 2009

The lovely block you see here is in the collections of the deeply awesome John Fam. The image of the Polar Bears, Ursus maritimus, is courtesy of the Fossil Huntress. 

Friday, 18 December 2020

CRETACEOUS EXTINCTION EVENT

66 million years ago, dinosaur still roamed the Earth. We know from abundant fossil bones, teeth and trackways that their reign lasted an impressive 230 million years. But a massive extinction event at the end of the Cretaceous wiped out three-quarters of the Earth's species — dinosaurs included. 

Our planet also lost the ammonites and our mighty marine reptiles — mosasaurs, ichthyosaurs and plesiosaurs. 

Never again would pterosaurs, flying reptiles, cruise our skies. Their departure gave rise to the age of mammals and the diversity we see today. 

One of the most well-known theories for the death of the dinosaurs is the Alvarez hypothesis, named after the father-and-son duo Luis and Walter Alvarez. In 1980, these two scientists proposed the notion that a meteor the size of a mountain slammed into Earth 66 million years ago, filling the atmosphere with gas, dust, and debris that drastically altered the climate.

Their key piece of evidence is an oddly high amount of the metal iridium in what’s known as the Cretaceous-Paleogene, or K-Pg, layer—the geologic boundary zone that seems to cap any known rock layers containing dinosaur fossils. 

Iridium is relatively rare in Earth's crust but is more abundant in stony meteorites, which led the Alvarezs to conclude that the mass extinction was caused by an extraterrestrial object. The theory gained even more steam when scientists were able to link the extinction event to a huge impact crater along the coast of Mexico’s Yucatán Peninsula. At about 93 miles wide, the Chicxulub crater seems to be the right size and age to account for the dino die-off.

In 2016, scientists drilled a rock core inside the underwater part of Chicxulub, pulling up a sample stretching deep beneath the seabed. This rare peek inside the guts of the crater showed that the impact would have been powerful enough to send deadly amounts of vaporized rock and gases into the atmosphere and that the effects would have persisted for years. 

And in 2019, palaeontologists digging in North Dakota found a treasure trove of fossils extremely close to the K-Pg boundary, essentially capturing the remains of an entire ecosystem that existed shortly before the mass extinction. Tellingly, the fossil-bearing layers contain loads of tiny glass bits called tektites—likely blobs of melted rock kicked up by the impact that solidified in the atmosphere and then rained down over Earth.

MIGHTY DOVE CREEK MOSASAUR

Dove Creek Mosasaur (Tylosaur) found by Rick Ross, VIPS
This specimen of the teeth and lower jawbone of a large marine reptile was discovered by Rick Ross, Vancouver Island Palaeontological Society, during the construction of the Inland Highway, near the Dove Creek intersection on Vancouver Island.

If you look closely, you can see several smaller disc-shaped objects to the upper right. These are part of this fellow's sclerotic eye-ring.

These bony plates allowed for safe hunting in deeper waters as the structures protected the delicate eye tissue from the intense water pressure. Diving birds have these same bony plates to aid them in the same way.

Mosasaurs had a hinged jaw that allowed them to swallow prey larger than themselves. They evolved special pterygoid teeth projecting back into the roof of their mouths that acted as guards against escaping prey. The jawbones Rick found were exposed just up to the hinge. Given the size, this toothy fellow could have been as much as seven (7) metres long and weighed up to a tonne.

Along with the significant find of the mosasaur, Rick Ross collected many ammonites and other marine invertebrates exposed during the construction of the Inland Island Highway. He donated the majority of them to the Royal BC Museum in Victoria. They now adorn a cabinet bearing his name and are tucked lovingly in with stories he wrote about his collecting adventures.

Urakawites heteromorph found by Rick Ross, VIPS
Science owes a great debt to the keen eye and fast thinking of Rick Ross for his work in recovering the specimen. Rick was out on a Sunday looking through the blocks that destined to be crushed to finish up the tail end of the new highway construction. The crews had just dropped a pile of massive blocks near the Dove Creek Road crossing.

Each of the blocks was one to five tonnes in size. Rick was looking through them when he spotted a concretion sticking out. It didn't look all that different from the hundreds he had been found up and down the highway. Interested to see what it might contain, Rick took his geology hammer and struck a blow. Off popped the end and inside was a large perfect mosasaur tooth.

Looking closer, he could see bone sticking out in several other places within this massive block. Excited for the find and not quite sure how to approach excavating it from an active construction site, Rick searched the highway and finally located a maintenance working greasing up some heavy machinery. Rick excitedly told the field mechanic about the find and inquired who would need to be called to save the block. His answer was disappointing. The block was destined to be bulldozed in the morning. 

Panicked but still hopeful, Rick asked who his supervisor was and how to reach him on a Sunday. While initially hesitant, the urgency and excitement in Rick's voice swayed him. With a warning that the supervisor would likely not be impressed to get his call, he relented and shared the telephone number. Rick dialled the number and received the predicted reaction. Unrelenting, Rick swayed the supervisor who agreed that if Rick could get a truck up to the site first thing in the AM, the block could be lifted onto the truck. The next hour was filled with phone calls and putting together a plan to get the mighty block.

Rick called Pat Trask from the Courtenay Museum. The two are fossil hunting buddies and Rick was sure that Pat would be up for the challenge. The next call was to Doug Embree, another fossil hunting buddy from the Comox Valley. As luck would have it, Doug's brother Sam had a two-tonne flatbed truck that they would be able to use. The struggle now was would it take the weight? Monday morning arrived and the block was lifted onto the flatbed with the aid of a drill hole and chain through one corner.

The truck groaned and leaned heavily all the way into town. They had to come in via the 17th Street Bridge as a safe route to the Courtenay Museum. the local building store lent the use of a large forklift to lift the block from the heavily tilted truckbed down onto the back deck of the museum. Once in place, it was far too big to move. It sat there for almost seven years before finally being shipped to a preparatory lab down in Washington. There it was prepped and whittled down to the still massive block we see today.

This specimen is now housed in the Courtenay and District Museum on Vancouver Island, British Columbia. The jaw and associated bones are tagged as a mosasaur, but exactly what kind will need more study. We may be looking at a Tylosaurus, a very large mosasaur with an elongated, cylindrical premaxilla (snout) from which it takes its name. These were the big boys of our ancient seas who snacked on plesiosaurs and other smaller marine reptiles.

T. proriger specimen found with a plesiosaur in its stomach
In 1918, Charles H. Sternberg found a Tylosaurus, with the remains of a plesiosaur in its stomach while collecting in the Smoky Hill Chalk of Logan County, Kansas. You can visit the specimen at the Smithsonian.

Like many other mosasaurs, the early history of this taxon is complex and involves the infamous rivalry between two early American palaeontologists, Edward Drinker Cope and Othniel Charles Marsh. Cope wins the day in terms of longevity in his naming of these mighty beasts.

Though many species of Tylosaurus have been named over the years, only a few are now recognized by scientists as taxonomically valid. They are: Tylosaurus proriger (Cope, 1869), from the Santonian and lower to middle Campanian of North America (Kansas, Alabama, Nebraska) and Tylosaurus nepaeolicus (Cope, 1874), from the Santonian of North America (Kansas). Tylosaurus kansasensis, named by Everhart in 2005 from the late Coniacian of Kansas, has been shown to be based on juvenile specimens of T. nepaeolicus.

It is likely that T. proriger evolved as a paedomorphic variety of T. nepaeolicus, retaining juvenile features into adulthood while attaining a much larger adult size.

Along with plesiosaurs, sharks, fish, and other mosasaurs, Tylosaurus was a dominant predator of the Western Interior Seaway during the Late Cretaceous. The genus was among the largest of the mosasaurs — along with Mosasaurus hoffmannii — with the possibly conspecific Hainosaurus bernardi reaching lengths up to 12.2 meters (40 ft), and T. pembinensis reaching comparable sizes. T. proriger, the largest species of Tylosaurus, reached a whopping 14 m (46 ft). While the Dove Creek Mosasaur was half that size, it may be one of T. proriger's smaller cousins.

Photo One: Dove Creek Mosasaur by Heidi Henderson. Courtenay Museum Collection.
Photo Two: Urakawites heteromorph ammonite by Rick Ross. RBCM Collection
Photo Three: T. proriger specimen which was found with a plesiosaur in its stomach. By Ryan Somma - Flickr, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=9004614

Thursday, 17 December 2020

DEINOTHERIUM GIGANTEUM

This partial specimen of Deinotherium giganteum hails from Middle-Upper Miocene, c. 15.97-5.33 Million Years outcrops near Cerecinos de Campos, Zamora Castile and León, northwestern Spain.

Deinotherium  means "terrible beast," which feels a bit unkind to this vegetarian — though he was one of the largest elephants to walk this Earth. 

are relatively recent in the evolutionary story of the Earth. They first appeared 17 million years ago, had a short run of it and became extinct relatively recently — just 1.6 million years ago. This fellow's cousin, Deinotherium bozasi would likely have interacted with some of our oldest relatives. Australopithecus, Homo habilis and Homo ergaster likely laid eyes on one of these big beasties.

One of the distinguishing features of Deinotherium is their curved tusks inserted only in the jaw. One of the tusks from this fellow, on display at the Museo Nacional De Ciencias Naturales in Madrid, Spain, while incomplete, was preserved rather nicely and shows the detail of where the tusk meets the jaw.

Deinotherium could reach a height of over 3.5 meters. Its structure and size are similar to those of the present-day elephant. 


Wednesday, 16 December 2020

PALAEONTOLOGIST EARL DOUGLASS: THE CARNEGIE QUARRY

Palaeontologist Earl Douglass, 1909
About 150 million years ago, a severe drought ravaged the western interior of North America. In eastern Utah, malnourished dinosaurs gathered near a dwindling river to live out their last days. 

Today, this site is known as the Carnegie Quarry at Dinosaur National Monument, and it is one of the most incredible fossil sites in the world.

The celebrated fossil quarry at what is now recognized as Dinosaur National Monument in Utah was discovered in 1909 by Carnegie Museum field collector Earl Douglass.

“I saw eight of the tail bones of a Brontosaurus in exact position. It was a beautiful sight.”  — Earl Douglass in his diary on August 17, 1909, recounting the moment he found the first dinosaur remains of a Brontosaurus at the Carnegie Quarry. Those vertebrae were part of a fully articulated skeleton that became the type for a new species, Apatosaurus louisae, (Gilmore, 1936), published a detailed quarry map showing the skeleton, with "outcrop" identifying the discovery bones. The specimen is now mounted in the Carnegie Museum and those eight tail bones, freed from their sandstone tomb. 

From 1909–1923, Douglass and his crews collected more than 350 tons (700,000 pounds) of fossils from that site alone. Several dinosaur skeletons discovered by Douglass at this quarry are featured in our core exhibition hall, Dinosaurs in Their Time.

Others grace the exhibit halls of other prominent North American museums, such as the American Museum of Natural History in New York, the Smithsonian Institution’s National Museum of Natural History in Washington, DC, the Denver Museum of Nature and Science, and the Royal Ontario Museum in Toronto.

If you would like to visit Dinosaur National Monument, you can explore extensive outcrops of the Morrison at the Dinosaur Quarry, on the Fossil Discovery Trail, the Sounds of Silence Trail, and other areas in the park.

To learn more about this fossil site, visit: https://carnegiemnh.org/celebrated-fossil-quarry/

Monday, 14 December 2020

CARNOTAURUS: FLESH-EATING BULL

Carnotaurus sastrei, a genus of large theropod dinosaurs that roamed the southern tip of Argentina, South America during the Late Cretaceous, 72 to 69.9 million years ago. His name means "flesh-eating bull,' and he lives up to it.

This fellow — or at least his robust skull with the short, knobby eyebrow horns and fierce-looking teeth — is on display at the Natural History Museum in Madrid, Spain. For now, he is the only known genus of this species of bipedal predator.

The first specimen of Carnotaurus sastrei was found in Chubut on vast plains between the Andes Mountains and the Atlantic Ocean. A physician, Dr. A'ngel Tailor noticed a large concretion showing some bone fragments. A team led by José F. Bonaparte excavated the find in 1984 as part of a paleontological expedition funded by the Argentine Museum of Natural Sciences.

Sadly, Bonaparte — the Maestro del Mesozoico — passed away the 18th February of this year at the age of 91. He spent the majority of his career as head of the Vertebrate Palaeontology Division of the Museo Argentino de Ciencias Naturales “Bernardino Rivadavia,” in Buenos Aires. Bonaparte opened up the vertebrate finds of Argentina to the world. He was instrumental in the finding, excavating and naming many iconic dinosaurs — Carnotaurus, Amargasaurus, Abelisaurus, Argentinosaurus, Noasaurus along with the finding of the first fossilised remains of Mesozoic South American mammals. He mentored many palaeontologists who will miss his keen eye and tremendous work ethic — Luis Chiappe, Rodolfo Coria, Agustín Martinelli, Fernando Novas, Jaime Powell, Guillermo Rougier, Leonardo Salgado, Sebastián Apesteguía and many others.

His excavation of Carnotaurus was the first of its kind and he recognized that the skull is quite unusual. Initially, it has a very marine reptile feel — but make no mistake this guy is clearly a terrestrial theropod. He had smallish, underdeveloped arms — teeny by theropod standards. Once you look closer you see his bull-like horns from whence he gets his name — horns that imply battle between rivals for the best meal, sexual partner and to be the one who leads the herd. 

He was covered in leathery skin lined with rows of cone-shaped nodules or bumps. These get larger as they move towards his spine. He had forward-facing eyes, similar to tyrannosaurs like T-rex and smaller theropods like Velociraptor and Troodon — who had better vision even that T-rex — which would have given him the advantage of binocular vision and depth perception. Forward-facing eyes are also quite helpful with nocturnal hunting — think owls and cats — as they take in more light and help with nighttime predation. So perhaps this flesh-eating bull fancied a late-night snack on his menu from time to time.

Species like squirrels, pigeons and crocodiles have eyes on the sides of their heads. They lack the important competitive feature of well-developed depth perception — being able to easily and estimate distance — but perhaps make up for it with a panorama that offers a wider field of view.   

Sunday, 13 December 2020

GIANT GROUND SLOTH

In 1788, this magnificent specimen of a Megatherium sloth was sent to the Royal Cabinet of Natural History from the Viceroyalty of Rio de la Plata.

The megaterios were large terrestrial sloths belonging to the group, Xenarthra. These herbivores inhabited large areas of land on the American continent. Their powerful skeleton enabled them to stand on their hind legs to reach leaves high in the trees, a huge advantage given the calories needed to be consumed each day to maintain their large size.

Avocados were one of the food preferences of our dear Giant ground sloths. They ate then pooped them out, spreading the pits far and wide. The next time you enjoy avocado toast, thank this large beastie. One of his ancestors may have had a hand (or butt) in your meal.

In 1788, Bru assembled the skeleton as you see it here. It is exhibited at the Museo Nacional De Ciencias Naturales in Madrid, Spain, in its original configuration for historic value. If you look closely, you'll see it is not anatomically correct. But all good palaeontology is teamwork. Based upon the drawings of Juan Bautista Bru, George Cuvier used this specimen to describe the species for the very first time.

Saturday, 12 December 2020

ICE AGE PROBOSCIDEANS: WOOLLY MAMMOTHS

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

He's now housed in the Museo Nacional De Ciencias Naturales in Madrid, Spain in a display that shows thoughtful comparisons between the proboscideans. They 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 — and I'm guessing stinky — 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.

Woolly Mammoth Tusk, Wrangel Island
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

Friday, 11 December 2020

LEMURS OF MADAGASCAR

These sweet babies are lemurs. You may have seen them as the stars in one of DreamWorks animated production Madagascar. 

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

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

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

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

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

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

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

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

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

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

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

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

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

Sunday, 6 December 2020

HETEROPTERA: SNEAKOPTERA


A sweet little water bug from the suborder Heteroptera (Latreille, 1810). He looks more like a cartoon character that any other specimen I've seen. 

This fun fellow is in the collections of Tim Dingman. The deeply awesome Jim Barkley gets credit for this charming photo. The cartoon effect comes from this guy missing his abdomen. He hails from Eocene deposits of the Green River Formation of Western Colorado.

The Green River Formation is an Eocene geologic formation that records a 12 million year history of sedimentation in a group of intermountain lakes in three basins along the present-day Green River in Colorado, Wyoming, and Utah. It is one of the most important outcrops we have for insight into life in the Eocene. It gives a window into what our world looked like about 50 million years ago. 

The first documented records of invertebrate fossils from what is now called the Green River Formation are in the journals of early missionaries and explorers such as S. A. Parker, 1840, and J. C. Fremont, 1845. Geologist Dr. John Evans collected the first fossil fish, described as Culpea humilis — later renamed Knightia eocaena — from the Green River beds in 1856.

Edward Drinker Cope collected extensively from the area and produced several publications on the fossil fish from 1870 onwards. Ferdinand Vandeveer Hayden, geologist-in-charge of the United States Geological and Geographical Survey of the Territories, the forerunner of the United States Geological Survey,  first used the name "Green River Shales" for the fossil sites in 1869.

Millions of fish fossils have been collected from the area, commercial collectors operating from legal quarries on state and private land have been responsible for the majority of Green River vertebrate fossils in public and private collections all over the world.

Saturday, 5 December 2020

EOCENE CRYPTODIRAN TURTLE

An Eocene Cryptodiran Fossil Turtle, Baena arenosa, from fine-grained lime mud outcrops in the Green River Formation, Wyoming, USA.

This fellow, with the extra-long tail, marks the last of his lineage. The now extinct family Baenidae appeared first in the Jurassic and died out at the end of the Eocene. We've found specimens of Baena, along with 14 other species of turtles in seven genera and five families in the Lower Eocene San Jose Formation, San Juan Basin of New Mexico.

This specimen is from the Green River Formation of Wyoming which was once the bottom of one of an extensive series of Eocene lakes. The Green River Formation is particularly abundant in beautifully preserved fossil fish, eleven species of reptiles including a 13.5ft crocodile, an armadillo-like mammal, Brachianodon westorum, bats, birds and other fresh-water aquatic goodies.

This specimen of a beautiful Baena was found and prepped by the Green River Stone Company. They purchased their private 12-acre quarry about 20 years ago. It's at the Eocene lake's centre, shared with Fossil Butte National Monument about 24 kilometres (15 miles) west of Kemmerer, Lincoln County, Wyoming.

Friday, 4 December 2020

DESHAYESITES VOLGENSIS BLOCK

From Russia with Love — a lovely iridescent block of ammonites with Deshayesites volgensis (Sasonova, 1958), and Aconeceras (Sinzovia) trautscholdi (Sinzow. 1870) with their natural pink, blue and purple candy colouring. These beauties are from Lower Cretaceous, Aptian, 120 - 112 million-year-old outcrops near Shilovka, Ulyanovsk Region, Russia. This lovely block was collected by and is in the collections of the deeply awesome Emil Black.

Aptian deposits near the Volga River between Ul'yanovsk and Saratov have been studied for more than a century. The age of lower Aptian deposits was traditionally established based on changing ammonite assemblages of the family Deshayesitidae.

The diverse assemblage of heteromorphic ammonites, Ancyloceratidae, inhabitants of relatively deep basins, has made it possible to propose a new scheme of ammonoid zonation in the lower Aptian epipelagic deposits of the Russian plate.

Many of the identified ancyloceratids were established here for the first time. The analysis of coexisting deshayesitids and heteromorphs enabled a correlation of stratigraphic schemes for the monomorphic Deshayesitidae and heteromorphic Ancyloceratidae. The described generic taxa and species are Volgoceratoides I. Michailova et Baraboshkin, gen. nov., V. schilovkensis I. Michailova et Baraboshkin, sp. nov., Koeneniceras I. Michailova et Baraboshkin, gen. nov., K. tenuiplicatum (von Koenen, 1902), K. rareplicatum I. Michailova et Baraboshkin, sp. nov.

In few sections of the Saratov Volga area (central part of the Russian Platform), representing both offshore and nearshore lithofacies of the epicontinental Middle Russian Sea, researchers have recognized simultaneous changes in ammonite and belemnite successions. The significant influence of anoxic events on faunal turnovers in marine communities is well-established. However, many studies are focused on the impact of anoxic conditions on benthic organisms, not on the hunter-gatherers living higher up in the sea column. This means that coeval changes in pelagic cephalopod assemblages remain relatively poorly understood.

Belemnites, represented by the late members of the family Oxyteuthididae, are common in the interval directly preceding the anoxic event, but totally disappear with the onset of the black shale deposition. We see a reduction in the shell size of the Deshayesites ammonites across the mudstone – black shale boundary (maximum shell diameter of adults reduces from ∼20 cm to 7–8 cm).

Some other ammonites become numerous (Sinzovia) within the black shale interval or show the first occurrence in it (Koeneniceras and Volgoceratoides). In our opinion diminishing of Deshayesites shell size during the early Aptian OAE could be caused by the coupling of palaeoenvironmental factors such as progressive warming and regional input of brackish water. Preliminary results of carbon isotope studies of aragonite deriving from the ammonite nacreous layer are also provided.

The significant influence of anoxic events on faunal turnovers in marine communities is well-established. However, many studies are focused on the impact of anoxic conditions on benthic organisms, not on the hunter-gatherers living higher up in the sea column. This means that coeval changes in pelagic cephalopod assemblages remain relatively poorly understood. The maximum diameter on the Deshayesites shown here in the photo by Emil Black is 70 mm.

Rogov, Mikhail & Shchepetova, Elena & Ippolitov, Alexei & Seltser, Vladimir & Mironenko, Aleksandr & Pokrovsky, Boris & Desai, Bhawanisingh. (2019). Response of cephalopod communities on abrupt environmental changes during the early Aptian OAE1a in the Middle Russian Sea. Cretaceous Research. 10.1016/j.cretres.2019.01.007.

E. Yu. Baraboshkin and I. A. Mikhailova. New Stratigraphic Scheme of the Lower Aptian in the Volga River Middle Courses. Stratigraphy arid Geological Correlation, Vol 10, No 6, 2002, pp 603-626 Translated from Stratigrafiy a Geologicheskaya Korrelyatsiya, Vol 10, No 6, 2002, pp 82-105

Wednesday, 2 December 2020

DEEPLY GROOVY DORIPPE SINICA

A beautiful example of the decapod, Dorippe sinica, from Holocene deposits near Shizuoka, Japan. This regal fellow has a strongly sculptured carapace. He looks like he would have been quite the bruiser moving about on the seafloor looking for tasty snacks. He likely enjoyed just about any form of meat, potentially dining on fish, worms, eggs, squid, starfish or even a few of his slow-moving cousins.

The carapace is deeply grooved with conspicuous wart-like tubercles; anterolateral margin, between the base of the exorbital tooth and cervical groove, smooth, without tubercles or denticles.

The teeth on the lower orbital margin in the cluster. Carpus of cheliped distinctly granulated on the upper surface and with a conspicuous row of granules along the anterior margin. Though missing here, the merus of second and third pereiopods are almost cylindrical. (Türkay 1995). This specimen was collected and is the collection of the deeply awesome Takashi Ito of Japan

Tuesday, 1 December 2020

HYPHANTOCERAS ORIENTALE

A stunning example of the heteromorph ammonite, Hyphantoceras orientale macroconch. This beauty corresponds to 'Morphotype C' from Aiba (2017). 

The specimen is a handful at 136 mm and was lovingly prepared by the hand holding it, that of the talented José Juárez Ruiz.

This an adult specimen (not the juvenile stage) from Upper Santonian outcrops near Ashibetsu, Hokkaido, Japan.

Aiba published on a possible phylogenetic relationship of two species of Hyphantoceras (Ammonoidea, Nostoceratidae) earlier this year, proposing that a phylogenetic relationship may exist based on newly found specimens with precise stratigraphic occurrences in the Kotanbetsu and Obira areas, northwestern Hokkaido.

Two closely related species, Hyphantoceras transitorium and H. orientale, were recognized in the examined specimens from the Kotanbetsu and Obira areas. Specimens of H. transitorium show wide intraspecific variation in the whorl shape. The stratigraphic occurrences of the two species indicate that they occur successively in the Santonian–lowermost Campanian, without stratigraphic overlapping. 

The similarity of their shell surface ornamentations and the stratigraphic relationships possibly suggest that H.orientale was derived from H. transitorium. The presumed lineage is likely indigenous to the northwestern Pacific realm in the Santonian–earliest Campanian. Hyphantoceras venustum and H. heteromorphum might stand outside a H. transitorium–H. orientale lineage, judging from differences of their shell surface ornamentation.

Aiba, Daisuke. (2019). A Possible Phylogenetic Relationship of Two Species of Hyphantoceras (Ammonoidea, Nostoceratidae) in the Cretaceous Yezo Group, Northern Japan. Paleontological Research. 23. 65-80. 10.2517/2018PR010.