PARTY OF TWO: ANGLERFISH

The festive lassie you see here is an Anglerfish. They always look to be celebrating a birthday of some kind, albeit solo. This party is happening deep in our oceans and for those that join in, I hope they like it rough.

The wee candle you see on her forehead is a photophore, a tiny bit of luminous dorsal spine. Many of our sea dwellers have these candle-like bits illuminating the depths. You may have noticed them glowing around the eyes of many of our cephalopod friends. 

These light organs can be a simple grouping of photogenic cells or more complex with light reflectors, lenses, colour filters able to adjust the intensity or angular distribution of the light they produce. Some species have adapted their photophores to avoid being eaten, in others, it's an invitation to lunch.

In anglerfish' world, this swaying light is dead sexy. It's an adaptation used to attract prey and mates alike.

Deep in the murky depths of the Atlantic and Antarctic oceans, hopeful female anglerfish light up their sexy lures. When a male latches onto this tasty bit of flesh, he fuses himself totally. He might be one of several potential mates. She's not picky, just hungry. Lure. Feed. Mate. Repeat.

A friend asked if anglerfish mate for life. Well, yes.... yes, indeed they do.

Mating is a tough business down in the depths. Her body absorbs all the yummy nutrients of his body over time until all that's left are his testes. While unusual, it is only one of many weird and whacky ways our fishy friends communicate, entice, hunt and creatively survive and thrive. The deepest, darkest part of the ocean isn't empty — its hungry.

The evolution of fish began about 530 million years ago with the first fish lineages belonging to the Agnatha, a superclass of jawless fish. We still see them in our waters as cyclostomes but have lost the conodonts and ostracoderms to the annals of time. Like all vertebrates, fish have bilateral symmetry; when divided down the middle or central axis, each half is the same. Organisms with bilateral symmetry are generally more agile, making finding a mate, hunting or avoiding being hunted a whole lot easier.

When we envision fish, we generally picture large eyes, gills, a well-developed mouth. The earliest animals that we classify as fish appeared as soft-bodied chordates who lacked a true spine. While they were spineless, they did have notochords, a cartilaginous skeletal rod that gave them more dexterity than the cold-blooded invertebrates who shared those ancient seas and evolved without a backbone. 

Fish would continue to evolve throughout the Paleozoic, diversifying into a wide range of forms. Several forms of Paleozoic fish developed external armour that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many species, including sharks, became formidable marine predators rather than just the prey of arthropods.

Fish in general respire using gills, are most often covered with bony scales and propel themselves using fins. There are two main types of fins, median fins and paired fins. The median fins include the caudal fin or tail fin, the dorsal fin, and the anal fin. Now there may be more than one dorsal, and one anal fin in some fishes.

The paired fins include the pectoral fins and the pelvic fins. And these paired fins are connected to, and supported by, pectoral and pelvic girdles, at the shoulder and hip; in the same way, our arms and legs are connected to and supported by, pectoral and pelvic girdles. This arrangement is something we inherited from the ancestors we share with fish. They are homologous structures.

When we speak of early vertebrates, we are often talking about fish. Fish is a term we use a lot in our everyday lives but taxonomically it is not all that useful. When we say, fish we generally mean an ectothermic, aquatic vertebrate with gills and fins.

Fortunately, many of our fishy friends have ended up in the fossil record. We may see some of the soft bits from time to time, as in the lovely fossil fish found in concretion in Brazil, but we often see fish skeletons. Vertebrates with hard skeletons had a much better chance of being preserved. 

Eohiodon Fish, McAbee Fossil Beds

In British Columbia, we have lovely two-dimensional Eocene fossil fish well-represented from the Allenby of Princeton and the McAbee Fossil Beds. 

We have the Tiktaalik roseae, a large freshwater fish, from 375 million-year-old Devonian deposits on Ellesmere Island in Canada's Arctic. Tiktaalik is a wonderfully bizarre creature with a flat, almost reptilian head but also fins, scales and gills. We have other wonders from this time. 

Canada also boasts spectacular antiarch placoderms, Bothriolepsis, found in the Upper Devonian shales of Miguasha in Quebec.

There are fragments of bone-like tissues from as early as the Late Cambrian with the oldest fossils that are truly recognizable as fishes come from the Middle Ordovician from North America, South America and Australia. At the time, South America and Australia were part of a supercontinent called Gondwana. North America was part of another supercontinent called Laurentia and the two were separated by deep oceans.

These two supercontinents and others that were also present were partially covered by shallow equatorial seas and the continents themselves were barren and rocky. Land plants didn't evolve until later in the Silurian Period. In these shallow equatorial seas, a large diverse and widespread group of armoured, jawless fishes evolved: the Pteraspidomorphi. The first of our three groups of ostracoderms. The Pteraspidomorphi are divided into three major groups: the Astraspida, Arandaspida and the Heterostraci.

The oldest and most primitive pteraspidomorphs were the Astraspida and the Arandaspida. You'll notice that all three of these taxon names contain 'aspid', which means shield. This is because these early fishes — and many of the Pteraspidomorphi — possessed large plates of dermal bone at the anterior end of their bodies. This dermal armour was very common in early vertebrates, but it was lost in their descendants. 

Arandaspida is represented by two well-known genera: Sacabampaspis, from South America and Arandaspis from Australia. Arandaspis have large, simple, dorsal and ventral head shields. Their bodies were fusiform, which means they were shaped sort of like a spindle, fat in the middle and tapering at both ends. Picture a sausage that is a bit wider near the centre with a crisp outer shell.

If you're a keen bean to see an anglerfish that recently washed up on the shores of Newport Beach this past May, hit this link: https://www.theguardian.com/us-news/2021/may/11/deep-sea-anglerfish-california-beach-finding-nemo. Kudos for my colleague, Giovanni, bringing this gloriously horrific lovely to my attention. 

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

NEVADA FOSSILS: CARNIAN-NORIAN BOUNDARY

Time Slows at Berlin-Ichthyosaur State Park

High on the hillside up a long entry road sits the entrance to Berlin-Ichthyosaur State Park in central Nevada.

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

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

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

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

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

Middle Triassic Ammonoids

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

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

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

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

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

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

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

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

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

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

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

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

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

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

ETHELDRED'S HOPLITES: A TALE OF A FEMALE PALAEONTOLOGIST

The species' name is a homage to Etheldred Benett, an early English geologist often credited with being the first female geologist — a fossil collector par excellence.

If you happened to join us for today's VIPS talk with Phil Hadland, Collections & Engagement Curator of Natural Sciences at the Hastings Museum & Art Gallery, UK, on 101 Fossils of Folkstone, you will have heard him mention her in his talk.

She was also credited with being a man  —  the Natural History Society of Moscow awarded her membership as Master Etheldredus Benett in 1836. The confusion over her name (it did sound masculine) came again with the bestowing of a Doctorate of Civil Law from Tsar Nicholas I.

The Tsar had read Sowerby's Mineral Conchology, a major fossil reference work which contained the second-highest number of contributed fossils of the day, many of the best quality available at the time. Forty-one of those specimens were credited to Benett. Between her name and this wonderous contribution to a growing science, the Russian Tsar awarded the Doctorate to what he believed was a young male scientist on the rise. He believed in education, founding Kyiv University in 1834, just not for women. He was an autocratic military man frozen in time — the thought that this work could have been done by a female was unthinkable. Doubly charming is that the honour from the University of St Petersburg was granted at a time when women were not allowed to attend St. Pete's or any higher institutions. That privilege arrived in 1878, twenty years after Nicholas I's death.

Benett took these honours (and social blunders) with grace. She devoted her life to collecting and studying fossils from the southwest of England, amassing an impressive personal collection she openly shared with geologist friends, colleagues and visitors to her home. Her speciality was fossils from the Middle Cretaceous, Upper Greensand in the Vale of Wardour — a valley in the county of Wiltshire near the River Nadder.

Etheldred was a local Wiltshire girl. Born Etheldred Benett on 22 July 1775 at Pyt House, Tisbury, Wiltshire, the eldest daughter of the local squire Thomas Benett. Etheldred's interest was cultivated by the botanist Aylmer Bourke Lambert (1761-1842), a founding member of the Linnean Society. Benett's brother had married Lucy Lambert, Aylmer's half-sister. Aylmer was a Fellow of the Royal Society and the Society of the Arts. He was also an avid fossil collector and member of the Geological Society of London. The two met and got on famously.

Aylmer kindled an interest in natural history in both of Benett's daughters. Etheldred had a great fondness in geology, stratigraphy and all things paleo, whilst her sister concentrated on botany. Etheldred had a distinct advantage over her near contemporary, the working-class Mary Anning (1799-1847), in that Benett was a woman of independent wealth who never married — and didn't need to — who could pursue the acquisition and study of fossils for her own interest.

While Anning was the marine reptile darling of the age, she was also greatly hindered by her finances. "She sells, seashells by the seashore..." while chanted in a playful spirit today, was not meant kindly at the time. Aylmer's encouragement emboldened Etheldred to go into the field to collect for herself — and collect she did. Profusely.

Benett’s contribution to the early history of Wiltshire geology is significant. She corresponded extensively with the coterie of gentlemen scientists of the day —  Gideon Mantell, William Buckland, James Sowerby, George Bellas Greenough and, Samuel Woodward. She also consorted with the lay folk and had an ongoing correspondence with William Smith, whose stratigraphy work had made a favourable impression on her brother-in-law, Aylmer.

Her collections and collaboration with geologists of the day were instrumental in helping to form the field of geology as a science. One colleague and friend, Gideon Mantell, British physician, geologist and palaeontologist, who discovered four of the five genera of dinosaurs and Iguanadon, was so inspired by Benett's work he named this Cretaceous ammonite after her — Hoplites bennettiana.

Benett's fossil assemblage was a valuable resource for her contemporaries and remains so today. It contains thousands of Jurassic and Cretaceous fossil specimens from the Wiltshire area and the Dorset Coast, including a myriad of first-recorded finds. The scientific name of every taxon is usually based on one particular specimen, or in some cases multiple specimens. Many of the specimens she collected serve as the Type Specimen for new species.

Fossil Sponge, Polypothecia quadriloba, Warminster, Wiltshire

Her particular interest was the collection and study of fossil sponges. Alcyonia caught her eye early on. She collected and recorded her findings with the hope that one of her colleagues might share her enthusiasm and publish her work as a contribution to their own.

Alas, no one took up the helm — those interested were busy with other pursuits (or passed away) and others were less than enthusiastic or never seemed to get around to it.

To ensure the knowledge was shared in a timely fashion, she finally wrote them up and published them herself. You can read her findings in her publication, ‘A Catalogue of Organic Remains of the County of Wiltshire’ (1831), where she shares observations on the fossil sponge specimens and other invert goodies from the outcrops west of town.

She shared her ideas freely and donated many specimens to local museums. It was through her exchange of observations, new ideas and open sharing of fossils with Gideon Mantell and others that a clearer understanding of the Lower Cretaceous sedimentary rocks of Southern England was gained.

In many ways, Mantell was drawn to Benett as his ideas went against the majority opinion. At a time when marine reptiles were dominating scientific discoveries and discussions, he pushed the view that dinosaurs were terrestrial, not amphibious, and sometimes bipedal. Mantell's life's work established the now-familiar idea that the Age of Reptiles preceded the Age of Mammals. Mantell kept a journal from 1819-1852, that remained unpublished until 1940 when E. Cecil Curwen published an abridged version. (Oxford University Press 1940). John A. Cooper, Royal Pavilion and Museums, Brighton and Hove, published the work in its entirety in 2010.

I was elated to get a copy, both to untangle the history of the time and to better learn about the relationship between Mantell and Benett. So much of our geologic past has been revealed since Mantell's first entry two hundred years ago. The first encounter we share with the two of them is a short note from March 8, 1819. "This morning I received a letter from Miss Bennett of Norton House near Warminster Wilts, informing me of her having sent a packet of fossils for me, to the Waggon Office..." The diary records his life, but also the social interactions of the day and the small connected community of the scientific social elite. It is a delight!

Though a woman in a newly evolving field, her work, dedication and ideas were recognized and appreciated by her colleagues. Gideon Mantell described her as, "a lady of great talent and indefatigable research," whilst the Sowerbys noted her, "labours in the pursuit of geological information have been as useful as they have been incessant."

Benett produced the first measured sections of the Upper Chicksgrove quarry near Tisbury in 1819, published and shared with local colleagues as, "the measure of different beds of stone in Chicksgrove Quarry in the Parish of Tisbury.” The stratigraphic section was later published by naturalist James Sowerby without her knowledge. Her research contradicted many of Sowerby’s conclusions.

She wrote and privately published a monograph in 1831, containing many of her drawings and sketches of molluscs and sponges. Her work included sketches of the fossil Alcyonia (1816) from the Green Sand Formation at Warminster Common and the immediate vicinity of Warminster in Wiltshire.

Echinoids and Bivalves. Collection of Etheldred Benett (1775-1845)

The Society holds two copies, one was given to George Bellas Greenough, and another copy was given to her friend Gideon Mantell. This work established her as a true, pioneering biostratigrapher following but not always agreeing with the work of William Smith.

If you'd like to read a lovely tale on William's work, check out the Map that Changed the World: William Smith and the Birth of Modern Geology by Simon Winchester. It narrates the intellectual context of the time, the development of Smith's ideas and how they contributed to the theory of evolution and more generally to a dawning realization of the true age of the earth.

The book describes the social, economic or industrial context for Smith's insights and work, such as the importance of coal mining and the transport of coal by means of canals, both of which were a stimulus to the study of geology and the means whereby Smith supported his research. Benett debated many of the ideas Smith put forward. She was luckier than Smith financially, coming from a wealthy family, a financial perk that allowed her the freedom to add fossils to her curiosity cabinet at will.

Most of her impressive collection was assumed lost in the early 20th century. It was later found and purchased by an American, Thomas Bellerby Wilson, who donated it to the Academy of Natural Sciences of Philadelphia. Small parts of it made their way into British museums, including the Leeds City Museum, London, Bristol and to the University of St. Petersburg. These collections contain many type specimens and some of the very first fossils found — some with the soft tissues preserved. When Benett died in 1845, it was Mantell who penned her obituary for the London Geological Journal.

In 1989, almost a hundred and fifty years after her death, a review of her collection had Arthur Bogen and Hugh Torrens remark that her work has significantly impacted our modern understanding of Porifera, Coelenterata, Echinodermata, and the molluscan classes, Cephalopoda, Gastropoda, and Bivalvia. A worthy legacy, indeed.

Her renown lives on through her collections, her collaborations and through the beautiful 110 million-year-old ammonite you see here, Hoplites bennettiana. The lovely example you see here is in the collection of the deeply awesome Christophe Marot.

Spamer, Earle E.; Bogan, Arthur E.; Torrens, Hugh S. (1989). "Recovery of the Etheldred Benett Collection of fossils mostly from Jurassic-Cretaceous strata of Wiltshire, England, analysis of the taxonomic nomenclature of Benett (1831), and notes and figures of type specimens contained in the collection". Proceedings of the Academy of Natural Sciences of Philadelphia. 141. pp. 115–180. JSTOR 4064955.

Torrens, H. S.; Benamy, Elana; Daeschler, E.; Spamer, E.; Bogan, A. (2000). "Etheldred Benett of Wiltshire, England, the First Lady Geologist: Her Fossil Collection in the Academy of Natural Sciences of Philadelphia, and the Rediscovery of "Lost" Specimens of Jurassic Trigoniidae (Mollusca: Bivalvia) with Their Soft Anatomy Preserved.". Proceedings of the Academy of Natural Sciences of Philadelphia. 150. pp. 59–123. JSTOR 4064955.

Photo credit: Fossils from Wiltshire.  In the foreground are three examples of the echinoid, Cidaris crenularis, from Calne, a town in Wiltshire, southwestern England, with bivalves behind. Caroline Lam, Archivist at the Geological Society, London, UK. http://britgeodata.blogspot.com/2016/03/etheldred-benett-first-female-geologist_30.html

Photo credit: Fossil sponges Polypothecia quadriloba, from Warminster, Wiltshire. The genus labels are Benett’s, as is the handwriting indicating the species. The small number, 20812, is the Society’s original accession label from which we can tell that the specimen was received in April 1824. The tablet onto which the fossils were glued is from the Society’s old Museum.

AMMONITE TIME KEEPERS

Argonauticeras besairei, José Juárez Ruiz

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

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

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

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

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

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

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

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

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

The Ammonoidea can be divided into six orders:

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

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

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

Hoplites bennettiana (Sowby, 1826) Christophe Marot

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

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

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

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

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

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

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

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

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

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

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

Photos: Argonauticeras besairei from the awesome José Juárez Ruiz.

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

JOSE BONAPARTE: MASTER OF THE MESOZOIC

One of the most delightful palaeontologists to grace our Earth was José Fernando Bonaparte (14 June 1928 – 18 February 2020). 

We often think of those who have shaped our past and found many of the firsts of their region as living in ancient history, but José left us just this past year in February. 

He was a prolific and hard-working Argentinian palaeontologist who you'll know as the discoverer of some of Argentina's iconic dinosaurs — Carnotaurus, along with Amargasaurus, Abelisaurus, Argentinosaurus and Noasaurus. 

His first love was mammals and over the course of his career, he unearthed the remains of some of the first South American fossil mammals from the Mesozoic. 

Between 1975 and 1977, Bonaparte worked on excavation of the Saltasaurus dinosaur with Martín Vince and Juan C. Leal at the Estancia "El Brete."  Bonaparte was interested in the anatomy of Saltasaurus, particularly the armoured plates or osteoderms embedded in its skin. 

Based on this discovery, together with twenty examples of Kritosaurus australis and a lambeosaurine dinosaur found in South America, Bonaparte hypothesized that there had been a large-scale migration of species between the Americas at the end of the Mesozoic period.

The supercontinent of Pangea split into Laurasia in the north and Gondwana in the south during the Jurassic. During the Cretaceous, South America pulled away from the rest of Gondwana. The division caused a divergence between the northern biota and the southern biota, and the southern animals appear strange to those used to the more northerly fauna. 

Bonaparte's finds illustrate this divergence. His work is honoured in his moniker given to him by palaeontologist Robert Bakker — "Master of the Mesozoic."

If you fancy a listen, he is the honoured guest in absentia on an episode of the Fossil Huntress Podcast. You can find the link here to listen: https://anchor.fm/.../Jos-Bonaparte-Master-of-the...

FOSSILS OF THE NORTH SEA

A lovely 12 cm creamy orange Bottlenose Dolphin, Tursiops sp. lumbar vertebrae found in the Brown Bank area of the North Sea, one of the busiest seaways in the world.

Bottlenose dolphins first appeared during the Miocene and swam the shallow seas of this region. We still find them today in warm and temperate seas worldwide though unlike narwhal, beluga and bowhead whales, Bottlenose dolphins avoid the Arctic and Antarctic Circle regions. 

Their name derives from the Latin tursio (dolphin) and truncatus for their characteristic truncated teeth

We find their remains in the sediments of the North Sea. There are two known fossil species from Italy that include Tursiops osennae (late Miocene to early Pliocene) from the Piacenzian coastal mudstone, and Tursiops miocaenus (Miocene) from the Burdigalian marine sandstone.

Many waterworn vertebrae from the Harbour Porpoise Phocoena sp., (Cuvier, 1816), Bottlenose dolphin Tursiops sp. (Gervais, 1855), and Beluga Whale, Delphinapterus sp. (Lacépède‎, 1804‎) are found by fishermen as they dredge the bottom of the Brown Bank, one of the deepest sections of the North Sea.  

The North Sea is a sea of the Atlantic Ocean located between the United Kingdom, Denmark, Norway, Germany, the Netherlands, Belgium and France. An epeiric sea on the European continental shelf, it connects to the ocean through the English Channel in the south and the Norwegian Sea in the north.

The fishermen use small mesh trawl nets that tend to scoop up harder bits from the bottom. This technique is one of the only ways this Pleistocene and other more recent material is recovered from the seabed, making them relatively uncommon. The most profitable region for fossil mammal material is in the Brown Bank area of the North Sea. I've circled this area on the map below to give you an idea of the region.

Brown Bank, North Sea, Pleistocene Dredging Area

In May 2019, an 11-day expedition by European scientists from Belgium and the United Kingdom was undertaken to explore three sites of potential geologic and archaeologic interest in the southern North Sea. 

It has long been suspected that the southern North Sea plain may have been home to thousands of people, and chance finds by fishermen over many decades support this theory. 

A concentration of archaeological material, including worked bone, stone and human remains, has been found within the area around the Brown Bank, roughly 100 km due east from Great Yarmouth and 80 km west of the Dutch coast. The quantities of material strongly suggest the presence of a prehistoric settlement. As such the Brown Bank provides archaeologists with a unique opportunity to locate a prehistoric settlement in the deeper and more remote areas of the North Sea, known today as Doggerland.

Until sea levels rose at the end of the last Ice Age, between 8-10,000 years ago, an area of land connected Great Britain to Scandinavia and the continent.  It has long been suspected that the southern North Sea plain was home to thousands of people, and chance finds by fishermen over many decades support this theory. 

Over the past decades a concentration of archaeological material, including worked bone, stone and human remains, has been found within the area around the Brown Bank, roughly 100 km due east from Great Yarmouth and 80 km west of the Dutch coast. 

The quantities of material strongly suggest the presence of a prehistoric settlement. 

As such the Brown Bank provides archaeologists with a unique opportunity to locate a prehistoric settlement in the deeper and more remote areas of the North Sea, known today as Doggerland.

Prospecting for such a settlement within the North Sea is a challenging activity.  Multiple utilities cross the area, bad weather is frequent, and visibility underwater is often limited.  Given these challenging conditions, researchers on the Belgian vessel, RV Belgica, used acoustic techniques and physical sampling of the seabed to unravel the topography and history of the areas chosen for the survey.  

During the survey, the team used a novel parametric echosounder from the Flanders Marine Institute (VLIZ). This uses sonar technology to obtain images of the sub-bottom with the highest possible resolution and was combined with the more traditional “sparker” seismic source to explore deeper sediments.  On the Brown Bank, the Belgica also deployed a grab and a Gilson dredge for sampling near-surface stratigraphy. Video footage was collated using VLIZ’s dedicated video frame and a simpler GoPro mounted on the Gilson dredge. A video showing the equipment in operation on the expedition can be seen at https://youtu.be/sGKfyrDCtmw

Additional reading: http://www.vliz.be/en/press-release/update-research-prehistoric-settlements-North-Sea

HOLLARDOPS: LE MAÎTRE

Hollardops sp. Devonian Trilobite

Hollardops is a genus of trilobite in the order Phacopida that lived during the Eifelian of the Middle Devonian. It was described by Le Maître in 1952 under type species Metacanthina mesocristata. 

The genus underwent reclassification in 1997 and emerged as Hollardops. We find this extinct arthropod in present-day Morocco. They share similarities with Greenops of New York and Canada but are generally larger than most Greenops species.

Hollardops have schizochroal eyes and a glabella that is slightly raised on the surface of the cephalon. Genal spines extend from the cephalon and extend to approximately the 6th thoracic segment.

Hollardops has eleven thoracic segments and also has five pairs of spines extending from the segments of the pygidium. Length ranges from approximately 3 to 9 cm.

Palaeo Coordinates — If you are a keen bean to head out in search of this lovely yourself, head to the Tazoulait Formation at Jbel (Jebel) Oufatène 30.8374368°N 4.9018067°W and Issimour 30.9669834°N 5.0373266°W SE of Alnif, western of Oued Alnif, Ma'ider region, Morocco.