GENTLE GENTOO PENGUINS

These black, white and grey cuties — looking very smart in their natural colouring akin to formal wear — are gentoo penguins.

They are foraging predators — dining on crustaceans, fish and squid in the cold nearshore waters of the Antarctic Peninsula, Falkland Islands, South Georgia and Sandwich Islands.

South Georgia, the South Sandwich Islands and the Falklands are inhospitable British Overseas Territories in the southern Atlantic Ocean.

The first scientific description of these romantic seabirds was done by Johann Reinhold Forster in 1781. He used the Falkland Islands population for both the type specimen and locality. These diminutive penguins are in the genus Pygoscelis, and are most closely related to their penguin cousins — the Adélie and Chinstraps. 

The gentoo penguin is one of three species in the genus Pygoscelis. Mitochondrial and nuclear DNA evidence suggests the genus split from other penguins around 38 million years ago, about 2 million years after the ancestors of the genus Aptenodytes. 

In turn, the Adelie penguins split off from the other members of the genus around 19 million years ago, and the chinstrap and Gentoo finally diverged around 14 million years ago.

Very fetching Gentoo penguins

Two subspecies of this penguin are recognised: Pygoscelis papua papua (the subantarctic Gentoo) and the smaller Pygoscelis papua ellsworthi (the Antarctic Gentoo). 

We will likely need to reclassify the gentle Gentoos into a species complex of four morphologically similar but separate species: the northern gentoo penguin (P. papua sensu stricto), the southern gentoo penguin (P. ellsworthi), the eastern gentoo penguin (P. taeniata), and the newly-described South Georgia gentoo penguin (P. poncetii).

We find breeding colonies of gentoo penguins on ice-free surfaces either directly on the shoreline or far inland. 

They prefer shallow coastal areas and often nest between tufts of grass. In South Georgia, breeding colonies are 2 km inland. 

In colonies farther inland, where the penguins nest in grassy areas, they shift location slightly every year because the grass will become trampled over time.

Gentoos breed on many sub-Antarctic islands. The main colonies are on the Falkland Islands, South Georgia and the South Sandwich Islands, and Kerguelen Islands; smaller colonies are found on Macquarie Island, Heard Islands, Crozet Islands, South Shetland Islands, and the Antarctic Peninsula. 

Their breeding populations number well over 600,000 birds. Once a breeding pair decide that their romance is a go, they stay together for life. 

These lovelies breed monogamously and infidelity is frowned upon. Punishment is banishment from the colony — strict but these birds know how to draw a firm line in the pebbles. 

Nests are usually made from a roughly circular pile of stones and can be quite large — up to 20 cm (7.9 in) high and 25 cm (9.8 in) in diameter. The chosen rocks are prized and jealously guarded. 

Just who owned which pebble is the subject of many noisy debates — some escalating to nasty physical altercations between disagreeing parties. "That rock is mine. Mine!" 

The pebbles are especially prized by the females, to the point that a male penguin can woo his lady love and secure a lifetimes' devotion by proffering a particularly choice stone — not unlike some human females.

TRIASSIC FOSSILS OF SVALBARD

Ice, Snow, Reindeer & Ichthyosaurs — Svalbard is just what I imagine my version of Valhalla to be like, without all the mead, murder and mayhem. 

Svalbard is a Norwegian archipelago between mainland Norway and the North Pole. 

One of the world’s northernmost inhabited areas, it is known for its rugged, remote terrain of glaciers and frozen tundra sheltering polar bears, reindeer and Arctic fox. 

The Northern Lights or Nordlys 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. 

I was asked recently if folk head out in the torrential rain or ice and snow to fossil collect. I would generally say yes for those where the potential prize always outweighs the weather. For Svalbard, it is a resounding yes. 

You have to remove the snow cover — or ice if you are impatient or unlucky — to get to the outcrops here. It is well worth the effort. Beneath the icy cover, you find lovely ammonoids and bivalves. 

Tastier still, ichthyosaur remains are found here. We had been expecting to, but it was not until the early 2000s that the first bones were found after a whole lot of looking.

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 spatial 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.

Svalbard was so remote that there were no First Nation settlements. It is certainly possible an earlier people came through these islands, but they did not leave any trace of their travels. 

The first documented travellers to explore Spitsbergen arrived in 1795 as part of a hunting expedition. They included people from the arctic town of Hammerfest in Norway's far north. They were an excellent choice as they were used to barren, inhospitable lands and sailed to discover more. 

We know them as the Coast Sámi — a hearty, rugged people probably best known in history for their chieftain, Ottar. He left Hammerfest in the 9th century to visit then join King Alfred the Great's court in a newly forming England. 

Expeditions to the remote islands of Svalbard continued into the early 1800s and finally, a settlement was eked out of the cold landscape and slowly expanded to the rest of the century. While today the islands are called Svalbard, I would have named them for the Norwegian word for remote — fjernkontroll.

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

Daonella and Monotis are important species for our understanding of biostratigraphy in the Triassic and are useful as Index fossils. 

Index fossils are fossils used to define and identify geologic periods (or faunal stages). To be truly useful, they need to have a short vertical range, wide geographic distribution and rapid evolutionary development.

Daonellids preferred soft, soupy substrates and we tend to find them in massive shell beds. Generally, if you find one, you find a whole bunch cemented together in coquina. The lovely block you see here is in the collections of the deeply awesome John Fam. 

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LANDMANNALAUGAR: AURORA BOREALIS

The Northern Lights over a sea of wildflowers in the marsh near Landmannalaugar, part of the Fjallabak Nature Reserve in the Highlands of Iceland.

Landmannalaugar is at the northern tip of the Laugavegur hiking trail that leads through natural geothermal hot springs and an austere yet poetically beautiful landscape. 

Here, you can see the Northern Lights play through the darkness of a night sky without light pollution and bask in the raw geology of this rugged land.

The Fjallabak region takes its name from the numerous wild and rugged mountains with deeply incised valleys, which are found there. 

The topography of the Torfajokull, a central volcano found within the Fjallabak Nature Reserve, is a direct result of the region being the largest rhyolite area in Iceland and the largest geothermal area (after Grimsvotn in Vatnajokull).

The Torfajokull central volcano is an active volcanic system but is now in a declining fumarolic stage as exemplified by numerous fumaroles and hot springs. The hot pools at Landmannalaugar are but one of many manifestations of geothermal activity in the area, which also tends to alter the minerals in the rocks, causing the beautiful colour variations from red and yellow to blue and green, a good example being Brennisteinsalda. Geologists believe that the Torfajokull central volcano is a caldera, the rim being Haalda, Suðurnamur, Norður-Barmur, Torfajokull, Kaldaklofsfjoll and Ljosartungur.

The bedrock of the Fjallabak Nature Reserve dates back 8-10 million years. At that time the area was on the Reykjanes – Langjokull ridge rift zone. 

The volcano has been most productive during the last 2 million years, that is during the last Ice Age Interglacial rhyolite lava (Brandsgil) and sub-glacial rhyolite (erupted under ice/water, examples being Blahnukur and Brennisteinsalda are characteristic formations in the area. 

To the north of the Torfajokull region, sub-glacial volcanic activity produced the hyaloclastites (Moberg) mountains, such as Lodmundur and Mogilshofdar.

On March 19, 2021, a volcanic eruption started in the Geldingadalir valley at the Fagradalsfjall mountain on the Reykjanes peninsula, South-West Iceland. The volcano is situated approximately 30 km from the country’s capital city, Reykjavík. The eruption is ongoing and the landscape in the valley and its surrounding area is constantly changing as a result.

Prior to the eruptive display earlier this year, volcanic activity over the past 10.000 years has been restricted to a few northeast-southwest fissures, the most recent one, the Veidivotn fissure from 1480, formed Laugahraun (by the hut at Landmannalaugar), Namshraun, Nordurnamshraun, Ljotipollur and other craters which extend 30 km, further to the north Eruptions in the area tend to be explosive and occur every 500 – 800 years, previous known eruptions being around AD 150 and 900.

HALENDID: ICELANDIC HIGHLANDS

Glaciers, mountains, active volcanoes — Iceland has it all. 

Sitting at the junction of the North Atlantic and Arctic Oceans is the ruggedly beautiful island of Iceland. It is Europe's second-largest island after Great Britain. 

Geologically, Iceland is part of the Mid-Atlantic Ridge — a wee bit of the oceanic crust sitting just above a mantle plume, hence all the showy volcanic eruptions and lava flows.

The interior of Iceland is usually referred to as the central highlands or as the locals call it — Halendid — which roughly translates to Highlands in Icelandic. It is considered one of the last great wilderness areas in all of Europe, covering nearly 40,000 square kilometres. Truly one of the last untamed regions on earth. Halendid contains high concentrations of waterfalls, volcanoes, glaciers, and rivers. Large expanses of black sand, lava fields, and fragile vegetation are found throughout the region.

Still, one of the features that make this region so unique are the rivers. These rivers carry glacial runoff and sediment from the interior of the island to the ocean. Along the way, this mix of minerals and water produces dramatic colours, complex systems, and vibrant patterns.

AMMONITE TIME PIECE: INDEX FOSSILS

Ammonites were prolific breeders that evolved rapidly. If you could cast a fishing line into our ancient seas, it is likely that you would hook an ammonite, not a fish.

They were prolific back in the day, living — and sometimes dying — in schools in oceans around the globe.  We find ammonite fossils, and plenty of them, in sedimentary rock from all over the world. In some cases, we find rock beds where we can see evidence of a new species that evolved, lived and died out in such a short time span that we can walk through time, following the course of evolution using ammonites as a window into the past.

For this reason, they make excellent index fossils. An index fossil is a species that allows us to link a particular rock formation, layered in time with a particular species or genus found there. Generally, deeper is older, so we use the sedimentary layers of rock to match up to specific geologic time periods, rather like the way we use tree rings to date trees.

GORGONS: APEX PREDATORS OF THE PERMIAN

The Mighty Gorgons — Apex Predators of the Permian. 

Back in the Paleozoic, some 540 million years ago, life in the seas was teaming with life but life on life amounted to a bit of moss and some low fungi. 

Cut to 240 million years later, the vertebrate animals evolved and a huge spectrum of variety was living on land. 

Gorgons or Gorgonopsia were sabre-toothed therapsids who roamed our ancient Earth from the Middle to Upper Permian — 265 to 252 million years ago — with their long claws, lizard eyes and massive canines.

I learned about the Karoo, and indeed the Gorgons, by a book of the same name by the deeply awesome Peter Ward. His introduction to what life and fieldwork are like in the arid, inhospitable ancestral home of the Gorgons in South Africa made me laugh out loud. It is a highly enjoyable read.

The Great Karoo formed in a vast inland basin 320 million years ago, at a time when the part of Gondwana which would eventually become Africa lay over the South Pole. The Karoo records a wonderful time in our evolutionary history when the world was inhabited by interesting amphibians and mammal-like reptiles — including the apex predators of the day, the Gorgons.

The link below will take you to the Fossil Huntress Podcast where you can travel back in time to visit the Great Karoo with me.

https://anchor.fm/.../The-Great-Karoo-of-South-Africa...

If you fancy a read, check out more geeky goodness over on the ARCHEA blog at https://fossilhuntress.blogspot.com/

If you like podcasts, check out the Fossil Huntress — Palaeo Sommelier Podcast at https://anchor.fm/fossil-huntress

Fossil Huntress Geeky Goodness on YouTube:

https://www.youtube.com/channel/UCUerL9urNX8fHb6nHc_vrBQ

Photo: National Geographic

LIPAROCERAS IN SEPTARIAN NODULE

Robin Hoods Bay is a small fishing village and a bay located in the North York Moors National Park, 5 miles (8 km) south of Whitby and 15 miles (24 km) north of Scarborough on the coast of North Yorkshire, England. 

Bay Town, its local name, is in the ancient chapelry of Fylingdales in the wapentake of Whitby Strand.

Here, 552 kilometres (343 miles) to the north of the Kimmeridge Clay exposures, near the picturesque town of Robin Hoods Bay on the Yorkshire Coast we find beautiful septarian nodules — and when we are very lucky, ammonites and other fossilized material along with them.

These photos show a delightful example of a lovely Liparoceras sp. from Robin Hoods Bay with some interesting septarian veins radiating away from the ammonite. The awesome Harry Tabiner gets full credit — and my unending respect — for the find, preparation and photo of this lovely Lower Jurassic, Lower Lias specimen.

Around Robin Hood’s Bay, well-developed platforms cut across outcrops of Liassic shales. The cliffs are primarily till resting on the Lias. Cliff falls at this location are common. The cliffs are about 50 m in height in the northern part of the bay where they are cut by two steep-sided valleys, Mill Beck and Stoupe Beck. Here the Lower Lias forms most of the slope, with near-vertical lower cliffs comprised entirely of Lower Lias rocks.

The rocks in the lower cliffs are dark grey marine shales from the Redcar Mudstone Formation. The Lias Group at Robin Hood’s Bay is represented, in ascending order, by the Redcar Mudstone Formation, Staithes Sandstone Formation, Cleveland Ironstone Formation and Whitby Mudstone Formation and contains stratotypes for several zones and horizons.

Most fossils are found either from the foreshore exposures during scouring conditions or in rocks, boulders and nodules. They can also be found after cliff falls. To search for septarian nodules, head north for several miles along the coast from Robin Hoods Bay.

Be mindful of the tides as this location should only be attempted on a retreating tide. Minerals can be found in both the large Septarian nodules and partially replacing the many fossilized tree limbs and roots found in the sandstone blocks from higher up in the cliffs. This site can be dangerous and is not appropriate for children.

To look for fossils, search through the rocks and concretions along the foreshore. Ammonites can often be found this way, but you will need the right tools and good eye protection.

Fossils loose on the foreshore are rare. You generally need to work for finds at this location. A few good storms help with collecting here. Robin Hood’s Bay yields little during the summer months. The best time to collect is after the winter storms.

The north side of the bay is rich in ammonite remains and these can mostly be found after cliff falls. The ammonites (Platypleuroceras, Tropidoceras, Acanthopleuroceras and Androgynoceras) can be found, along with the large bivalve, Pinna. Within the calcareous shales, exposed in the low tide reefs at the centre of the bay, you can find the ammonites, Arnioceras and Caenisites.

Robin Hoods Bay Directions from the good folk at UK Fossils Network:

At Robin Hood’s Bay village, you can park in either the small car park at the top of the hill or the second larger one just a short walk away.

• From here, the best end to visit is the north side. You will find a footpath at the top of the hill, to the left of the main street leading to the beach. This winds around and passes a picnic area.
• You can also visit the south and middle part of the bay. To do this, go down into the main street at the bottom of the hill and follow round to the right. You will see some steps, which follow the sea defence and lead to the shore.
• Paleo-coordinates: 54.43442°N, 0.53079°W

Photos: The deeply awesome Harry Tabiner gets full credit (and my unending respect) for the find, preparation and photo of this lovely Liparoceras sp. in a septarian nodule, Lower Jurassic, Lower Lias specimen.

Reference: Humberside Geologist No. 14, Humberside Geologist Online, The geology of East Yorkshire coast.http://www.hullgeolsoc.co.uk/hg146t.htm

Reference: UK Fossils Network: https://ukfossils.co.uk/2007/03/18/robin-hoods-bay/ This website provides a wealth of information and is very well done. Highly recommend checking them out!
Reference: https://www.mindat.org/loc-267536.html

ROCKY MOUNTAIN TRENCH

Trapper Cabin on Isaac Lake / Bowron Provincial Park

The Bowron Canoe Circuit is a 149,207 hectare geologic wonderland, where a fortuitous combination of plate tectonics and glacial erosion have carved an unusual 116 kilometre near-continuous rectangular circuit of lakes, streams and rivers bound on all sides by snow capped mountains.

From all descriptions, something like heaven.

The east and south sides of the route are bound by the imposing white peaks of the Cariboo Mountains, the northern boundary of the Interior wet belt, rising up across the Rocky Mountain Trench, and the Isaac Formation, the oldest of seven formations that make up the Cariboo Group (Struik, 1988).

Some 270 million years ago, had one wanted to buy waterfront property in what is now British Columbia, you’d be looking somewhere between Prince George and the Alberta border. The rest of the province had yet to arrive but would be made up of over twenty major terranes from around the Pacific. The rock that would eventually become the Cariboo Mountains and form the lakes and valleys of Bowron was far out in the Pacific Ocean, down near the equator.

With tectonic shifting, these rocks drifted north-eastward, riding the continental plate until they collided with and joined the Cordillera in what is now British Columbia. Continued pressure and volcanic activity helped create the tremendous slopes of the Cariboo Range we see today with repeated bouts of glaciation during the Pleistocene carving their final shape.

PLIENSBACHIAN APODEROCERAS OF DORSET

The lovely large specimen (macroconch) of Apoderoceras pictured here is likely a female. Her larger body perfected for egg production.

Apoderoceras is a wonderful example of sexual dimorphism within ammonites as the macroconch (female) shells grew to diameters in excess of 40 cm – many times larger than the diameters of the smaller microconch (male) shells.

Apoderoceras has been found in the Lower Jurassic of Argentina, Hungary, Italy, Portugal, and most of North-West and central Europe, including as this one is, the United Kingdom. This specimen was found on the beaches of Charmouth in West Dorset and prepped by the wonderfully talented Lizzie Hingley.

Neither Apoderoceras nor Bifericeras donovani are strictly index fossils for the Taylori subzone, the index being Phricodoceras taylori. Note that Bifericeras is typical of the earlier Oxynotum Zone, and ‘Bifericeras’ donovani is doubtfully attributable to the genus. The International Commission on Stratigraphy (ICS) has assigned the First Appearance Datum of genus Apoderoceras and of Bifericeras donovani the defining biological marker for the start of the Pliensbachian Stage of the Jurassic, 190.8 ± 1.0 million years ago.

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

The Pacific ammonite Andicoeloceras, known from Chile, appears quite closely related and may be ancestral, but the time correlation of Pacific and NW European ammonite faunas is challenging. Even if Andicoeloceras is ancestral to Apoderoceras, no other preceding ammonites attributable to Coeloceratidae are known. We may yet find clues in the Lias of Canada. Apoderoceras remains present in NW Europe throughout the Taylori Subzone, showing endemic evolution. It becomes progressively more inflated during this interval of time, the adult ribs more distant, and there is evidence that the diameter of the macroconch evolved to become larger. At the end of the Taylori Subzone, Apoderoceras disappeared as suddenly as it appeared in the region, and ammonite faunas of the remaining Jamesoni Zone are dominated by the Platypleuroceras–Uptonia lineage, generally assigned (though erroneously) to the Family Polymorphitidae.

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

DACTYLIOCERAS OF THE HOLDERNESS

Dactylioceras ammonite, Photo: Harry Tabiner

A lovely Dactylioceras ammonite from the Lower Jurassic Upper Lias Holderness of the Yorkshire Coast. This beauty measures over 8cm with especially attractive colouring.

Holderness is an area of the East Riding of Yorkshire, on the east coast of England. An area of rich agricultural land, Holderness was marshland until it was drained in the Middle Ages. Topographically, Holderness has more in common with the Netherlands than with other parts of Yorkshire. To the north and west are the Yorkshire Wolds.

Geologically, Holderness is underlain by Cretaceous chalk but in most places, it is so deeply buried beneath glacial deposits that it has no influence on the landscape.

The landscape is dominated by deposits of till, boulder clays and glacial lake clays. These were deposited during the Devensian glaciation. The glacial deposits form a more or less continuous lowland plain which has some peat filled depressions (known locally as meres) which mark the presence of former lake beds. There are other glacial landscape features such as drumlin mounds, ridges and kettle holes scattered throughout the area.

Dactylioceras ammonite, Photo: Harry Tabiner

The well-drained glacial deposits provide fertile soils that can support intensive arable cultivation. Fields are generally large and bounded by drainage ditches. There is very little woodland in the area and this leads to a landscape that is essentially rural but very flat and exposed. The coast is subject to rapid marine erosion.

The Geology of Yorkshire in northern England shows a very close relationship between the major topographical areas and the geological period in which their rocks were formed. The rocks of the Pennine chain of hills in the west are of Carboniferous origin whilst those of the central vale are Permo-Triassic.

The North York Moors in the north-east of the county are Jurassic in age while the Yorkshire Wolds to the southeast are Cretaceous chalk uplands. The plain of Holderness and the Humberhead levels both owe their present form to the Quaternary ice ages.

The strata become gradually younger from west to east. Much of Yorkshire presents heavily glaciated scenery as few places escaped the direct or indirect impact of the great ice sheets as they first advanced and then retreated during the last ice age. This beauty is in the collection of the deeply awesome Harry Tabiner.

CRETACEOUS AFRICA SUPER CROC

Sarcosuchus imperator

An impressive Super Croc tooth and scute from Sarcosuchus imperator, an extinct genus of giant crocodile-like reptiles that lived in the rivers of an ancient tropical plain in the Sahara of Africa during the Lower Cretaceous.

Sarcosuchus were ambush hunters, eating anything that entered their watery homes from wee fish to large dinosaurs. These big beasties were the precursors to our modern crocodiles -- and they were big. Really big. 

Almost twice as large as their modern saltwater cousins, weighing in at 8-10 tons. They lived 50-60 years. Modern Saltwater & Nile crocodiles live 70-100 years on average. This scute and tooth are from the Elrhaz Formation, Gadoufaoua, Ténéré Desert, Niger. Photo care of the deeply awesome Andy Chua.

SARCOSUCHUS IMPERATOR

This mighty beast is Sarcosuchus. He is an extinct genus of crocodyliform, so not quite a crocodile as we know them but the distant relative of crocodylians that lived ~129-112 million years ago. 

We have learned about them through fossil remains that date from the Lower Cretaceous of what is now Africa and South America.

Strictly speaking, Sarcosuchus was not a crocodile as we know them today, but a kind of pre-crocodile. These early croc-types were Crocodylomorphs.

This crocodylian lineage (clade Pseudosuchia, formerly Crurotarsi) was a very diverse and adaptive group of reptiles. We used to lump all known living and extinct crocodiles indiscriminately into the order Crocodilia. Sometime in the late 1980s, we finally moved all living species into the order Crocodilia, segregating closely related extinct relatives such as Mekosuchus. Our true "modern" crocodiles, now all safely ensconced in the order Crocodilia without their ancient ancestors, arrived millions of years after the first crocodylomorphs, with the first members of the modern species arriving on the scene in the Upper Cretaceous.

The Crocodylomorpha were a very ancient group of animals, at least as old as the dinosaurs, who evolved into a very diverse spectrum of weird and wonderful forms you might not recognize as croc-like. During the Jurassic and the Cretaceous, marine Crocodylomorphs in the family Metriorhynchidae, such as Metriorhynchus, evolved forelimbs that were paddle-like and had a tail similar to modern fish. Dakosaurus andiniensis, a species closely related to Metriorhynchus, had a skull that was adapted to feast upon large marine reptiles. We see several (unexpected) herbivorous terrestrial species during the Cretaceous, such as the tiny and adorable Simosuchus clarki and Chimaerasuchus paradoxus, both roughly the size of a dog. During the Cenozoic, a number of lineages left their ancient river homes and became wholly terrestrial predators.

Sarcosuchus was one of the largest early crocodile-like reptiles, reaching up to 9.5 m in body length and weighing up to 8 to 10 tons. He was almost twice as long as our modern saltwater crocodiles, so one big croc! These big beasts lived and hunted in ancient rivers, grabbing and crushing prey that came too close to the water.

The first remains were discovered during field expeditions in the Sahara led by French paleontologist, Albert-Félix de Lapparent, from 1946 to 1959. Remains were found of skull fragments, vertebrae, teeth, and scutes.

In 1964, an almost complete skull was found in Niger by the French CEA, but it was not until 1997 and 2000 that most of its anatomy became known to science when an expedition led by the American paleontologist Paul Sereno discovered six new specimens, including one with about half the skeleton intact and most of the spine.

A common method to estimate the size of crocodiles and crocodile-like reptiles is the use of the length of the skull measured in the midline from the tip of the snout to the back of the skull table since in living crocodilians there is a strong correlation between skull length and total body length in subadult and adult individuals irrespective of their sex, this method was used by Sereno et al. (2001) for Sarcosuchus due to the absence of a complete enough skeleton. Two regression equations were used to estimate the size of S. imperator, they were created based on measurements gathered from 17 captive gharial individuals from northern India and from 28 wild saltwater crocodile individuals from northern Australia, both datasets supplemented by available measurements of individuals over 1.5 m (4.92 ft) in length found in the literature.

The largest known skull of Sarcosuchus imperator (the type specimen) is 1.6 m (5.25 ft) long (1.5 m (4.92 ft) in the midline), and it was estimated that the individual it belonged to had a total body length of 11.65 m (38.2 ft), its snout-vent length of 5.7 m (18.7 ft) was estimated using linear equations for the saltwater crocodile and in turn, this measurement was used to estimate its body weight at 8 tonnes (8.8 short tons). These new measurements meant Sarcosuchus was able to reach a maximum body size not only greater than previously estimated but also greater than that of the Miocene "Beak crocodile" Rhamphosuchus, the Late Cretaceous Deinosuchus crocodilian related to our modern alligators, and the Miocene Purussaurus.

However, extrapolation from the femur of a subadult individual as well as measurements of the skull width further showed that the largest S. imperator was significantly smaller than was estimated by Sereno et al. (2001) based on modern crocodilians. O’Brien et al. (2019) estimated the length of the largest S. imperator specimen at 9.5 meters and body weight at 4.7 tons based on longirostrine crocodylians skull width to total length ratio. This estimate is very close to the femur based estimate is 9.1 m (29.9 ft).

Sereno, Paul C.; Larson, Hans C. E.; Sidor, Christian A.; Gado, Boubé (2001). "The Giant Crocodyliform Sarcosuchus from the Cretaceous of Africa". Science. 294 (5546): 1516–9. Bibcode:2001Sci...294.1516S. doi:10.1126/science.1066521. PMID 11679634.

OUR EARLY ATMOSPHERE

Our early Earth was a molten world

When the Earth formed 4.5 billion years ago, it was an inhospitable place. 

Even with a Sun some 25 per cent weaker than it is today, ours was a molten world that needed to undergo a long period of cooling before the conditions for life would arise.

And arise they did. On the planet's surface, volcanoes spewed lava and volatile gasses into what would become our earliest atmosphere. 

Again, in composition, it looked very different from the one we know today. Nitrogen, carbon dioxide, ammonia, methane and small amounts of water vapour made up the gassy soup surrounding our world.

But that first water would change everything. As the water vapour condensed, it came back to the surface bit by bit. Over a very long period of time, those waters pooled and gathered and became our first oceans. It was in this early ocean some 2.7 billion years ago that cyanobacteria, or blue-green algae, wonderous photosynthetic microbes, would take up that weakened sunlight and water vapour to process the carbon dioxide from the atmosphere, producing other chemical compounds and oxygen as a by-product.  

RED LIPPED BATFISH

Red Lipped Batfish, Ogcocephalus darwini

This sexy monkey with her luscious red pucker is a Red Lipped Batfish, Ogcocephalus darwini.

Our world's oceans have some of the most amazing, beautiful, ugly and interesting creatures on the planet. Red Lipped Batfish are no exception. They can be found along the sandy ocean floor and reefs around the Galapagos Islands and off the shores of Peru.

Their most distinguishing feature is revealed in their name and one look at this photo gives it away — they have very distinctive bright red lips. They also have a rather fetching illicium, the dangling projection you see here. It's a lure to attract prey to those luscious lips so she can enjoy a tasty snack. Above the illicium is an esca, an unusual feature that emits a bright light. Between the light and the lure, small fish and curious invertebrates — shrimp, molluscs, crab — deep in the Southeast Pacific investigate the light and get swallowed up by those lips.

Most of their flattened flounder-like bodies are light brown and a greyish in colour with white colouring on the underside. They are roughly the size of a dinner plate. On the top side of the batfish, there is usually a dark brown stripe starting at the head and going down the back to the tail.

Their face has a definite red sheen. Comically, with the red face and bored expressions, it looks like they're perpetually unimpressed and slightly embarrassed.

Once you get past those lips, the next thing that stands out with these interesting beauties is how they move. They're not terribly good swimmers but do walk rather well on their highly adapted fins. They march or waddle across the seafloor in search of more interesting sights to practise the art of deep-sea fishing.

Batfish are descendants of lophiiform fishes. In 2011, a new genus and species of batfish, Tarkus squirei, was described from Eocene (Ypresian) limestone deposits in the celebrated locality of Monte Bolca, Italy. Tarkus squirei was a tropical batfish that inhabited the inner-shelf palaeobiotopes of the central-western Tethys Sea.  Tarkus gen. nov. shows a certain degree of phenetic affinity with the extant shallow-water batfish genera Halieutaea and —more particularly — Halieutichthys. The specimens of this taxon are the first articulated skeletal remains of the Ogcocephalidae ever recorded as fossils, also representing the oldest members of the family known to date.

Reference: CARNEVALE, G., & PIETSCH, T. (2011). Batfishes from the Eocene of Monte Bolca. Geological Magazine, 148(3), 461-472. doi:10.1017/S0016756810000907

FROM RUSSIA WITH LOVE: AULACOSTEPHANUS

A beautiful example of Aulacostephanus undorae (Pavlow, 1886), a Late Jurassic, Upper Kimmeridgian, upper zone Eudoxus ammonite from an old quarry near the river Serena, near the village Lipitsy, Kaluga Region, Russia. 

Kaluga is known for its most famous resident, Konstantin Tsiolkovsky, a rocket scientist who pioneered astronautic theory.

The Tsiolkovsky State Museum of the History of Cosmonautics in Kaluga is dedicated to his work and its practical applications for space research. The city's coat of arms and motto gives a respectful nod to work — the Cradle of Space Exploration.

Kaluga, founded in the mid-14th century as a border fortress on the southwestern borders of the Grand Duchy of Moscow. The city's name has changed over time. If you poke through historical records and chronicles from the 14th century, you'll see it written as Koluga — derived from the Old Russian word for bog or quagmire. 

Historically, Kolunga has sat on the sidelines of history. It is the sort of place you might have a country home away from the hubbub of the bustling city. Indeed, the area has served as such for many of Russia's Royals. In the Middle Ages Kaluga was a smallish settlement owned by the Princes Vorotynsky whose relationship with the townsfolk looked more akin to how you and I might picture slaver versus a liege lord. 

Over time, the village grew more prosperous and opened its first drama theatre in 1777. As in many parts of the world, the first geologic exploration and mapping were done to locate natural resources that would be used to fund monarchies, wars and infrastructure.  

Kaluga is connected to Moscow by a railway line and by the ancient roadway, the Kaluga Road (now partly within Moscow — as Starokaluzhskoye Shosse - the Old Kaluga Highway — partly the A101 road. This road offered Napoleon his favoured escape route from the Moscow trap in the fall of 1812. 

General Kutuzov repelled Napoleon's advances in this direction and forced the retreating French army onto the old Smolensk road, previously devastated by the French during their invasion of Russia — an event that may be attributed to poor planning and tin buttons, but that is for another post.

On several occasions during the Russian Empire Kaluga was the residence of political exiles and prisoners such as the last Crimean khan Şahin Giray (1786), the Kyrgyz sultan Arigazi-Abdul-Aziz (1828), the Georgian princess Thecla (1834–1835), and the Avar leader Imam Shamil (1859–1868).

The German army briefly occupied Kaluga during the climactic Battle of Moscow, as part of Operation Barbarossa. The city was under full or partial German occupation from October 12th to December 30, 1941. In 1944, the Soviet Government used its local military buildings to intern hundreds of Polish prisoners of war — soldiers of the Polish underground Home Army — whom the advancing Soviet front had arrested in the area around Vilnius. This specimen is in the collection of the deeply awesome Emil Black. Maximum diameter of 58mm. 

FOOL'S GOLD: A PERSONAL GOLD RUSH

When I was little, maybe 5 or 6 years old, I struck gold! Well, it wasn't real gold, but I was most convinced. 

Someone had dumped a tailings pile near the woods where I lived and in the sun, those crushed pieces of rock sparkled. I had already been bitten by the love of minerals and fossils and so naturally I filled my pockets and brought as much home as a youngster can carry.

Where I was told that it was Fool's Gold. 

But, still... it was so compelling and just so gold-like. So, secretly I continued my forays and dragged as many of those lovely sparkly bits home as I could. The pile soon amassed to what could not be concealed in a youngsters room — those socks have to live somewhere. So we struck a bargain. My folks would let me keep my gold if I kept it under the house. I suspect it is still there to this day. 

I did eventually find gold up in Atlin, British Columbia — and loads of it — but none that I could keep. I met a fellow who pans for it and had built out a sluicing system to great success. He showed me an ice cream bucket full of gold nuggets that I still ponder to this day.

So, what exactly is Fool's Gold? Is it gold mixed with another mineral or something else altogether? Turns out it is pyrite which has a brass-yellow colour and metallic lustre similar to gold, but pyrite is brittle and will break rather than bend as gold does. 

A good field test is to give it a streak test. Gold leaves a yellow streak, while pyrite’s streak is brownish-black. 

Pyrite is named from the Greek word for fire, "pyr" because pyrite can create sparks for starting a fire when struck against metal or stone — also fun to try in the field. Pyrite was once a source of sulfur and sulfuric acid, but today most sulfur is obtained as a byproduct of natural gas and crude oil processing.

We sometimes see pyrite sold as a novelty item or made into costume jewellery. But pyrite does have its uses beyond amusing youngsters dreaming of their own gold rush. 

Pyrite can sometimes help you find real gold because the two form together under similar conditions. Gold can even occur as inclusions inside pyrite, sometimes in mineable quantities depending on how effectively the gold can be recovered.

Fool’s Gold is truly pyrite or iron sulfide (FeS2) and is one of the most common sulfide minerals. Sulfide minerals are a group of inorganic compounds containing sulfur and one or more elements. 

I still have a fondness for it and share a wry smile when I find it out in the field. It is remarkably common. And, I do still want it to be real gold even though my grown-up brain knows it is not. 

When I am very lucky, however, I find pyritized fossils — even better than gold!

FOSSILS OF THE LONDON CLAY

Birds, Snakes & Mammals, London Clay

Birds, mammals, snakes and crocodiles — these do not immediately spring to mind when you think of marine deposits — but these are some of the wonderful fossil specimens that make the London Clay so interesting to collect from.

The London Clay Formation is a marine geological formation of Ypresian (early Eocene Epoch, c. 56–49 Ma) age which outcrops in the southeast of England. 

The exposures are well-known for their variety of fossil fauna. The fossils from the lower Eocene sections tell us about a moderately warm, tropical to subtropical climate.

It was with the greatest pleasure that I came across some of the wonderful fossil specimens found by Martin Rayner and his father over the better part of 40-years worth of dedicated collecting. These excellent examples of the London Clay fauna hail from Sheppey, Seasalter and Tankerton. 

You may recall that Martin is a co-author of London Clay Fossils of Kent and Essex.  The book is a collectors' guide to the fossil animals and plants of the London Clay from river and coastal exposures in Kent and Essex. It is known locally as the Fossil Bible.

This superb book is published by the Medway Fossil and Mineral Society and was written by four of the Society members, David Rayner, Tony Mitchell, Martin Rayner and Fred Clouter. 

It the essential field guide for use by both beginners and the more experienced — and likely the definitive work on the subject for many years to come. 

The book includes when to collect, equipment, cleaning, preparation and preservation of specimens, sieving, storage and cataloguing, geology and a list of fourteen collecting sites  — six with site location maps, access details and collecting techniques.

There is a hugely useful identification section and comprehensive terminology for the invertebrates, vertebrates and plants of the London Clay. Here you'll find all of the yummy foraminifera, bryozoa, worms, trace fossils, corals, barnacles, lobsters, stomatopods, crabs, insects, brachiopods, bivalves, scaphopods, gastropods, nautili, coleoids, crinoids, echinoids and starfish. Also included are the sharks, rays, chimaera, bony fish, otoliths, turtles, snakes, crocodiles, birds, mammals and plant material.

If you fancy picking up a copy, here is the UKGE link: https://www.ukge.com/en-ie/London-Clay-Fossils-of-Kent-and-Essex__p-3291.aspx

Photo One: Martin Rayner: Snake, Bird and Mammal finds from the London Clay, mostly from Sheppey and Seasalter, UK

Photo Two: Martin Rayner: A rare skull from the remains of the sea snake Palaeophis toliapicus.  

EOSUCHUS OF SEASALTER

Most people consider the Early Eocene, Ypresian fossils of the Isle of Sheppey off the northern coast of  Kent, UK to be the best site for collecting London Clay fossils. Indeed, this area has been known for its outstanding fossils since the early part of the 18th Century. 

But for Martin Rayner and his father, the best finds hail from nearby Seasalter, a village in the Canterbury District on the northern coast of Kent. It was here, during the mid-1990s, that Martin found this spectacular Eosuchus sp. fossil crocodile along the foreshore.

Eosuchus or the Dawn Crocodile, is an extinct genus of eusuchian crocodylomorph, generally regarded as a gavialoid crocodilian. It might have been among the most basal of all gavialoids, lying crownward of all other known members of the superfamily, including earlier putative members such as Thoracosaurus and Eothoracosaurus. 

We find their fossil remains at Seasalter in the UK, in France and along the eastern seaboard of  North America in Maryland, Virginia, and New Jersey. Their remains date back to the late Paleocene and early Eocene.

Martin's Eosuchus sp. was found in-situ spread out over a small area of Seasalter's clay rich foreshore. His significant find was originally collected in hundreds of pieces, many of these fragmented and spread around before fossilization. Careful excavation, preparation and articulation over a two year period was necessary to piece them all together. 

It took another year or more to reconstruct the skull and much more time again to research the find with the help of those working at the Natural History Museum in London. 

A few of the pieces you see here were generously donated to Martin by fellow collectors who had plucked some of the bones from the collecting site then realized each held a small part of a large important specimen.

Once fully articulated, the near complete specimen measures around 1.2 meter in length. Had all the bones been recovered, the complete specimen would likely be closer to 2m in length.

We now get to enjoy this magnificent specimen in its entirety. It also shows what can be found in the foreshore material and will hopefully encourage those used to collecting on Seasalter's beaches to give this prolific area the attention is surely deserves.  

On the foreshore where the clay is exposed it is possible to find fossils in situ and washing out. The foreshore platforms are constantly eroding and at a faster rate than the nearby cliffs. It is a large area to search, but the large expanses of foreshore offer newly revealed specimens, often in stunning condition.

When you visit Seasalter, you may arrive after wind and tide have scoured away the silt and exposed the fossiliferous clay. You can find nice crab fossils and other marine goodies. 

There are far more London Clay sites without cliff exposures than ones with cliff exposures. As at Sheppey, Seasalter's foreshore exposures yield a large amount of fossil specimens in addition to the beach finds derived from the cliffs. Foreshore sites are scientifically significant as they provide a snapshot of a more specific time versus the fossils retrieved from cliff falls which can often span millions of years.

The photo above shows all of the bones laid out together. A frame has been created for them into which each individual vertebrae fit snug so that it can be displayed at potential shows and exhibitions.

Martin's Seasalter find helps us to understand both the anatomy of Eosuchus and place this basal gavialoid geographically. It is the occurrence of Eosuchus in the London Clay that pushes the gavialoid clade beyond the Paleocene and firmly and unambiguously into the early Eocene.

The strata from which both species of Eosuchus have been found were thought to have formed in a marginal marine depositional environment, and thus probably reflect the actual environments that these animals would have inhabited. It has been proposed that early gavialoids were originally salt-tolerant coastal forms, and the evidence seen in the case of Eosuchus is consistent with this theory. 

When we are lucky, the fossil evidence comes together to paint a picture of the environment and provide clues to our ancient world. One specimen of E. minor from the Aquia Formation, USNM 299730, has a fossil oyster attached to the dorsal surface of the rostrum.

The fact that the two species of Eosuchus lived on either side of the Atlantic Ocean implies that these populations may have been separated geographically from one another while not necessarily having to be separated stratigraphically (that is, if the temporal ranges of the two species coincide with one another). 

More importantly, the separate biogeographic ranges of the two species may be evidence for a transoceanic dispersal event from one continent to the other. Since the presumed ages of the localities from which specimens have been found are quite similar yet inexact, it is currently unknown just what continent this dispersal event may have originated. A recent reevaluation of the holotype material of E. lerichei, which in the past has been poorly studied, suggests that it is the more basal species and thus would have been the ancestor of E. minor in Europe.

We'll likely find more Eosuchus material which will provide additional insights. More specimens will likely be found at Seasalter. The London Clay fossils at Seasalter are found out on the foreshore at low tides in the bay between Seasalter and Whitstable Harbour to the east. 

If you're headed out and want to try your luck, walk the area from the bottom of the beach halfway or more toward the oyster nets. The fossil material you will find will be 50 million years old.

If you fancy a read and armchair inspiration, check out the wonderfully informative book on the London Clay Fossils of Kent and Essex by David Rayner, Tony Mitchell, Martin Rayner and Fred Clouter. These four genius minds have produced the definitive book on the area — greatly expanding our insight and understanding through their years of earned knowledge.  

References:

Dollo, L. (1907). "Les reptiles de l'Éocène Inférieur de la Belgique et des régions voisines". Bulletin de la Société Belge de Géologie, de Paléontologie et d'Hydrologie. 21: 81–85.

Norell, M. A.; Storrs, G. W. (1986). "Catalogue and review of the type fossil crocodilians in the Yale Peabody Museum". Postula. 203: 1–28.

Brochu, C. A. (2006). "Osteology and phylogenetic significance of Eosuchus minor (Marsh, 1870) new combination, a longirostrine crocodylian from the Late Paleocene of North America". Journal of Paleontology. 80 (1): 162–186. doi:10.1666/0022-3360(2006)080[0162:OAPSOE]2.0.CO;2.

Michael S. Y. Lee; Adam M. Yates (2018). "Tip-dating and homoplasy: reconciling the shallow molecular divergences of modern gharials with their long fossil record". Proceedings of the Royal Society B: Biological Sciences. 285 (1881): 20181071. doi:10.1098/rspb.2018.1071. PMC 6030529. PMID 30051855.

Taplin, L. E.; Grigg, G. C. (1989). "Historical zoogeography of the eusuchian crocodilians: A physiological perspective". American Zoologist. 29: 885–901. doi:10.1093/icb/29.3.885.

Delfino, M.; Pira, P.; Smith, T. (2005). "Anatomy and phylogeny of the gavialoid crocodylian Eosuchus lerichei from the Paleocene of Europe". Acta Palaeontologica Polonica. 50 (3): 565–580.

Broom, Robert (1925). "On the South African rhynchocephaloid reptile "Eosuchus" colletti, Watson". Records of the Albany Museum. 3: 300–306.

WETTERSTEIN LIMESTONE

Ammonoid and gastropod coquina, Wetterstein Limestone

A very busy white to light cream ammonoid and gastropod coquina of Upper Triassic (Carnian/Julian) Wetterstein limestone.

The lovely example of the Wetterstein limestone you see here is equivalent in age to the typically creamy orange limestones from nearby Hallstatt. The Wetterstein limestones are an adjacent  Ladinian to Lower Carnian reef facies that provide a window into the end of the Carnian Pluvial Event (CPE). 

The Carnian Pluvial Event is sometimes called the Carnian Pluvial Episode and is also known as Reingrabener Wende (meaning Reingrabener turnover), or Raibl Event — named after the Raibl area, Friuli-Venezia Giulia region of northeastern Italy.

By any name, the Carnian Pluvial Event (CPE) was a time of major change in our global climate and biotic turnover in the early Late Triassic, between 234 and 232 million years ago. For its significance, it is all but neglected in the body of our palaeontological studies that favour other global ecosystem turnovers during the Mesozoic. It had a huge impact on marine and terrestrial ecosystems. This interval saw a climatic shift from the arid climate of the Late Triassic to the markedly more humid conditions of the Carnian Pluvial Event (CPE), then back to arid again.

The base of the CPE is marked by a ≈4‰ negative shift in carbon stable isotopes (δ13C) of fossil molecules (n-alkanes) from higher plants and total organic carbon. 

A ≈1.5‰ negative shift in oxygen stable isotopes (δ18O) of conodont apatite suggests a global warming of 3 to 4 °C and a change in seawater salinity.

Major changes in organisms responsible for calcium carbonate production occurred during the CPE. In the world's oceans, we see mass biological turnover. Conodonts, ammonoids, bryozoa, and green algae were severely hit by the CPE and experienced high extinction rates. 

Most noticeable were the radiations of, among other groups, calcareous nanofossils, corals, and crinoids. 

This is especially interesting as ammonoids and conodonts, the two most important groups for the biostratigraphy of the Triassic, had a significant turnover.

Outside of Austria, many localities in Itlay place a primary role in our understanding of the CPE as paradigmatic examples of the geological and biotic processes that were occurring during this interesting moment in time — particularly concerning our future understanding of the evolution of shallow marine and terrestrial groups. 

The collective research to date has been focussed on more global and on the deepwater records of the CRP. Italy boasts the most expanded and complete shallow-water successions in the Raible area of northeastern Italy and the most prolific amber site with reef associations in the Dolomites near Veneto.

A halt of carbonate sedimentation is observed in nearby southern Italy in deepwater settings that were probably caused by the rise of the carbonate compensation depth (CCD). High extinction rates occurred among ammonoids, conodonts, bryozoa, and crinoids. 

Major evolutionary innovations followed the CPE, as the first occurrence of dinosaurs, lepidosaurs, an expansion of coniferous trees, calcareous nanofossils and scleractinian corals

After the CPE, reef growth starts again. We see this as the Dachsteinkalk — the Dachstein Formation or Dachstein Limestones — a Norian geologic formation in the Alps and other Tethyan mountain ranges in Austria

The beautiful block you see here was kindly prepared by mother nature. She did most of the prep but Andreas did the excavation, soaked it for a few days in water and carefully washed it clean to photograph. A very special thank you to him for continuing to inspire me with his wonderful eye and deep knowledge of our world.

Photo: Andreas / Size: 15 cm x 15 cm.

TURTLE SHELLS: HOME SWEET ARMOUR

Turtle shells are different from the body armour or armoured shells we see adorning dinosaurs like the ankylosaurs. 

Ankylosaurs were blessed with huge plates of bone embedded into their skin that acted as a natural shield against predators. Crocodilians have these same bony plates, or osteoderms, embedded in their skin to give them extra protection. 

We find similar body armour on armadillos. Yet, armadillos, crocodiles and ankylosaurs each evolved body armour that differs significantly from that found in turtles. 

Remarkably, the carapace we see in fully grown turtles is formed from different parts of their skeletons. And, once fully formed, turtle shell fully integrates with the backbone and ribs, growing over the animal in a domed carapace — both protection and home sweet home. 

When we look to the oldest known members of the turtle lineage, Proterochersis and Proganochelys, found as fossils in 210 million-year-old outcrops in present-day Germany and Poland. Like the turtles we find today, these stem-turtles already had fully formed shells — special bony or cartilaginous shell that originates in their ribs. It is a useful adaptation to help deter predators as their soft interior makes for a tasty snack. 

Though I have never eaten turtle (and never will), it was a common and sought after meat for turtle soup. Years ago, I read of Charles Darwin craving it after trying it for the first time on his trip in 1831 aboard the HMS Beagle. It seems Charlie like to taste every exotic new species he had the opportunity to try.

Turtle armour is made of dermal bone and endochondral bones from their vertebrae and rib cage. It is fundamentally different from the armour seen on our other vertebrate friends and the design creates some unique features in turtles. 

Because turtle ribs fuse together with some of their vertebrae, they have to pump air in and out of the lungs with their leg muscles. 

Another unusual feature in turtles is their limb girdles, pectoral and pelvic, which have come to lie within their rib cage, a feature that allows some turtles to pull their limbs inside the shell for protection. 

Sea turtles didn't develop this behaviour or ability and do not retract into their shells like other turtles.

Armadillos have armour formed by plates of dermal bone covered in relatively small, overlapping epidermal scales called scutes, composed of bone with a covering of horn. In crocodiles, their exoskeletons form their armour, similar to ankylosaurs. A bit of genius design, really. It is made of protective dermal and epidermal components that begin as rete Malpighii: a single layer of short, cylindrical cells that lose their nuclei over time as they transform into a horny layer.

Depending on the species and age of the turtle, turtles eat all kinds of food including seagrass, seaweed, crabs, jellyfish, and shrimp,. That tasty diet shows up in the composition of their armour as they have oodles of great nutrients to work with. The lovely example you see here is from the Oxford Museum collections.