OSTEOLOGIE DU MEGATHERIUM

This lovely illustration of Megatherium, a fossil sloth discovered in South America was published in 1825 by Georges Cuvier as part of his work comparing specimens from South America to those from the Paris Basin.

Jean Louis Denis was the engraver who created this lovely plate. We have Leonard C. Bruno to thank for access to this image. He took black and white photos of the plate and published them in 1987 to the Library of Congress with full open access. Illus. in: Recherches sur les ossemens fossiles / Georges Cuvier. Third ed. Paris: G. Dufour et E. d'Ocagne, 1825, pl. 16. Published in: The tradition of science / Leonard C. Bruno. Washington, D.C. : Library of Congress, 1987, p. 215.

SLOTHS AND AVOCADOS

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

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

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

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

GASTROPODA

ZENAPIS PODOLICA

A Devonian fish mortality plate showing all lower shields of Zenaspis podolica (Lankester, 1869) and Stensiopelta pustulata (and possibly Victoraspis longicornualis) from Lower Devonian deposits of Podolia, Ukraine.

Zenaspis is an extinct genus of jawless fish which existed during the early Devonian period. Due to it being jawless, Zenaspis was probably a bottom feeder.

The lovely 420 million-year-old plate you see here is from Podolia or Podilia, a historic region in Eastern Europe, located in the west-central and south-western parts of Ukraine, in northeastern Moldova. Podolia is the only region in Ukraine where Lower Devonian remains of ichthyofauna can be found near the surface.

For the past 150 years, vertebrate fossils have been found in more than 90 localities situated in outcrops along banks of the Dniester River and its northern tributaries, and in sandstone quarries. At present faunal list of Early Devonian agnathans and fishes from Podolia number 72 species, including 8 Thelodonti, 39 Heterostraci, 19 Osteostraci, 4 Placodermi, 1 Acanthodii, and 1 Holocephali (Voichyshyn 2001a, modified).

In Podolia, Lower Devonian redbeds strata (the Old Red Formation or Dniester Series) can be found up to 1800 m thick and range from Lochkovian to Eifelian in age (Narbutas 1984; Drygant 2000, 2003). In the lower part (Ustechko and Khmeleva members of the Dniester Series) they consist of multicoloured, mainly red, fine-grained cross-bedded massive quartz sandstones and siltstones with seams of argillites (Drygant 2000).

We see fossils beds of Zenaspis in the early Devonian of Western Europe. Both Zenaspis pagei and Zenaspis poweri can be found up to 25 centimetres long in Devonian outcrops of Scotland.

Reference: Voichyshyn, V. 2006. New osteostracans from the Lower Devonian terrigenous deposits of Podolia, Ukraine. Acta Palaeontologica Polonica 51 (1): 131–142. Photo care of Fossilero Fisherman.

THE LAST ICE AGE

The massive ice sheets of the Pleistocene covered much of the planet. They contained so much of the Earth's water that sea levels dropped to 100 metres lower than they are today.

FIRST ITALIAN FOSSILS OF AGRIOTHERIUM

Agriotherium / Short-Faced Bear

Fossil remains of Agriotherium, the short-faced giant bear, have been found in Collepardo, Italy. A fragment of a mandible was unearthed back in 2015 in the province of Frosinone. Thanks to several years of research and a recent CT scan, the team from Sapienza University of Rome were finally ready to publish.

Agriotherium is one of the largest of the mighty carnivores that lived in Europe back in the Pleistocene. They weighed as much as 900 kilos (almost 2,000 lbs) and grew up to 2.5 meters tall. These ancient bears roamed prehistoric Italy amid a humid and temperate climate, competing for food resources with some of our ancestors as they only becoming extinct 2.6 million years ago.

CAMBRIAN SEA ANEMONE

A stunning Cambrian soft-bodied Sea Anemone from outcrops near Malong, China. Collection of Marc R. Hänsel

PREHISTORIC BUGS: WANNERIA DUNNAE

Wanneria dunnae, an impressive trilobite from British Columbia's Eager Formation near Cranbrook. Trilobites were among the earliest fossils with hard skeletons. They were the dominant form of life at the beginning of the Cambrian Period. This specimen of Wanneria dunnae from the East Kootenay of British Columbia is typical of the group. Trilobite eyes were compound like those of modern crustaceans and insects. The eyes of these earliest trilobites are not well-known as the visual surface dropped away and was lost during molting long before they ever became fossils.

ZITRONENFALTER: GONEPTERYX RHAMNI

NATURE AS ART: IRIDESCENT EUHOPLITES

This beautiful Euhoplites, measuring just 37 millimetres across, comes from the celebrated fossil beds of Folkestone in southeastern England.

Preserved within the rocks of the Lower Cretaceous, it offers us a glimpse into oceans that existed some 100 million years ago, during the middle to upper Albian Stage. Euhoplites belonged to the ammonoids, an extinct group of cephalopods related, albeit distantly, to the living nautilus and more closely allied to squid and octopus. Its shell was both elegant and elaborate.

Strong ribs sweep across the whorls, sometimes running in graceful curves from the inner margin before folding over the outer edge of the shell. In other species, the ribs form subtle zigzags between small nodules and ventrolateral clavi, giving the shell a richly ornamented appearance.

A narrow groove often traces a path along the centre of the outer rim, accentuating the remarkable symmetry of the spiral. And then there are those curious lumps and bumps — the tubercles that adorn the shell so beautifully. Their precise function remains one of palaeontology's enduring mysteries. They may have served as protection against predators, strengthened the shell against pressure, or perhaps influenced how the animal moved through the water.

Intriguingly, such ornamentation may have increased hydrodynamic drag, suggesting that Euhoplites was not built for speed.

Rather than pursuing prey in rapid bursts, it may have adopted a more measured existence within the warm Cretaceous seas. Though modest in size, with shells typically only reaching a few inches across, Euhoplites was part of a thriving marine community. In the Albian seas of France, it lived alongside ammonites such as Hoplites, Anahoplites, Pleurohoplites, Puzosia, and Desmoceras.

In Brazil, it shared the waters with Anahoplites and the extraordinary corkscrew-shaped Turrilites. Fossils attributed to this genus have even been recorded from rocks of Texas, attesting to the wide distribution of these ancient mariners. Yet nowhere is Euhoplites more closely associated than with the Folkestone Beds of Kent. Here, within the weathered cliffs and clay-rich sediments of England's southeast coast, they are among the most frequently encountered ammonites.

Each specimen recovered from these deposits tells a story of a vanished world — a subtropical sea alive with cephalopods, fishes, marine reptiles, and countless other organisms whose lives have been distilled into stone. This particular specimen, from the collections of José Juárez Ruiz, is a small masterpiece of natural architecture. Its intricate ribs and sculptured ornamentation have survived across immense spans of geological time, inviting us to pause and wonder. For in these delicate spirals lies one of nature's most profound gifts: the ability to connect us, however briefly, with the deep and ancient history of life on Earth.

FIRE-KISSED ARTHROPOD

This fellow is Chengjiangocaris kunmingensis, a rather glorious fuxinhuiid arthropod. While he looks like he could be from the inside of the Lascaux Caves and their fire-kissed Palaeolithic paintings, albeit by a very ancient Picasso, he was found at a Cambian fossil site in southern China.

As his name indicates, he is from a fossil site in the Yunnan region near Kunming. He is unusual in many ways, both because of the remarkable level of preservation and the position in which he was found. This fellow was a bit of a tippy arthropod. His carapace had flipped over before fossilisation, allowing researchers to to examine this fuxianhuiid's head and legs in great detail without a carapace in the way.

The roughly 518-million-year-old site contains a dizzying abundance of beautifully preserved weird and wonderful life-forms, from jellyfish and comb jellies to arthropods and algae and is about 10 million years older than the Burgess Shale. Photo credit: Yie Jang (Yunnan University)

ANCIENT ONES

WASH ON, WASH OFF

If you were a fish living in the warm turquoise waters off the coast of Bonaire, you may not hear those words, but you'd see the shrimp sign language equivalent. It seems Periclimenes yucatanicus or Spotted Cleaner Shrimp is doing a booming business in the local reefs by setting up a fish washing service.

That's right, a Fish Wash. You'd be hard pressed to find a terrestrial Molly Maid with two opposable thumbs as studious and hardworking as this wee marine beauty.

This quiet marine mogul is turning out to be one of the ocean's top entrepreneurs. Keeping its host and diet clean and green, the spotted shrimp hooks up with the locals, in this case, local sea anemones and sets up a fish wash. Picture a car wash but without the noise and teenage boys. The signage posted is the shrimps' natural coloring which attracts fish from around the reefs.

Wash on, wash off.

Once within reach, the shrimp cleans the surface of the fish, giving the fish a buff and the shrimp its daily feed.