#Miocene bivalve fossil

[uk-fossils]

Crepidula Fossil Bivalve – Lower Miocene, Clallam Formation, Washington USA, Genuine Specimen

A genuine and well-preserved Crepidula fossil bivalve from the Lower Miocene epoch, approximately 16–20 million years old. This fossil was discovered in the Clallam Formation of Northwestern Washington, USA, an important geological unit known for preserving a diverse assemblage of marine molluscs.

The genus Crepidula, commonly known as slipper shells, is a marine gastropod mollusc (often mistaken for a bivalve due to its shell shape) with a distinctive internal shelf structure. This specimen reflects the shallow marine environments of the early Miocene in the Pacific Northwest.

Fossil Type: Gastropod (commonly called a slipper shell, not a true bivalve)

Genus: Crepidula

Geological Age: Lower Miocene (approx. 16–20 million years ago)

Formation: Clallam Formation

Depositional Environment: The Clallam Formation was deposited in a shallow, warm marine setting with good water circulation, supporting abundant marine life. The sediments include sandstone and siltstone beds that preserved mollusc shells in fine detail.

Morphological Features:

Convex outer shell with a smooth to slightly ridged surface

Internal “shelf” typical of Crepidula species visible in some specimens

Preservation may include original shell material or internal moulds

Notable:

Authentic specimen from the Clallam Formation, Washington State

A well-known genus with evolutionary and ecological interest

Ideal for fossil collectors, educators, and marine paleontology enthusiasts

Actual item shown – photo depicts the exact specimen you will receive

Authenticity: All of our fossils are 100% genuine natural specimens and come with a Certificate of Authenticity. The photo includes a 1cm scale cube for reference – please view the image for accurate sizing.

Add this genuine Crepidula fossil to your collection – a classic marine mollusc from the Lower Miocene seas of the Pacific Northwest, showcasing a beautifully preserved snapshot of ancient ocean life.

[drhoz]

#2759 - Waiparia sp. - Lamp Shell

A genus of Brachiopods from the Oligocene and Miocene of New Zealand, when most of the microcontinent of Zealandia was submerged. Exactly which species of Waiparia would be a matter of contention, as paleontologists working on the group named new species with gay abandon (including three different species from another genus in a single geological deposit) without considering the likelihood of morphological variation within the species.

Quite common fossils in the Kokoamu Greensand, a sedimentary unit better known for its giant penguins and XBOX HUEG sharks.

Despite their resemblance to clams, brachiopods are not molluscs - for one thing the shells are symmetrical from right to left. Internally they're very different too - their feeding structure or lophophore is a crown of tentacles with cilia (fine hairs) to filter food out of the water. The hole visible in both fossils above is the pedicle opening, through which they attached to the seafloor or other organisms with a stiff stalk.

Living brachiopod species are not as common as they used to be - prior to the Permian-Triassic mass extinction, they outnumbered bivalved molluscs.

University of Otago Geology Museum, Dunedin, Aotearoa New Zealand.

[a-dinosaur-a-day]

Round Two: Conflicto vs Annakacygna

Conflicto antarcticus

Artwork by @otussketching, written by @zygodactylus

Name Meaning: Contradiction from Antarctica 

Time: 65 million years ago (Danian stage of the Paleocene epoch, Paleogene period) 

Location: Seymour Island, López de Bertodano Formation, Antarctica 

The evolutionary history of the fowl - chickens and ducks - is a controversial one, owing in no small part to the sheer diversity of basal taxa from the Galloanseran group. Existing prior to the end-Cretaceous extinction, Galloanserans went through the same adaptive radiation that everything did following the extinction - leading to a wide disparity of animals that show a weirdly diverse mosaic of traits. Conflicto is one of such taxa. Literally occurring in a fossil formation that tracks the transition from Cretaceous to Paleogene, Conflicto appears on the Paleogene side of the boundary, possibly a direct descendant of other Anseriformes that were present in Antarctica in the latest Cretaceous. But it's survivorship is not, in fact, the weirdest thing about it. Conflicto, despite being a stem-anseriform, and thus early on in the evolution of the group, had a weirdly duck/goose like beak. It was similar in structure to the bill of waterfowl, just not as wide. It also had large nostrils, much wider openings than modern ducks and geese. The problem with this is the fact that the earliest branching-off members of Anseriformes - the Screamers - have chicken-like beaks. As such, the original hypothesis for bill evolution in Anseriformes was that they started with chicken beaks, and later the group composed of geese, ducks, and magpie-geese evolved a spatulate bill the one time. However, Conflicto coming prior to the splitting off of screamers and having such a bill throws this idea into question - and this won’t be the last word on the subject, I assure you. Showcasing a partially-spatulate bill makes Conflicto an important piece of the puzzle of anseriform evolution. In its post-apocalyptic world, Conflicto was surprisingly not alone - living in a temperate to subpolar fern forest, it was able to feast on a wide variety of gastropods, bivalves, worms, and echinoids. When it comes to vertebrates, however, Conflicto was alone - the last survivor of a previously vibrant Cretaceous environment. 

Annakacygna hajimei, A. yoshiiensis

Artwork by @otussketching, written by @zygodactylus

Name Meaning: Swan from Annaka (Hajime’s or of Yoshii-machi) 

Time: 11.5 million years ago (Tortonian stage of the Miocene epoch, Neogene period)

Location: Haraichi Formation, Annaka, Japan

Annakacygna was dubbed during its research “the ultimate bird”, and honestly, I don’t even blame the scientists for doing so - I may have even done the same. Both large species of swan, A. hajimei was about the size of a black swan, and A. yoshiiensis was larger than even the mute swan. They were weird in so many ways it boggles the mind: they were adapted for filter feeding in the water, their wings and tails were so flexible they could form a cradle for their young on their backs like modern mute swangs, said tails and wings were probably great and flashy display structures, its head was extremely large weird looking and had a slightly spoon-like bill, they had wide and heavy vertebrae but still had long and flexible necks, it may have even been a flightless bird or at least a poor flier based on its sternum and coracoids, though its scapula is extremely strong and unlike flightless animals - more research is needed to better understand this aspect of its mobility. That said, it did have very short wing birds, weirdly curved and short among birds, with weirdly shaped finger bones coming together to create weirdly formed curved wings. Its hips were arched up, creating a dip in its back, and it had narrow leg bones, allowing for efficient movement in the water like living *grebes and loons*. So while it had this whole weird display structure with its wings and tail going on, and its robust but long neck, and that strangely boat-shaped body (what the actual f-), it was zooming through the water like a grebe or loon. It had a similar beak to living shovelers, possibly, and it could move its jaw back and forth in a seesaw like motion, not like any living swans. It could then filter food through its jaws via this motion, eating a variety of plankton through soft lamellae within its bill. It was probably very social, given its display structures, and communicated both vocally (imagine the power of those calls with that robust neck) and visually. Annakacygna also took care of its young, extensively, keeping them on their back protected in their wings, to the point that they may not have spent much time on land (like living loons and grebes). It wasn’t a deep diver, but was stable at sea while foraging on food and moving along the surface of the water, living primarily in the ocean. Found in a marine environment, Annakacygna lived with sharks, seals, many kinds of whales, and desmostylians.   

[sciencespies]

These eerie 'living stones' in Romania are fantastical, and totally real

https://sciencespies.com/nature/these-eerie-living-stones-in-romania-are-fantastical-and-totally-real/

These eerie 'living stones' in Romania are fantastical, and totally real

A small town in Romania called Costesti is home to unusual geological manifestations – bulging bulbous boulders called trovants. These stones have long intrigued locals, with their organic-looking shapes and strange cement oozings, inspiring myths about the stones’ ability to grow and move – like living beings rather than inanimate objects.

Trovants vary greatly in size and shape – some can snugly fit in your palm, while others loom overhead, up to 4.5 metres tall. Of the 100s of known trovants, seen across at least 20 sites through Romania, some were only unearthed after the sand around them was quarried away.

Trovant from Ulmet, Romania. (bereta/Getty Images Plus)

While mysteriously moving stones do sail across valleys elsewhere in the world, these trovants probably aren’t going anywhere without help any time soon.

In fact, some are firmly (if precariously) fixed to the ground below with a solid rock base, like the ‘Old Ladies’ from Ulmet.

Their bizarre, and sometimes seemingly gravity-defying bulges have to do with their origins.

(michalz86/Getty Images Plus)

Likely shaped by earthquakes around 6 million years ago, trovants are a type of concretion – sedimentary sand grains or rocks bound together by a limestone (calcium carbonate) cement. 

“Some are made from sandstone, others from gravel,” Buila-Vanturarita National Park manager Florin Stoican told Radio Romania International back in 2010.  “In geological terminology, they are made from gritstone and conglomerates.”

Researchers have found no difference between the trovants and surrounding sand substrate. So they suspect the spheroid shapes were formed by the unusually long-lasting and intense seismic activity of the Middle Miocene. Shockwaves emanating from the earth compacted the sandy sediments and concentrated the limestone cement to mould their spherical lumps.

More trovants in Ulmet, known as the ‘Old Ladies’. (pfongabe33/Getty Images Plus)

Over time, the elements wore away the looser sandstone around them, exposing the denser trovants.

When exposed to heavy rains, some of their cement can leak out to their surface, gradually adding to the stone’s outer circumference over time. Not much has been written about this process, but it is said to occur at only about 4-5 cm over 1,200 years.

The surrounding sandstone beds have laminations – a sequence of fine layering – suggesting the area was an ancient marine environment when the stones and base sediment were laid down, as do the bivalve and gastropod fossils that can be found within some of the trovants.

So, while they might not be ‘living’ stones in a literal sense, these incredible rocks have seen more of life than even the oldest human.

#Nature

[lwhittierart]

I went on an optional field trip today for Paleobiology class to the Oregon Coast to prospect some marine fossils from the Astoria Formation. Most of what we found were bivalve and gastropod shells from the Miocene epoch as well as one vertebra and petrified wood. Some other prospectors found the dolphin and fish vertebrae pictured above. We had a really fun time and it was a good primer for our next field trip.

[uk-fossils]

Fossil Barnacle, Miocene Epoch, Hampton Virginia USA | Authentic Marine Invertebrate Specimen + COA

Fossil Barnacle – Miocene Epoch, Hampton, Virginia, United States

This authentic fossil barnacle comes from the Miocene-aged marine sediments of Hampton, Virginia, part of the geologically significant Chesapeake Group. Dating back approximately 15 to 10 million years, this fossil represents a once-thriving marine invertebrate that lived in the warm shallow seas covering the coastal southeastern United States during the Miocene Epoch.

Fossil Type & Classification:

Type: Invertebrate Fossil (Barnacle – Cirripede)

Phylum: Arthropoda

Subphylum: Crustacea

Class: Maxillopoda

Subclass: Thecostraca

Infraclass: Cirripedia (barnacles)

Order: Sessilia (acorn barnacles)

Family & Genus: Undetermined for this specimen (commonly Balanus species in the region)

Geological & Stratigraphic Details:

Location: Hampton, Virginia, USA

Formation: Likely part of the Chesapeake Group (e.g. Eastover or Yorktown Formations)

Epoch: Miocene (Neogene Period)

Age: ~15–10 million years ago

Depositional Environment: Shallow marine shelf with sandy to silty substrates, excellent for epifaunal marine organisms such as barnacles

Biozone: Associated with bivalves, gastropods, corals, and crustaceans of the Mid-Atlantic Miocene

Morphology & Features:

Calcareous plates forming the barnacle wall typically hexagonal or polygonal

Well-defined orifice and base plate characteristic of sessile barnacles

May occur as a solitary specimen or in cluster formation

Preserved in sandy matrix or as isolated calcareous fossil, showing growth ring patterns

Notable: Barnacle fossils like these are important for reconstructing nearshore marine habitats during the Miocene. Their presence in the fossil record helps researchers interpret palaeoecological conditions, such as salinity and substrate preferences, in ancient Atlantic coastal environments. Hampton and other Chesapeake localities are internationally known for Miocene marine invertebrate diversity.

Specimen Details:

Origin: Hampton, Virginia, USA

Fossil Type: Barnacle (Sessile Cirripede)

Geological Epoch: Miocene

Formation: Chesapeake Group (specific unit unconfirmed)

Size Reference: Scale cube = 1cm (see photo for full specimen size)

Note: The specimen shown in the listing photo is the exact item you will receive

Authenticity & Quality: This is a 100% genuine fossil, carefully sourced and not altered or reconstructed. It comes with a Certificate of Authenticity.

Why Choose This Fossil? Great for:

Marine invertebrate fossil collections

Educational displays in palaeontology or marine biology

Natural history décor and gifts

Miocene fossil enthusiasts and US coastal collectors

Shipping & Packaging: All items are packaged securely using eco-conscious materials and shipped with tracking. Fossils are handled with care to ensure safe delivery.

Own a real piece of North America’s Miocene shoreline with this fossil barnacle from the marine sediments of Hampton, Virginia.

All of our Fossils are 100% Genuine Specimens & come with a Certificate of Authenticity.

[uk-fossils]

Fossil Gastropod Bruclarkia acuminata Sooke Formation Vancouver Island Canada Genuine Specimen

This listing features a genuine and well-preserved Bruclarkia acuminata fossil, a beautifully defined marine gastropod from the Sooke Formation, collected at Muir Creek beach on southwestern Vancouver Island, British Columbia, Canada. This specimen provides a striking example of marine life from a richly fossiliferous region.

Geology & Origin:

The Sooke Formation comprises shallow marine sedimentary rocks that accumulated during the Paleogene period, specifically in a coastal environment. The area around Muir Creek is renowned for preserving numerous mollusc fossils, including gastropods and bivalves. Fossils like Bruclarkia acuminata were buried in fine sand and silt, allowing for excellent preservation of shell detail.

Fossil Type & Classification:

Type: Fossil Gastropod (Extinct marine mollusc)

Species: Bruclarkia acuminata

Formation: Sooke Formation

Geological Context: Likely Paleogene (Oligocene-Miocene boundary, pending local stratigraphy)

Preservation: Excellent, with clearly defined shell whorls and tapering form

Features:

100% genuine, natural fossil specimen

Includes a Certificate of Authenticity

Carefully selected for scientific and display value

The exact specimen shown in the listing photos

Scale cube = 1cm: Please refer to image for accurate sizing

Why Buy From Us? We specialise in authentic, carefully curated fossils collected and prepared to high standards. Each specimen includes a Certificate of Authenticity, offering full confidence in your purchase.

A distinctive and eye-catching addition to any fossil collection, educational setting, or natural history display.