#lamp shell

[critter-creature-or-beast]

This is a...

critter

creature

beast

Voting ended onNov 15, 2024

By Marilynne Box - CC BY 4.0

[written-nature]

Her companions were all sleeping when the train entered a band of marine fossils. Here exoskeletons, there ancient seaweeds, there a spray of tiny brachiopods.

"The Descent" - Jeff Long

[patheticmosasaur1]

today's invertebrate..............lingula adamsi

he has an objectively correct and wrong answer to every question that has been and will ever be asked

if you pay him a tiny/large amount then maybe he'll give you the answer to an age old question like 'what does it all mean?' or 'why is the sky red now?', but only if you've never flicked or wiggled his stalk (like many have done before)

if you've ever touched his stalk at some point in your life he'll remember it forever and will never talk to you unless you sincerely apologise to him about it

glorpiness rating: peduncle activities

photographed by 渔喵 (fishingcatt) (CC BY-NC-SA 4.0)

no idea how these creatures work but I love them

[vintagewildlife]

Lamp shells (Glottidea) By: K. E. Lucas From: The Complete Encyclopedia of the Animal World 1980

[vintagewildlife]

A colony of lamp shells (Calloria inconspicua) By: Kim Westerskov From: The Complete Encyclopedia of the Animal World 1980

[fossilroulette]

Name: Leptodus Age: 260-299 million years ago, Permian Period Location: Texas, USA, Glass Mountains

Fossils of Leptodus like the one in the photograph are neither fish nor snails, though they’ve been called both. They are shells of brachiopods, and are one of the stranger members of the group.

The soft body of a brachiopod is protected by two shells that meet at a hinge, reminiscent of clams and other bivalves. However, brachiopods are more closely related to colonial, microscopic moss animals, than they are to clams.

Unlike clams, the two shells of brachiopods are never mirror images of each other. They always at least slightly different. Often, one shell is deeper, like a cup, and the other is flatter, like a cap.

Shells of Leptodus are an extreme variation on that asymmetry. One shell has dozens of vanes branching out from a sinouous center line, more like a fern than a clamshell. The other has internal ridges like rowing benches on a long boat, and pinches together to half-cover itself at one end.

The upper, flatter valve is so small that researchers debated whether it protected the animal at all or if it had become surrounded by the animal’s soft parts like an internal skeleton. A study of the muscle scars and notches on excellently preserved shells supported the more likely explanation that the flatter valve still functioned like an unusually shaped cap that fit an unusually shaped cup.

Specimen Number: NPL 62496 References: Stehli, Francis G. “Notes on oldhaminid brachiopods.” Journal of Paleontology 30(1956):305-313. Williams, Alwyn. “The morphology and classification of the oldhaminid brachiopods.” Journal of the Washington Academy of Sciences 43(1953):279-287.

Where are similar fossils found?

Note: Glass Mountains is not a formation. It is a mountain range that preserves almost 40 million years’ worth of rock record in multiple formations in a stack of sediment about 1500-2000 meters thick. Whoever collected the photographed fossil, along with others, did not pass along from exactly where and when they collected. It’s too bad because now that the fossil is out of the rock that information is gone forever. If you collect, always record where you did so and which rocks you collected from in as much detail as you can

[drhoz]

#953 - Magellania flavescens - Lamp Shell

I literally jumped and yelled when I picked this up on the beach at Leschenault, and realised what it was. Sure, the orange sponge was pretty, but I’d initially thought it was just some bivalve species.

It ain’t. It’s a freakin’ BRACHIOPOD.

I’ve never seen a Brachipod in real life before, except as a fossil - they’re an ancient lineage, unrelated to the molluscs, that have come through mass extinctions since at least the Cambrian, and may have evolved from the Tommotiids of the earliest Cambrian series, 540 million years ago. They have two shells, like bivalves, but the structure and symmetry is completely different, and the internal anatomy even more so. This species, in the Terebratulida has a hole at the rear of the shell, through which the peduncle emerges to attach it to the rocky seafloor. That gives the shell a resemblance to the ancient oil lamps that give them their common name.

Inside the shell brachiopods have a lophophore, a crown of tentacles which filter seawater for food particles. They’re supported on a brachidium - which was still intact in this one!

As you can imagine, I was hugely pleased with this find :)

[fossilroulette]

Name: Marginifera Location: Texas, USA, Glass Mountains Age: 260-299 million years ago, Carboniferous-Permian Periods

The delicate, nearly microscopic detail preserved in this fossil was only achieved through acid. Preparators took advantage of acid's destructive nature and the chemical differences between this fossil and its surrounding rock to keep those details intact.

This fossil contains a small, cup-shaped colony of small, filter-feeding bryozoan animals that grew on a shell of a dead brachiopod. The remains of this small community were buried in mud at the bottom of the ocean 268-314 million years ago. The mud later compressed and altered into limestone. As water heavy with silica permeated the shells, they also altered. Chemical reactions in the water removed the calcium carbonate and left the silica behind in the fossils.

Limestone is hard enough that it's used in buildings and statues, including the Great Sphinx in Egypt. If researchers tried to chip or hammer this fossil from solid limestone, they would also inevitably break off the thin spines on the outside of this brachiopod and shatter the bryozoan colony.

Luckily, limestone and silica-based fossils react differently to an acid bath. Limestone fizzes away when exposed to even a diluted acid, but silica is more resistant. The block of rock containing this fossil sat in a bucket of acid for days, or even weeks. After the acid digested all of the limestone rock, only these fossils remained.

Specimen Number: NPL 62495

References: Baars, Christian. "Acid digestion of silicified shells." The Geological Curator 9(2009):29-33. Ross, Charles A. "Standard Wolfcampian Series (Permian), Glass Mountains, Texas." Geological Society of America Memoirs 88(1963):1-230.

Where are similar fossils found? Note: Glass Mountains is not a formation. It is a mountain range that preserves almost 40 million years’ worth of rock record in multiple formations in a stack of sediment about 1500-2000 meters thick. Whoever collected the photographed fossil, along with others, did not pass along from exactly where and when they collected. It’s too bad because now that the fossil is out of the rock that information is gone forever. If you collect, always record where you did so and which rocks you collected from in as much detail as you can