#priapulid

[onenicebugperday]

What about the priapulids!

That's a penis

[alphynix]

Cambrian Explosion #34: Phylum Priapulida

Named for their resemblance to human penises, priapulids (or "penis worms") are marine scalidophoran worms that live on or in muddy seafloor sediment, with some species having a surprisingly high tolerance for oxygen-poor environments and toxic levels of hydrogen sulfide. Despite being a rather low-diversity phylum with only around 20 living species, they're widespread and sometimes very numerous, with over 80 adult individuals per square meter (~10ft²) recorded in some locations.

The earliest definite modern-style priapulid in the fossil record comes from the late Carboniferous (~308 million years ago), but their ancestry was probably somewhere in the early Cambrian among the taxonomic mess of palaeoscoloecids and archaeopriapulids.

Xiaoheiqingella peculiaris was a very priapulid-like scalidophoran known from the Chinese Chengjiang fossil deposits (~518 million years ago). Around 1cm long (0.4") it had a ringed spiny body with a swollen proboscis region at the front and a bulbous rear end with a pair of long tail-like appendages.

It's generally considered to be a close relative or early representative of the modern priapulid family Priapulidae, but some analyses have instead suggested it was part of a "stem" priapulid lineage of much earlier forms.

Living alongside it in the Chengijiang region was another potential early priapulid, Paratubiluchus bicaudatus. Also about 1cm long (0.4"), this species was chunkier with a spiny proboscis, a bumpy body lacking rings, and two short rear appendages, and its overall proportions were very similar to the larvae of some modern priapulids.

It may have been closely related to the modern tubiluchid priapulids, but some studies disagree – one analysis even places it as much closer to kinorhynchs and loriciferans than to priapulids!

Both of these species were fairly rare elements of their ecosystem, and seem to have had very similar ecologies to each other. They would have been burrowing carnivores using their retractable proboscises to grab small invertebrate prey, sometimes also feeding detritivorously on decaying organic matter in the mud around them.

Their anatomical and ecological similarities to modern priapulids suggest that the group as a whole rapidly developed in the early Cambrian and then just… didn't ever really need to change their body plan or lifestyle much for the next half a billion years.

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[typhlonectes]

Ferocious 'penis worms' were the hermit crabs of the ancient seas

These phallus-shaped worms were some of the top predators of the ancient seas, but even they needed protection.

The Cambrian period (543 million to 490 million years ago) brought the first great explosion of biodiversity to Earth, with the ancestors of practically all modern animals first appearing. One of the most feared among them was the penis worm.

Technically known as priapulids — named for Priapus, the well-endowed Greek god of male genitals — penis worms, as they’re commonly known, are a division of marine worms that have survived in the world's oceans for 500 million years. 

Their modern descendants live largely unseen in muddy burrows deep underwater, occasionally freaking out fishermen with their floppy, phallus-shaped bodies. But fossils dating back to the early Cambrian show that penis worms were once a scourge of the ancient seas, widely distributed around the world and in possession of extendible, fang-lined mouths that could make a snack out of the poor marine creature that crossed them.

But, fearsome as they were, penis worms themselves were not without fear. In a new study published Nov. 7 in the journal Current Biology, researchers discovered four priapulid fossils that were nestled into the cone-shaped shells of hyoliths, a long-extinct group of marine animals...

Read More: https://www.livescience.com/penis-worms-hermit-shell-behavior

[penisworms]

Our prey response evolved because of worms. My anxiety won't like me catch a bus because worm scare bad.

[virtualfossilmuseum]

Above image: Nice example of the sharp and spiny teeth of priapulid (penis worm - a Cambrian predator) teeth from the Burgess Shale

Those Nasty Little Teeth of Cambrian Priapulid Worm Predators

The images are fine examples of high resolution electron and optical microscopy used in modern paleontology. of macroscopic The study, just published in today’s journal Paleontology provides a basis for  differentiating two Ottoia species, Ottoia prolifica, and a new species, Ottoia tricuspida.

Also see priapulid worm fossils from the Marjum Formation in Utah, and the Burgess Shale in Canada.

[virtualfossilmuseum]

Ottoia prolifica Priapulid Worm Fossil from Burgess Shale

Ottoia prolifica Phylum Priapulida, Family Ottoidae Geological Time: Early Cambrian (~520 million years ago) Size: 40 mm long Fossil Site: Burgess Shale, Stephen Formation, Burgess Pass, British Columbia, Canada

Ottoia was a carnivorous marine worm of the Cambrian Explosion. The proboscis (lower right in picture) is seen here everted, with the hook-like spines which it presumably used to capture prey showing. Read more here.

Also see a priapulid worm from Utah named Selkirkia.

[lostbeasts]

Ottoia. A (pretty disturbing-looking) Cambrian priapulid- priapulid meaning "penis worm". It would have burrowed beneath the ocean sediment of prehistoric British Columbia, and captured prey with it's spiny, eversible proboscis. There have been an astounding number of specimens found in the British Columbia Burgess Shale formation, suggesting both that it was abundant, and that the disintegration of the limestone cliffs they have been found below would have caused many casualties due to the relative immobility of the animal. (reconstruction by Michelle Bakay)