#haplophrentis

[opalescent-apples]

Mermay Prompts (Unofficial)- Prehistoric Edition

Anomalocaris

Trilobite

Megalodon

Essexella

Dunkleosteus

Ammonite

Icthyosaur

Plesiosaur

Cameroceras

Opabinia

Tamisiocaris borealis

Hurdia victoria

Hallucigenia

Wiwaxia

Ottoia prolifica

Haplophrentis carinatus

Isoxys

Marrella

Leanchoilia

Dickinsonia

Syllipsimopodi bideni

Styletoctopus

Tusoteuthis

Priscomyzon riniensis

Asterotrygon maloneyi

Glyphithyreus

Leedsichthys

Tylosaurus

Metriorhynchus

Kronosaurus

Prehistoric hominid (Reverse Mermaid!)

The last prompt is a bit of a wild card, with the human side being prehistoric as well as the fish.

(I personally will not be able to post every day, but I intend to fill all 31 prompts).

This is not intended to be scientific, more of an exploration of sea creature art, and the extinct sealife I see getting passed over in most MerMays. I'll still be making traditional mermaid art for most of these (with a twist). I hope you enjoy.

[alphynix]

Cambrian Explosion Month #30: Phylum(?) Hyolitha

Hyoliths were a group of small shelled animals that first appeared in the fossil record just after the start of the Cambrian, about 536 million years ago. They had conical calcareous shells with a lid-like operculum, and some species also featured long curling spines that made them look like ice-cream cones with mammoth tusks.

They were so odd that for a long time their evolutionary relationships were unknown. They were generally accepted to be lophotrochozoans, but some studies considered them to be part of their own unique phylum while others tended to place them as being closely related to molluscs.

It wasn't until 2017 that well-preserved soft tissue fossils revealed a tentacled feeding structure that resembled a lophophore – and hyoliths finally found their place in the lophotrochozoan family tree as close relatives of brachiopods and horseshoe worms, possibly even being a stem lineage within the brachiopod phylum.

However, this isn't universally accepted and some recent studies continue to dispute it. The feeding organ of a different hyolith fossil has been interpreted as not being a lophophore, classifying the group as an early lophotrochozoan stem lineage, while an analysis of shell microstructure has instead suggested realigning them with molluscs. I'm grouping them with brachiopods here, but future discoveries might still make this obsolete.

———

Lingulosacculus nuda might represent another possible link between brachiopods and hyoliths.

Discovered in the Mural Formation in Alberta, Canada (~524-522 million years ago), it was about 4cm long (1.6") and had a long conical shell that was either poorly-mineralized or completely unmineralized.

Its position within brachiozoan evolution is uncertain. It was originally proposed as a stem-phoronid, but other analyses place it as a stem-brachiopod, an early linguliform brachiopod related to lingulellotretids, or possibly a stem-hyolith.

———

The earliest true hyoliths were the conical orthothecids, which mostly lived resting on top of the seafloor feeding on organic detritus around themselves. A few have also been found vertically oriented in the sediment, suggesting they may have been filter-feeders collecting particles from surrounding water currents.

Later members of the lineage, the hyolithids, developed distinctive long tusk-like spines on each side of their opercula. These moveable structures have been termed "helens" and were probably used as stilts, holding up the front end of the animal slightly above the seafloor.

There's also some evidence that helens gave hyoliths the ability to move themselves around, albeit probably rather awkwardly. They may have dug out shallow scrape-like "burrows" in the surface of the seafloor to shelter from stronger currents that could overturn them, and clusters of individuals found around carcasses of larger animals indicate they might have been opportunistic scavengers.

Haplophrentis reesei was a typical hyolithid, known from Utah and Idaho, USA, about 509-504 million years ago. A closely related species, Haplophrentis carinatus, is also known from Canada (~508 million years ago) and southwest China (~516-513 million years ago).

Up to about 6cm long (2'4"), this hyolith was one of the first found to preserve soft tissue feeding organs, showing up to 16 tentacles in a lophophore-like arrangement.

———

Whatever they actually were, the hyoliths were highly successful animals for a time, found abundantly worldwide for most of the Cambrian. They later began to decline, but still hung on throughout the rest of the Paleozoic and only finally went completely extinct during the catastrophic "Great Dying" mass extinction at the end of the Permian, about 252 million years ago.

———

Nix Illustration | Tumblr | Pillowfort | Twitter | Patreon

[afieldguidetoprehistoriclife]

A FIELD GUIDE TO CAMBRIAN FAUNA is part of a series of zines about prehistoric life. A mix of illustration, speculation and science, this second volume contains 50+ pages as well as 20 full-color illustrations.

How you can support the project:

Purchase the 1st volume here! (limited supply)

Reblog/like/spread the word!

[retronym]

Gogia

Agnostus

Tribrachidium

Haplophrentis

N・Burgess shale

[netmassimo]

An article published in the journal "Nature" describes a research on Haplophrentis carinatus and in general of the group of hyoliths, animals that lived during the Cambrian period, starting from about 530 million years ago. A team of researchers from the University of Toronto found evidence that these animals are related to the brachiopods (phylum Brachiopoda), marine invertebrates that existed at the time of which some species still exist today.

[b4inalternative]

Paleontologists Classify Mysterious Ancient Cone-Shaped Sea Creatures

One branch on the tree of life is a bit more crowded today. A team of scientists led by 20-year-old University of Toronto (U of T) undergraduate student Joseph Moysiuk has finally determined what a bizarre group of extinct cone-shaped animals actually are.Known as hyoliths, these marine creatures evolved over 530 million years ago during the Cambrian period and are among the first animals known to have produced mineralized external skeletons.Long believed to belong to the same family as snails, squid and other molluscs, a study published today in the prestigious scientific journal Nature shows that hyoliths are instead more closely related to brachiopods - a group of animals which has a rich fossil record, although few living species remain today.This illustration shows the hyolith Haplophrentis extending the tentacles of its feeding organ (lophophore) from between its shells. The paired spines, or 'helens', are rotated downwards to prop the animal up off the ocean floor.Artist: Danielle Dufault. © Royal Ontario MuseumBrachiopods have a soft body enclosed between upper and lower shells (valves), unlike the left and right arrangement of valves in bivalve molluscs. http://beforeitsnews.com/science-and-technology/2017/01/paleontologists-classify-mysterious-ancient-cone-shaped-sea-creatures-2869283.html?utm_source=dlvr.it&utm_medium=tumblr

[before-its-news]

Paleontologists Classify Mysterious Ancient Cone-Shaped Sea Creatures

One branch on the tree of life is a bit more crowded today. A team of scientists led by 20-year-old University of Toronto (U of T) undergraduate student Joseph Moysiuk has finally determined what a bizarre group of extinct cone-shaped animals actually are.Known as hyoliths, these marine creatures evolved over 530 million years ago during the Cambrian period and are among the first animals known to have produced mineralized external skeletons.Long believed to belong to the same family as snails, squid and other molluscs, a study published today in the prestigious scientific journal Nature shows that hyoliths are instead more closely related to brachiopods - a group of animals which has a rich fossil record, although few living species remain today.This illustration shows the hyolith Haplophrentis extending the tentacles of its feeding organ (lophophore) from between its shells. The paired spines, or 'helens', are rotated downwards to prop the animal up off the ocean floor.Artist: Danielle Dufault. © Royal Ontario MuseumBrachiopods have a soft body enclosed between upper and lower shells (valves), unlike the left and right arrangement of valves in bivalve molluscs. http://beforeitsnews.com/science-and-technology/2017/01/paleontologists-classify-mysterious-ancient-cone-shaped-sea-creatures-2869283.html?utm_source=dlvr.it&utm_medium=tumblr

[retronym]

Machina-noi No.23

Haplophrentis

N・Burgess shale

[netmassimo]

Un articolo pubblicato sulla rivista "Nature" descrive una ricerca sull'aplofrentide (Haplophrentis carinatus) e in generale del gruppo degli ioliti, o iolitidi, animali vissuti durante il periodo Cambriano, a partire da 530 milioni di anni fa circa. Un team di ricercatori dell'Università di Toronto ha raccolto le prove che questi animali sono imparentati con i brachiopodi (phylum Brachiopoda), invertebrati marini che esistevano già a quell'epoca di cui alcune specie esistono anche oggi.