Infinity Imagined
Multicellular Organic
Neural Network
Lives in Nitrogen-Oxygen Atmosphere
270 K - 300 K
Eats, Breathes, Thinks, Creates

February on this blog is going to be Daily Paleo Art Month! Because doing dinosaurs all last July was so much fun I want to do this thing again. Every weekday for the rest of the month I’ll be posting a new image of something strange, obscure, or just plain interesting from the fossil record — only this time we’re staying firmly outside of the Avemetatarsalia (pterosaurs and dinosaurs/birds) to give some less famous critters the spotlight.
#1: Helicoprion
A cartilaginous fish from off the southwest coast of the ancient supercontinent Gondwana (and later Pangaea), Helicoprion first appeared in the late Carboniferous (310 million years ago) and survived up until just past the massive Permian-Triassic extinction (250mya). Despite looking rather shark-like and possibly reaching sizes of around 6m (20ft) long, it was actually closer related to the chimaeras.
For a long time, the only parts of this animal known were bizarre buzzsaw-like spiral whorls of teeth, since cartilage skeletons very rarely fossilize. The ideas for just where in the body this structure was positioned were ridiculously varied.
The most recent reconstruction is based on CT scans of a well-preserved fossil with jaw and skull elements, which showed the whorl taking up the whole lower jaw. It also turns out Helicoprion had no upper teeth at all. It’s thought to have used this arrangement to shred and crush up squid and other soft-bodied marine prey, but there’s still very little known about how such a unique type of teeth evolved in the first place.

Dunkleosteus and Cladoselache by John Sibbick

Dunkleosteus and a Devonian Coelacanth
A Dunkleosteus skull, photographed at the Royal Tyrrell Museum in Drumheller Alberta.  Dunkleosteus was a placoderm fish that lived in the late Devonian, 380 to 360 million years ago.  It was a hypercarnivorous apex predator, feeding on armored prey such as ammonites, arthropods, and other placoderms.  Fully grown individuals had more than 700 kilograms of bite force, enough to easily shear through bone and protective tissues.  Members of the largest species could grow up to 10 meters in length and weigh almost four tonnes.

Parayunnanolepis and Psarolepis by *Gogosardina
Sometime, in the Devonian, on the floors of shallow, green seas, the fish looked like stones. They lives their lives encased in tight-fitting armor. Bodies locked in cuirass, plackart, and pauldron. Arms: gauntlets. Just a keyhole in the helmet for peeking eyes. Life was lived hidden in an envelope of bone; and the world was only touched through chinks in the walls built against one’s own flesh.

Daily Paleo Art Month #2: Vetulicola
Known from the 525-520 million-year-old Lower Cambrian Chengjiang Lagerstätte, Vetulicola is a member of a strange group of creatures known as vetulicolians. About 9cm (3.5in) long, it’s thought to have been an active swimmer that fed on either plankton or seafloor debris.
And nobody’s sure just what these animals are. They were originally thought to be early limbless arthropods, but more recently opinions have swung in the opposite direct and they’re now considered to be early deuterostomes instead.

The ancient inhabitant, Vetulicola (1987)
Phylum : VetulicoliaFamily : VetulicolidaeGenus : VetulicolaSpecies : V. cuneata, V. rectangulata, V. gantoucunensis, V. monile
Middle Cambrian
9 cm long (size)
China (map)
The type species, Vetulicola cuneata (Hou, 1987) has a body composed of two distinct parts of approximately equal length. The front part is rectangular with a carapace-like structure of four rigid cuticular plates, with a large mouth at the front end. The posterior section is slender, strongly cuticularised and placed dorsally. Paired openings connecting the pharynx to the outside run down the sides. These features are interpreted as possible primitive gill slits. Vetulicola cuneata could be up to 9 cm long. The Vetulicola are thought to have been swimmers that were either filter feeders or detritivores.
Vetulicola’s taxonomic position is controversial. Vetulicola cuneata was originally assigned to the crustaceans on the assumption that it was a bivalved arthropod like Canadaspis and Waptia, but the lack of legs, the presence of gill slits, and the four plates in the “carapace” were unlike any known arthropod. Shu et al. placed Vetulicola in the new family Vetulicolidae, order Vetulicolida and phylum Vetulicolia, among the deuterostomes. Shu (2003) later argued that the vetulicolians were an early, specialized side-branch of deuterostomes. Dominguez and Jefferies classify Vetulicola as an urochordate, and probably a stem-group appendicularian. In contrast, Butterfield places Vetulicola among the arthropods.

Ancient sea creatures filtered food like modern whales

The animals lived 520 million years ago during the Early Cambrian, a period known as the ‘Cambrian Explosion’ in which all the major animal groups and complex ecosystems suddenly appeared. Tamisiocaris belongs to a group of animals called anomalocarids, a type of early arthropod that included the largest and some of the most iconic animals of the Cambrian period. They swam using flaps down either side of the body and had large appendages in front of their mouths that they most likely used to capture larger prey, such as trilobites.However, the newly discovered fossils show that those predators also evolved into suspension feeders, their grasping appendages morphing into a filtering apparatus that could be swept like a net through the water, trapping small crustaceans and other organisms as small as half a millimetre in size.

Read more from the press release. 
The abstract of the scientific paper. 
Read how the Daily Mail butchered this information by labelling it an ancestor of whales. 
And for good measure, the Daily Mail song.

Oldest Complex Fossils on Earth
Millions of years before hikers and livestock roamed the Ediacara Hills, the region was home to ancient creatures that mark the birth of animal life. In 1946, geologist Reg Sprigg was exploring the mountainous region in the Flinders Ranges, South Australia, when he came across fossilised imprints of soft-bodied organisms on slabs of quartzite and sandstone. Some had disc-shaped forms like jellyfish, others bore resemblance to worms and arthropods, and others were completely foreign. Sprigg first thought these fossils were from the Cambrian period, but later work showed they were Precambrian—a new geological period was created, set immediately before the Cambrian from 635–541 million years ago, and it was named after the Ediacara Hills. “Ediacara” comes from the Indigenous phrase for “veinlike spring of water”, so it’s pretty fitting that at that time, the region was underwater. The fossils are actually of marine animals, and they existed before animals had skeletons—they represent the oldest complex organisms on Earth. Other fossils of Precambrian soft-bodied organisms had been found before, scattered all over the world, but Ediacara Hills’ collection is the most diverse and most well-preserved. Over 40 different types of organisms have been identified so far, and NASA has even funded some work in the region in the hopes it will shed light on how life might evolve on other planets.
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