The Cambrian explosion produced a host of bizarre and complex lifeforms, like this filter-feeding sea monster, dubbed Tamiscolaris borealis, that was unearthed in Greenland.
A “nude” sponge-like animal with no organs and just one orifice that lived 500,000 years ago is offering compelling new clues about a bizarre group of ancient creatures.
Though it somewhat resembles a sponge, the newcomer — now called Allonnia nuda — belonged to the now-extinct chancelloriids. Like sponges, they lived attached to the ocean bottom, and their bodies were generally covered with spines. However, this newfound species of chancelloriid was “naked,” with spines that were much smaller than is typical for the group.
Are you jelly?
Scientists had assumed that comb jellies that lived during the Cambrian period were likely just as much of blobs as today’s ctenophores, or members of the phylum Ctenophora. But new evidence from the fossil-rich site Chengjiang, in southwestern China, suggests otherwise. Here the fossil imprints of some of the comb jellies, which lived about 520 million years ago and showed the telltale cilia or hairlike structures on their bodies. The imprints belong to: Thaumactena ensis (A to D), Galeactena hemispherica (E to I), and Batofasciculus ramificans (J to N).
The comb jellies, which are not true jellyfish and did not have stinging cells nor did they sport tentacles, were protected with hard, spiny skeletons. The little creatures may have resembled Christmas ornaments, as shown in this illustration. The research, which you can read more about in the full news article, was detailed on July 10, 2015, in the journal Science Advances.
A “super-armored” worm fossil discovered in what is now southern China was rather leggy. Called Collinsium ciliosum, or Hairy Collins’ Monster (after paleontologist Desmond Collins who discovered a fossil in this family in Canada in the 1980s), the creature would’ve sported 30 legs — 18 of which were tipped with claws to anchor the animal to penetrable surfaces and 12 feathery limbs would have waved back and forth in order to catch nutrients in the water.
Collinsium ciliosum was one the world’s first armored animals, the researchers said. It used its spiky covering to protect itself from predators some 518 million years ago during the Cambrian explosion, when an array of diverse creatures of all shapes burst onto Earth starting about 540 million years ago.
Researchers found 29 fossils of Collinsium ciliosum, a wormlike animal with legs, in the early Cambrian Xiaoshiba biota of China.
The odd worm Hallucigenia sparsa gets its moniker from the word “hallucination,” due to the animal’s bizarre body — its head looks like its tail, it sports multiple leg pairs and strange back spines. The 1.3-inch-long (35 millimeters) worm lived on the seafloor during the Cambrian explosion.
Velvet worm claw
The ancient worm had a row of spines along its back and seven or eight pairs of clawed legs. It was these leg claws that revealed the worm’s family relationships. Its claws are made up of a fingernail-like material that was stacked like cups; its structure matched that found in the modified chewing claws of modern-day velvet worms.
Hallucigenia Worm Illustration
The Hallucigenia sparsa worm was uncovered in Canada’s Burgess Shale, one of the world’s richest fossil sites. The ancient creature, which lived during the Cambrian period some 508 million years ago, had a 0.6-inch-long (15 millimeters) wormy body covered in spines on top and 10 pairs of spindly legs down below. And because of the animal’s odd body plan and specimens available, only recently were researchers able to decipher where its face was. Turns out, it has a doozy of a mouth: a circular opening lined with teeth. The inside of its mouth and throat were also lined with teeth pointed toward the gut.
Hallucigenia worm illustration
The Hallucigenia sparsa worm had quite a grin — a circular mouth lined with needlelike teeth. More teeth lined the inside of its mouth and throat, researchers found.
Hallucigenia worm fossil
The Hallucigenia sparsa worm was uncovered in Canada’s Burgess Shale, one of the world’s richest fossil sites.
The Cambrian period saw a rise in complex life forms like this early arthropod from simple multi-cellular creatures.
Because the ancient arthropods, fuxhianhuiid, were fossilized in a flipped position in a region of Southwest China, they are only example of preserved feeding limbs in this species.
A site in Southwest China has revealed a rich trove of creatures from the Cambrian period, including the only example of a nervous system that extends past the head.
Rich fossil mine
Arthropods from the Burgess shale, such as the trilobite Olenoides and a chelicerate called Sidneyia, exploded in morphological diversity following the so-called Cambrian Explosion.
Trilobites are a common find at the Burgess Shale.
A chain of trilobites preserved in Poland’s Holy Cross Mountains.
Paleontologists have also identified a a slug-like creature covered with prickly armor at the Burgess Shale
The Cambrian also saw the rise of larger creatures, such as this 2-foot-long ancient shrimplike creatures called anomalocaridids, which had spiny head limbs for catching prey
Cambrian sea monster
The Cambrian also saw the rise of larger creatures, such as this 2-foot-long ancient shrimplike creatures called anomalocaridids had long, which had spiny head limbs for catching prey
During the Cambrian explosion, the diversity of life exploded and bizarre sea creatures such as the Helcocystis moroccoensis flourished.
The strange animal had a set of five spiral grooves around its cigar-shaped body that it used to filter food from the water. This unique five point symmetry may shed light on when echinoderms such as starfish and sea urchins evolved their unique body plan symmetry.
A spectacularly preserved creature, dubbed Lyrarapax unguispinus, was unearthed in China. The 520-million-year-old sea creature was so well-preserved that parts of its brain and nervous system were clearly defined.
Meet Ovatiovermis cribratus. This lobopodian (a worm-like creature with legs) was naked, meaning it didn’t have any armor covering it. Perhaps it used camouflage or toxins to protect itself, the researchers said.
The 500-million-year-old Ovatiovermis cribratus had a unique way of catching its meals. It likely anchored its bottom limbs to the seafloor, and then waved its upper limbs around to catch tiny morsels, such as zooplankton, floating by in the water.