Trisha Shetty

Helicoplacus

Updated on
Share on FacebookTweet on TwitterShare on LinkedIn
Kingdom  Animalia
Genus  Helicoplacus
Phylum  Echinodermata
Rank  Class
Helicoplacus PALEO amp GEO TOPICS Comments by R L Squires Helicoplacus an
Similar  Homalozoa, Eocrinoidea, Ophiocistioidea, Edrioasteroidea, Paracrinoidea

Helicoplacus (often misspelled Helioplacus) is the earliest well-studied fossil echinoderm. Fossil plates are known from several regions. Complete specimens were found in Lower Cambrian strata of the White Mountains of California.

Helicoplacus Helicoplacus Wikipedia

The animal was a cigar-shaped creature up to 7 centimetres (2.8 in) long that stood upright on one end. Unlike more typical echinoderms such as sea stars, Helicoplacus does not have fivefold symmetry. Instead, there is a spiral food groove on the outside along which food was moved to a mouth that is thought to be on the side. The respiratory system appears to be primitive. Although the animal does not look like a typical echinoderm, the plates are composed of the characteristic calcareous plates known as stereom that are common to all echinoderms. The ambulacrum is similar to that of the Edrioasteroidea; as a result, Helicoplacoidea may belong to Pelmatozoa.

Helicoplacus httpsuploadwikimediaorgwikipediacommonsthu

Other contemporaneous echinoderms are known to have existed from their dissociated plates, but other than a few possible edrioasteroids, Helicoplacus is the earliest echinoderm that is well enough preserved to analyze its characteristics. One much earlier form called Arkarua has been hypothesized to be an ancestral echinoderm because of its fivefold symmetry. But Arkarua appears to lack both stereoms and a mouth.

Helicoplacus Life Before the Dinosaurs Helicoplacus

Helicoplacoids seem to have existed for about 15 million years in the Lower Cambrian, around 525 million years ago.

Helicoplacus Animal A Day Helicoplacus

Helicoplacoids are thought to have been suspension feeders living at moderate depths in highly oxygenated water with strong enough currents to ensure a steady food supply. They are typically found in greenish shales and are rarely found in shallow water sandstones and limestones. The helically spiraling rows of plates radiating from the base, which in life probably was anchored in the muddy substrate.

Helicoplacus Dr Wilbur Geology 2
Helicoplacus The Helicoplacoidea
Helicoplacus Cienciaescom Helicoplacus la peonza marina Podcasts de Ciencia
Helicoplacus Helicoplacus guthi

References

Helicoplacus Wikipedia


Similar Topics
Edrioasteroidea
Eocrinoidea
Homalozoa
Topics