Staurinidia

Last updated

Staurinidia
Temporal range: Ediacaran
Scientific classification
Kingdom:
Phylum:
Class:
Family:
Genus:
Staurinidia

Fedonkin, 1985
Species:
S. crucicula
Binomial name
Staurinidia crucicula
Fedonkin, 1985

Staurinidia is a genus of Ediacaran soft-bodied organism from the deposits of the Ust'-Pinega formation. It is a monotypic genus and only contains the species Staurinidia crucicula. [1] The genus was first described in 1985 by Russian palaeontologist Mikhail A. Fedonkin. S. crucicula's four-fold symmetry is present as a result of four canals radiating from the middle of a small cavity in the middle of the body. [1] Other forms with four way symmetry, mainly Medusoid forms, from the Ediacaran (Conomedusites, Persimedusites) comprise an essential chunk of the Ediacaran diversity of symmetry; their organisations are similar to, though smaller than, those of a modern-day Scyphozoan Cnidarian. [2]

Contents

Description

S. crucicula fossils are preserved as a small discoidal form baring four radial canals emitting from the fossils centre in which a small cavity is present. The ends of the canals are often swollen when pointing towards the organisms periphery. [1] In very rare instances, tentacles are present and preserved around the outside of the disc's margin. The margins of the disc are very thin with there being no indication of an encircling ridge or canal. [1] Rather deep impressions are preserved of Staurinidia suggesting that the animal would've had significant relief.

The diameter of the body of Staurinidia ranges from 6 millimeters (0.24 in)-10 millimeters (0.39 in), the width of the radial canals is 1 millimeter (0.039 in) and the length of the marginal tentacles being 4 millimeters (0.16 in)-5 millimeters (0.20 in). [1] The canals give the animal a four-fold symmetry typical to that of other Ediacaran Cnidarians. [2] Staurinidia is regarded as one of the simplest of all Ediacaran Cnidarians that show four-way rotational axis. [3]

See also

Related Research Articles

<i>Kimberella</i> Primitive Mollusc-like organism

Kimberella is an extinct genus of bilaterian known only from rocks of the Ediacaran period. The slug-like organism fed by scratching the microbial surface on which it dwelt in a manner similar to the gastropods, although its affinity with this group is contentious.

<i>Tribrachidium</i> Extinct genus of invertebrates

Tribrachidium heraldicum is a tri-radially symmetric fossil animal that lived in the late Ediacaran (Vendian) seas. In life, it was hemispherical in form. T. heraldicum is the best known member of the extinct group Trilobozoa.

<i>Inaria</i> Extinct genus of aquatic animals

Inaria is an Ediacaran fossil. It is found in the Chace Range in Australia, and the White Sea area in Russia.

<i>Hiemalora</i> Genus of cnidarians

Hiemalora is a fossil of the Ediacaran biota, reaching around 3 cm in diameter, which superficially resembles a sea anemone. The genus has a sack-like body with faint radiating lines originally interpreted as tentacles, but discovery of a frond-like structure seemingly attached to some Heimalora has added weight to a competing interpretation: that it represents the holdfast of a larger organism.

<span class="mw-page-title-main">Trilobozoa</span> Extinct phylum of triradially symmetrical animals

Trilobozoa is a phylum of extinct, sessile animals that were originally classified into the Cnidaria. The basic body plan of trilobozoans is often a tri-radial or radial sphere-shaped form with lobes radiating from its centre. Fossils of trilobozoans are restricted to marine strata of the Late Ediacaran period.

<i>Albumares</i> Extinct genus of soft-bodied Trilobozoan

Albumares brunsae is a tri-radially symmetrical fossil animal that lived in the late Ediacaran seafloor. It is a member of the extinct group Trilobozoa.

Anfesta stankovskii is a tri-radially symmetrical fossil animal that lived in the late Ediacaran (Vendian) seafloor. It is a member of the extinct group Trilobozoa.

<i>Rugoconites</i> Extinct genus of invertebrates

Rugoconites is a genus of Ediacaran biota found as fossils in the form of a circular or oval-like impression preserved in high relief, six or more centimeters in diameter. The fossils are surrounded by frills that have been interpreted as sets of tentacles. The bifurcating radial ribs, spreading from a central dome, serve to distinguish this genus from the sponge Palaeophragmodictya, and may represent the channels of the gastrovascular system. Fossils of Rugoconites have been interpreted as early sponges, although this is countered by Sepkoski et al. (2002), who interpreted the organism as a free-swimming jellyfish-like cnidarian; similar to Ovatoscutum. However, the fossil is consistently preserved as a neat circular form and its general morphology does not vary, therefore a benthic and perhaps slow-moving or sessile lifestyle is more likely. Ivantstov & Fedonkin (2002), suggest that Rugoconites may possess tri-radial symmetry and be a member of the Trilobozoa.

Vaveliksia is an extinct genus of Ediacaran Sponge-like organism with a long, tubular-shaped body and a attachment disk similar to that of Petalonamids. The Vaveliksia genus contained two species, Vaveliksia velikanovi as well as Vaveliksia vana. The two species vary in appearance to one another, with V. velikanovi having a more tubular-shaped, sack-like morphology with a crown of wrinkles on top of one of its ends as well as possessing a much more disk-like holdfast with V. vana having an appearance more similar to that of a Poriferan, with V. vana having a much more dome-shaped holdfast and a capsule-like body with no crown of wrinkles unlike V. velikanovi.

<i>Veprina</i>

Veprina is a rare Ediacaran coelenterate cnidarian found on the Zimny coast of the White Sea, Russia and was first described by Mikhail Fedonkin in 1980.

Palaeoplatoda is a genus from the Ediacaran biota. It is a soft-bodied organism with a segmented body that resembles Dickinsonia, another Ediacaran organism.

<i>Ventogyrus</i> Extinct genus of invertebrates

Ventogyrus is an Ediacaran fossil found in the White Sea-Arkhangelsk region of Russia. It was first discovered in the Teska member of the Ust'-Pinega formation, in a thick lens of sandstone, originally sand dumped by storm waves that cut a deep channel through the shallow sea bottom where the organisms lived. Many individuals were preserved on top of each other, often torn or in distorted positions. As a result, it was originally thought to have had a "boat shaped" form and to have lived anchored in the sea floor. However, a nearby site discovered later by Mikhail Fedonkin yielded separate specimens which were beautifully preserved in an upright position and showed the internal anatomy.

Eoporpita is a disc or ellipse-shaped Ediacaran fossil with unsure taxonomy/classification. It is known from its type species, Eoporpitamedusa, the only species within the genus Eoporpita.

Conomedusites was a creature from the Ediacaran biota. The Ediacaran period ranged from 635 to 539 million years ago. Its fossil was first discovered in 1966 by Martin F. Glaessner and Mary Wade in South Australia. Conomedusites is believed to have been part of the phylum Cnidaria due to its similar structure to jellyfish and other cnidarians, but this is not known for certain. Conomedusites is thought to have been a stationary osmotroph.

<span class="mw-page-title-main">Ichnusa (genus)</span> Discoidal-pyramidal shaped Cnidarian

Ichnusa is a genus of discoidal Cnidarians that existed during the Ediacaran, 635-541 Million Years ago (MYA) discovered on the island of Sardinia, Italy. The genus is monotypic, only containing the species Ichnusa cocozzi. Palaeontologists think that Ichnusa represented a cnidarian of unknown affinities, with I. cocozzi being put in the Scyphozoa.

<i>Zolotytsia</i> Unidentified animal which is a probable cnidarian

Zolotytsia is an extinct genus of fossil animals from the late Ediacaran period (Vendian) which contains only one known species, Z. biserialis. Specimens of this species have been found in Russia, Ukraine and India.

Bonata is a monotypic, disk-shaped genus of Ediacaran organism that were originally found in the Ediacaran deposits of the White Sea area, Russia. It has been poorly studied because of the lack of fossil specimens found in the region since the 1980's. It contains a single species, Bonata septata.

Petalostoma kuibis is a species of enigmatic fossil organism from the Ediacaran period, possibly a member of the Petalonamae, of Namibia, Dabris Formation, Farm Aar.

<span class="mw-page-title-main">Pseudorhizostomites</span> Alleged fossil of unknown origin

Pseudorhizostomites howchini is a enigmatic member of the Ediacaran Biota which was originally been thought to have been a jellyfish of some kind. P. howchini is now though to either have been a pseudofossil, a gas escape structure or perhaps the result of a rangeomorph holdfast being pulled by currents or, if any of these possibilities are not true, some other force from the sediments which enclosed the fossil.

Nasepia altae is a species of Ediacaran Erniettomorph which was described in 1973 from the farms of Vrede and Chamis, Namibia. Nasepia has an appearance similar to that of most other Erniettomorphs from Namibia, with it having a leaf-like body with thin ribs and spindle-shaped bodies, however it differentiates itself from other taxa such as Pteridinium and Rangea in the sense that it has smaller petaloids and with the configuration of the ribs being sub-parallel to its axis.

References

  1. 1 2 3 4 5 Fedonkin, Mikhail A.; Sciences), Mikhail A. (Head Fedonkin, Laboratory of Precambrian Organisms Russian Academy of; Gehling, James G.; Museum), James G. (Senior Curator Gehling, retired 6 27 2019 South Australian; Grey, Kathleen; Narbonne, Guy M.; Vickers-Rich, Patricia; University), Patricia (Director Vickers-Rich, Monash (Mar 16, 2007). The Rise of Animals: Evolution and Diversification of the Kingdom Animalia. JHU Press. ISBN   9780801886799 . Retrieved July 1, 2022 via Google Books.{{cite book}}: CS1 maint: multiple names: authors list (link)
  2. 1 2 Origin and Early Evolution of the Metazoa. Springer. 21 November 2013. ISBN   9781489924278.
  3. The Vendian System: Vol. 1 Paleontology. Springer. 27 August 1990. ISBN   9783540501428.