Dendrogramma has a body plan similar to animals in the phyla Cnidaria and Ctenophora, but the observed specimens lack the stinging cells that define cnidarians and the tentacles that define ctenophorans.
Is Dendrogramma a Ctenophora?
Dendrogramma has a body plan similar to animals in the phyla Cnidaria and Ctenophora, but the observed specimens lack the stinging cells that define cnidarians and the tentacles that define ctenophorans.
How many species of Dendrogramma are there?
When initially discovered, Dendrogramma' s relationships were unclear. The two purported species were assigned their own genus, Dendrogramma, and family, Dendrogrammatidae; and the researchers even considered putting them in their own phylum.
What does a Dendrogramma look like?
Preserved specimens of Dendrogramma. The specimens first collected were roughly mushroom-shaped, and with a mostly asymmetrical structure. So far, no sex organs or nervous system have been detected. The specimens consist of a flattened, somewhat circular disc and a stalk with what was originally interpreted as mouth on the end, surrounded by lobes.
What is the relationship between Dendrogramma and mushrooms?
But the relationship ends there. What looks like a mushroom's stalk on Dendrogramma has a mouth at the base leading to a digestive canal that forks repeatedly once it reaches a disk, which looks like a mushroom cap. The animals' lifestyle is as mysterious as their appearance.
What does a Dendrogramma look like?
What looks like a mushroom's stalk on Dendrogramma has a mouth at the base leading to a digestive canal that forks repeatedly once it reaches a disk, which looks like a mushroom cap. The animals' lifestyle is as mysterious as their appearance.
How is Dendrogramma classified?
Dendrogramma enigmatica is a species of siphonophore, the only one in its genus....DendrogrammaKingdom:AnimaliaPhylum:CnidariaClass:HydrozoaOrder:Siphonophorae9 more rows
Is Dendrogramma a new phylum?
Dendrogramma also appears to lack any specialized sensory structures such as those seen in some cnidarians and ctenophores. As a result, Just et al. conclude that Dendrogramma could represent a new phylum of Metazoa, most closely related to Cnidaria or Ctenophora (or the two together united as Coelenterata).
What sea creature looks like a mushroom?
Dendrogramma enigmaticaA mushroom-shaped animal found deep in the ocean doesn't fit anywhere on the tree of life. Dendrogramma enigmatica and Dendrogramma discoides are only a few millimeters wide, with a wide disc at one end and long stalk with a mouth on the other end.
Who discovered phylum?
Ernst HaeckelGeneral description. The term phylum was coined in 1866 by Ernst Haeckel from the Greek phylon (φῦλον, "race, stock"), related to phyle (φυλή, "tribe, clan").
Who discovered invertebrates?
Although remembered mostly for his development of binomial nomenclature and biotic systematics in his Systema Naturae (1735), Carl Linnaeus also described many prehistoric marine invertebrates which he had observed within Silurian strata in his native Sweden.
Is there a sea mushroom?
A mushroom-shaped sea animal discovered off the Australian coast has defied classification in the tree of life. A team of scientists at the University of Copenhagen says the tiny organism does not fit into any of the known subdivisions of the animal kingdom.
Are there underwater fungi?
Nevertheless, fungi have been found in nearly every marine habitat explored, from the surface of the ocean to kilometers below ocean sediments. Fungi are hypothesized to contribute to phytoplankton population cycles and the biological carbon pump and are active in the chemistry of marine sediments.
What are the similarities between dendrogramma and cnidarians?
Dendrogramma show some general similarities in body structure to comb jellies ( which are also known as ctenophores) and to cnidarians, which include jellyfish, corals, and sea anemones. Like these animals, the new species also appear to have only a single digestive opening where food enters and waste leaves.
Which fossils have a disk laced with forking channels?
Though no living animal closely resembles Dendrogramma, at least three fossils bear a striking resemblance. Albumares, Anfesta, and Rugoconites appear to also to have possessed a disk laced with forking, radiating channels.
Does Dendrogramma have convergent evolution?
It is possible that Dendrogramma independently evolved a similar structure as a response to the same conditions as the three extinct species , a common phenomenon called convergent evolution. "There is this most intriguing similarity to certain Ediacaran forms," Conway Morris says.
Is Dendrogramma a larval stage?
The University of Florida's Moroz says that it's possible that Dendrogramma are fragments or larval stages of larger animals, but that he is nevertheless "really excited" by the new animals.
Is the Dendrogramma a descendant of the Ediacaran?
Still, there is a chance that Dendrogramma are Ediacaran descendants, potentially making these animals the first to survive to modern times in recognizable form.
What is a dendrogram in phylogenetics?from en.wikipedia.org
in phylogenetics, it displays the evolutionary relationships among various biological taxa. In this case, the dendrogram is also called a phylogenetic tree. The name dendrogram derives from the two ancient greek words δένδρον ( déndron ), meaning "tree", and γράμμα ( grámma ), meaning "drawing, mathematical figure".
What does the name Dendrogramma mean?from en.wikipedia.org
The genus name Dendrogramma derives from the two ancient greek words δένδρον ( déndron ), meaning "tree", and γράμμα ( grámma ), meaning "drawing, mathematical figure". It alludes to the branching pattern of the digestive canals, which resemble dendrograms, i.e., branching diagrams frequently used by biologists to illustrate the evolutionary relationships among organisms.
How accurate is a dendrogram?from displayr.com
To use some jargon, a dendrogram is only accurate when data satisfies the ultrametric tree inequality, and this is unlikely for any real-world data. The consequence of the information loss is that the dendrograms are most accurate at the bottom, showing which items are very similar.
What is a dendrogram in email?from displayr.com
Email. A dendrogram is a diagram that shows the hierarchical relationship between objects. It is most commonly created as an output from hierarchical clustering. The main use of a dendrogram is to work out the best way to allocate objects to clusters.
What is the difference between enigmatica and discoides?from en.wikipedia.org
The specific name enigmatica of the type species refers to the mysterious nature of the organisms, while discoides — the species epithet of the purported second species — alluded to the disc-like shape of the animals.
What is the vertical line at the bottom of the tree of life?from en.wikipedia.org
This phylogenetic tree is adapted from Woese et al. rRNA analysis. The vertical line at bottom represents the last universal common ancestor (LUCA).
Where were the first dendrogramma collected?from en.wikipedia.org
The first Dendrogramma specimens were collected off the south-east coast of Australia during a scientific expedition in 1986. They were collected at water depths of 400 metres (1,300 ft) and 1,000 metres (3,300 ft) on the continental slope near Tasmania, using a sled that was dragged over the sea floor to collect bottom-dwelling animals. The researchers were immediately struck by the unusual characteristics of the 18 specimens they collected. These were preserved in formaldehyde, and later in ethanol, for further study.
Where is the dendrogramma from?
2014. Dendrogramma, New Genus, with Two New Non-Bilaterian Species from the Marine Bathyal of Southeastern Australia (Animalia, Metazoa incertae sedis) – with Similarities to Some Medusoids from the Precambrian Ediacara. PLOS ONE.
How many dendrogramma specimens are there?
15 Dendrogramma specimens. Credit: Jean Just from PLOS One.
How big is the holotype of Dendrogramma Enigmatica?
Holotype of Dendrogramma enigmatica. About 2 mm across.
What is the least commonly known early diverging phylum of animals?
Placozoa. The least commonly known early diverging phylum of animals. WikiImages, taken by O. Voigt.
What are the names of the four phyla?
This would place them among four phyla: Porifera (sponges), Cnidaria (jellyfish, corals and kin), Ctenophora (comb jellies), and Placozoa (no common name because they are not commonly known). But these animals appear to have no characters that would tie them specifically to any of these groups.
What are the two species of dendrogramma?
The two Dendrogramma species are multicellular (metazoans), non-bilaterian, apparently diploblastic animals with a dense mesoglea between an outer epidermis and an inner gastrodermis. The animals are composed of a body divided into a stalk with a mouth opening terminally, and a flattened disc. The mouth is set in a specialised, lobed epidermis field, leading into a gastrodermis-lined gastrovascular canal (pharynx) in the stalk which aborally branches dichotomously into numerous radiating canals in the disc. While the animals are certainly multicellular, the precise structural identity of the epithelia lining the gastrovascular canal and the external remain to be studied and compared to that of other metazoans.
Where is the dendrogramma from?
Citation: Just J, Kristensen RM, Olesen J (2014) Dendrogramma, New Genus, with Two New Non-Bilaterian Species from the Marine Bathyal of Southeastern Australia (Animalia, Metazoa incertae sedis) – with Similarities to Some Medusoids from the Precambrian Ediacara. PLoS ONE 9 (9): e102976. https://doi.org/10.1371/journal.pone.0102976
How many paratypes are there in Dendrogramma gen. nov.?
Figure 1. Dendrogramma gen. nov., all 15 paratypes of D. enigmatica and (with *) D. discoides.
What is the genus of dendrogrammatidae?
discoides, are described from the south-east Australian bathyal (400 and 1000 metres depth). A new family, Dendrogrammatidae, is established for Dendrogramma . These mushroom-shaped organisms cannot be referred to either of the two phyla Ctenophora or Cnidaria at present, because they lack any specialised characters of these taxa. Resolving the phylogenetic position of Dendrogramma depends much on how the basal metazoan lineages (Ctenophora, Porifera, Placozoa, Cnidaria, and Bilateria) are related to each other, a question still under debate. At least Dendrogramma must have branched off before Bilateria and is possibly related to Ctenophora and/or Cnidaria. Dendrogramma, therefore, is referred to Metazoa incertae sedis. The specimens were fixed in neutral formaldehyde and stored in 80% ethanol and are not suitable for molecular analysis. We recommend, therefore, that attempts be made to secure new material for further study. Finally similarities between Dendrogramma and a group of Ediacaran (Vendian) medusoids are discussed.
What is the purpose of the paper "Dendrogrammatidae"?
The aim of this paper is to present a group of non-bilaterian metazoan organisms that cannot at present be placed in an existing phylum. The two species described, D. enigmatica and D. discoides ( Figs 1 – 7) in new genus Dendrogramma of the new family Dendrogrammatidae were collected at 400 and 1000 metres on the Australian continental slope off eastern Bass Strait and Tasmania during a cruise in 1986. The first author subsequently worked up the entire material at Museum Victoria, Melbourne, Australia. The specimens in question were not recognised in the field, but were extracted from bulk samples in the laboratory during sorting (see further under Material and Methods below).
How long is a stem?
Stem short, length approximately 1/10 disc diameter; not longer than wide at base of disc. Disc diameter approximately 17 mm (3 mm after shrinkage), stalk length approximately 4.5 mm (cf. Fig. 6 C). Disc circular with entire margin. Mouth-field of three lobes, two lobes of equal length both longer than the third lobe. Disc with 63 terminals of the gastrovascular branches.
Is Ctenophora related to Dendrogramma?
We suggest that Dendrogramma most likely is related to Ctenophora and/ Cnidaria (red arrows) due to general similarities in body organisation (see Discussion). However, depending on the position of Ctenophora and on whether certain aspects of Dendrogramma (e.g., mesoglea and gastrovascular system) are ancestral for Metazoa or modified, Dendrogramma can be positioned in a variety of ways below Bilateria (yellow oval).