Taxonomy of commonly fossilised invertebrates
Encyclopedia
Although the phylogenetic classification of sub-vertebrate animals (both extinct and extant) remains a work-in-progress, the following taxonomy
attempts to be useful by combining both traditional (old) and new (21st-century) paleozoological
terminology.
So the paleobiologic
systematics
which follows is not intended to be all-inclusive or completely comprehensive. For practical reasons and relevancy, the below classification and annotations emphasize invertebrates that (a) are popularly collected as fossils and/or (b) no longer continue alive on this planet. Therefore, as a result, some phyla, classes
, and orders
of invertebrates are not listed.
If a non-vertebrate animal is mentioned below using its common, vernacular, everyday name, the creature is usually a living, present-day
invertebrate. But if, on the other hand, a non-vertebrate is cited below by its scientific, taxonomic genus
(in italics
), then it is typically an extinct invertebrate, known only from the fossil record.
Invertebrate clade
s that are (a) very important as fossils (for example, ostracod
s frequently used as index fossil
s), and/or (b) very abundant as fossils (for example, crinoid
s easily found in crinoidal limestone
), are highlighted with a bracketed exclamation mark [ ! ].
Invertebrate groups that (a) are now substantially extinct, and/or (b) contain a large proportion of extinct species, are followed by a dashed notation [ – such as this ]. But invertebrate clades which are now totally – that is, 100 percent – extinct are designated with a bracketed dagger/cross [ † ]:
s / eukaryans / all cellular
organism
s bearing a central, organized nucleus with DNA
)
s, proto-fungal microsporidians, true fungi, and true animals
Kingdom of Animal
(metazoans / many-celled true animal
s / multi-cellular creatures that grab and ingest their organic food
)
Sub-kingdom of Parazoa
(parazoans / typically sessile
, basal
non-eumetazoa
ns / the most-primitive
animals / the simplest, colonial
, attached
, bottom-dwelling, marine invertebrates)
Phylum Archaeocyatha
(cone-shaped archaeocyathids/archeocyathids / cup-shaped archaeocyathans/archeocyathans / reef
-building pleosponges / calcareous
"ancient-cups")
(includes fossil genera such Archaeocyathus, Cambrocyathus, Atikonia,
Tumuliolynthus, Kotuyicyathus, Metaldetes, Ajacicyathus and Paranacyathus)
(Archaeocyatha is sometimes classified as a class
of Porifera below)
Phylum Porifera / Nuda
(quintessential true sponges
/ marine, colonial, pore
-bearing animals / organized collar-flagellates
/ poriferans; today mostly siliceous) – half of all documented species of Porifera are fossils and extinct
(Porifera may eventually be broken up into separate phyla
)
Sub-kingdom of Eumetazoa
(eumetazoans / true metazoans / typically mobile, multicellular animals)
(Eumetazoa contains most of the living and deceased species of recorded life, including most invertebrates (alive and extinct), as well as all vertebrate animals)
Phylum Cnidaria
(cnidarians / coelenterates)
Super-phylum of Lophotrochozoa
(lophotrochozoa
n bilateria
ns, such as flatworm
s, ribbon worms, lophophorates, and molluscs)
Phylum Bryozoa
(bryozoans / moss animals) – half of all documented species of Bryozoa are fossils and extinct
(lampshells, brachiopods or "brachs
," not to be confused with the hard-shelled marine
mollusks below) – 99 percent of all documented species of Brachiopoda are now extinct
s and leech
es)
Phylum Mollusca
(molluscs or mollusks, not to be confused with the hard-shelled marine
brachiopod
s above)
Super-phylum of Ecdysozoa
(ecdysozoa
ns, such as nematode
s, horsehair worms, and molting bilateria
ns / panarthropods
))
s, including proto-arthropodic fossils of Arthropleura and Aysheaia)
)
ns called deuterostomians, such as chordate
s and echinoderm
s)
Phylum Hemichordata
(hemichordates such as extant acorn worm
s) – Less than half of the documented species of Hemichordata are fossils and extinct
)
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
attempts to be useful by combining both traditional (old) and new (21st-century) paleozoological
Paleozoology
Paleozoology, also spelled as palaeozoology , is the branch of paleontology or paleobiology dealing with the recovery and identification of multicellular animal remains from geological contexts, and the use of these fossils in the reconstruction of prehistoric environments and ancient...
terminology.
So the paleobiologic
Paleobiology
Paleobiology is a growing and comparatively new discipline which combines the methods and findings of the natural science biology with the methods and findings of the earth science paleontology...
systematics
Systematics
Biological systematics is the study of the diversification of terrestrial life, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees...
which follows is not intended to be all-inclusive or completely comprehensive. For practical reasons and relevancy, the below classification and annotations emphasize invertebrates that (a) are popularly collected as fossils and/or (b) no longer continue alive on this planet. Therefore, as a result, some phyla, classes
Class (biology)
In biological classification, class is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, order, family, genus, and species, with class fitting between phylum and order...
, and orders
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
of invertebrates are not listed.
If a non-vertebrate animal is mentioned below using its common, vernacular, everyday name, the creature is usually a living, present-day
Holocene
The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...
invertebrate. But if, on the other hand, a non-vertebrate is cited below by its scientific, taxonomic genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
(in italics
Italic type
In typography, italic type is a cursive typeface based on a stylized form of calligraphic handwriting. Owing to the influence from calligraphy, such typefaces often slant slightly to the right. Different glyph shapes from roman type are also usually used—another influence from calligraphy...
), then it is typically an extinct invertebrate, known only from the fossil record.
Invertebrate clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
s that are (a) very important as fossils (for example, ostracod
Ostracod
Ostracoda is a class of the Crustacea, sometimes known as the seed shrimp because of their appearance. Some 65,000 species have been identified, grouped into several orders....
s frequently used as index fossil
Index fossil
Index fossils are fossils used to define and identify geologic periods . They work on the premise that, although different sediments may look different depending on the conditions under which they were laid down, they may include the remains of the same species of fossil...
s), and/or (b) very abundant as fossils (for example, crinoid
Crinoid
Crinoids are marine animals that make up the class Crinoidea of the echinoderms . Crinoidea comes from the Greek word krinon, "a lily", and eidos, "form". They live both in shallow water and in depths as great as 6,000 meters. Sea lilies refer to the crinoids which, in their adult form, are...
s easily found in crinoidal limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
), are highlighted with a bracketed exclamation mark [ ! ].
Invertebrate groups that (a) are now substantially extinct, and/or (b) contain a large proportion of extinct species, are followed by a dashed notation [ – such as this ]. But invertebrate clades which are now totally – that is, 100 percent – extinct are designated with a bracketed dagger/cross [ † ]:
Domain of Eukaryota / Eukarya
(eukaryoteEukaryote
A eukaryote is an organism whose cells contain complex structures enclosed within membranes. Eukaryotes may more formally be referred to as the taxon Eukarya or Eukaryota. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear...
s / eukaryans / all cellular
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
organism
Organism
In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...
s bearing a central, organized nucleus with DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
)
- comprises most of the speciesSpeciesIn biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of lifeLifeLife is a characteristic that distinguishes objects that have signaling and self-sustaining processes from those that do not, either because such functions have ceased , or else because they lack such functions and are classified as inanimate...
which have been documented by biologistBiologistA biologist is a scientist devoted to and producing results in biology through the study of life. Typically biologists study organisms and their relationship to their environment. Biologists involved in basic research attempt to discover underlying mechanisms that govern how organisms work...
s and paleontologists as either living or deceased
- includes a wide variety of single-celled protistProtistProtists are a diverse group of eukaryotic microorganisms. Historically, protists were treated as the kingdom Protista, which includes mostly unicellular organisms that do not fit into the other kingdoms, but this group is contested in modern taxonomy...
s, all algaeAlgaeAlgae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
, most planktonPlanktonPlankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
, most moldMoldMolds are fungi that grow in the form of multicellular filaments called hyphae. Molds are not considered to be microbes but microscopic fungi that grow as single cells called yeasts...
s, the green plants, and all animal-related kingdomsKingdom (biology)In biology, kingdom is a taxonomic rank, which is either the highest rank or in the more recent three-domain system, the rank below domain. Kingdoms are divided into smaller groups called phyla or divisions in botany...
- but does not include the primal, sub-nuclear, prokaryotic domains of ArchaeaArchaeaThe Archaea are a group of single-celled microorganisms. A single individual or species from this domain is called an archaeon...
and BacteriaBacteriaBacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
– nor the enigmatic domain of VirusVirusA virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
es
- but does not include the primal, sub-nuclear, prokaryotic domains of Archaea
Sub-domain of Opisthokonta
(opisthokonts / the animal-related kingdoms / the proto-spongal choanoflagellateChoanoflagellate
The choanoflagellates are a group of free-living unicellular and colonial flagellate eukaryotes considered to be the closest living relatives of the animals...
s, proto-fungal microsporidians, true fungi, and true animals
- comprises most life forms documented as either living or deceased
- excludes many molds, all one-celled protists (or protoctists), all algae, and all green plants
Kingdom of AnimalAnimalAnimals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
ia / Metazoa --- All Invertebrates and Vertebrates
(metazoans / many-celled true animalAnimal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
s / multi-cellular creatures that grab and ingest their organic food
Food
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...
)
- comprises most living and deceased species which have ever been recorded by paleontological and life scientists
- excludes all unicellular and fungal opisthokonts
Sub-kingdom of ParazoaParazoaThe Parazoa are an ancestral subkingdom of animals, literally translated as "beside the animals".-Description:Parazoans differ from their choanoflagellate ancestors in that they are not microscopic and have differentiated cells. However, they are an outgroup of the animal phylogenetic tree being...
(parazoans / typically sessileSessility (zoology)
In zoology, sessility is a characteristic of animals which are not able to move about. They are usually permanently attached to a solid substrate of some kind, such as a part of a plant or dead tree trunk, a rock, or the hull of a ship in the case of barnacles. Corals lay down their own...
, basal
Basal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...
non-eumetazoa
Eumetazoa
Eumetazoa is a clade comprising all major animal groups except sponges, placozoa and several other little known animals. Characteristics of eumetazoans include true tissues organized into germ layers, and an embryo that goes through a gastrula stage...
ns / the most-primitive
Primitive (biology)
Primitive in the sense most relevant to phylogenetics means resembling the first living things and in particular resembling them in the simple nature of their anatomy and behaviour...
animals / the simplest, colonial
Colony (biology)
In biology, a colony reference to several individual organisms of the same species living closely together, usually for mutual benefit, such as stronger defense or the ability to attack bigger prey. Some insects live only in colonies...
, attached
Sessility (zoology)
In zoology, sessility is a characteristic of animals which are not able to move about. They are usually permanently attached to a solid substrate of some kind, such as a part of a plant or dead tree trunk, a rock, or the hull of a ship in the case of barnacles. Corals lay down their own...
, bottom-dwelling, marine invertebrates)
Phylum ArchaeocyathaArchaeocyathaThe Archaeocyatha or archaeocyathids were sessile, reef-building marine organisms of warm tropical and subtropical waters that lived during the early Cambrian period. It is believed that the centre of the Archaeocyatha origin is in East Siberia, where they are first known from the beginning of...
/ Archeocyatha / Archaeocyathida / Archeocyathida / Pleospongia [†]
(cone-shaped archaeocyathids/archeocyathids / cup-shaped archaeocyathans/archeocyathans / reefReef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
-building pleosponges / calcareous
Calcareous
Calcareous is an adjective meaning mostly or partly composed of calcium carbonate, in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines.-In zoology:...
"ancient-cups")
(includes fossil genera such Archaeocyathus, Cambrocyathus, Atikonia,
Tumuliolynthus, Kotuyicyathus, Metaldetes, Ajacicyathus and Paranacyathus)
(Archaeocyatha is sometimes classified as a class
Class (biology)
In biological classification, class is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, order, family, genus, and species, with class fitting between phylum and order...
of Porifera below)
Phylum Porifera / NudaNudaNuda is a class of comb jellies. As their name implies, they are distinguished from other comb jellies by the complete absence of tentacles. Nudans are found in all the world's oceans and seas, where they swim freely in the plankton.-Anatomy:...
/ SpongiaSpongiaSpongia is a genus of marine animals, originally described by Linnaeus in 1759. Some species, including thepictured Spongia officinalis, are used as cleaning tools, but have mostly been replaced in that use by synthetic or plant material....
(quintessential true spongesSea sponge
Sponges are animals of the phylum Porifera . Their bodies consist of jelly-like mesohyl sandwiched between two thin layers of cells. While all animals have unspecialized cells that can transform into specialized cells, sponges are unique in having some specialized cells, but can also have...
/ marine, colonial, pore
Lateral line
The lateral line is a sense organ in aquatic organisms , used to detect movement and vibration in the surrounding water. Lateral lines are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail...
-bearing animals / organized collar-flagellates
Choanoflagellate
The choanoflagellates are a group of free-living unicellular and colonial flagellate eukaryotes considered to be the closest living relatives of the animals...
/ poriferans; today mostly siliceous) – half of all documented species of Porifera are fossils and extinct
(Porifera may eventually be broken up into separate phyla
Phylum
In biology, a phylum The term was coined by Georges Cuvier from Greek φῦλον phylon, "race, stock," related to φυλή phyle, "tribe, clan." is a taxonomic rank below kingdom and above class. "Phylum" is equivalent to the botanical term division....
)
- Sub-phylum Calcarea / Calcispongiae (primitive calcareousCalcium carbonateCalcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...
poriferans such as yellow lemon sponge, sphinctozoans, pharetronids, Scypha, Leucetta, Gravestockia, Grantia, Astraeospongium, Clathrina, Lelapia, Rhaphidonema, and Girtyocoelia)- Class CalcineaCalcineaCalcinea is a subclass of the calcareous sponges....
- Class CalcaroneaCalcaroneaCalcaronea is a subclass in the class Calcarea....
- Class StromatoporoideaStromatoporoideaStromatoporoidea is a class of aquatic invertebrates common in the fossil record from the Ordovician through the Cretaceous. They were especially abundant in the Silurian and Devonian. These invertebrates were important reef-formers throughout the Paleozoic and the Late Mesozoic. The group was...
/ Stromatoporata / Stromatoporida / Spongliomorphida [†] (limeLime (mineral)Lime is a general term for calcium-containing inorganic materials, in which carbonates, oxides and hydroxides predominate. Strictly speaking, lime is calcium oxide or calcium hydroxide. It is also the name for a single mineral of the CaO composition, occurring very rarely...
-layered stromatoporoids / reef-building stromatoporates / button-shaped stromatoporids / disc-shaped spongliomorphids; e.g., Stromatopora, Aulacera, Stromatactis, Actinostroma, Discophyllum, Parallelopora and Amphipora) - Class Heteractinida [†] (Paleozoic calciticCalciteCalcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380-470°C, and vaterite is even less stable.-Properties:...
heteractinids such as Eiffelia)
- Class Calcinea
- Sub-phylum Silicea / Silicospongia (siliceous poriferans)
- Class Demospongea / Demospongiae (most living sponges hardened by opalineOpalineThe opalines are a small group of peculiar protists, currently assigned to the family Opalinidae, in the order Slopalinida. Their name is derived from the opalescent appearance of these microscopic organisms when illuminated with full sunlight...
silica or sponginSponginSpongin, a modified type of collagen protein, forms the fibrous skeleton of most organisms among the phylum Porifera, the sponges. They are secreted by sponge cells known as spongocytes...
; for instance, horny sponge, bath spongeSea spongeSponges are animals of the phylum Porifera . Their bodies consist of jelly-like mesohyl sandwiched between two thin layers of cells. While all animals have unspecialized cells that can transform into specialized cells, sponges are unique in having some specialized cells, but can also have...
, stove-pipe sponge, yellow boring sponge, carnivorous sponge, bristle sponge, chaetids, lithistids, Astroclera, Ceractinomorpha, Clionoides, Hindia, Ventriculites, Laosoiadia, Clionolithes, Tetractinella, and Astylospongia) - Class Hexactinellida / Hyalospongiae / Sclerospongiae (siliceous, deep-sea glass sponges, e.g. glassy-latticed Venus flower basket, bird's nest sponge, cloud spongeCloud spongeCloud sponge is a primitive organism of the order Hexactinosa in the class Hexactinellida. It is a deep-water reef-forming animal. The species was first described by F.E. Schulze in 1886....
, Hexactinella, Hydroceras, Dictyonina, Brachiospongia, Titusvillea, and Rhizopoterion)
- Class Demospongea / Demospongiae (most living sponges hardened by opaline
Sub-kingdom of EumetazoaEumetazoaEumetazoa is a clade comprising all major animal groups except sponges, placozoa and several other little known animals. Characteristics of eumetazoans include true tissues organized into germ layers, and an embryo that goes through a gastrula stage...
(eumetazoans / true metazoans / typically mobile, multicellular animals)(Eumetazoa contains most of the living and deceased species of recorded life, including most invertebrates (alive and extinct), as well as all vertebrate animals)
Phylum CnidariaCnidariaCnidaria is a phylum containing over 9,000 species of animals found exclusively in aquatic and mostly marine environments. Their distinguishing feature is cnidocytes, specialized cells that they use mainly for capturing prey. Their bodies consist of mesoglea, a non-living jelly-like substance,...
/ CoelenterataCoelenterataCoelenterata is an obsolete term encompassing two animal phyla, the Ctenophora and the Cnidaria . The name comes from the Greek "koilos" , referring to the hollow body cavity common to these two phyla...
(cnidarians / coelenterates)- Class HydrozoaHydrozoaHydrozoa are a taxonomic class of very small, predatory animals which can be solitary or colonial and which mostly live in saltwater. A few genera within this class live in freshwater...
(hydraHydra (genus)Hydra is a genus of simple fresh-water animal possessing radial symmetry. Hydras are predatory animals belonging to the phylum Cnidaria and the class Hydrozoa. They can be found in most unpolluted fresh-water ponds, lakes, and streams in the temperate and tropical regions and can be found by...
or hydroidHydroid-Marine biology:Hydroids are a life stage for most animals of class Hydrozoa, small predators related to jellyfish.-Botany:In mosses, hydroids form the innermost layer of the stem of long, colourless, thin walled cells of small diameter.The cells are dead and lack protoplasm.They function as water...
group)- Subclass StromatoporoideaStromatoporoideaStromatoporoidea is a class of aquatic invertebrates common in the fossil record from the Ordovician through the Cretaceous. They were especially abundant in the Silurian and Devonian. These invertebrates were important reef-formers throughout the Paleozoic and the Late Mesozoic. The group was...
[†] (lime-layered stromatoporoids) - Subclass Conulata [†] (four-sided, pyramidal conularians)
- Subclass Stromatoporoidea
- Class AnthozoaAnthozoaAnthozoa is a class within the phylum Cnidaria that contains the sea anemones and corals. Unlike other cnidarians, anthozoans do not have a medusa stage in their development. Instead, they release sperm and eggs that form a planula, which attaches to some substrate on which the cnidarian grows...
(coralCoralCorals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
s / polypPolypA polyp in zoology is one of two forms found in the phylum Cnidaria, the other being the medusa. Polyps are approximately cylindrical in shape and elongated at the axis of the body...
s)- Subclass Receptaculidea [†] (receptaculites, a.k.a. sunflower corals)
- Subclass Octocorallia / AlcyonariaAlcyonariaOctocorallia is a subclass of Anthozoa comprising ~3,000 species of water-based organisms formed of colonial polyps with 8-fold symmetry. It includes the blue coral, soft corals, sea pens, and gorgonians within three orders: Alcyonacea, Helioporacea, and Pennatulacea...
(soft corals and sea penSea penSea pens are colonial marine cnidarians belonging to the order Pennatulacea. There are 14 families within the order; they are thought to have a cosmopolitan distribution in tropical and temperate waters worldwide...
s) - Subclass ZoanthariaZoanthariaZoanthids are an order of cnidarians commonly found in coral reefs, the deep sea and many other marine environments around the world. These animals come in a variety of different colonizing formations and in numerous colors...
[!] (sea anemoneSea anemoneSea anemones are a group of water-dwelling, predatory animals of the order Actiniaria; they are named after the anemone, a terrestrial flower. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Zoantharia. Anthozoa often have large polyps that allow for digestion of larger...
s and most extant coralCoralCorals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
s)- Order RugosaRugosaDisambiguation:The Rugosa Rose is also sometimes just called "Rugosa". For the moon in Star Wars: The Clone Wars, see .The Rugosa, also called the Tetracoralla, are an extinct order of coral that were abundant in Middle Ordovician to Late Permian seas.Solitary rugosans are often referred to...
/ Tetracoralla [†] [!] (wrinkled, horn-shaped tetracorals such as Petoskey coralPetoskey stoneA Petoskey stone is a rock and a fossil, often pebble-shaped, that is composed of a fossilized coral, Hexagonaria percarinata. The stones were formed as a result of glaciation, in which sheets of ice plucked stones from the bedrock, grinding off their rough edges and depositing them in Michigan's...
, Caninia and Heliophyllum) - Order Tabulata / Schizocoralla [†] [!] (tabulate coralTabulate coralThe tabulate corals, forming the order Tabulata, are an extinct form of coral. They are almost always colonial, forming colonies of individual hexagonal cells known as corallites defined by a skeleton of calcite, similar in appearance to a honeycomb. Adjacent cells are joined by small pores...
s, for instance, FavositesFavositesFavosites is an extinct genus of tabulate coral characterized by polygonal closely packed corallites . The walls between corallites are pierced by pores which allowed transfer of nutrients between polyps....
and AuloporaAuloporaAulopora is an extinct genus of tabulate coral characterized by a bifurcated budding pattern and conical corallites. Colonies commonly encrust hard substrates such as rocks, shells and carbonate hardgrounds....
) - Order ScleractiniaScleractiniaScleractinia, also called stony corals, are exclusively marine animals; they are very similar to sea anemones but generate a hard skeleton. They first appeared in the Middle Triassic and replaced tabulate and rugose corals that went extinct at the end of the Permian...
/ Hexacoralla [!] (stony corals such as brain coralBrain coralBrain coral is a common name given to corals in the family Faviidae so called due to their generally spheroid shape and grooved surface which resembles a brain...
, Favia, Meandrina, and most living coralCoralCorals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
s)
- Order Rugosa
Super-phylum of LophotrochozoaLophotrochozoaThe Lophotrochozoa are a major grouping of protostome animals. The taxon was discovered based on molecular data. Molecular evidence such as a result of studies of the evolution of small-subunit ribosomal RNA supports the monophyly of the phyla listed in the infobox shown at right.-Terminology:The...
/ Protostomia # 1
(lophotrochozoaLophotrochozoa
The Lophotrochozoa are a major grouping of protostome animals. The taxon was discovered based on molecular data. Molecular evidence such as a result of studies of the evolution of small-subunit ribosomal RNA supports the monophyly of the phyla listed in the infobox shown at right.-Terminology:The...
n bilateria
Bilateria
The bilateria are all animals having a bilateral symmetry, i.e. they have a front and a back end, as well as an upside and downside. Radially symmetrical animals like jellyfish have a topside and downside, but no front and back...
ns, such as flatworm
Flatworm
The flatworms, known in scientific literature as Platyhelminthes or Plathelminthes are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrate animals...
s, ribbon worms, lophophorates, and molluscs)
Phylum BryozoaBryozoaThe Bryozoa, also known as Ectoprocta or commonly as moss animals, are a phylum of aquatic invertebrate animals. Typically about long, they are filter feeders that sieve food particles out of the water using a retractable lophophore, a "crown" of tentacles lined with cilia...
/ Ectoprocta / Polyzoa
(bryozoans / moss animals) – half of all documented species of Bryozoa are fossils and extinct
- Class StenolaemataStenolaemataStenolaemata are a class of marine bryozoans with tubular with strongly calcified walls. They are characterized by a lophophore which is protruded by the action of annular muscles. Most forms lack an operculum....
/ GymnolaemataGymnolaemataGymnolaemata is a class of the phylum Bryozoa. Gymnolaemata typically live under seawater and grow on surfaces of rocks, kelps, and even in some cases, on animal species like fish. They are mostly marine bryozoans with cylindrical or flattened zooids. The lophophore is protruded by action of...
[!] (mostly marineMarine (ocean)Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
, calcareousCalcareousCalcareous is an adjective meaning mostly or partly composed of calcium carbonate, in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines.-In zoology:...
bryozoans)- Order CheilostomataCheilostomataCheilostomata, an order of Bryozoa in the class Gymnolaemata, are exclusively marine, colonial invertebrate animals. Cheilostome colonies are composed of calcium carbonate and grow on a variety of surfaces, including rocks, shells, seagrass and kelps. The colony shapes range from simple encrusting...
[!] (living, rimmed-mouthed moss animals) - Order CyclostomatidaCyclostomatidaCyclostomatida, or cyclostomes, are an ancient order of stenolaemate bryozoans which first appeared in the Lower Ordovician. It consists of 7+ suborders, 59+ families, 373+ genera, and 666+ species. The cyclostome bryozoans were dominant in the Mesozoic; since that era, they have decreased...
(uncontracted, round-mouthed bryozoans including fossil Stomatopora) - Order Cystoporata [†] (extinct, minor group of moss animals)
- Order Trepostomata [†] [!] (changed-mouthed bryozoans such as extinct Constellaria and Monticulipora)
- Order CryptostomataCryptostomataCryptostomata is a fossil order of Bryozoa....
[†] [!] (round hidden-mouthed bryozoans such as Archimedes, Fenestrellina and Rhombopora) - Order Ctenostomata [†] (uncommon, comb-mouthed bryozoans)
- Order Phylactolaemata (living, fresh-water bryozoans)
- Order Cheilostomata
Phylum Brachiopoda
Brachiopod
Brachiopods are a phylum of marine animals that have hard "valves" on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection...
," not to be confused with the hard-shelled marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
mollusks below) – 99 percent of all documented species of Brachiopoda are now extinct
- Subphylum LinguliformeaLinguliformeaLinguliformea is a subphylum of inarticulate brachiopods. These were the earliest of brachiopods, ranging from the Cambrian into the Holocene. They rapidly diversified during the Cambrian into the Ordovician, but most families went extinct by the end of the Devonian.The articulation in these...
(inarticulateInarticulataInarticulata was historically defined as one of the two classes of the phylum Brachiopoda and referred to those having no hinge. The other class was Articulata, meaning articulated – having a hinge between the dorsal and ventral valves...
atremates, such as "living fossilLiving fossilLiving fossil is an informal term for any living species which appears similar to a species otherwise only known from fossils and which has no close living relatives, or a group of organisms which have long fossil records...
" LingulaLingula (genus)Lingula is a genus of brachiopods within the class Lingulata. Lingula is known since the Tertiary.-Species:The following species are recognised:*Lingula adamsi Dall, 1873*Lingula anatina Lamarck, 1801*Lingula dregeri Andreae, 1893...
) – but mostly extinct - Subphylum Craniiformea (inarticulateInarticulataInarticulata was historically defined as one of the two classes of the phylum Brachiopoda and referred to those having no hinge. The other class was Articulata, meaning articulated – having a hinge between the dorsal and ventral valves...
neotremates, such as extant Crania) – but mostly extinct - Subphylum RhynchonelliformeaRhynchonelliformeaRhynchonelliformea is the name now given to the articulate brachiopods, Class Articulata, revised as a subphylum. Articulate brachiopods are those with hard, articulated, shells with a simple set of opening and closing muscles....
[!] (articulateArticulata (Brachiopoda)The Articulata is a class of brachiopods which comprises those with hinged, calcareous shells that generally bear well developed teeth and sockets and a simple muscle system...
brachiopodBrachiopodBrachiopods are a phylum of marine animals that have hard "valves" on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection...
s with hinged valves; includes most extinct and living brachs)- Class RhynchonellataRhynchonellataThe Rhynchonellata is a class of articulate brachiopods that combines certain orders from within the Rhynchonelliformea . The class ranges from the Lower Cambrian to Recent....
[!]- Order OrthidaOrthidaOrthida is an extinct order of Brachiopods which appeared during the Early Cambrian period and became very diverse by the Ordovician, living in shallow-shelf seas. Orthids are the oldest member of the subphylum Rhynchonelliformea , and is the order from which all other brachiopods of this group...
[†] [!] (orthidOrthidaOrthida is an extinct order of Brachiopods which appeared during the Early Cambrian period and became very diverse by the Ordovician, living in shallow-shelf seas. Orthids are the oldest member of the subphylum Rhynchonelliformea , and is the order from which all other brachiopods of this group...
brachs such as fossil Orthis) - Order PentameridaPentameridaPentamerida is a brachiopods order in the class Rhynchonellata.Pentamerida have narrow hinge lines and looped brachidia....
[†] (pentamerid brachs such as Conchidium) - Order RhynchonellidaRhynchonellidaThe taxonomic order Rhynchonellida is one of the two main groups of living articulate brachiopods, the other being the order Terebratulida. They are recognized by their strongly ribbed wedge-shaped or nut-like shells, and the very short hinge line....
[!] (rhynchonellidRhynchonellidaThe taxonomic order Rhynchonellida is one of the two main groups of living articulate brachiopods, the other being the order Terebratulida. They are recognized by their strongly ribbed wedge-shaped or nut-like shells, and the very short hinge line....
brachs such as fossils Rhynchotrema and Rhynchonella) - Order SpiriferidaSpiriferidaSpiriferida is an order of extinct articulate brachiopod fossils which are known for their long hinge-line, which is often the widest part of the shell. In some genera it is greatly elongated, giving them a wing-like appearance. They often have a deep fold down the center of the shell...
[†] [!] (spiriferidSpiriferidaSpiriferida is an order of extinct articulate brachiopod fossils which are known for their long hinge-line, which is often the widest part of the shell. In some genera it is greatly elongated, giving them a wing-like appearance. They often have a deep fold down the center of the shell...
brachs)- Suborder Spiriferinida [†] [!] (spiriferid brachs such as Spirifer and Eospirifer)
- Suborder Atrypida [†] [!] (atrypid brachs such as Atrypa)
- Order TerebratulidaTerebratulidaTerebratulids are one of only three living orders of articulate brachiopods, the others being the Rhynchonellida and the Thecideida. Craniida and Lingulida include living brachiopods, but are inarticulates. The name, Terebratula, may be derived from the Latin "terebra", meaning "hole-borer"...
[!] (most living brachiopods; includes fossil Dielasma)
- Order Orthida
- Class Strophomenata [†] [!] (so-called petrified butterflies)
- Order StrophomenidaStrophomenidaStrophomenida is a large, extinct order of articulate brachiopods that existed from the lower Ordovician to the lower Jurassic period. It was the largest known order of brachiopods, encompassing over 400 genera, including the largest and heaviest of known brachiopod shells...
[†] [!] (strophomenid brachs) - Order Productida [†] [!] (spiny or productid brachs)
- Suborder Chonetidina [†] [!]
- Suborder Productidina [†] [!]
- Order Strophomenida
- Class Rhynchonellata
Phylum Annelida
(segmented worms such as earthwormEarthworm
Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...
s and leech
Leech
Leeches are segmented worms that belong to the phylum Annelida and comprise the subclass Hirudinea. Like other oligochaetes such as earthworms, leeches share a clitellum and are hermaphrodites. Nevertheless, they differ from other oligochaetes in significant ways...
es)
- Class Polychaeta (marineMarine (ocean)Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
annelids / polychaetePolychaeteThe Polychaeta or polychaetes are a class of annelid worms, generally marine. Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. Indeed, polychaetes are sometimes referred to as bristle worms. More than 10,000...
s)- Order Scolecodonta [!] (mostly chitinChitinChitin n is a long-chain polymer of a N-acetylglucosamine, a derivative of glucose, and is found in many places throughout the natural world...
ous jaws of scolecodontsScolecodontsA scolecodont is the jaw of a polychaete annelid, a common type of fossil-producing segmented worm useful in invertebrate paleontology. Scolecodonts are common and diverse microfossils, which range from the Cambrian period to the present...
)
- Order Scolecodonta [!] (mostly chitin
Phylum MolluscaMolluscaThe Mollusca , common name molluscs or mollusksSpelled mollusks in the USA, see reasons given in Rosenberg's ; for the spelling mollusc see the reasons given by , is a large phylum of invertebrate animals. There are around 85,000 recognized extant species of molluscs. Mollusca is the largest...
(molluscs or mollusks, not to be confused with the hard-shelled marineMarine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
brachiopod
Brachiopod
Brachiopods are a phylum of marine animals that have hard "valves" on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection...
s above)
- Class MonoplacophoraMonoplacophoraMonoplacophora, meaning "bearing one plate", is a polyphyletic class of mollusks with a cap-like shell, living on the bottom of deep sea. Extant representatives were unknown until 1952; previously they were known only from the fossil record.- Definition :...
(extinct, except for "living fossilLiving fossilLiving fossil is an informal term for any living species which appears similar to a species otherwise only known from fossils and which has no close living relatives, or a group of organisms which have long fossil records...
" NeopilinaNeopilinaNeopilina is a highly derived genus of modern monoplacophoran.However, molecular methods show that they fall within the polyplacophoran clade, and fossil and morphological data show that they are rather derived and bear very little resemblance to an 'ancestral mollusc'.- Anatomy :Its anatomy led...
) - Class BivalviaBivalviaBivalvia is a taxonomic class of marine and freshwater molluscs. This class includes clams, oysters, mussels, scallops, and many other families of molluscs that have two hinged shells...
/ Pelecypoda (bivalves / pelecypods) – half of all documented species of Bivalvia are fossils and extinct- Subclass Lamellibranchia [!] (clamClamThe word "clam" can be applied to freshwater mussels, and other freshwater bivalves, as well as marine bivalves.In the United States, "clam" can be used in several different ways: one, as a general term covering all bivalve molluscs...
s, oysterOysterThe word oyster is used as a common name for a number of distinct groups of bivalve molluscs which live in marine or brackish habitats. The valves are highly calcified....
s, musselMusselThe common name mussel is used for members of several families of clams or bivalvia mollusca, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval.The...
s and scallopScallopA scallop is a marine bivalve mollusk of the family Pectinidae. Scallops are a cosmopolitan family, found in all of the world's oceans. Many scallops are highly prized as a food source...
s)
- Subclass Lamellibranchia [!] (clam
- Class GastropodaGastropodaThe Gastropoda or gastropods, more commonly known as snails and slugs, are a large taxonomic class within the phylum Mollusca. The class Gastropoda includes snails and slugs of all kinds and all sizes from microscopic to quite large...
(gastropods / snailSnailSnail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
group)- Subclass ProsobranchiaProsobranchiaNot to be confused with the bivalve order Protobranchia.Prosobranchia was a large taxonomic subclass of sea snails, land snails and freshwater snails. This taxon of gastropods dates back to the 1920s...
(marineMarine (ocean)Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
snails and conchConchA conch is a common name which is applied to a number of different species of medium-sized to large sea snails or their shells, generally those which are large and have a high spire and a siphonal canal....
es) - Subclass OpisthobranchiaOpisthobranchiaOpisthobranchs are a large and diverse group of specialized complex marine gastropods previously united under Opisthobranchia within the Heterobranchia, but no longer considered to represent a monophyletic grouping...
(sea slugs) - Subclass PulmonataPulmonataThe Pulmonata, or "pulmonates", are an informal group of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills...
(land snailSnailSnail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
s)
- Subclass Prosobranchia
- Class Cephalopoda (cephalopods) – 97 percent of all documented species of Cephalopoda are now extinct
- Subclass Nautiloidea (mostly extinct, but includes "living fossilLiving fossilLiving fossil is an informal term for any living species which appears similar to a species otherwise only known from fossils and which has no close living relatives, or a group of organisms which have long fossil records...
" NautilusNautilusNautilus is the common name of marine creatures of cephalopod family Nautilidae, the sole extant family of the superfamily Nautilaceae and of its smaller but near equal suborder, Nautilina. It comprises six living species in two genera, the type of which is the genus Nautilus...
)- Order OrthoceridaOrthoceridaOrthocerida is an order of extinct nautiloid cephalopods also known as the Michelinocerda that lived from the Early Ordovician possibly to the Late Triassic . A fossil found in the Caucasus suggests they may even have survived until the Early Cretaceous...
[†] [!] (long, straight-shelled nautiloidNautiloidNautiloids are a large and diverse group of marine cephalopods belonging to the subclass Nautiloidea that began in the Late Cambrian and are represented today by the living Nautilus. Nautiloids flourished during the early Paleozoic era, where they constituted the main predatory animals, and...
s)
- Order Orthocerida
- Subclass Ammonoidea [†] [!] (generally coiled-shelled ammonoids)
- Agoniatitic (agoniatites) [†]
- Goniatitic (goniatiteGoniatiteGoniatites are extinct ammonoids, shelled cephalopods related to squid, octopus, and belemnites, that form the order Goniatitida. The Gonatitida originated from within the more primitive anarcestine ammonoids in the Middle Devonian some 390 million years ago...
s) [†] [!] (ammonoids with simple suturesSuture (anatomical)In anatomy, a suture is a fairly rigid joint between two or more hard elements of an animal, with or without significant overlap of the elements....
) - Ceratitic (ceratites) [†]
- AmmoniticAmmoniteAmmonite, as a zoological or paleontological term, refers to any member of the Ammonoidea an extinct subclass within the Molluscan class Cephalopoda which are more closely related to living coleoids Ammonite, as a zoological or paleontological term, refers to any member of the Ammonoidea an extinct...
[†] [!] (the true ammoniteAmmoniteAmmonite, as a zoological or paleontological term, refers to any member of the Ammonoidea an extinct subclass within the Molluscan class Cephalopoda which are more closely related to living coleoids Ammonite, as a zoological or paleontological term, refers to any member of the Ammonoidea an extinct...
s, bearing complex suturesSuture (anatomical)In anatomy, a suture is a fairly rigid joint between two or more hard elements of an animal, with or without significant overlap of the elements....
)
- Subclass ColeoideaColeoideaSubclass Coleoidea, or Dibranchiata, is the grouping of cephalopods containing all the primarily soft-bodied creatures. Unlike its sister group Nautiloidea, whose members have a rigid outer shell for protection, the coleoids have at most an internal bone or shell that is used for buoyancy or support...
(includes the living squidSquidSquid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...
, cuttlefishCuttlefishCuttlefish are marine animals of the order Sepiida. They belong to the class Cephalopoda . Despite their name, cuttlefish are not fish but molluscs....
, and octopusOctopusThe octopus is a cephalopod mollusc of the order Octopoda. Octopuses have two eyes and four pairs of arms, and like other cephalopods they are bilaterally symmetric. An octopus has a hard beak, with its mouth at the center point of the arms...
)- Order BelemnoideaBelemnoideaBelemnoids are an extinct group of marine cephalopod, very similar in many ways to the modern squid and closely related to the modern cuttlefish. Like them, the belemnoids possessed an ink sac, but, unlike the squid, they possessed ten arms of roughly equal length, and no tentacles...
[†] (extinct orthoconic belemnoids)
- Order Belemnoidea
- Subclass Nautiloidea (mostly extinct, but includes "living fossil
Super-phylum of EcdysozoaEcdysozoaEcdysozoa is a group of protostome animals, including Arthropoda , Nematoda, and several smaller phyla. They were first defined by Aguinaldo et al. in 1997, based mainly on trees constructed using 18S ribosomal RNA genes...
/ Protostomia # 2
(ecdysozoaEcdysozoa
Ecdysozoa is a group of protostome animals, including Arthropoda , Nematoda, and several smaller phyla. They were first defined by Aguinaldo et al. in 1997, based mainly on trees constructed using 18S ribosomal RNA genes...
ns, such as nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
s, horsehair worms, and molting bilateria
Bilateria
The bilateria are all animals having a bilateral symmetry, i.e. they have a front and a back end, as well as an upside and downside. Radially symmetrical animals like jellyfish have a topside and downside, but no front and back...
ns / panarthropods
Panarthropoda
Panarthropoda is a taxon combining the phyla Arthropoda, Tardigrada, and Onychophora. Dunn et al. in 2008 suggested that the tardigrades could be grouped along with the nematodes, leaving Onychophora as the sister group to the arthropods...
))
Phylum Onychophora
(panarthropodic velvet wormVelvet worm
The velvet worms are a minor ecdysozoan phylum. These obscurely segmented organisms have tiny eyes, antennae, multiple pairs of legs and slime glands. They have variously been compared to worms with legs, caterpillars and slugs...
s, including proto-arthropodic fossils of Arthropleura and Aysheaia)
Phylum Arthropoda
(arthropods; jointed legged creatures with an exoskeletonExoskeleton
An exoskeleton is the external skeleton that supports and protects an animal's body, in contrast to the internal skeleton of, for example, a human. In popular usage, some of the larger kinds of exoskeletons are known as "shells". Examples of exoskeleton animals include insects such as grasshoppers...
)
- Subphylum Crustacea (crustaceans)
- Class Ostracoda (ostracods)
- Class MalacostracaMalacostracaMalacostraca is the largest of the six classes of crustaceans, containing over 25,000 extant species, divided among 16 orders. Its members display a greater diversity of body forms than any other class of animals, and include crabs, lobsters, shrimp, krill, woodlice, scuds , mantis shrimp and many...
(true crabCrabTrue crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
s, lobsterLobsterClawed lobsters comprise a family of large marine crustaceans. Highly prized as seafood, lobsters are economically important, and are often one of the most profitable commodities in coastal areas they populate.Though several groups of crustaceans are known as lobsters, the clawed lobsters are most...
and most shrimpShrimpShrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
) - Class BranchiopodaBranchiopodaBranchiopoda is a class of crustaceans. It is the sister group to the remaining crustaceans, and comprises fairy shrimp, clam shrimp, Cladocera, Notostraca and the Devonian Lepidocaris...
(brine shrimpBrine shrimpArtemia is a genus of aquatic crustaceans known as brine shrimp. Artemia, the only genus in the family Artemiidae, has changed little externally since the Triassic period...
)- Order NotostracaNotostracaThe order Notostraca comprises the single family Triopsidae, containing the tadpole shrimp or shield shrimp. The two genera, Triops and Lepidurus, are considered living fossils, having not changed significantly in outward form since the Triassic. They have a broad, flat carapace, which conceals the...
- Order Notostraca
- Class Cirripedia (barnacleBarnacleA barnacle is a type of arthropod belonging to infraclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive settings. They are sessile suspension feeders, and have...
s) - Class Arachnoidea
- Subphylum Trilobitomorpha [†] (extinct trilobiteTrilobiteTrilobites are a well-known fossil group of extinct marine arthropods that form the class Trilobita. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period , and they flourished throughout the lower Paleozoic era before...
group)- Class Trilobita [†] (the armored trilobites)
- Subphylum HexapodaHexapodaThe subphylum Hexapoda constitutes the largest grouping of arthropods and includes the insects as well as three much smaller groups of wingless arthropods: Collembola, Protura, and Diplura . The Collembola are very abundant in terrestrial environments...
- Class Insecta (insects, best preserved in amberAmberAmber is fossilized tree resin , which has been appreciated for its color and natural beauty since Neolithic times. Amber is used as an ingredient in perfumes, as a healing agent in folk medicine, and as jewelry. There are five classes of amber, defined on the basis of their chemical constituents...
)
- Class Insecta (insects, best preserved in amber
- Subphylum ChelicerataChelicerataThe subphylum Chelicerata constitutes one of the major subdivisions of the phylum Arthropoda, and includes horseshoe crabs, scorpions, spiders and mites...
- Class Arachnida (spiderSpiderSpiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
s, best preserved in amberAmberAmber is fossilized tree resin , which has been appreciated for its color and natural beauty since Neolithic times. Amber is used as an ingredient in perfumes, as a healing agent in folk medicine, and as jewelry. There are five classes of amber, defined on the basis of their chemical constituents...
) - Class MerostomataMerostomataMerostomata is the name given to a grouping of the extinct Eurypterida and the Xiphosura . The term was originally used by James Dwight Dana to refer to Xiphosura only, but was emended by Henry Woodward to cover both groups....
("living fossilLiving fossilLiving fossil is an informal term for any living species which appears similar to a species otherwise only known from fossils and which has no close living relatives, or a group of organisms which have long fossil records...
" horseshoe crabHorseshoe crabThe Atlantic horseshoe crab, Limulus polyphemus, is a marine chelicerate arthropod. Despite its name, it is more closely related to spiders, ticks, and scorpions than to crabs. Horseshoe crabs are most commonly found in the Gulf of Mexico and along the northern Atlantic coast of North America...
and extinct eurypteridEurypteridEurypterids are an extinct group of arthropods related to arachnids which include the largest known arthropods that ever lived. They are members of the extinct order Eurypterida ; which is the most diverse Paleozoic chelicerate order in terms of species...
)
- Class Arachnida (spider
- Subphylum MyriapodaMyriapodaMyriapoda is a subphylum of arthropods containing millipedes, centipedes, and others. The group contains 13,000 species, all of which are terrestrial...
- Class Diplopoda
- Class Chilopoda
Super-phylum of Deuterostomia / Enterocoelomata
(second-mouthed bilateriaBilateria
The bilateria are all animals having a bilateral symmetry, i.e. they have a front and a back end, as well as an upside and downside. Radially symmetrical animals like jellyfish have a topside and downside, but no front and back...
ns called deuterostomians, such as chordate
Chordate
Chordates are animals which are either vertebrates or one of several closely related invertebrates. They are united by having, for at least some period of their life cycle, a notochord, a hollow dorsal nerve cord, pharyngeal slits, an endostyle, and a post-anal tail...
s and echinoderm
Echinoderm
Echinoderms are a phylum of marine animals. Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone....
s)
Phylum Echinodermata
(echinoderms) – 72 percent of all documented species of Echinodermata are fossils and extinct- Subphylum CrinozoaCrinoidCrinoids are marine animals that make up the class Crinoidea of the echinoderms . Crinoidea comes from the Greek word krinon, "a lily", and eidos, "form". They live both in shallow water and in depths as great as 6,000 meters. Sea lilies refer to the crinoids which, in their adult form, are...
(sessileSessility (zoology)In zoology, sessility is a characteristic of animals which are not able to move about. They are usually permanently attached to a solid substrate of some kind, such as a part of a plant or dead tree trunk, a rock, or the hull of a ship in the case of barnacles. Corals lay down their own...
echinoderms) – 91 percent of all documented species of Crinozoa are now extinct- Class CrinoidCrinoidCrinoids are marine animals that make up the class Crinoidea of the echinoderms . Crinoidea comes from the Greek word krinon, "a lily", and eidos, "form". They live both in shallow water and in depths as great as 6,000 meters. Sea lilies refer to the crinoids which, in their adult form, are...
ea (crinoids / sea lilies) – See Crinozoa above
- Class Crinoid
- Subphylum BlastozoaBlastozoaBlastozoa is a subphylum of extinct animals belonging to Phylum Echinodermata. This subphylum is characterized by the presence of hydrospires.-External links:*...
[†] (extinct blastoidBlastoidBlastoids are an extinct type of stemmed echinoderm. Often called sea buds, blastoid fossils look like small hickory nuts. They originated, along with many other echinoderm classes, in the Ordovician period and reached their greatest diversity in the Mississippian subperiod of the Carboniferous...
s)- Class Diploporita
- Class Rhombifera
- Subphylum EchinozoaEchinozoaEchinozoa is a subphylum of free-living echinoderms in which the body is essentially globoid with meriodional symmetry. They lack arms, brachioles, or other appendages, and do not at any time exhibit pinnate structure....
(mobilePopulation mobilityPopulation mobility, geographic mobility or more simply mobility is a statistic that measures migration within a population. It is most commonly used in demography and human geography, it may also be used to describe the movement of animals between populations.Mobility estimates in the Current...
echinoderms) – 89 percent of all documented species of Echinozoa are now extinct- Class Echinoidea (echinoids or sea urchinSea urchinSea urchins or urchins are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum. They inhabit all oceans. Their shell, or "test", is round and spiny, typically from across. Common colors include black and dull...
s) – See Echinozoa above
- Class Echinoidea (echinoids or sea urchin
- Subphylum AsterozoaAsterozoaAsterozoa is a subphylum in the phylum Echinodermata. Characteristics include a star-shaped body and radially divergent axes of symmetry. The phylum includes the two orders Asteroidea, the starfish, and Ophiuroidea, the brittle stars and basket stars and perhaps the extinct order...
- Class Asteroidea (sea starSea starStarfish or sea stars are echinoderms belonging to the class Asteroidea. The names "starfish" and "sea star" essentially refer to members of the class Asteroidea...
s / starfish) - Class Ophiuroidea
- Class Asteroidea (sea star
Phylum HemichordataHemichordataHemichordata is a phylum of marine deuterostome animals, generally considered the sister group of the echinoderms. They date back to the Lower or Middle Cambrian and include two main classes: Enteropneusta , and Pterobranchia. A third class, Planctosphaeroidea, is known only from the larva of a...
(hemichordates such as extant acorn wormAcorn worm
The Acorn worms or Enteropneusta are a hemichordate class of invertebrates, closely related to the echinoderms. There are about 90 species of acorn worm in the world, the main species for research being Saccoglossus kowaleskii....
s) – Less than half of the documented species of Hemichordata are fossils and extinct
- Class Graptoloidea [†] (extinct graptoliteGraptoliteGraptolithina is a class in the animal phylum Hemichordata, the members of which are known as Graptolites. Graptolites are fossil colonial animals known chiefly from the Upper Cambrian through the Lower Carboniferous...
s)- Order Dendroidea [†]
- Order Graptoloidea [†]
- Suborder Didymograptina [†]
- Suborder Diplograptina [†]
- Suborder Monograptina [†]
Phylum Chordata
(both invertebrate and vertebrate chordates; animals possessing a notochordNotochord
The notochord is a flexible, rod-shaped body found in embryos of all chordates. It is composed of cells derived from the mesoderm and defines the primitive axis of the embryo. In some chordates, it persists throughout life as the main axial support of the body, while in most vertebrates it becomes...
)
Invertebrate subphyla
- Subphylum Urochordata (invertebrate tunicateTunicateTunicates, also known as urochordates, are members of the subphylum Tunicata, previously known as Urochordata, a group of underwater saclike filter feeders with incurrent and excurrent siphons that is classified within the phylum Chordata. While most tunicates live on the ocean floor, others such...
such as sea squirts)
- Subphylum CephalochordataCephalochordataCephalochordata is a chordate subphylum defined by the presence of a notochord that persists throughout life. It is represented in the modern oceans by the lancelets...
(invertebrate lanceletLanceletThe lancelets , also known as amphioxus, are the modern representatives of the subphylum Cephalochordata, formerly thought to be the sister group of the craniates. They are usually found buried in sand in shallow parts of temperate or tropical seas. In Asia, they are harvested commercially as food...
s)
Subphylum Vertebrata
- Vertebrates such as hagfishHagfishHagfish, the clade Myxini , are eel-shaped slime-producing marine animals . They are the only living animals that have a skull but not a vertebral column. Along with lampreys, hagfish are jawless and are living fossils whose next nearest relatives include all vertebrates...
es, lampreyLampreyLampreys are a family of jawless fish, whose adults are characterized by a toothed, funnel-like sucking mouth. Translated from an admixture of Latin and Greek, lamprey means stone lickers...
s, conodontConodontConodonts are extinct chordates resembling eels, classified in the class Conodonta. For many years, they were known only from tooth-like microfossils now called conodont elements, found in isolation. Knowledge about soft tissues remains relatively sparse to this day...
s [†], ostracodermOstracodermOstracoderms are any of several groups of extinct, primitive, jawless fishes that were covered in an armor of bony plates. They belong to the taxon Ostracodermi, and their fossils are found in the Ordovician and Devonian Period strata of North America and Europe...
s [†], placoderms [†], sharkSharkSharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....
s, ray-finned fishes, lobe-finned fishes, amphibianAmphibianAmphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...
s, reptileReptileReptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...
s, dinosaurDinosaurDinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
s [†], birdBirdBirds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s and mammalMammalMammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s.