 | This article provides insufficient context for those unfamiliar with the subject.(December 2023) |
| Carinachitidae Temporal range: | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Cnidaria |
| Class: | † Conulata |
| Order: | † Conularina |
| Family: | † Carinachitidae He, 1987 |
| Genera [1] | |
| |
Carinachitidae is a family of small shelly fossils identified as cnidarian sclerites based on articulated specimens from the Kuanchuanpu formation. [2]
They grade in morphology to conulariids. [3]
A sclerite is a hardened body part. In various branches of biology the term is applied to various structures, but not as a rule to vertebrate anatomical features such as bones and teeth. Instead it refers most commonly to the hardened parts of arthropod exoskeletons and the internal spicules of invertebrates such as certain sponges and soft corals. In paleontology, a scleritome is the complete set of sclerites of an organism, often all that is known from fossil invertebrates.
Microdictyon is an extinct armoured worm-like panarthropod coated with net-like scleritic plates, known from the Early Cambrian Maotianshan shale of Yunnan China and other parts of the world. Microdictyon is part of the ill-defined taxon – Lobopodia – that includes several other odd worm-like animals that resembling worm with legs, such as Hallucigenia, Onychodictyon, Cardiodictyon, Luolishania, and Paucipodia. The isolated sclerites of Microdictyon are known from other Lower Cambrian deposits. Microdictyon sclerites appear to have moulted; one sclerite seems to have been preserved during ecdysis.
Olenellina is a suborder of the order Redlichiida of trilobites that occurs about halfway during the Lower Cambrian, at the start of the stage called the Atdabanian. The earliest trilobites in the fossil record are arguably Olenellina, although the earliest Redlichiina,Ptychopariida, and Eodiscina follow quickly. The suborder died out when the Lower Cambrian passed into the Middle Cambrian, at the end of the stage called Toyonian. A feature uniting the Olenellina is the lack of rupture lines in the headshield, which in other trilobites assist the periodic moulting, associated with arthropod growth. Some derived trilobites have lost facial sutures again, but all of these are blind, while all Olenellina have eyes.
The halkieriids are a group of fossil organisms from the Lower to Middle Cambrian. Their eponymous genus is Halkieria, which has been found on almost every continent in Lower to Mid Cambrian deposits, forming a large component of the small shelly fossil assemblages. The best known species is Halkieria evangelista, from the North Greenland Sirius Passet Lagerstätte, in which complete specimens were collected on an expedition in 1989. The fossils were described by Simon Conway Morris and John Peel in a short paper in 1990 in the journal Nature. Later a more thorough description was undertaken in 1995 in the journal Philosophical Transactions of the Royal Society of London and wider evolutionary implications were posed.
Callavia is an extinct, monotypic genus of trilobite arthropods. C. broegeri lived during the late Atdabanian stage, which lasted from 530 to 524 million years ago during the early part of the Cambrian Period in what are today Canada and the United States.
Chancelloria is a genus of early animals known from the Middle Cambrian Burgess Shale, the Comley limestone, the Wheeler Shale, the Bright Angel Shale and elsewhere. It is named after Chancellor Peak. It was first described in 1920 by Charles Doolittle Walcott, who regarded them as one of the most primitive groups of sponges. However, they are currently thought to be member of the group Chancelloriidae. 178 specimens of Chancelloria are known from the Greater Phyllopod bed, where they comprise 0.34% of the community.
The small shelly fauna, small shelly fossils (SSF), or early skeletal fossils (ESF) are mineralized fossils, many only a few millimetres long, with a nearly continuous record from the latest stages of the Ediacaran to the end of the Early Cambrian Period. They are very diverse, and there is no formal definition of "small shelly fauna" or "small shelly fossils". Almost all are from earlier rocks than more familiar fossils such as trilobites. Since most SSFs were preserved by being covered quickly with phosphate and this method of preservation is mainly limited to the late Ediacaran and early Cambrian periods, the animals that made them may actually have arisen earlier and persisted after this time span.
Trilobites are used as index fossils to subdivide the Cambrian period. Assemblages of trilobites define trilobite zones. The Olenellus-zone has traditionally marked the top of the Lower Cambrian, and is followed by the Eokochaspis zone.
Allonnia is a genus of coeloscleritophoran known as complete scleritomes from the Middle Cambrian Burgess Shale. It is also a constituent of the small shelly fauna.
The Marjum Formation is a Cambrian geological formation that overlies the Wheeler Shale in the House Range, Utah. It is named after its type locality, Marjum Pass, and was defined in 1908. The formation is known for its occasional preservation of soft-bodied tissue, and is slightly younger than the Burgess Shale, falling in the Ptychagnostus praecurrens trilobite zone.
Mongolitubulus is a form genus encapsulating a range of ornamented conical small shelly fossils of the Cambrian period. It is potentially synonymous with Rushtonites, Tubuterium and certain species of Rhombocorniculum, and owing to the similarity of the genera, they are all dealt with herein. Organisms that bore Mongolitubulus-like projections include trilobites, bradoriid arthropods and hallucigeniid lobopodians.
Shelbyoceras is a genus of Cambrian monoplacophora which was one of the genera mistaken for a cephalopod, since the characteristics differentiating monoplacophora from cephalopods are few. Shelbyoceras was reclassified based on a depressed groove that forms a band around the shell, which is similar to a feature seen in Hypseloconus. The septa in this genus are either closely or irregularly spaced.
Mickwitziids are a Cambrian group of shelly fossils with originally phosphatic valves, belonging to the Brachiopod stem group, and exemplified by the genus Mickwitzia – the other genera are Heliomedusa and Setatella. The family Mickwitziidae is conceivably paraphyletic with respect to certain crown-group brachiopods.
Reticulosa is an extinct order of sea sponges in the class Hexactinellida and the subclass Amphidiscophora. Reticulosans were diverse in shape and size, similar to their modern relatives, the amphidiscosidans. Some were smooth and attached to a surface at a flat point, others were polyhedral or ornamented with nodes, many were covered in bristles, and a few were even suspended above the seabed by a rope-like anchor of braided glass spicules.
The Olenelloidea are a superfamily of trilobites, a group of extinct marine arthropods. They lived during the late Lower Cambrian and species occurred on all paleocontinents.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 2015.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 2016.
This list of fossil arthropods described in 2018 is a list of new taxa of trilobites, fossil insects, crustaceans, arachnids, and other fossil arthropods of every kind that were described during the year 2018, as well as other significant discoveries, and events related to arthropod paleontology that are scheduled to occur in the year 2018.
2022 in arthropod paleontology is a list of new arthropod fossil taxa, including arachnids, crustaceans, insects, trilobites, and other arthropods that were announced or described, as well as other significant arthropod paleontological discoveries and events which occurred in 2022.
{{cite web}}: CS1 maint: postscript (link)