Helicoplacus is the earliest well-studied fossil echinoderm. Fossil plates are known from several regions. Complete specimens were found in Lower Cambrian strata of the White Mountains of California.
Olenellus is an extinct genus of redlichiid trilobites, with species of average size. It lived during the Botomian and Toyonian stages (Olenellus-zone), 522 to 510 million years ago, in what is currently North-America, part of the palaeocontinent Laurentia.
Edrioasteroidea is an extinct class of echinoderms. The living animal would have resembled a pentamerously symmetrical disc or cushion. They were obligate encrusters and attached themselves to inorganic or biologic hard substrates. A 507 million years old species, Totiglobus spencensis, is actually the first known echinoderm adapted to live on a hard surface after the soft microbial mats that covered the seafloor were destroyed in the Cambrian substrate revolution.
Eoagnostus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the terminal Lower Cambrian (Toyonian), until the earliest Middle Cambrian.
Mummaspis is an extinct genus from a well-known class of fossil marine arthropods, the trilobites, with five known species. It lived during the early part of the Botomian stage, which lasted from approximately 524 to 518.5 million years ago. This faunal stage was part of the Cambrian Period.
Wanneria is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the later part of the Botomian stage, which lasted from approximately 524 to 518.5 million years ago. This faunal stage was part of the Cambrian Period. Wanneria walcottana is the only known species in this genus.
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.
Camptostroma roddyi is an extinct echinoderm from the Bonnia-Olenellus Zone the Early Cambrian Kinzers Formation near York and Lancaster, Southeastern Pennsylvania. In life, it would have resembled a cupcake, with the axial skeleton forming a star pattern on the upper surface. It was originally thought, on the basis of its medusoid shape, to be a jellyfish-like organism, but the fossils themselves clearly rule out the possibility of a gelatinous body - the stereom plates are clearly preserved and possess the calcitic cleavage pattern diagnostic of echinoderms. It has been placed in a class of basal echinoderms, the Edrioasteroids.
Dibrachicystis is an extinct genus of rhombiferan echinoderm from the early Middle Cambrian. It is a stalked echinoderm within the family Dibrachicystidae which lived in what is now northernmost Iberian Chains, northern Spain. It is known from the holotype MPZ2009/1230 and from the paratypes MPZ2011/2–6. It was found in the uppermost part of the Murero Formation at Purujosa, Moncayo Natural Park, dating to the Lower Languedocian and referred to the Solenopleuropsis thorali Zone. It was first named by Samuel Zamora and A. B. Smith in 2011 and the type species is Dibrachicystis purujoensis.
Rhenopyrgus is an extinct echinoderm in the class Edrioasteroidea, which existed during the Devonian in what is now France and Germany, the Ordovician in Iowa and Illinois, U.S.A.; and the Silurian of Argentina. It was described by Dehm in 1961, and the type species is R. coronaeformis, which was originally described by J. Rievers as a species in the genus Pyrgocystis, in 1961. A new species, R. piojoensis, was described by Colin D. Sumrall, Susana Heredia, Cecilia M. Rodríguez and Ana I. Mestre in 2012, from 116 specimens collected from the Los Espejos Formation in the Loma de Los Piojos locality near San José de Jáchal, Argentina. The species epithet refers to the locality where the specimens were collected from. In 2019 another species, R. viviani, was described by researchers from the Natural History Museum, London, led by Tim Ewin.
Bristolia is an extinct genus of trilobite, fossil marine arthropods, with eight or more small to average size species. It is common in and limited to the Lower Cambrian shelf deposits across the southwestern US, which constitutes part of the former paleocontinent of Laurentia.
Fritzolenellus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites, with three known species. It lived during the early part of the Botomian stage, which lasted from approximately 524 to 518.5 million years ago. This faunal stage was part of the Cambrian Period. Fritzolenellus occurred in parts of the paleocontinent Laurentia in what are now Northwestern Canada, Northwestern Scotland, and North-Greenland.
The Kinzers Formation is a geologic formation in Pennsylvania. It preserves fossils dating back to the Cambrian Period.
The Verulam Formation is a geologic formation and Lagerstätte in Ontario, Canada. It preserves fossils dating back to the Katian stage of the Ordovician period, or Shermanian to Chatfieldian in the regional stratigraphy.
Cincta is an extinct class of echinoderms that lived only in the Middle Cambrian epoch. Homostelea is a junior synonym. The classification of cinctans is controversial, but they are probably part of the echinoderm stem group.
Soluta is an extinct class of echinoderms that lived from the Middle Cambrian to the Early Devonian. The class is also known by its junior synonym Homoiostelea. Soluta is one of the four "carpoid" classes, alongside Ctenocystoidea, Cincta, and Stylophora, which made up the obsolete subphylum Homalozoa. Solutes were asymmetric animals with a stereom skeleton and two appendages, an arm extending anteriorly and a posterior appendage called a homoiostele.
Ctenocystoidea is an extinct clade of echinoderms, which lived during the Cambrian and Ordovician periods. Unlike other echinoderms, ctenocystoids had bilateral symmetry, or were only very slightly asymmetrical. They are believed to be one of the earliest-diverging branches of echinoderms, with their bilateral symmetry a trait shared with other deuterostomes. Ctenocystoids were once classified in the taxon Homalozoa, also known as Carpoidea, alongside cinctans, solutes, and stylophorans. Homalozoa is now recognized as a polyphyletic group of echinoderms without radial symmetry. Ctenocystoids were geographically widespread during the Middle Cambrian, with one species surviving into the Late Ordovician.
Yanjiahella biscarpa is an extinct species of Ediacaran and Early Cambrian deuterostome which may represent the earliest stem group echinoderm.
Titanokorys is a genus of extinct hurdiid radiodont that existed during the mid Cambrian. It is the largest member of its family from the Cambrian, with a body length of 50 cm (20 in) long, making it one of the largest animals of the time. It bears a resemblance to the related genus Cambroraster. Fossils of T. gainesi were first found within Marble Canyon in 2018. The fossils were not named until 2021 because they were assumed to be giant specimens of Cambroraster.
Lepidocystis is a Palaeozoic genus of imbricate lepidocystoid eocrinoid, closely related to Kinzercystis, It bore a stalk, with which it attached to firm substrates; and brachioles arising as lateral branches from its arms.
