The Ordovician is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period 485.4 million years ago (Mya) to the start of the Silurian Period 443.8 Mya.
Baltica is a paleocontinent that formed in the Paleoproterozoic and now constitutes northwestern Eurasia, or Europe north of the Trans-European Suture Zone and west of the Ural Mountains. The thick core of Baltica, the East European Craton, is more than three billion years old and formed part of the Rodinia supercontinent at c. 1 Ga.
Gogia is a genus of primitive eocrinoid blastozoan from the early to middle Cambrian.
Cothurnocystis is a genus of small enigmatic echinoderms that lived during the Ordovician. Individual animals had a flat boot-shaped body and a thin rod-shaped appendage that may be a stem, or analogous to a foot or a tail. Fossils of Cothurnocystis species have been found in Nevada, Scotland, Czech Republic, France and Morocco.
The stylophorans are an extinct, possibly polyphyletic group allied to the Paleozoic Era echinoderms, comprising the prehistoric cornutes and mitrates. It is synonymous with the subphylum Calcichordata. Their unusual appearances have led to a variety of very different reconstructions of their anatomy, how they lived, and their relationships to other organisms.
The Eocrinoidea are an extinct class of echinoderms that lived between the Early Cambrian and Late Silurian periods. They are the earliest known group of stalked, arm-bearing echinoderms, and were the most common echinoderms during the Cambrian.
Echinosphaerites is a genus of rhombiferan cystoid echinoderms that lived in the Early to Middle Ordovician of North America and Europe.
Paracrinoidea is an extinct class of blastozoan echinoderms. They lived in shallow seas during the Early Ordovician through the Early Silurian. While blastozoans are usually characterized by types of respiratory structures present, it is not clear what types of respiratory structures paracrinoids likely had. Despite the taxon's name, the paracrinoids are not closely related to crinoids.
Cystoidea is a class of extinct crinozoan echinoderms, termed cystoids, that lived attached to the sea floor by stalks. They existed during the Paleozoic Era, in the Middle Ordovician and Silurian Periods, until their extinction in the Devonian Period.
The Kope Formation is one of the three component bedrock formations of the Maquoketa Group that primarily consists of shale (75%) with some limestone (25%) interbedded. In general, it has a bluish-gray color that weathers light gray to yellowish-gray and it occurs in northern Kentucky, southwest Ohio, and southeast Indiana, United States.
The Gogiida are an order of early echinoderms known from late Early to Middle Cambrian deposits.
Lyracystis radiata is a Cambrian eocrinoid echinoderm known from the Burgess Shale. It is related to Gogia
The Bromide Formation is a geological formation in Oklahoma, USA. It is well known for its diverse echinoderm and trilobite fossil fauna.
The Outram Formation is a stratigraphic unit of Early Ordovician age that is present on the western edge of the Western Canada Sedimentary Basin in the Canadian Rockies of Alberta and British Columbia. It was named for Mount Outram in Banff National Park by J.D. Aitken and B.S. Norford in 1967. The Outram Formation is fossiliferous and includes remains of trilobites and other marine invertebrates, as well as stromatolites and thrombolites.
The Skoki Formation is a stratigraphic unit of Early to Middle Ordovician age that is present on the western edge of the Western Canada Sedimentary Basin in the Canadian Rockies of Alberta and British Columbia. It was named for Skoki Mountain near Lake Louise in Banff National Park by Charles Doolittle Walcott in 1928. The Skoki Formation is fossiliferous and includes remains of brachiopods and other marine invertebrates, as well as conodonts and oncolites.
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.
Jerzy Dzik is a Polish paleontologist.
Diploporita is an extinct class of blastozoan that ranged from the Ordovician to the Devonian. These echinoderms are identified by a specialized respiratory structure, called diplopores. Diplopores are a double pore system that sit within a depression on a single thecal (body) plate; each plate can contain numerous diplopore pairs.
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.
Rozhnov, S.V. 2009. Eocrinoids and paracrinoids of the Baltic Ordovician basin: a biogeographical report. IGCP Meeting, Ordovician palaeogeography and palaeoclimate, Copenhagen, p. 16.
Rozhnov, S.V. and Kushlina, V.B. 1994. Interpretation of new data on Bolboporites Pander, 1830 (Echinodermata; Ordovician), p. 179-180, in David, B., Guille, A., Féral, J.-P. & Roux, M. (eds.), Echinoderms through time (Balkema, Rotterdam).
