The Tremadocian is the lowest stage of Ordovician. Together with the later Floian stage it forms the Lower Ordovician epoch. The Tremadocian lasted from 485.4 to 477.7 million years ago. The base of the Tremadocian is defined as the first appearance of the conodont species Iapetognathus fluctivagus at the GSSP section on Newfoundland.
The Furongian is the fourth and final series of the Cambrian. It lasted from 497 to 485.4 million years ago. It succeeds the Miaolingian series of the Cambrian and precedes the Lower Ordovician Tremadocian stage. It is subdivided into three stages: the Paibian, Jiangshanian and the unnamed 10th stage of the Cambrian.
Kazakhstania, the Kazakh terranes, or the Kazakhstan Block, is a geological region in Central Asia which consists of the area roughly centered on Lake Balkhash, north and east of the Aral Sea, south of the Siberian craton and west of the Altai Mountains. The Junggar basin in Xinjiang, China is also part of Kazakhstania, though sometimes referred to as the Junggar Block. Because the Kazakh terranes merged during the Late Ordovician as part of the Central Asian Orogenic Belt they are also referred to as the Kazakh Orogen. These terranes are located in what is today Kazakhstan, north-eastern Uzbekistan, northern Kyrgyzstan, south-western China. Today Kazakhstania is surrounded by three large, former continents: to the north-east the Gornostaev Shear Zone separates it from Siberia with which it collided during the Carboniferous; to the north-west is Baltica which lay adjacent to the Kazakh Tourgai terrane but far away from Kazakhstania; to the south and east was Gondwana stretching from the South Pole to the Equator. Not far away from the dispersed Kazakh terranes were South China, North China, and Tarim, but how these continental blocks were positioned relative to Gondwana is not known.
Megistaspis is a genus of trilobites in the order Asaphida and family Asaphidae.
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.
Trinodus is a very small to small blind trilobite, a well known group of extinct marine arthropods, which lived during the Ordovician, in what are now the Yukon Territories, Virginia, Italy, Czech Republic, Poland, Denmark, Sweden, Svalbard, Ireland, Scotland, Wales, Iran, Kazakhstan and China. It is one of the last of the Agnostida order to survive.
Cyclopyge is a genus of small to average size trilobites that lived during the Ordovician. Like all members of the family Cyclopigidae, it has very large convex eyes, that cover most of the free cheeks, and in some species touch each other. The eyes almost touch the large glabella. The occipital ring has merged with the rest of the glabella. The glabella does not extend into a frontal thorn. The cephalon lacks genal spines. The 6 thorax segments have short pleurae. The pygidium is rather large, and often rather effaced. These are features that also occur in other Cyclopygidae, and are indications of a pelagic lifestyle.
Sagavia is a genus of trilobites that lived during the Middle and Upper Ordovician in what are now Northwest and Southeast China, North Kazakhstan and Wales. It is a typical cyclopygid that can be distinguished by its large but separate eyes, elongated glabella, five thorax segments and a pygidium with clearly defined axis and border.
Pricyclopyge is a genus of trilobites assigned to the family Cyclopygidae that occurs throughout the Ordovician. Pricyclopyge had an extratropical distribution, and there is evidence that it lived in darker parts of the water column. Pricyclopyge has huge eyes, an inverted pear-shaped glabella, six thorax segments, with on the 3rd two small discs. Pricyclopyge is known from what are today China, the Czech Republic, France, and the United Kingdom.
Raphiophoridae is a family of small to average-sized trilobites that first occurred at the start of the Ordovician and became extinct at the end of the Middle Silurian.
Taklamakania is a genus of asaphid trilobites of the family Raphiophoridae that lived during the late Caradoc of Inner Mongolia, China. Like all raphiophorids it is blind, with a headshield that is subsemicircular, carrying genal spines and a forward directed spine on the central raised area, with the front of the glabella inflated and the natural fracture lines of the cephalon coinciding with its margin. It is easily distinguished from most other raphiophorids by the 3 thorax segments. Pseudampyxina, Nanshanaspis, and Kongqiangheia also have only 3 such segments, but all three lack the frontal spine that emanates from the glabellum of Taklamakania species. All other raphiophorid genera have at least 5 thorax segments. Three species, T. tarimensis, T. tarimheensis, and T. xinjiangensis, have been assigned to this genus sofar.
Genevievella is a genus of trilobites with a short inverted egg-shaped outline, a wide headshield, small eyes, and long genal spines. The backrim of the headshield is inflated and overhangs the first of the 9 thorax segments. The 8th thorax segment from the front bears a backward directed spine that reaches beyond the back end of the exoskeleton. It has an almost oval tailshield with 5 pairs of pleural furrows. It lived during the Upper Cambrian in what are today Canada and the United States.
Telephinidae is a family of pelagic trilobites with large wide-angle eyes, occupying most of the free cheeks, downward directed facial spines and 9-10 thorax segments. The family is known during the entire Ordovician and occurred in deep water around the globe.
Kongqiaoheia rotundata is an asaphid trilobites of the family Raphiophoridae that lived during the late Caradoc of Inner Mongolia, China. K. rotundata was originally grouped with the so-called Taklamakaniinae, a paraphyletic group of tiny, dwarfed raphiophorids that lived in a deepwater environment in what is now the Tarim Basin, including Pseudampyxina, Nanshanaspis, and Taklamakania. Like these other genera, K. rotundata has only three thoracic segments, probably due to paedomorphic dwarfism: other raphiophorid trilobites have at minimum five thoracic segments.
Nanshanaspis is a genus of asaphid trilobites of the family Raphiophoridae that lived during the late Caradoc of Inner Mongolia, China. Like all raphiophorids it is blind, with a headshield that is subsemicircular, carrying genal spines and a forward directed spine on the central raised area, with the front of the glabella inflated and the natural fracture lines of the cephalon coinciding with its margin. It is easily distinguished from most other raphiophorids by the 3 thorax segments. Pseudampyxina, Taklamakania, and Kongqiangheia also have only 3 such segments, while all other raphiophorid genera have at least 5 thorax segments, leading to the erection of the subfamily "Taklamakaniinae" to contain these four genera. "Taklamakaniinae" was dissolved and its members absorbed into Raphiophorinae when further study showed the close similarities the "taklamakaniids" had to the juvenile forms of various raphiophorinids. Specimens of Nanshanaspis, for example, closely resemble juveniles of Globampyx trinucleoides.
Acanthodus is an extinct genus of conodonts.
Kallidontus is an extinct genus of conodonts.
Histiodella is an extinct genus of conodonts.
