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| a drawing of a Tchernyshevioides ninae, based on specimens from Tian-Shan (Sulyukta region) Siberia | |
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| Genus: | Tchernyshevioides Hajrullina 1975 |
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Tchernyshevioides is a diminutive trilobite that lived during the early Middle Cambrian (Amgaian) and has been found in the Russian Federation (Pseudanomocarina-zone, Sulyukta region, Tian-Shan) and the Jbel Wawrmast Formation of Morocco. [1]
Tchernyshevioides has been named in honor of the Russian paleontologist N.E. Tchernysheva.
The central raised area (or glabella) of the headshield (or cephalon) is long and reaches the anterior border furrow. The occipital ring is well defined and carries a long posterodorsal spine. Otherwise the glabella has no transvers furrows. The border furrow is distinct and the border wide. The free cheeks (or librigenae) are very short. The cephalic angle carries a slender spine of almost equal length as the glabella, directed backwards and outwards at about 45°. The thorax is unknown. Pygidium with axis of six rings plus terminus. There are five well defined pleural furrows and the border is narrow and smooth. [1]
Paradoxides is a genus of large to very large trilobites found throughout the world during the Mid Cambrian period. One record-breaking specimen of Paradoxides davidis is 37 cm (15 in). It has a semicircular head, free cheeks each ending with a long, narrow, recurved spine, and sickle-shaped eyes, providing almost 360° view, but only in the horizontal plane. Its elongated trunk was composed of 19-21 segments and was adorned with longish, recurved lateral spines. Its pygidium was comparatively small. Paradoxides is a characteristic Middle Cambrian trilobite of the 'Atlantic' (Avalonian) fauna. Avalonian rocks were deposited near a small continent called Avalonia in the Paleozoic Iapetus Ocean. Avalonian beds are now in a narrow strip along the East Coast of North America, and in Europe.
Acimetopus is a genus of trilobites that lived during the Botomian stage.
Analox is an extinct genus of agnostid trilobite. It lived during the Botomian stage. It can easily be distinguished from other trilobites by the two furrows that extend forwards and sidewards from the front of the glabella.
Meniscuchus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the Botomian stage, which lasted from approximately 522 to 516 million years ago. This faunal stage was part of the Cambrian Period. Meniscuchus has been found in the USA, Canada, Russia and Australia.
Parapagetia is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the Botomian stage, which lasted from approximately 524 to 518.5 million years ago. This faunal stage was part of the Cambrian Period.
Dicerodiscus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the early part of the Botomian stage, in China. Four species have been assigned to it. Dicerodiscus is unique for an eodiscoid in having conspicuous and curved spines that are attached anteriorly, and at their base are directed outward perpendicular to the midline, before gradually bending further backwards.
Semadiscus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It has been collected from the Lower Cambrian of Canada (Newfoundland), Russia, and the United States. Only the headshield is known, and it may well be that it would be better to include it in Serrodiscus.
Egyngolia is a genus of very small sized Trilobites, that lived during the Lower Cambrian in what are today the Russia Federation, Mongolia, and South Australia.
Conocoryphe is a genus of primarily eyeless trilobites belonging to the family Conocoryphidae. They lived during the Middle Cambrian period, about 505 million years ago. These arthropods lived on the sea bottom (epifaunal) and lived off dead particulate organic matter.
Mallagnostus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the upper Lower Cambrian, with remains found in USA, Canada (Newfoundland), Spain, England, Russia, Mongolia, and the lower Middle Cambrian according to fossils from China and Russia (Yakutia).
Geragnostus is a genus of very small agnostid trilobites whose fossils are found Ordovician-aged marine strata from Eurasia, North America and Argentina.
Eodiscidae is a family of agnostid trilobites that lived during the final Lower Cambrian and the Middle Cambrian. They are small or very small, and have a thorax of two or three segments. Eodiscidae includes nine genera.
Tannudiscus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the upper Lower Cambrian, with remains found in Canada (Newfoundland), China (Gansu), The United Kingdom (England), and the Russian Federation.
Jinghediscus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the lover Middle Cambrian, with remains found in China (Xinjiang) and Australia (Queensland).
Psychopyge is a genus of trilobite, that lived during the upper Emsian and has been found in Germany and Morocco. It is characterized by the swordlike extension from the front of the head.
Cedaria is a small, rather flat trilobite with an oval outline, a headshield and tailshield of approximately the same size, 7 articulating segments in the middle part of the body and spines at the back edges of the headshield that reach halflength of the body. Cedaria lived during the early part of the Upper Cambrian (Dresbachian), and is especially abundant in the Weeks Formation.
Kendallina is a genus of trilobite with an inverted egg-shaped outline, a wide headshield, small eyes, small deflected spines, 12 thorax segments and a small, short tailshield. It lived during the Upper Cambrian in what are today Canada and the United States.
Orygmaspis is a genus of asaphid trilobite with an inverted egg-shaped outline, a wide headshield, small eyes, long genal spines, 12 spined thorax segments and a small, short tailshield, with four pairs of spines. It lived during the Upper Cambrian in what are today Canada and the United States.
Anabaraspis is a genus of redlichiid trilobite. A. splendens occurs in the uppermost Lower Cambrian and lowest Middle Cambrian of Russia. In Anabaraspis there is a long area in front of the glabella which is not differentiated in a border and a preglabellar field. This is a unique character in the family Paradoxididae. The frontal lobe of the central raised area of the headshield is slightly pointed, rather than rounded or truncate, a character shared with Plutonides, though, in Plutonides it hangs over the short anterior border.
Serrodiscus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It has been collected from the Lower Cambrian of Canada, Germany (Silesia), Poland, Russia, the United Kingdom (Wales) and the United States. It is named for the spines on the ventral side of the tailshield (or pygidium, which give it a serrated impression.
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