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Olenellina
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 and Eodiscina follow quickly. The suborder died out when the Lower passed into the Middle Cambrian, at the end of the stage called Toyonian. A feature uniting the Olenellina is the lack of rupture lines (or sutures) in the headshield, which in other trilobites assist the periodic moulting (or ecdysis), associated with arthropod growth. Some derived trilobites have lost facial sutures again (some Eodiscina, all Agnostina, and a few Phacopina), but all of these are blind, while all Olenellina have eyes. Taxonomy The suborder contains four superfamilies: Olenelloidea (with 3 families and 5 stemgroup genera), Judomioidea (with 1 family and 3 stemgroup genera), Nevadioidea, and Fallotaspidoidea (with 3 familie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fallotaspidoidea
The ”Fallotaspidoidea” are a superfamily of trilobites, a group of extinct marine arthropods. It lived during the Lower Cambrian (Atdabanian)Whittington, H. B. et al. Part O, Treatise on Invertebrate Paleontology. Revised, Volume 1 – Trilobita – Introduction, Order Agnostida, Order Redlichiida. 1997 and species occurred on all paleocontinents except for the Gondwana heartland (currently Latin America, most of Africa, Australia, Antarctica, India and China). A member of this group, '' Profallotaspis jakutensis'', has long been the earliest known trilobite, but recently the redlichiid Lemdadella has been claimed as occurring even earlier. Distribution ”Fallotaspidoidea” occur in the Lower Cambrian of North America (Cordilleran region and northern Greenland), Europe (United Kingdom, Comley area; Ukraine), northwestern Africa and northern Asia (Siberia). Dispersion of the “Fallotaspidoidea” Lieberman (2002) suggests that fallotaspidoids, the first hard-shelled ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redlichiida
Redlichiida is an order of trilobites, a group of extinct marine arthropods. Species assigned to the order Redlichiida are among the first trilobites to appear in the fossil record, about halfway during the Lower Cambrian. Due to the difficulty to relate sediments in different areas, there remains some discussion, but among the earliest are '' Fallotaspis'' (suborder Olenellina), and ''Lemdadella'' (suborder Redlichiina), both belonging to this order. The first representatives of the orders Corynexochida and Ptychopariida also appear very early on and may prove to be even earlier than any redlichiid species. In terms of anatomical comparison, the earliest redlichiid species are probably ancestral to all other trilobite orders and share many primitive characters. The last redlichiid trilobites died out before the end of the Middle Cambrian. Description Most redlichiids are rather flat (or have low dorso-ventral convexity) and their exoskeleton typically has an oval outline, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olenelloidea
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. Taxonomy Palmer and Repina assigned '' Gabriellus'' and ''Callavia'' to the Olenelloidea, but the ocular lobes in these two genera circumscribe the entire lateral border of the frontal lobe of the glabella, and thus, do not belong to this superfamily, but to the Judomioidea. Geyer assigned '' Cambropallas'' to the Olenelloidea, but it lacks the diagnostic features and appears to be closely related to '' Andalusiana'', and is now considered to be an advanced member of the Nevadioidea. Distribution In western Laurentia Fallotaspididae and Archaeaspididae proceed the first Olenelloidea. The Holmiidae occur at the late Atdabanian, and are contemporary with the Nevadioidea. They are followed by Biceratopsidae and Olenellidae. Description As with most early trilobites, the Olenelloidea have an almost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callavia
''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. Taxonomy The position of ''Callavia'' in relation to other Olenellina has shifted repeatedly over time. Initially it was assigned to the Holmiinae by Pierre Hupé, and was later moved back and forth to the Callaviinae. Lieberman, however, argues ''Callavia'' is a basal member of the Judomioidea. Reassigned species * ''C. brevioculata'' = '' Nevadella cartlandi'' * ''C. burri'' = '' Pleisionevadella burri'' * ''C. callavei'' = '' Callavalonia callavei'' * ''C. cartlandi'' = '' Nevadella cartlandi'' * ''C. cobboldi'' = '' Nevadella cartlandi'' * ''C. eucharis'' = ''Nevadella eucharis'' * ''C. hastata'' = '' Callavalonia callavei'' * ''C. lotzei'' = '' Sdzuyomia lotzei'' * ''C. perfecta'' = '' Nevadella perfecta'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilobite
Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period () and they flourished throughout the lower Paleozoic before slipping into a long decline, when, during the Devonian, all trilobite orders except the Proetida died out. The last extant trilobites finally disappeared in the mass extinction at the end of the Permian about 252 million years ago. Trilobites were among the most successful of all early animals, existing in oceans for almost 270 million years, with over 22,000 species having been described. By the time trilobites first appeared in the fossil record, they were already highly diversified and geographically dispersed. Because trilobites had wide diversity and an easily fossilized exoskeleton, they left an extensive fossil record. The stu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilobite
Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period () and they flourished throughout the lower Paleozoic before slipping into a long decline, when, during the Devonian, all trilobite orders except the Proetida died out. The last extant trilobites finally disappeared in the mass extinction at the end of the Permian about 252 million years ago. Trilobites were among the most successful of all early animals, existing in oceans for almost 270 million years, with over 22,000 species having been described. By the time trilobites first appeared in the fossil record, they were already highly diversified and geographically dispersed. Because trilobites had wide diversity and an easily fossilized exoskeleton, they left an extensive fossil record. The stu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeaspididae
''Archaeaspis'' is an extinct genus of redlichiid trilobites. It lived during the late Atdabanian stage, which lasted from 521 to 515 million years ago during the early part of the Cambrian Period. The first specimens were first found in Siberia, where they were originally thought to have been endemic. Later, though, more specimen were found in the Inyo Mountains in Southern California. An Ediacarian proarticulatan was given the same name, ''Archaeaspis'' Ivantsov, 2001. This is however a junior homonym. The name ''Archaeaspis'' Repina in Khomentovskii and Repina, 1965, for the trilobite has priority. The new valid name for the proarticulate is ''Archaeaspinus'' Ivantsov, 2007. Etymology The genus name is the combination of the Ancient Greek ἀρχαῖος (archaīos) meaning "ancient" and ἀσπίς (aspis) meaning "shield". The names of the species have the following derivations. * ''A. hupei'' is named in honor of Pierre Hupé, a distinguished French paleontologist. * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Judomioidea
The Judomioidea are a superfamily of trilobites, a group of extinct marine arthropods. Its species lived during the Lower Cambrian (Atdabanian Cambrian Stage 3 is the still unnamed third stage of the Cambrian. It succeeds Cambrian Stage 2 and precedes Cambrian Stage 4, although neither its base nor top have been formally defined. The plan is for its lower boundary to correspond approx ...).Whittington, H. B. et al. Part O, Treatise on Invertebrate Paleontology. Revised, Volume 1 – Trilobita – Introduction, Order Agnostida, Order Redlichiida. 1997 References Olenellina Cambrian trilobites Cambrian first appearances Terreneuvian extinctions Arthropod superfamilies {{redlichiida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holmiidae
Holmiidae is a family of trilobites, that lived during the Lower Cambrian (Atdabanian). The Holmiidae is a diverse family of eight genera containing at least 17 species. It includes some of the earliest trilobites of Baltica. Holmiidae occur throughout Baltica (Scandinavia and the eastern seaboard of the Baltic Sea) and Western Laurentia (in the Great Basin of the US and northwestern Canada), and also in Morocco. Taxonomy Hupé (1953) defined the Holmiidae as a subfamily (Holmiinae) within the Olenellidae containing ''Holmia'', ''Kjerulfia'' and ''Bondonella''. Harrington et al. (1959) excluded ''Kjerulfia'', while assigning ''Schmidtiellus'' to it. Bergström (1973) included ''Holmia'', '' Elliptocephala'', ''Esmeraldina'', ''Schmidtiellus'' and '' Wanneria''. Repina (1979) assigned ''Holmia'', ''Schmidtiellus'', ''Kjerulfia'', ''Elliptocephala'', ''Bondonella'', ''Andalusiana'' and ''Holmiella'' to the Holmiinae, that together with the monotypic Callaviinae comprised the Hol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olenellidae
Olenellidae is an extinct family of redlichiid trilobite arthropods. Olenellids lived during the late Lower Cambrian (Botomian/Toyonian) in the so-called ''Olenellus''-zone in the former paleocontinent of Laurentia plus parts of what became the Famatinian orogen in what is now Argentina. This family can be distinguished from most other Olenellina by the partial merger of the frontal (L3) and middle pair (L2) of lateral lobes of the central area of the cephalon, that is called glabella The glabella, in humans, is the area of skin between the eyebrows and above the nose. The term also refers to the underlying bone that is slightly depressed, and joins the two brow ridges. It is a cephalometric landmark that is just superior to ..., creating two isolated slits. Key to the subfamilies References Olenelloidea Trilobite families Cambrian first appearances Cambrian Series 2 extinctions {{Redlichiida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fallotaspididae
''Fallotaspis'' is a genus of redlichiid trilobites found in Early Cambrian-aged strata of the United States and Morocco. Etymology The generic name, Fallotaspis, is a compound crassis word that honors Paul Fallot (1889-1960), a French paleontologist who researched Cambrian fossils in Spain, in combination with the Greek word ἀσπίς, ''aspis'', meaning shield. Description As with most early trilobites, ''Fallotaspis'' has an almost flat exoskeleton, that is only thinly calcified, and has crescent-shaped eye ridges. As part of the Olenellina suborder, ''Fallotaspis'' lacks dorsal sutures. As part of the superfamily Fallotaspidoidea ''Fallotaspis'' can be distinguished from Olenelloidea, Judomioidea and Nevadioidea by features of the cephalon and in particular the glabella. The glabella tapers forward. The frontal lobe of the glabella (because it is counted from the back, it is numbered L4) is as long as the most backward lobe (L0), less than in these other Olenelli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wanneria
''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 (i.e. the genus is monotypic). Description As with most early trilobites, ''Wanneria walcottana'' has an almost flat exoskeleton, that is only thinly calcified, and has crescent-shaped eye ridges. As part of the Olenellina suborder, ''Wanneria'' lacks dorsal sutures. Like all other members of the Olenelloidea superfamily, the eye-ridges spring from the back of the frontal lobe (L4) of the central area of the cephalon, that is called glabella. The dorsal exoskeleton of ''Wanneria'' has an inverted egg shaped outline, approximately 1½ times longer than wide, ignoring the pleural spines, and is at its widest at the back of the cephalon. The horizontal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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