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Paciphacops
''Paciphacops'' is a genus of trilobites from the order Phacopida, suborder Phacopina. This genus is easily mistaken for the more common and popular genus ''Phacops'' and ''Kainops''. It takes a careful eye to spot the difference. One major difference between ''Paciphacops'' and ''Phacops'' is that the central raised area (or glabella) of the headshield (or cephalon) extends beyond its anterior margin. The difference between Paciphacops and ''Kainops'' is that ''Kainops'' has more eye facets than ''Paciphacops''. The skin (or sclera) is thickened and bulges compared to the edge of each lens. This genus can be found primarily in the United States and Australia. Species *''Paciphacops birdsongensis'', Tennessee. *''Paciphacops campbelli'', Oklahoma. *''Paciphacops claviger'', Nevada. *''Paciphacops logani'', Oklahoma. *''Paciphacops crosslei'', Australia. *''Paciphacops latigenalis ''Paciphacops'' is a genus of trilobites from the order Phacopida, suborder Phacopina. This gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phacops
''Phacops'' is a genus of trilobites in the order Phacopida, family Phacopidae, that lived in Europe, northwestern Africa, North and South America and China from the Late Ordovician until the very end of the Devonian, with a broader time range described from the Late Ordovician.''Phacops'' at .org It was a rounded animal, with a globose head and large eyes, and probably fed on . ''Phacops'' is often found rolled up (" volvation"), a biological defense ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paciphacops Birdsongensis
''Paciphacops'' is a genus of trilobites from the order Phacopida, suborder Phacopina. This genus is easily mistaken for the more common and popular genus ''Phacops'' and ''Kainops''. It takes a careful eye to spot the difference. One major difference between ''Paciphacops'' and ''Phacops'' is that the central raised area (or glabella) of the headshield (or cephalon) extends beyond its anterior margin. The difference between Paciphacops and ''Kainops'' is that ''Kainops'' has more eye facets than ''Paciphacops''. The skin (or sclera) is thickened and bulges compared to the edge of each lens. This genus can be found primarily in the United States and Australia. Species *'' Paciphacops birdsongensis'', Tennessee. *'' Paciphacops campbelli'', Oklahoma. *'' Paciphacops claviger'', Nevada. *'' Paciphacops logani'', Oklahoma. *'' Paciphacops crosslei'', Australia. *''Paciphacops latigenalis ''Paciphacops'' is a genus of trilobites from the order Phacopida, suborder Phacopina. Thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kainops
''Kainops'' is a genus of trilobites from the family Phacopidae, order Phacopida Phacopida ("lens-face") is an order of trilobites that lived from the Late Cambrian to the Late Devonian. It is made up of a morphologically diverse assemblage of taxa in three related suborders. Characteristics Phacopida had 8 to 19 thorac .... It can be distinguished from '' Paciphacops'' by the greater number of facets to the eye (6–8 per row, compared to 3–4 in ''Paciphacops''). The form of the furrow between the palpebral area and the palpebral lobe also distinguishes ''Kainops'' from the genera ''Paciphacops'' and '' Viaphacops''. Species included in the genus are: *'' Kainops chlupaci'' Budil & Kolář, 2004 *'' Kainops ekphymus'' (Jones ''et al.'', 1986) *'' Kainops guttulus'' (Campbell 1967) *'' Kainops invius'' (Campbell 1977) *'' Kainops microps'' (Chatterton, Johnson and Campbell, 1979) *'' Kainops raymondi'' (Delo 1935) *'' Kainops veles'' (Chlupac 1972) References Phac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phacopidae
Phacopidae is a family of phacopid trilobites that ranges from the Lower Ordovician to the Upper Devonian, with representatives in all paleocontinents. Description As in all Phacopina, the eyes (if present) consist of very large (0.5 mm in ''Phacops rana''), separately set lenses without a common cornea (so called schizochroal eyes). However, several phacopids have very few lenses, such as the species of the genera ''Cryphops'', ''Denckmannites'', ''Dienstina'', ''Eucryphops'', ''Nephranops'', and ''Plagiolaria'', or lack eyes altogether, like ''Afrops'', ''Dianops'', ''Ductina'', and ''Trimerocephalus''. The natural fracture lines (sutures) of the head run along the top edges of the compound eye. From the back of the eye these cut to the side of the head ( proparian) and not to the back. In front of the eye, the right and left facial sutures connect in front of the inflated glabella and consequently the free cheeks (or librigenae) are yoked as a single piece. In some of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phacopida
Phacopida ("lens-face") is an order of trilobites that lived from the Late Cambrian to the Late Devonian. It is made up of a morphologically diverse assemblage of taxa in three related suborders. Characteristics Phacopida had 8 to 19 thoracic segments and are distinguishable by the expanded glabella, short or absent preglabellar area, and schizochroal (Phacopina) or holochroal (Cheirurina and Calymenina) eyes. Schizochroal eyes are compound eyes with up to around 700 separate lenses. Each lens has an individual cornea which extended into a rather large sclera. The development of schizochroal eyes in phacopid trilobites is an example of post-displacement paedomorphosis. The eyes of immature holochroal Cambrian trilobites were basically miniature schizochroal eyes. In Phacopida, these were retained, via delayed growth of these immature structures (post-displacement), into the adult form. ''Eldredgeops rana'' ( Phacopidae) and '' Dalmanites limulurus'' (Dalmanitidae) are ... [...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. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalon (arthropod Anatomy)
The cephalon is the head section of an arthropod. It is a tagma, i.e., a specialized grouping of arthropod segments. The word cephalon derives from the Greek κεφαλή (kephalē), meaning "head". Insects In insects, ''head'' is a preferred term. The insect head consists of five segments, including three (the labial, maxillary and mandibular) necessary for food uptake, which are altogether known as the gnathocephalon and house the suboesophageal ganglion of the brain, as well as the antennal segment, and an ocular segment, as well as a non segmented fused section of the head where the archicerebrum is housed known as the acron. See also arthropod head problem. Chelicerates and crustaceans In chelicerates and crustaceans, the cephalothorax is derived from the fusion of the cephalon and the thorax, and is usually covered by a single unsegmented carapace. In relation with the arthropod head problem, phylogeny studies show that members of the Malacostraca class of c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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