Die Lagenida sind eine Ordnung gehäusetragender, meeresbewohnender Einzeller aus der Gruppe der Foraminiferen.
Die Arten der Ordnung sezernieren ihre Gehäuse aus Niedrig-Magnesium-Kalzit (Magnesium). Die Gehäuse sind perforat, einkammerig oder mehrkammerig mit entweder serieller oder planispiraler Anordnung der Kammern, die Wandung ist monolamellar.
Die Ordnung ist seit dem oberen Trias fossil belegt und besteht aus zwei Überfamilien:
Die Lagenida sind eine Ordnung gehäusetragender, meeresbewohnender Einzeller aus der Gruppe der Foraminiferen.
Lagenida is an order of benthic foraminiferal protists in which the tests (shells) are monolamellar, with walls composed of optically and ultra-structurally radiate calcite, with the crystallographic c-axes perpendicular to the surface. Lagenids first appear in the Upper Silurian and continue to the Recent. They are currently divided into two superfamilies, the older Robuloidacea which range from the Upper Silurian to the Lower Cretaceous (Albian) and the younger Nodosariacea, ranging from the Permian to Recent.
Lagenida (suborder Lagenina in Loeblich and Tappan 1988) is an emendation of the rotaliid superfamily Nodosariacea, removing it from the Rotaliina in the Treatise on Invertebrate Paleontology (Loeblich and Tappan, 1964) and combining it with the Robuloidacea, named by Reiss, 1963, to form a new order Lagenida.
Robuloidacea includes families previously included in the Fusulinida and found in either of the superfamilies Parathuramminacea and Endothyracea. Provided that robuloidaceans did actually give rise to nodoceriacea in the Triassic, the ultimate ancestry of Lagenida can be found within Fusulinida, but not the better known Fusulinacea.
Shells (tests) of Lagenida are generally serial in form, with chambers in a line. They may be unilocular with chambers singularly one after the other, or in sets of twos or threes, (bilicular or trilocular). Some trochoidally coiled forms are known. Some have later chambers that are flared out like a fan, others are shaped like leaves.
Lagenida differ from Rotaliida in the manner in which new septa are formed. In both, when a new chamber is formed a new layer of material is added to the outer surface of the entire shell. In the Lagenida, that layer is used to form only the last, or new, septum. All septa remain monolamellar. In the Rotaliida the outer layer not only forms the final septum, but also coats the front of the previous septum, so that only the final septum in monolamellar.
Lagenida is an order of benthic foraminiferal protists in which the tests (shells) are monolamellar, with walls composed of optically and ultra-structurally radiate calcite, with the crystallographic c-axes perpendicular to the surface. Lagenids first appear in the Upper Silurian and continue to the Recent. They are currently divided into two superfamilies, the older Robuloidacea which range from the Upper Silurian to the Lower Cretaceous (Albian) and the younger Nodosariacea, ranging from the Permian to Recent.
Lagenida es un orden de foraminíferos (clase Foraminiferea, o Foraminifera),[1] tradicionalmente considerado suborden Lagenina del orden Foraminiferida.[2] Su rango cronoestratigráfico abarca desde el Carbonífero hasta la Actualidad.
Son un grupo de foraminíferos bentónicos que presentan una concha calcítica radial, finamente perforada, en la que los cristales aparecen envueltos por membranas orgánicas. Presentan pared monolamelar o multilamelar, aunque las lamelas solo la recubren parcialmente. La laminación secundaria es típica de las formas más avanzadas, no apareciendo en los taxones primitivos. Las conchas pueden ser de planiespiraladas a desenrolladas. La abertura es generalmente terminal, situada sobre una serie de cortes o arrugas radiales, pudiendo llegar a constituir un verdadero trematóporo.[3]
Lagenida incluye a las siguientes superfamilias:
Lagenida es un orden de foraminíferos (clase Foraminiferea, o Foraminifera), tradicionalmente considerado suborden Lagenina del orden Foraminiferida. Su rango cronoestratigráfico abarca desde el Carbonífero hasta la Actualidad.
Це незавершена стаття про найпростіших.
