|
Proetida
Proetida is an order of trilobite that lived from the Ordovician to the Permian. It was the last surviving order of trilobite, dying out in the Permian-Triassic extinction event. Description These typically small trilobites resemble those of the order Ptychopariida, from which the new order Proetida was separated in 1975 by Richard Fortey, Fortey and Owens. Like the order Phacopida, the proetids have exoskeletons that sometime have pits or small tubercles, especially on the glabella (trilobite anatomy), glabella (middle portion of the head). Because of their resemblance to the Ptychopariida in some features, the proetids are included in the subclass Librostoma. Unlike the trilobites of the phacopid suborder Phacopina, whose trilobite eye, eyes are Eye#Apposition eyes, schizochroal, the proetids have the more common holochroal eyes. These eyes are characterized by close packing of biconvex Lens (anatomy), lenses beneath a single corneal layer that covers all of the lenses. Each ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proetidae
Proetidae is a family (biology), family of Proetida, proetid trilobites. The first species appeared in the Upper Ordovician, and the last genera survived until the Middle Permian. However, if the closely related family Phillipsiidae is actually a subfamily of Proetidae, then the proetids of Proetidae survive until the end of the Permian, where the last perish during the Permian–Triassic extinction event. Genera Proetidae ostensibly contains these following genera, though many may be placed in Phillipsiidae if the latter is, indeed, a distinct family. *''Aayemenaytcheia'' *''Aceroproetus'' *''Alaskalethe'' *''Altajaspis'' *''Anambon'' *''Anglibole'' *''Angustibole'' *''Anujaspis'' *''Appendicysta'' *''Aprathia'' *''Archaeocoryphe'' *''Ascetopeltis'' *''Astroproetus'' (syn=''Xiushuiproetus'', ''Zhejiangoproetus'') *''Australokaskia'' *''Bailielloides'' *''Bapingaspis'' *''Basidechenella'' *''Beleckella'' *''Belgibole'' *''Benesovella'' *''Bitumulina'' *''Blodgettia'' *''Bohemipro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |