Redlichiida Redlichiida Scientific classification Kingdom: Animalia Phylum: Arthropoda Class: Trilobita Order: Redlichiida Families Suborder Olenellina    Superfamily Olenelloidea     Olenellidae     Holmiidae    Superfamily Fallotaspidoidea     Archaeaspididae     Fallotaspididae     Judomiidae     Neltneriidae     Nevadiidae Suborder Redlichiina    Superfamily Emuelloidea     Emuellidae    Superfamily Redlichioidea     Abadiellidae     Chengkouaspidae     Dolerolenidae     Gigantopygidae     Kuechowiidae     Mayiellidae     Menneraspididae     Metadoxididae     Redlichiidae     Redlichinidae     Saukiandidae     Yinitidae    Superfamily Paradoxidoidea     Centropleuridae     Paradoxididae     Xystriduridae Redlichiida is an Order within the major extinct arthropod class Trilobita. The Redlichids are one of the four older classes of trilobites that originated in the early Cambrian. The earliest known trilobite seems to be the genus Fallotaspis which is a Redlichid. Redlichids look primitive. They typically have a large, semicircular cephalon and a highly-segemented thorax that tapers back to a small pygidium. Unlike many other trilobite orders, the Redlichids were probably not capable of defensive enrollment. The Redlichids generally have prominent, long, crescent-shaped eyes. The Redlichids are often quite spiny with genal, and/or glabular, and/or tail, and/or segment spines. One Redlichid family, the Olenellids, typically have long spines on the third thoracic segment. The Redlichids are divided into three suborders. The Olenellids are found in North America and associated areas that comprised the Cambrian continent of Laurentia. They are very common and are used to define the scope of Laurentia. Their abrupt disappearance marks the Lower-Middle Cambrian boundary in areas where the Olenellids are found. Olenellids do not have a facial suture. Redlichids are associated with Cambrian regions other than Laurentia. They have facial sutures and their remains are frequently found without their librigena, or 'free cheeks'. The relatively uncommon Bathynotids had facial sutures, long genal spines, and long spines on the final thoracic segment. The Redlichids died out before the end of the Middle Cambrian. The appendages have been preserved in a few specimens. They follow typical trilobite patterns in terms of the number, placement, and types of legs, antennae, gills, etc. Redlichid trilobites are the first arthropods to appear in the fossil record. They are common fossils in Lower Cambrian faunas worldwide. Most Popular Articles: Music    Musical Instruments    Guitar    Classical Music    History    Music Definition    Country Music    Rock Music    Pop Music    Hip Hop    Rap    DJ    Video Games    Casino Games    Poker    Blackjack    Casinos    Real Estate    Loan    Auction    eBay    Marketing    Search Engine Optimization    File Sharing    MP3    Music Industry    Kazaa    Internet    Supermodel    Fashion    Fashion Designers    Erotica    Modeling    Clothing    Boots    Shoes    Diamond Engagement Rings    Diamond    Rugs    Gospel Music    Affiliate    E-Commerce    Radio This article is licensed under the GNU Free Documentation License at http://www.gnu.org/copyleft/fdl.html You may copy and modify it as long as the entire work (including additions) remains under this license. You must provide a link to http://www.gnu.org/copyleft/fdl.html To view or edit this article at Wikipedia go to http://www.wikipedia.org/wiki/Redlichiida