Information: - Insects (from Latin ', a calque of Greek ['], "cut into sections") are a class of invertebrates within the arthropod phylum that have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed legs, compound eyes and one pair of antennae. They are the most diverse group of animals on the planet, including more than a million described species and representing more than half of all known living organisms. The number of extant species is estimated at between six and ten million, and potentially represent over 90% of the differing animal life forms on Earth. Insects may be found in nearly all environments, although only a small number of species reside in the oceans, a habitat dominated by another arthropod group, crustaceans. - The Ordovician is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.2 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Celtic tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in northern Wales into the Cambrian and Silurian periods, respectively. Lapworth, recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian periods, and placed them in a period of their own. It received international sanction in 1960, when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. - Invertebrates are animals that neither possess nor develop a vertebral column (commonly known as a "backbone" or "spine"), derived from the notochord. This includes all animals apart from the subphylum Vertebrata. Familiar examples of invertebrates include insects; crabs, lobsters and their kin; snails, clams, octopuses and their kin; starfish, sea-urchins and their kin; and worms. - An exoskeleton (from Greek , "ex" "outer" and , "skeletos" "skeleton") is the external skeleton that supports and protects an animal's body, in contrast to the internal skeleton (endoskeleton) of, for example, a human. In usage, some of the larger kinds of exoskeletons are known as "shells". Examples of animals with exoskeletons include insects such as grasshoppers and cockroaches, and crustaceans such as crabs and lobsters. The shells of certain sponges and the various groups of shelled molluscs, including those of snails, clams, tusk shells, chitons and nautilus, are also exoskeletons. Some animals, such as the tortoise, have both an endoskeleton and an exoskeleton. - The Cambrian Period (or ) was the first geological period of the Paleozoic Era, of the Phanerozoic Eon. The Cambrian lasted 55.6 million years from the end of the preceding Ediacaran Period 541 million years ago (mya) to the beginning of the Ordovician Period mya. Its subdivisions, and its base, are somewhat in flux. The period was established (as Cambrian series) by Adam Sedgwick, who named it after Cambria, the Latinised form of "Cymru", the Welsh name for Wales, where Britain's Cambrian rocks are best exposed. The Cambrian is unique in its unusually high proportion of lagerstatte sedimentary deposits, sites of exceptional preservation where "soft" parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Cambrian biology surpasses that of some later periods. - In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer layer or covering), either at specific times of the year, or at specific points in its life cycle. - A body plan (also written bodyplan), Bauplan (German plural Bauplane), or ground plan is "an assemblage of morphological features shared among many members of a phylum-level group". The vertebrate body plan is one of many: invertebrates consist of many phyla. - A Lagerstatte (from "Lager" 'storage, lair' "Statte" 'place'; plural "Lagerstatten") is a sedimentary deposit that exhibits extraordinary fossils with exceptional preservationsometimes including preserved soft tissues. These formations may have resulted from carcass burial in an anoxic environment with minimal bacteria, thus delaying decomposition. "Lagerstatten" span geological time from the Neoproterozoic era to the present. Worldwide, some of the best examples of near-perfect fossilization are the Cambrian Maotianshan shales and Burgess Shale, the Devonian Hunsruck Slates and Gogo Formation, the Carboniferous Mazon Creek, the Jurassic Solnhofen limestone, and the Cretaceous Santana and Yixian formations. - Cindarella is genus of trilobite - like Cambrian arthropod known from the Chengjiang biota of China . It is classified as a stem group of trilobites in the clade Xandarellida , along with Phytophilaspis , Sinoburius , and Xandarella . - Wales is a country that is part of the United Kingdom and the island of Great Britain. It is bordered by England to the east, the Irish Sea to the north and west, and the Bristol Channel to the south. It had a population in 2011 of 3,063,456 and has a total area of . Wales has over of coastline and is largely mountainous, with its higher peaks in the north and central areas, including Snowdon, its highest summit. The country lies within the north temperate zone and has a changeable, maritime climate. - Vertebrates comprise all species of animals within the subphylum Vertebrata (chordates with backbones). Vertebrates represent the overwhelming majority of the phylum Chordata, with currently about 64,000 species described. Vertebrates include the jawless fish and the jawed vertebrates, which include the cartilaginous fish (sharks and rays) and the bony fish. - Arachnids are a class (Arachnida) of joint-legged invertebrate animals (arthropods), in the subphylum Chelicerata. All arachnids have eight legs, although the front pair of legs in some species has converted to a sensory function, while in other species, different appendages can grow large enough to take on the appearance of extra pairs of legs. The term is derived from the Greek word ("arachn"), meaning "spider". Spiders are the largest order in the class. - The Permian is a geologic period and system which spans 46.7 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 252.2 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the city of Perm. - An arthropod (from Greek "arthro-", joint + "podos", foot) is an invertebrate animal having an exoskeleton (external skeleton), a segmented body, and jointed appendages (paired appendages). Arthropods form the phylum Arthropoda, which includes the insects, arachnids, myriapods, and crustaceans. Arthropods are characterized by their jointed limbs and cuticle made of chitin, often mineralised with calcium carbonate. The arthropod body plan consists of segments, each with a pair of appendages. The rigid cuticle inhibits growth, so arthropods replace it periodically by moulting. Their versatility has enabled them to become the most species-rich members of all ecological guilds in most environments. They have over a million described species, making up more than 80% of all described living animal species, some of which, unlike most animals, are very successful in dry environments. - In biology, a phylum (plural: phyla) is a taxonomic rank below kingdom and above class. Traditionally, in botany the term division was used instead of "phylum", although from 1993 the International Code of Nomenclature for algae, fungi, and plants accepted the designation "phylum". Depending on definitions, the kingdom Animalia contains approximately 35 phyla, Plantae contains about 12, and Fungi contains around 7. Current research in phylogenetics is uncovering the relationships between phyla, which are contained in larger clades, like Ecdysozoa and Embryophyta. - The Ediacaran Period, spans 94 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 541 Mya. It marks the end of the Proterozoic Eon, and the beginning of the Phanerozoic Eon. It is named after the Ediacara Hills of South Australia. - Animals are multicellular, eukaryotic organisms of the kingdom Animalia (also called Metazoa). The animal kingdom emerged as a basal clade within Apoikozoa as a sister of the choanoflagellates. Sponges are the most basal clade of animals. Animals are motile, meaning they can move spontaneously and independently at some point in their lives. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later in their lives. All animals are heterotrophs: they must ingest other organisms or their products for sustenance. - The Devonian is a geologic period and system of the Paleozoic, spanning 60 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. Various terrestrial arthropods also became well-established. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the "Age of Fish". The first ray-finned and lobe-finned bony fish appeared, while the placodermi began dominating almost every known aquatic environment. - Chitin (CHON) is a long-chain polymer of an "N"-acetylglucosamine, a derivative of glucose, and is found in many places throughout the natural world. It is a characteristic component of the cell walls of fungi, the exoskeletons of arthropods such as crustaceans (e.g., crabs, lobsters and shrimps) and insects, the radulae of molluscs, and the beaks and internal shells of cephalopods, including squid and octopuses and on the scales and other soft tissues of fish and lissamphibians. The structure of chitin is comparable to the polysaccharide cellulose, forming crystalline nanofibrils or whiskers. In terms of function, it may be compared to the protein keratin. Chitin has proved versatile for several medicinal, industrial and biotechnological purposes. - Trilobites (meaning "three lobes") are a fossil group of 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 era before beginning a drawn-out decline to extinction when, during the Devonian, all trilobite orders except the Proetids died out. Trilobites finally disappeared in the mass extinction at the end of the Permian about . The trilobites were among the most successful of all early animals, roaming the oceans for over 270 million years. What is the relationship between 'cindarella' and 'arthropoda'?
parent taxon