Cambrian The Cambrian System is named after Wales (Cambria) and, being the oldest of the three Early (Lower) Palaeozoic systems, constitutes the first of the Phanerozoic systems of rocks. Much of the fascination that this system holds for geologists is on account of its fossils, which represent the first great successes of invertebrate animals. It was formed over a time-span from about 450 Ma to around 495 Ma, and during this time the major patterns of invertebrate diversity were established.

The first mention of the name Cambrian was in 1835 by Adam Sedgwick and R. I. Murchison, both of whom were pioneer explorers of the older rocks of Wales and the Welsh Borderlands. Sedgwick, who was the first professor of geology at the University of Cambridge, took particular interest in recording the rock succession between Anglesey and the Berwyn Hills of North Wales, and in similar formations in the north of England. He was able to discover the general sequence of these sparsely fossiliferous and rather deformed rocks and referred to them as ‘Cambrian’. The base of the system was never clearly defined, but it was generally taken to be where the first abundant shelly fossils occur. As for the top, it too was a matter of some disagreement. The ultimately bitter dispute that arose a few years later between Sedgwick and Murchison as to the boundary between the Sedgwick's Cambrian and Murchison's lowest Silurian was finally resolved by Charles Lapworth in 1879 with the creation of the Ordovician system. Lapworth offered a compromise, but it was a wise and practical one.

Many suggestions have been made about the best level for the base of the system. The inception of the Phanerozoic Eon is seen as marked by a revolution in the organic world with the first great radiation of new marine invertebrate groups to be ‘written’ into the geological record. Many of these creatures possessed little or no preservable hard tissues, and fossils are thus rare. It has always been difficult to designate the fossils that can widely be found and identified, as the earliest that are essentially and distinctively Cambrian. The base of the system has consequently been hard to define. Since Sedgwick's day and the number of known early Cambrian and late Precambrian fossils has greatly increased, but this has not made the problem much easier to solve. The matter has been studied by working group of the International Commission on Stratigraphy, and a level at or near the base of the Tommotian Stage with its many shelly microfossils is favoured. A stratotype section and point in eastern Newfoundland appear to satisfy the requirements. Other important comparative sections are in China and Siberia. How readily the geological community accepts and uses this choice remains to be seen during the next decade or so.

The Cambrian System is divided into three series. The lower is subdivided into four stages, the middle into two, and the upper into three. As originally defined, these were basically lithostratigraphical divisions, but palaeontological—or rather biostratigraphical—criteria now prevail. Cambrian biostratigraphy has from the outset been largely based upon the distribution of the trilobites (a group of extinct marine arthropods). These fossils, present above the basal Tommotian Stage, have proved to be useful in inter-regional, and even in some intercontinental, correlations. Trilobite faunas, nevertheless, exhibit some provincialism and cannot be used for global correlation. Other marine groups, such as sponges, archaeocyathids, echinoderms, brachiopods, and some primitive molluscs are known from parts of the Cambrian, while problematic fossils of unknown affinities or uncertain taxonomic status are locally common, especially as microfossils.

An exceptional, though not unique, view of Middle Cambrian marine life is afforded by the Burgess Shale fauna of British Columbia. There, about a hundred genera of mainly soft-bodied creatures have been exceptionally and exquisitely preserved. They indicate a more taxonomically diverse and ecologically versatile assemblage of animals than is apparent elsewhere. The fauna also includes some taxa surviving from the Precambrian Ediacarian stage. The Burgess Shale fossils, and others from China and Greenland, record the major adaptive radiations that were in progress at the time—the ‘Cambrian explosion’ of the invertebrates as it is often called. There is much debate about the extent to which the Cambrian biota spread throughout the breadth and the depth of the oceans, but there seems to be little doubt that the continental seas were effectively exploited, at least within the tropical and temperate latitudes.

There is no convincing direct evidence of life in Cambrian terrestrial or freshwater environments, but primitive forms such as algae and bacteria were undoubtedly present in soils and fresh waters. They were pioneering the spread of life into the continental parts of the world, and in the following Ordovician period this spread was to gather pace.

Cambrian palaeogeography was characterized by considerable continental movement. Much of the Proterozoic supercontinental mass persisted in the lower latitudes, but the continental blocks of Baltica, Laurentia, Siberia, Kazakhstania, and China were separated from it and from each other by narrow oceans, spread out for the most part within the tropics (Fig. 1). As time progressed the Gondwana supercontinent rotated clockwise and swung into a south polar location.

The effects of this, together with those of climate and depositional environment, were to produce several regionally distinct faunas throughout the period. The Lower Cambrian archaeocyathids, for example, seem to be confined to Siberia and the nearby margin of Gondwana at first, but later spread to include Laurentia and Eastern Gondwana. Trilobite provinciality was manifest throughout the entire period. To what extent it was controlled by climate and geography is debated, but it must have been considerable.

Cambrian sedimentation was profoundly influenced by rising sea-level. Lower Cambrian successions almost everywhere are dominantly clastic and transgressive. Commonly they rest unconformably upon Precambrian rocks and the derivation of new sediment from a thick regolith (superficial unconsolidated rock) gave rise to extensive spreads of quartzites across the shallowly flooded floors of the continental margins. Carbonate precipitation (in the form of limestones and dolomites) had been facilitated in the Precambrian by the relatively higher proportion of atmospheric carbon dioxide. Then, during the Precambrian-Cambrian transition, world atmospheric conditions went from ‘ice house’ to ‘greenhouse’. Such changes were to take place several times later in earth history. Carbonate-secreting organisms spread rapidly across the cratonic margins and other basins, giving rise to a new major phase of carbonate deposition. Plate-tectonic activity with much oceanic volcanism was more conspicuous during Cambrian times, so that calcium carbonate precipitation was again favoured, especially in northern and central Laurentia and Siberia. Evaporites are found associated with the shallow-marine areas of Siberia and north-western Gondwana of early Cambrian time.

The active continental margins of Laurentia, western Baltica, and parts of eastern and western Gondwana were the sites of deposition of thick turbidite sequences and, later, volcanic rocks. Mountain-building activity within the Cambrian period seems to have been limited, but a major event in Scotland and mild tectonism in Iberia are known to have occurred. The long time during which the continental interiors had been subaerially weathered and lowered by erosion was succeeded by one of progressive flooding and coverage by shallow seas. The shallow-marine realm for the expansion of life's activities was continually expanding, and the opportunity it afforded for new arrivals was not neglected. By the end of the period the tectonic unrest had died out and a quiet passage into the Ordovician ensued.

Late Cambrian time also witnessed a lowering of sea level, and the idea has been put forward that cool, oxygen-poor waters from the deep levels of the oceans spread repeatedly up on to the continental shelves. These chills brought about a series of closely spaced marine extinctions, and the deposition of anoxic black shales. Trilobites, conodonts, and brachiopods suffered most during these crises; the archaeocyathids had suddenly vanished at the end of the Early Cambrian epoch, together with the olenellid group of trilobites.

Cambrian magnetostratigraphy appears to be remarkably simple overall. It begins with a span of mainly reverse polarization to 530 Ma, followed by a normal episode (to about 526 Ma) and then mainly reverse polarization to the end of the period. If geomagnetic activity is the result of changes within the core and mantle, its Cambrian low level seems to accord with the low level of plate-tectonic events; but this is only speculation at the moment.

D. L. Dineley

Bibliography

Brasier, M. D. (1992) Background to the Cambrian explosion. Journal of the Geological Society of London, 149, 585–7. [This is the first of a thematic set of papers on the Precambrian-Cambrian boundary in this part of the Journal.]
Cocks, L. R. M. (1978) Cambrian. In McKerrow, W. S. (ed.) The ecology of fossils. Duckworth, London.
Holland, C. (ed.) (1974) Cambrian of the world. Wiley Interscience, New York.
Whittington, H. B. (1985) The Burgess Shale. Yale University Press, New Haven.

Cambrian period

Cambrian is the name given to a period of time in Earth's history (i.e., Cambrian Period), which spanned 570–510 million years ago. The proper name Cambrian is also given to all the rocks that formed during that time (i.e., Cambrian System). In other words, the Cambrian System is the rock record of events that occurred—and organisms that lived—during an interval of geological time called Cambrian Period. Cambrian is the initial period of the Paleozoic Era .

Cambrian is a name derived from the Roman name for Wales, which was Cambria. Wales was the original study location for sedimentary rock formed during this interval of Earth history. The term Cambrian was first used in 1835 by Professor Adam Sedgwick (1785–1873) of Cambridge University, who was studying the lower part of what was then called Transition strata (the oldest known sedimentary rocks ) in Wales. Sedgwick was working in the same general area as another prominent stratigrapher of the day, Roderick Merchison (1792–1871), whose focus was upon the overlying Silurian System. Merchison eventually showed that there was some overlap in the original concept of Sedgwick's Cambrian System and his own Silurian System, and ultimately advocated (c. 1852) that the Cambrian System was in fact part of the Silurian. It was not until a comprehensive study of the Cambrian-Silurian overlap problem produced the intervening Ordovician System (1879), that the Cambrian System was fully accepted by all geologists. Since their recognition and definition during the nineteenth century, Cambrian strata have been mapped on all the world's continents.

During Cambrian, the breakup of the supercontinent of Gondwana began with the separation of some landmasses including part of Asia and the ancient continents called Baltica and Laurentia (i.e., proto-North America). During its separation from the main Gondwana land mass, Laurentia had a collision with the southern end of what is now South America (specifically western Argentina), which resulted in some crustal deformation and mountain building. At this time, there was essentially a single world ocean, which is referred to as Panthalassa.

During most of Cambrian, global sea levels were at relatively high elevations as compared with most of the balance of Earth's history. The world's continents were mainly low-lying deserts and alluvial plains, and the rising Cambrian sea—in what is known as the Sauk transgression—encroached upon these areas, thus forming vast epicontinental seas . For example, during most of Cambrian, sea level was so high that an epicontinental sea covered North America except for a series of low islands running southwest-northeast along the elevated middle part of the continent (i.e., the Transcontinental Arch) and some parts of the low-lying Canadian cratonic shield region.

Cambrian was a time of rising global temperatures and Cambrian global climate ultimately became warmer than today. During Cambrian, there were essentially no polar or high-altitude glaciers . Further, there were no continents located at polar positions. The Cambrian Earth likely had more equitable climates than present because of the large amount of surficial seawater (approximately 85% or more, compared to approximately 70% at present) and lack of significant topographic relief . Winds were likely confined to rather well-defined belts, and there is good evidence of persistent trade winds preserved in vast cross-bedded Cambrian sandstones.

Cambrian life in the oceans was very plentiful, but rather primitive by modern standards. The transition of pre-Cambrian life forms (mainly soft-body impressions in rock) to Cambrian life (shell-bearing fossils and other fossils with hard parts) has been referred to as the "Cambrian explosion." This explosion is more apparent than real, as the main change was the advent of preservable hard parts and shells, which seem to suddenly appear at a level near the onset of Cambrian sedimentation . Cambrian faunas include some very unusual creatures that may represent extinct phyla of organisms or organisms so primitive that they are not easily assigned to extant phyla. The most famous of fossil localities with such Cambrian fossils is at Mount Wapta, British Columbia, Canada (i.e., Burgess Shale outcrops). In these strata, the earliest known chordate (spinal cord-bearing animal), Pikaia, was first found. Other marine creatures of Cambrian seas included the archaeocyathids and stromatoporoids (two extinct, sponge-like organisms that formed reefs), primitive sponges and corals, simple pelecypods and brachiopods (two kinds of bivalves), simple molluscs, primitive echinoderms and jawless fishes, nautiloids, and a diverse group of early arthropods (including many species of trilobites). Trilobites were particularly abundant and diverse, and over 600 genera of Cambrian trilobites are known. Some species of trilobites were the first organisms to develop complex eye structures. Numerous Cambrian reefs, patch reefs, and shallow-water mounds were formed by stromatolites, a layered mass of sediment formed by the daily trapping and binding action of a symbiotic growth of blue-green algae and bacteria.

Cambrian life on land was probably quite limited. There is evidence that stromatolitic growth of blue-green algae and bacteria covered rocks and formed sediment layers at or near oceanic shorelines and lake margins. However, complex life forms are not found in Cambrian terrestrial sediments. It is possible that some arthropods may have lived partially or entirely upon land at this time, but this is speculative in the absence of fossil evidence. There were no land plants at this time, and thus Cambrian landscapes were at the mercy of wind and water erosion without any protection from vegetation. The minimal level of photosynthetic activity before and during Cambrian raised oxygen levels in Earth's atmosphere to approximately 10% of that found in the modern atmosphere.

The end of Cambrian came gradually with falling sea levels and the onset of slightly cooler global temperatures. During Late Cambrian, trilobite species became the first organisms known to experience widespread mass extinction. In several events during Late Cambrian, trilobite faunas were wiped out over vast areas for causes that are not completely understood. Reasons proposed for the mass extinctions include competition with other organisms and rapid shifts in global temperature and/or sea-level changes. Trilobites persisted into Late Paleozoic, but not as prominently as they did in Cambrian seas. Ordovician succeeded Cambrian life and conditions. During Ordovician, plant and animal life continued to diversify, tectonic activity began to be more extensive, and global climate change became more intensive.

See also Stratigraphy; Supercontinents

Cambrian Period

The Cambrian period (570 million years ago) marks an extraordinary shift in the evolution of life. It ushers in the beginning of the Paleozoic Era (the age of ancient life).

Cambrian period and surrounding time periods.

In the Precambrian, a three-billion-year period of evolutionary stasis, the dominant life-forms were prokaryotes (tiny one-celled bacteria) and blue-green algae, both of which thrived in the steaming waters and nitrogen-and sulfur-rich air of a geologically turbulent Earth. Prokaryotes are the simplest forms of life, undifferentiated cells with no nucleus that reproduce by fission, the splitting of the parent cell into two. Prokaryotes live off hydrogen, sulfur, and nitrogen and they release free oxygen as a waste product. The prokaryotes' leisurely existence continued for five-sixths of recorded time, during which their massive colonies of cyanobacteria, fossilized as stromatilites, bubbled out enough oxygen to form eventually an atmosphere and a corresponding ozone shield against sterilizing ultraviolet radiation. This development appears to have set the stage for what has been described as the Big Bang of Biology, the Cambrian Explosion.

Cambrian rock is named after the Latin "Cambria," meaning Wales. It was there that Cambrian rock was first studied for fossils in the late 1800s. Since then it has been found on every continent, with a particularly fertile deposit having been discovered in British Columbia, Canada. The latter is known as the Burgess Shale , a fine-grained, mudstone siltstone rock unit only about 200 feet long and 8 feet thick. Stephen Jay Gould has described it as the most important fossil deposit ever found. Dating to the mid-Cambrian of about 520 million years ago, the Burgess Shale has more than 120 animal species represented in it. The Burgess fossils demonstrate that the Cambrian period was a riot of experimentation in size, shape, and abilities. Animals that swam, that burrowed, and that foraged appeared at this time. A huge diversity of forms emerged. Some would succeed and continue to exist, while many others would disappear forever. The beginnings of every existing major phyla of animals can be found in the Burgess Shale and in other layers of Cambrian rock in Greenland and China. Over 900 species of marine life have been discovered at these locations, including sponges, jellyfish, annelids, mollusks, arthropods, and chordates with rudimentary backbones. One of the most interesting innovations found in Cambrian period animals was their ability to secrete a mineralized skeleton.

What could have caused this remarkable outburst of evolutionary life? The single most galvanizing event of the late Precambrian was the appearance of eukaryota , life-forms that stored DNA in a nucleus and were capable of organizing bodies consisting of more than one cell. Eukaryotes allowed for the possibility of specialization, since the individual cells did not each have to perform every task as long as they could communicate chemically with one another. This cooperation between cells set life-forms free to explore every design and variable in size and shape imaginable. Eukaryotes also developed the capability for sexual reproduction, which increases genetic diversity. Rather than duplicating the genetic material exactly as simple fission does, sexual reproduction ensures that a constant shuffling of genetic material will maximize the number of mutations and variations possible. This again allows for radical divergences in the exploration of the environment. These advances in eukaryote organisms, combined with the new, oxygenated atmosphere of the planet, would appear to have allowed for the outburst of metazoans—multicelled animals—in the Cambrian rocks.

see also Geological Time Scale.

Nancy Weaver

Bibliography

Fortey, Richard. Fossils: The Key to the Past. Cambridge, MA: Harvard University Press, 1991.

Friday, Adrian, and David S. Ingram, eds. The Cambridge Encyclopedia of Life Sciences. London: Cambridge University Press, 1985.

Lambert, David. The Field Guide to Prehistoric Life. New York: Facts on File, 1985.

McLoughlan, John C. Synapsida: A New Look into the Origin of Mammals. New York: Viking Press, 1980.

Steele, Rodney, and Anthony Harvey, eds. The Encyclopedia of Prehistoric Life. New

York: McGraw Hill, 1979.

Cambrian period [Lat. Cambria =Wales], first period of the Paleozoic geologic era (see Geologic Timescale , table) extending from approximately 570 to 505 million years ago. It was named by the 19th-century English geologist Adam Sedgwick, who first studied the great sequence of rocks characteristic of the period near Cambria, Wales. During the Cambrian, the continents and seas differed from present day configurations. Four major continents, Gondwanaland, Angara, and the two sections of Euramerica, were inundated with a rising sea level, accumulating thick sedimentary deposits (see sediment ). This sedimentary rock, i.e., conglomerate, sandstone, shale, and limestone, was formed in shallow seas that covered large areas of present-day North America, Europe, and Asia. In the United States, Lower Cambrian formations are found in the Appalachian; the sandstones near Waucoba Springs, S Calif.; and the thick layers of conglomerates and sandstones in Georgia, Tennessee, and North Carolina. Middle Cambrian rocks are found in New Brunswick, near Braintree, Mass. Upper Cambrian formations include the St. Croix sandstone of Wisconsin and the upper Mississippi valley, parts of the Arbuckle limestone of Oklahoma, and the Potsdam sandstone in New York's Adirondacks. In Russia, the Cambrian beds are remarkable in that they comprise mostly undisturbed and unconsolidated sand and clay despite their great age. The Cambrian rocks are the first rock layers to contain many easily recognizable fossils. The known Cambrian fauna—all marine—includes every phylum of invertebrates; the possibility that vertebrate fossils may be found cannot be excluded. The dominant animal was the trilobite, along with sea snails, brachiopods, sponges, and archaeocyathids. The ages of the various rock layers are distinguished according to the different genera of fossils they contain. The sudden appearance of highly developed and diversified fauna in Cambrian rock is best explained by the assumption that more primitive forms flourished during a missing stratigraphic interval between the close of the Precambrian and the beginning of the Cambrian. Remnants of these early organisms were either destroyed by erosion or their soft bodies easily decayed in a short period of time. In addition, at the beginning of the Cambrian, numerous animals eventually developed skeletons, or hard parts, capable of leaving behind fossil remains.

Cambrian The earliest geological period of the Palaeozoic era. It is estimated to have begun about 570 million years ago and lasted for some 100 million years. During this period marine animals with mineralized shells made their first appearance and Cambrian rocks are the first to contain an abundance of fossils. Cambrian fossils are all of marine animals; they include trilobites, which dominated the Cambrian seas, echinoderms, brachiopods, molluscs, and primitive graptolites (from the mid Cambrian). Trace fossils also provide evidence for a variety of worms.

Cambrian The first of six periods of the Palaeozoic Era, from about 570–510 Ma ago, during which sediments deposited include the first organisms with mineralized skeletons. Common fossils include Brachiopoda, Trilobitomorpha, Ostracoda, and, late in the period, Graptolithina. The plant fossils are mainly of algae and fungi. Trilobites (arthropods) are important in the stratigraphic subdivision of the period. See Burgess Shale.

Cam·bri·an / ˈkambrēən; ˈkām-/ • adj. 1. (chiefly in names or geographical terms) Welsh. 2. Geol. of, relating to, or denoting the first period in the Paleozoic era, between the end of the Precambrian eon and the beginning of the Ordovician period. ∎  [as n.] (the Cambrian) the Cambrian period or the system of rocks deposited during it.

Cambrian Earliest period of the Palaeozoic era, lasting from c. 590 million to 505 million years ago. Cambrian rocks are the earliest to preserve the hard parts of animals as fossils. They contain a large variety of fossils, including all the animal phyla, with the exception of the vertebrates. The commonest animal forms were trilobites, Brachiopoda, sponges and snails. Plant life consisted mainly of seaweeds.

Cambrian The first of six periods of the Palaeozoic Era, which began about 570 Ma ago and ended about 510 Ma ago. Sediments deposited during the period include the first organisms with mineralized skeletons. Common fossils include brachiopods, trilobites, ostracods, and, late in the period, graptolites. Trilobites are important in the stratigraphic subdivision of the period.

Cambrian The first of six periods of the Palaeozoic Era, from about 542–488.3 Ma ago, during which sediments deposited include the first organisms with mineralized skeletons. Common fossils include Brachiopoda, Trilobitomorpha, Ostracoda, and, late in the period, Graptolithina. Trilobites are important in the stratigraphic subdivision of the period.

Cambrian The first of six periods of the Palaeozoic Era, from about 590–505 Ma ago, during which sediments deposited include the first organisms with mineralized skeletons. The plant fossils are mainly of algae and fungi. Trilobites (arthropods) are important in the stratigraphic subdivision of the period.

Cambrian Welsh. XVII (preceded by Camber XVI). f. Cambria, var. of Cumbria, latinization of W. Cymru Wales :- OCelt. *Kombroges, f. *kom- together, COM- + *brog- border, region; see -IAN.

Cambrian •antipodean, Crimean, Judaean, Korean •Albion •Gambian, Zambian •lesbian •Arabian, Bessarabian, Fabian, gabion, Sabian, Swabian •amphibian, Libyan, Namibian •Sorbian •Danubian, Nubian •Colombian • Serbian • Nietzschean •Chadian, Trinidadian •Andean, Kandyan •guardian •Acadian, Akkadian, Arcadian, Barbadian, Canadian, circadian, Grenadian, Hadean, Orcadian, Palladian, radian, steradian •Archimedean, comedian, epicedian, median, tragedian •ascidian, Derridean, Dravidian, enchiridion, Euclidean, Floridian, Gideon, Lydian, meridian, Numidian, obsidian, Pisidian, quotidian, viridian •Amerindian, Indian •accordion, Edwardian •Cambodian, collodion, custodian, melodeon, nickelodeon, Odeon •Freudian • Bermudian • Burundian •Burgundian •Falstaffian, Halafian •Christadelphian, Delphian, Philadelphian •nymphean • ruffian • Brobdingnagian •Carolingian • Swedenborgian •logion, Muskogean •Jungian •magian, Pelagian •collegian •callipygian, Cantabrigian, Phrygian, Stygian •Merovingian • philologian • Fujian •Czechoslovakian • Pickwickian •Algonquian • Chomskian •Kentuckian •battalion, galleon, medallion, rapscallion, scallion •Anglian, ganglion •Heraklion •Dalian, Malian, Somalian •Chellean, Machiavellian, Orwellian, Sabellian, Trevelyan, triskelion •Wesleyan •alien, Australian, bacchanalian, Castalian, Deucalion, episcopalian, Hegelian, madrigalian, mammalian, Pygmalion, Salian, saturnalian, sesquipedalian, tatterdemalion, Thessalian, Westphalian •anthelion, Aristotelian, Aurelian, carnelian, chameleon, Karelian, Mendelian, Mephistophelian, Pelion, Sahelian •Abbevillian, Azilian, Brazilian, caecilian, Castilian, Chilean, Churchillian, civilian, cotillion, crocodilian, epyllion, Gillian, Lilian, Maximilian, Pamphylian, pavilion, postilion, Quintilian, reptilian, Sicilian, Tamilian, vaudevillian, vermilion, Virgilian •Aeolian, Anatolian, Eolian, Jolyon, Mongolian, napoleon, simoleon •Acheulian, Boolean, cerulean, Friulian, Julian, Julien •bullion •mullion, scullion, Tertullian •Liverpudlian •Bahamian, Bamian, Damian, Mesopotamian, Samian •anthemion, Bohemian •Endymion, prosimian, Simeon, simian •isthmian • antinomian •Permian, vermian •Oceanian •Albanian, Azanian, Iranian, Jordanian, Lithuanian, Mauritanian, Mediterranean, Panamanian, Pennsylvanian, Pomeranian, Romanian, Ruritanian, Sassanian, subterranean, Tasmanian, Transylvanian, Tripolitanian, Turanian, Ukrainian, Vulcanian •Armenian, Athenian, Fenian, Magdalenian, Mycenaean (US Mycenean), Slovenian, Tyrrhenian •Argentinian, Arminian, Augustinian, Carthaginian, Darwinian, dominion, Guinean, Justinian, Ninian, Palestinian, Sardinian, Virginian •epilimnion, hypolimnion •Bosnian •Bornean, Californian, Capricornian •Aberdonian, Amazonian, Apollonian, Babylonian, Baconian, Bostonian, Caledonian, Catalonian, Chalcedonian, Ciceronian, Devonian, draconian, Estonian, Etonian, gorgonian, Ionian, Johnsonian, Laconian, Macedonian, Miltonian, Newtonian, Oregonian, Oxonian, Patagonian, Plutonian, Tennysonian, Tobagonian, Washingtonian •Cameroonian, communion, Mancunian, Neptunian, Réunion, union •Hibernian, Saturnian •Campion, champion, Grampian, rampion, tampion •thespian • Mississippian • Olympian •Crispian •Scorpian, scorpion •cornucopian, dystopian, Ethiopian, Salopian, subtopian, Utopian •Guadeloupian •Carian, carrion, clarion, Marian •Calabrian, Cantabrian •Cambrian • Bactrian •Lancastrian, Zoroastrian •Alexandrian • Maharashtrian •equestrian, pedestrian •agrarian, antiquarian, apiarian, Aquarian, Arian, Aryan, authoritarian, barbarian, Bavarian, Bulgarian, Caesarean (US Cesarean), centenarian, communitarian, contrarian, Darien, disciplinarian, egalitarian, equalitarian, establishmentarian, fruitarian, Gibraltarian, grammarian, Hanoverian, humanitarian, Hungarian, latitudinarian, libertarian, librarian, majoritarian, millenarian, necessarian, necessitarian, nonagenarian, octogenarian, ovarian, Parian, parliamentarian, planarian, predestinarian, prelapsarian, proletarian, quadragenarian, quinquagenarian, quodlibetarian, Rastafarian, riparian, rosarian, Rotarian, sabbatarian, Sagittarian, sanitarian, Sauveterrian, sectarian, seminarian, septuagenarian, sexagenarian, topiarian, totalitarian, Trinitarian, ubiquitarian, Unitarian, utilitarian, valetudinarian, vegetarian, veterinarian, vulgarian •Adrian, Hadrian •Assyrian, Illyrian, Syrian, Tyrian •morion • Austrian •Dorian, Ecuadorean, historian, Hyperborean, Nestorian, oratorian, praetorian (US pretorian), salutatorian, Salvadorean, Singaporean, stentorian, Taurean, valedictorian, Victorian •Ugrian • Zarathustrian •Cumbrian, Northumbrian, Umbrian •Algerian, Cancerian, Chaucerian, Cimmerian, criterion, Hesperian, Hitlerian, Hyperion, Iberian, Liberian, Nigerian, Presbyterian, Shakespearean, Siberian, Spenserian, Sumerian, valerian, Wagnerian, Zairean •Arthurian, Ben-Gurion, centurion, durian, holothurian, Khachaturian, Ligurian, Missourian, Silurian, tellurian •Circassian, Parnassian •halcyon • Capsian • Hessian •Albigensian, Waldensian •Dacian • Keatsian •Cilician, Galician, Lycian, Mysian, Odyssean •Leibnizian • Piscean • Ossian •Gaussian • Joycean • Andalusian •Mercian • Appalachian • Decian •Ordovician, Priscian •Lucian •himation, Montserratian •Atlantean, Dantean, Kantian •bastion, Erastian, Sebastian •Mozartian • Brechtian • Thyestean •Fortean • Faustian • protean •Djiboutian •fustian, Procrustean •Gilbertian, Goethean, nemertean •pantheon •Hogarthian, Parthian •Lethean, Promethean •Pythian • Corinthian • Scythian •Lothian, Midlothian •Latvian • Yugoslavian •avian, Batavian, Flavian, Moldavian, Moravian, Octavian, Scandinavian, Shavian •Bolivian, Maldivian, oblivion, Vivian •Chekhovian, Harrovian, Jovian, Pavlovian •alluvion, antediluvian, diluvian, Peruvian •Servian • Malawian • Zimbabwean •Abkhazian • Dickensian •Caucasian, Malaysian, Rabelaisian •Keynesian •Belizean, Cartesian, Indonesian, Milesian, Salesian, Silesian •Elysian, Frisian, Parisian, Tunisian •Holmesian •Carthusian, Malthusian, Venusian