THE PHANEROZOIC TIME SCALE 543 Phanerozoic period •Fossils with recognisable affinities with forms of present. •Evolution of animal shell •Increases Paleobiological record •Secreted calcium carbonate, calcium phosphate and silica •Remains deposited as sediment •Geologically known period •All major animal phyla and vascular plants quickly established •Evolution of atmosphere at near its present levels of oxygen • Paleozoic eratem Lasted nearly 300 milion years Lower Paleozoic – Cambrian – Devonian, Upper Paleozoic – Carboniferous-Permina Some authors Lower, Middle, Upper Paleozoic Paleozoický eratem je součást fanerozoika tvořeného ještě mesozoickým a kenozoickým eratemem. Má rozpětí zhruba 300 milionů let a je nejdelším ve fanerozoiku. Dělí se na 6 útvarů, z nichž první čtyři jsou někdy označovány jako starší (spodní) paleozoikum a poslední dva jako mladší (svrchní) paleozoikum. Původně jednotný superkontinent Rodinia se začal rozpadat již během nejvyššího proterozoika a jeho rozpadání pokračovalo i v nejspodnějším paleozoiku. Na počátku paleozoika můžeme ještě sledovat doznívání kadomské (assyntské) orogeneze. Kolize kontinentů v paleozoiku měla za následek kaledonskou (spodní paleozoikum - uzavírání Japetu) a variskou (především svrchní paleozoikum - uzavírání Paleotethydy) orogenezi, která byla ukončena opětovným vznikem nového superkontinentu Pangei. Paleozoikum se na rozdíl od prekambria vyznačuje bohatým rozvojem fauny a flóry. V kambriu se explozívně objevují zástupci všech dnes známých živočišných kmenů. Ve vývoji živočichů patří k charakteristickým znakům paleozoika zejména vývoj trilobitů (maximum v kambriu a ordoviku), velké rozšíření brachiopodů, bohatý rozvoj tabulátních a rugózních korálů a stromatoporoideí (hlavně silur a devon), bohatý rozvoj nautiloidních hlavonožců (od ordoviku) a ammonoidních hlavonožců) od devonu, radiace ryb (od siluru), celosvětové rozšíření obojživelníků (karbon) a plazů (perm). Vývoj paleozoické fauny byl ukončen zatím největším známým vymíráním na hranici paleozoika a mesozoika. Osídlení pevnin vyššími cevnatými rostlinami můžeme sledovat až od siluru. V devonu se již objevuje v klimaticky příznivých podmínkách relativně souvislý rostlinný pokryv. Explozivní rozvoj a velké rozšíření výtrusných rostlin ve svrchním paleozoiku umožnilo vznik ložisek černého uhlí. V nejvyšším paleozoiku (svrchní perm) můžeme sledovat výraznou změnu ve složení flóry - výtrusné rostliny ustupují rychle se rozvíjejícím nahosemenným (hranice paleofytikum-mesofytikum). Historical Geology The Cambrian Fauna Trilobites •Phylum: Arthropoda •Class: Trilobita •Species: >600 Olenellus thompsoni Dikelocephalus minnesotensis Paradoxides harlani Paleozoic fauna In Cambrian representatives of all animal phyla Great development of trilobites (Cambrian-Ordovician), high representtaion of brachiopods, nautiloid and ammonoid cephalopods. Rugose and tabulate corals (Silurian, Devonian), radiation of fishes (since Devonian), Amphibians (Carboniferous), reptiles (Permian). Biggest mass extinction at the end, smaller at the end of Ordovician and Devonian. Paleozoic flora LAND FLORA SINCE ordovician, Silurian – vascular plants, larger representation and continuous cover in Devonian. Explosive development of spore plants in Carboniferous – coal. Boundary between Paleophyticum and Mesophyticum In middle Permian Era Breakdown chart Largest mass extinction First winged insects First reptiles First land vertebrates First seed plants First insects First jawed fish First land plants First vertebrates “Cambrian Explosion” of skeletal animals PERMIAN PENNSYLVANIAN MISSISSIPPIAN DEVONIAN SILURIAN ORDOVICIAN CAMBRIAN 245 290 325 360 410 440 500 540 PALEOZOIC ORDOVICIAN CAMBRIAN SILURIAN DEVONIAN CARBONIFEROUS PERMIAN tetrapods dinosaurs Early Paleozoic: Age of Invertebrates Coelomate radiation (Cambrian explosion) - origin of major groups of organisms; nervous system, behavior patterns and simple consciousness (the nascent Noosphere); continents drift apart. Middle Paleozoic: Age of Fish Tropical conditions. Extinction of many "experimental" animal groups; diversification of surviving invertebrate groups, rise of vertebrates (fish). Life moves on land (rhyniophytes, lycopods, uniramious arthropods, proto-amphibians) Late Paleozoic: Age of Tetrapods* and Reptiles Ice age. Coal forests of giant lycopods, calamites, pteridophytes and ferns cover the tropical landmasses. Southern landmass of Gondwanaland buried under glaciers; continents drift together. Reptiles conquer the land. Paleozoic era trilobite placoderm Pelycosaur Of the three main eras that make up the Phanerozoic, the Paleozoic is the longest and most diverse, spanning the period from very early multicellular life that only inhabited the oceans to quite advanced tetrapods* and reptiles and extensive forests on land. The Age of Ancient Life - Paleozoic Paleozoic Early Paleozoic Reg_Ordovician Z hlediska vývoje fauny můžeme ve spodním paleozoiku roslišit kambrickou faunu, kde dominovali členovci a více diversifikovanou faunu ordoviku-devonu, kdy došlo k většímu zastoupení a rozrůznění dalších živočišných kmenů jako jsou mechovky, brachiopodi, měkkýši (hlavně hlavonožci), ostnokožci, strunatci, láčkovci (korály) a houby(zejména stromatoporoidea). Early Paleozoic Two types of distinct evolutionary fauna – Cambrian and Ordovician to Devonian INVERTEBRATES •In Cambrian –trilobites - now gone - 60% of Cambrian fossils –brachiopods - rare now - 30% of Cambrian Paleozoic fauna Cambrian Lower Middle Upper Olenellus Paradoxides Olenus V kambriu byla největším kontinentem Gondwana protínaná rovníkem a tvořená prekambricky konsolidovaným jihoamerickým, africkým, indickým, arabským, australským a antarktickým kratonem, Arábií a jižní Evropou a čínskými kontinenty, které zasahovaly do nižších zeměpisných šířek. V nízkých zeměpisných šířkách se nacházely kontinent laurentský, sibiřský a kazašský. Baltika ve vyšších zeměpisných šířkách jižní polokoule. Rozsah kambrické teplé klimatické zóny dokumentují archeocyátové vápence, ložiska evaporitů a facie červených pískovců zjištěné na území Kanady, Indie a Austrálie. Zatímco na počátku kambria ležely kontinenty ještě blízko sebe, během kambria docházelo k jejich rychlému vzdalování. Paleogeography 514.jpg (130509 bytes) Paleogeography – disintegration of Rodinia. Biggest continent - Gondwana The Cambrian Period is the first period of the Paleozoic Era. It was named in 1835 by the geologist Adam Sedqwick, after the region of Cambria in North Wales, where rocks of this age were first found. The name "Cambria" is a version of Cumbria, a latinisation the Welsh Cymry (= countryman, compatriot against the (invading) Anglo-Saxons). Accordingly, the International Subcommission on Cambrian Stratigraphy (through its Working Group on the Precambrian-Cambrian Boundary) made the official decision in 1991 to draw the base on the Cambrian at the first appearence date (FAD) of Trichophycus pedum (formerly known as "Phycodes pedum"). in the reference section at Fortune Head. southeastern Newfoundland, which belonged to the Cambrian continent Avalonia n02 Phycodes Trichophycus pedum (28472 bytes) The horizontal burrow trace fossil, Trichophycus (formerly Phycodes) pedum defines the lower boundary of the Cambrian in the reference section at Fortune Head, southeastern Newfoundland. It has been suggested that newly evolved, burrowing organisms like this may have closed the taphonomic door on the peculiar ‘Ediacaran preservation’. [Image courtesy of Dr. Gerd Geyer The top of the Cambrian The Cambrian-Ordovician Boundary Working Group finally decided in 1998 by majority that the base of the Ordovician should be placed at the base of the conodont zone with Iapetognathus fluctivagus, The GSSP for this boundary was chosen at the Green Point section, Newfoundland. chron-1 Geochronological framework Latest Proterozoic and base of the Cambrian 595±15 m.y. mid-Dahai Mb., Meishucun, South China (Rb-Sr whole rock age; Zhang et al., 1984) 575±7.6 m.y. volcanics, Carolina Slate Belt, eastern United States (U-Pb age, Kozuch et al., 198) 550±26 m.y. volcanics, Puncoviscana Foldbelt, northwestern Argentina (K-Ar age, Omarini et al., 1996) 551.4±5.8 m.y. rhyolite flow, Mooring Cove Fm., Fortune Bay, Nfld. (isotope dilution U-Pb age; Tucker and McKerrow, 1995) 543.6±0.24 m.y. volcanic breccias, Lessyusa Fm., Nemakit-Dal'dyn Stage, Khorbusuonka, Olenek uplift, Siberia (U-Pb zircon age; Bowring et al., 1993) 535±7 m.y. granitoids, Puncoviscana Foldbelt, northwestern Argentina (U-Pb age, Bachmann et al., 1987) 534.6±0.4 fluvial conglomerates, between Nemakit-Dal'dyn and Tommotian stages, Kharaulakh Mountains, Siberia (U-Pb zircon age; Bowring et al., 1993) 525±7 m.y., max. 539±34 m.y. K-bentonite, Zhongyicun Mb., Dengying Fm., Meishucun, South China (SHRIMP zircon ages; Compston et al., 1992) Cambrian Life •Base of the Cambrian is easy to spot in most places - set at the place where you first get shelled fossils •There were a few Precambrian shelled species, but the “Cambrian Explosion” produced many more •All phyla with hard parts (except Bryozoa) began in Cambrian, and many without hard parts too. EARLY PALEOZOIC LIFE Cambrian Explosion Evolution’s “big bang” lasted about 10 million years All principal animal phyla except Bryozoa appeared between 535 to 520 myBP The Cambrian Explosion Historical Geology Cambrian Life The Cambrian Explosion Origin of skeletons (shells) Function: 1.Support for muscles, etc. 2.Protection against environment & other organisms, predators 3.Aid in locomotion 4. Possible reasons for the advent of skeletonization: Increasing oxygen levels Evidence: modern low O2 environments have only small, soft-bodied forms. The abundant shelly fauna – beginning of the Cambrian Cambrian Timeline The typical small shelly fossils (SSFs, or early shelly fossils, ESFs) are tiny (generally 1 to 5 mm) tubes, spines, cones and plates that are not clearly allied with modern groups. Many of these organisms were recognized either as of unknown affinity or as representatives or groups that became extinct before the end of the Cambrian. Frequent phosphatic skeletons. Known as the "Tommotian fauna." Cambrian Marine Community •Many body plans and experiments are observed in Cambrian fossils, more than in any other period –trilobites - benthonic mobile sediment-deposit feeders that crawled or swam across the sea floor –brachiopods - primitive benthonic sessile suspension feeders –archaeocyathids - benthonic sessile suspension feeders and reef builders Archaeocyathids, an extinct group of sponges benthonic sessile suspension feeders constructed reeflike structures Archeocyathids (“ancient cup”) archaeocyatha archaeocyathids2 archaeocyathid archaeocyathids •Reef builders: archaeocyathid sponges (in Early Cambrian only: almost no Middle or Late Cambrian reefs) n27 Thin section of archaeocyath "bioherm" showing cross-sections of archaeocyaths and intergrowing calcimicrobes. Lower Cambrian Lemdad Formation, Lemdad syncline, High Atlas, Morocco ARCHCYTH.jpg (109192 bytes) Archaeocrack Archaeocyaths are an extinct group of sponges that had a very brief (geologically speaking) and spectacular history. The first archaeocyaths appear roughly 530 million years ago, during the Lower Cambrian. Archaeocyath species were very important members of Lower Cambrian communities. They diversified into hundreds of species during this time period and some of these species contributed greatly to the creation of the first reefs. Reef ecosystems tend to support a wide variety of organisms both in the present and in the past. Despite their great success in terms of numbers, the archaeocyaths were a short-lived group. They were almost completely non-existent by the middle Cambrian, some 10 to 15 million years after their first appearance. Early Cambrian reef Reconstruction of an Early Cambrian reef community (from 97). 1. Renalcis (calcified cyanobacterium); 2: branching archaeocyath sponges; 3: solitary cup-shaped archaeocyath sponges; 4: chancellorid (?sponge); 5: radiocyath (?sponge); 6: small, solitary archaeocyath sponges; 7: cryptic "coralomorphs"; 8: Okulitchicyathus (archaeocyath sponge); 9; early fibrous cement forming within crypts; 10: microburrows (traces of a deposit-feeder) within geopetal sediment; 11: cryptic archaeocyaths and coralomorphs; 12: cryptic cribricyaths (problematic, attached skeletal tubes); 13: trilobite trackway; 14: cement botryoid; 15: sediment with skeletal debris. •Brachiopods: •Two-shelled filter feeders •Dominant groups in Cambrian are “inarticulates”: linguates (infaunal forms with calcium phosphate shells) and craniids epifaunal forms with calcite shells) •Articulate brachiopods (epifaunal with calcite shells) are present but rare BC001p Lingulella ampla Período: Cámbrico superior Localización: Eau Claire Form. Colfax. Wisconsin. USA. bohrom Bohemiella roemingeri •Most conspicuous element of the Cambrian marine invertebrate community –about half of the total fauna –nectobenthonic –mobile –sediment-deposit feeders •Appeared in the Early Cambrian and rapidly diversified –reached their maximum diversity in the Late Cambrian –mass extinctions near the end of the Cambrian, never fully recovered Trilobites •Trilobites: •Group of arthropod found only in Paleozoic •EXTREMELY common in Cambrian and Ordovician; still common but lower diversity in rest of Paleozoic •Benthic epifaunal detritovores (backwards facing mouth). •Known from many growth stages, thousands of species, trace fossils, etc. •The main index fossils of the Cambrian. Historical Geology The Cambrian Fauna Trilobites •Phylum: Arthropoda •Class: Trilobita •Species: >600 Olenellus thompsoni Dikelocephalus minnesotensis Paradoxides harlani • Ptychoparia striata #252 Middle Cambrian, 530 million years old Jince, Czech Republic 252ptychoparia.jpg (12005 bytes) Olenellus fowleri, Lower Cambrian, Pioche Formation, Lincoln County, Nevada Olenellus fowleri (31379 bytes) Hydrocephalus minor Middle Cambrian, 530 million years old Jince, Czech Republic Paradoxides gracilis Middle Cambrian, 530 million years old Jince, Czech Republic 280newparadox.jpg (11400 bytes) 006 Hydrocephalus.JPG (13272 bytes) ellipso2 Ellipsocephalus hoffi eh3 1 Eccaparadoxides M. Cambrian Location: France 253conoco.jpg (11184 bytes) Conocoryphe sulzeri #253 Middle Cambrian, 530 million years old Jince, Czech Republic 350saohirsuta.jpg (12203 bytes) Sao hirsuta, Middle Cambrian, Skryje sh Sao hirsuta cs Conocoryphe sulzeri F0403 Olenus •Wounds to the body of the trilobite Olenellus robsonensis –wounds have healed, demonstrating that they occurred when the animal was alive and were not inflicted on an empty shell Wounded Trilobite WICHG31202b Hyoliths (extinct forms thought to be related to mollusks), Bivalves – mainly Polyplacophors, monoplacophors Molluscs Mopalia lignosa Lives between the high and low tides and can be found on the undersides of rocks. Occasionally found on pilings and floating docks. EARLY PALEOZOIC LIFE Metazoan Invertebrates Mollusca Chitons •Ancestor is flattened, elongated •Mantle and shell dominate head, foot •Mantle produces shell in 8 plates •Radula scrapes encrusting vegetation Late Cambrian to Recent chitons2 chiton monoplacophora Phylum Echinodermata Subphylum Blastozoa ..........Class Eocrinoidea (Cambrian - Silurian, 30-32 genera) Subphylum Crinozoa ..........Class Crinoidea - sea lilies (Cambrian? Early Ordovician - Recent, 1005 genera) Subphylum Echinozoa ..........Class Echinoidea (Sea Urchins) (Ordovician - Recent, 765 genera) ..........Class Edrioasteroidea (terčovci) (Early Cambrian) - Carboniferous, 35 genera) ..........Class Helicoplacoidea (Cambrian, 3 genera) Echinoderms Most eocrinoids were sessile and fed with their long brachioles (the arm-like structures, which in this specimen are spirally twisted). • The body was covered by plates; in early eocrinoids the holdfast was also covered by plates, but later eocrinoids evolved a stalk with columnals, like crinoids and blastoids. Gogia from the Middle Cambrian House Range of Utah. Eocrinoidea • Eocrinoids are among the earliest groups of echinoderms to appear, ranging from the Early Cambrian to the Silurian. Helicoplacoids • The Helicoplacoidea is a small group of fossil echinoderms known only from the Lower Cambrian. • In life, they were shaped somwhat like a slender football or a fat cigar, and were able to extend or contract the length of their bodies. • Their "skin" was covered in spirals of overlapping ossicles that functioned like armor; their "mouth" was a long groove that also spiralled around their body. • It is thought that helicoplacoids lived in burrows, extending their bodies outward to feed. • The helicoplacoids are among the oldest groups of echinoderms to appear in the fossil record, along with eocrinoids Echinoderms cont. Fossil of Helicoplacus from the Lower Cambrian strata of the White Mountains in California Cambrian Echinoderms Helioplacus Helicoplacoidea are known only from the early Cambrian of western North America, Graptolites range from the middle Cambrian to the Carboniferous. Dendroidea are found across this entire span while Graptoloida are found from the Ordovician until the earlyDevonian. Graptolites are most commonly found in deep water, dysoxic facies (black shales), but do extend into shallow facies. Because they did not biomineralize an easily preservable skeleton they are nearly always carbonized. The process of carbonization combined with the highly compressible nature of shales made most graptolite fossils extremely flat and therefore difficult to study. Graptolites caplangrap27 caplangrap21 haplo_wis Haplograptus wisconsinensis Cambrian, Wisconsin, U.S.A. Holotype. Burgess Shale type fauna Burgess Pass – middle Cambrian Chengjiang fauna – early Cambrian The fauna is composed of a range of soft bodied organisms; creatures with hard, mineralised skeletons are rare, although trilobites are quite commonly found. The major soft-bodied groups are arthropods, sponges, worms Burgess Animals Arthropoda Anomolacaris Canadaspis Marrella Sanctacaris Opabinia Yohoia Burgess Animals Chordata Annelida Onychophora Hallucigenia Aysheaia Pikaia Canadia Marella EARLY PALEOZOIC LIFE THE BURGESS SHALE Animals With Shells Marrella (crustacean) most common Burgess Shale fossil burgess burgess Burgess1 Mid Cambrian scene, a reconstruction of the famous Burgess Shale lagerstätten of what is now British Columbia. In the foreground a swimming Laggania cambria has captured a hapless trilobite. On the sea floor from left to centre respectively are a solitary specimen of the proto-annelid Wiwaxia and three specimens of the lobopod Hallucigenia. Note in both animals the defensive array of spines. Further to the right is the lobopodian Aysheaia with its anterior prongs around the mouth, as well as the protoarthropod Opabina, a close relative of Laggania Descending to the sea floor are two individuals of the basal arachnomorph Marrella. Also visible in this scene are sessile epifauna in the form of the deuterostome lophophorate Dinomischus (yellow) and the Hexactinellid sponge Vauxia (blue). Chordates pikaia Pikaia tu_94 Early Cambrian (about 530 million years ago) This is oldest known example of a cephalochordate. The form of Cathaymyrus resembles that of Pikaia from the Middle Cambrian Burgess Shale of Canada, but this animal is about 10 million years older. Some palaeontologists have suggested that the vertebrates, which include humans, evolved from cephalochordates like Cathaymyrus cathaymyrus Cathaymyrus diadexus Early Cambrian (about 530 million years ago) Vertebrates originated about 525 million years ago during the Cambrian explosion, which saw the rise in organism diversity. The earliest known vertebrate is believed to be the Myllokunmingia.[1] Another early vertebrate is Haikouichthys ercaicunensis. Unlike the other fauna that dominated the Cambrian, these groups had the basic vertebrate body plan: a notochord, rudimentary vertebrae, and a well-defined head and tail.[17] All of these early vertebrates lacked jaws in the common sense and relied on filter feeding close to the seabed.[18] A vertebrate group of uncertain phylogeny, small-eel-like conodonts, are known from microfossils of their paired tooth segments from the late Cambrian to the end of the Triassic Vertebrata File:Haikouichthys 3d.png Haikouichthys ercaicunensis AGNATHA (jawless “fish”): •Cambrian vertebrates known from bony plates and impressions of lamprey-like forms from Chengjiang. AGNATHA (Ostracoderms) - Upper Cambrian of Wyoming CONODONTS •conodonts are small tooth shaped structures –have been found in fossil record for many years –important biostratigraphically –made of phosphate (like most vertebrate bones) –Ordovician conodont over 1 foot long (1995) –probably a predator in Chordata Conodonta1 •Conodonta (appear in Late Cambrian): •A group of chordates, very likely craniates, and possibly even vertebrates •Known almost exclusively from their hard (calcium phosphate) tooth-like elements •Soft tissue preservation allows us to see that they had flattened elongate “eel-like” bodies •Were probably fast swimming micropredators Cambrian - Triassic File:Fish evolution.png File:Evolution of jawless fish.png Fig. 6. Hypothesis of relationships among chordates that is primarily based on refs. 27 and 30. Evidence from molecular data supports monophyly of cyclostomes and shows that the closest relatives of vertebrates are the tunicates, not the cephalochordates (31). The relationships among euconodonts are derived from ref. 32. Blue circles indicate the presence of a lingual cartilage. Cambrian Timeline Cambrian Tectonics (NA) and Climate •Break-up of Rodinia and Pannotia •Passive-margin seds from Newfoundland to AL—Iapetus Ocean (Cambrian to Middle Ordovician) 514.jpg (130509 bytes) Generally temperate climate; no evidence of large glaciers Y520_zonef.jpg (64115 bytes) Cambrian faunal guilds se2597621002.jpg (181132 bytes) The Cambrian plankton was more abundant and diverse than that of the Precambrian oceans. The acritarchs radiated during the Cambrian, radiolarians occupied tropical latitudes, whereas chitinozoans were present in Cambrian plankton but not abundant. Larval phases of benthic organisms together with the agnostic trilobites (illustration above) dominated a zooplankton still apparently free of macrophagous predators.