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Paleozoic Life. Life forms in the Paleozoic. The paleozoic begins with the appearance of fossils of marine animals. For the first time, ocean animals that have easily fossilized hard parts. - PowerPoint PPT Presentation
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Paleozoic LifePaleozoic Life
Life forms in the PaleozoicLife forms in the Paleozoic• The paleozoic begins with the appearance of fossils of
marine animals. For the first time, ocean animals that have easily fossilized hard parts.
• The paleozoic contains the history of animal and plant diversification in the oceans and colonization of land
Crinoids
Important Paleozoic InvertebratesImportant Paleozoic Invertebrates
• First we will examine the anatomical plans of Trilobites, Brachiopods, Molluscs (clams, snails and cephalopods), Echinoderms (starfish, sea urchins and especially crinoids), and Graptolites.
• Later we will look at corals and sponges
Trilobite shell morphologyTrilobite shell morphologyArthropod – “jointed-leg”
Related to Horseshoe crabsWhat other arthropods do you know of?
Varied niche, predators, scavengers or filter feeders. Some swam, feeding on plankton
Brachiopod morphologyBrachiopod morphology
Sessile benthic filter feeders related to bryozoans
Articulate BrachiopodsArticulate BrachiopodsBrachiopod life positions 1Brachiopod life positions 1
Brachiopods sort of look like a clam. However, notice that each valve is symmetrical about its middle line.
Brachiopod life positions 2 Brachiopod life positions 2 Inarticulate Brachiopod Inarticulate Brachiopod
Lingula Infaunal sessile benthic filter feeders intertidal
Bivalve morphologyBivalve morphology
Clams, Scallops Individual valve is not symmetrical about a middle line
Gastropod (snail) shapesGastropod (snail) shapes
Cephalopod shell morphologyCephalopod shell morphology
Crinoid morphologyCrinoid morphology
Stalked Stalked echinoderm echinoderm related to related to
starfishes, sea starfishes, sea urchins, etcurchins, etc
GraptolitesGraptolitesRelated to ??? Often found in black shales, deep shelf waters, no other fossils
Great index fossils
What was the What was the Cambrian Cambrian ExplosionExplosion??
• The Paleozoic is marked by the abrupt appearance of animals with skeletons in the rock record– a mechanism that would trigger this event is not
agreed upon, but is surely due to a combination of geologic and biologic factors
– Predators prominent – shallow water, animals must be protected from UV.
The Emergence of The Emergence of Shelly FaunaShelly Fauna
• Organisms with hard parts have many advantages– protection against UV rays, allowing animals to
move into shallower water– helps prevent drying out in an intertidal environment– provides protection against predators
Small shelly faunaSmall shelly faunaPhotos
Drawings
Late Proterozoic (Ediacaran) to Early Cambria, before trilobites.
A. Mollusk B. Sponge
Cambrian Marine CommunityCambrian Marine Community
• Many body plans are observed in Cambrian fossils, more than in any other period– trilobites – many niches, e.g. 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
Trilobites
Sponges
BrachiopodsNote how the valves have symmetry
Crinoids
Invertebrates with hard parts
The Burgess Shale BiotaThe Burgess Shale Biota• Consists of a rare preservation of soft-bodied organisms – Mid Cambrian
– Some phyla near the basic stock from which some present-day invertebrates have evolved
– Other unique and without issue– current debate centers around how many phyla arose and how many extinction
events took place in the Cambrian
Charles Walcott’s Burgess Shale
-middle Cambrian shale in the Rockies of western Canada
PikaiaA chordate!!! Sidneyia
Hallucigenia
AnomalocarisA huge predaor
Remarkable preservation of animals’ soft tissues, plus the first predator, Anomalocaris
Modern Brine Shrimp Modern Brine Shrimp Artemia salinaArtemia salinaSimilar swimming mode to Anomalocaris?
AnomalocarisA huge predaor
Anomalocaris and some known prey.Bite marks on fossils
Marella, a trilobitomorphor “Lace Crab”
Leanchoilia--China
Leanchoilia--Burgess
Opabina
Interpreting Interpreting HallucigeniaHallucigenia
Like the modern Peripatus, moist forests of Cameroon, Discussion: preadaptations to land if food is present
PikaiaPikaia
Pikaia – an early chordate! from the Burgess Shale
Totally unexpected find. Cartilage but no bone.Jawless ancestor to fish, and us.Maori legend of Pikea, the ancestor.Lancelets in comparative anatomy
Link to lancelet info
Paradoxides bohemicus Barrande
YPM 72949 Cambrian, Etage C. Koneprussy, Bohemia, Czechoslovakia.
Cambrian Trilobites
Archaeocyathids (sponges?)Archaeocyathids (sponges?)
Ordovician Marine CommunityOrdovician Marine Community• Vast epeiric seas
opened new marine habitats– bryozoans,
stromatoporoids, tabulate and rugose coral reef builders
– reefs with high diversity - suspension feeders
– massive extinctions end Ordovician, glaciation in Gondwana & falling sea-level
Note large OrthocerasA Cephalopod Mollusk
Cephalopods as Index Fossils
BryozoansBryozoans• Possibly related to Brachiopods
•“Moss Animals”
•Filter Feeders
•Mostly marine tropical
•Make hard exoskeleton, chitin or CaCO3
BryozoansBryozoans
In fossils, just the exoskeleton is preserved
Halysites Tabulate Coral O-SHalysites Tabulate Coral O-S
Stromatoporoid - Hydrozoan coral Stromatoporoid - Hydrozoan coral or Sponge? or Sponge? CC - K - K-
http://www.yale.edu/ypmip/Didymograptus denticulatus Berry
YPM 20252 Early Ordovician, Marathon Ls. Didymograptus bifidus zone, upper Marathon, 14.5 ft below Marathon top, section XVIII, bed of Alsate Creek, 3 mi W of Picnic Picnic Grounds & 0.1 S54W of Marathon, Brewster Co., Texas, USA. Collector: Berry, W.B.
Graptolite
Silurian and Devonian Marine Silurian and Devonian Marine CommunitiesCommunities
• Rapid diversification and recovery followed the Ordovician mass extinction– reef building by tabulate and
rugose corals– NEW PREDATOR :
Eurypterids were abundant
– Ammonoids evolved quickly and are important as index fossils
– mass extinction at the end of the Devonian collapsed the massive reefs
Marine “Scorpions”Track ways in coastal sandsProbably laid eggs as horseshoe crabs doalong the foreshore
Pterygotus
Rugose Corals – individual animalsRugose Corals – individual animals
Field Trip, Stroudsburg, PA
Devonian Tabulate CoralsDevonian Tabulate Corals
Favosites conicus Hall YPM 7115 Early Devonian, Oriskany Sandstone. Loc. C6644, Cumberland, Allegany Co., Maryland, USA. Collector: Gordon, R.H. & Hartley, F.
Colonial
Leptaena rhomboidalis (Wilkens) YPM 19154 Early Devonian, Helderberg Grp, New Scotland Ls. Lower Helderberg, Indian Ladder, Thatcher State Park, near New Salem, Albany Co., New York, USA. Collector: Beecher, C.E.
Brachiopod
Phacops rana (Green)
YPM 6593 Middle Devonian, Hamilton Grp. Eighteen Mile Creek, Erie Co., New York, USA. Collector: Beecher, C.E.
Carboniferous and Permian Carboniferous and Permian Marine CommunitiesMarine Communities
• Renewed diversity and recovery with adaptations mark the Late Paleozoic marine communities– bryozoans and crinoids
reach their greatest diversity
– patch reefs replace the massive reefs of the Devonian –TEMPS?
– fusulinid formanifera are important index fossils
Types of Staked Echinoderms 1 Types of Staked Echinoderms 1 CystoidsCystoids
Anomalocystis cornutus Hall YPM 36413 Early Devonian, Helderberg Grp. Lower Helderberg, Jerusalem Hill, Herkimer Co., New York, USA.
Types of Staked Echinoderms 2 Types of Staked Echinoderms 2 BlastoidsBlastoids
Pentremites sulcatus
YPM 36130 Pennsylvanian, Gaptank Fm. Unit 7 (27 ft thick), Section 32, 1.25 mi S60W of the Brooks Ranch House, Glass Mountains, Pecos Co., Texas, USA. Collector: Ross, C.A.
Barycrinus hoveyi (Hall) YPM 34788 Early Mississippian, Edwardsville Fm. Crawfordsville, Montgomery Co., Indiana, USA. Collector: Bassett, D.A. 1888.
Types of Staked EchinodermsTypes of Staked Echinoderms 3 - Crinoids
Fragments on Field TripStroudsburg PA
Vertebrate EvolutionVertebrate Evolution• Chordates have, during at least part of their
life, a notochord, dorsal hollow nerve chord, and gill slits– Vertebrates have backbones and are a sub-
phylum of chordates– ancestors were soft-bodied and left few fossils– a close relationship exists between echinoderms
and chordates and they may have shared a common ancestor
FishFish• Fish range from the Late Cambrian to
the present and consist of five classes• Ostracoderms• Placoderms• Acanthodians • Cartilaginous fish – sharks and rays• Bony fish
Classes of fish through timeClasses of fish through time
Ostracoderms- Jawless fishOstracoderms- Jawless fishField TripBony plates in Shf Silurian High Falls at Delaware Water Gap
Evolution of jawsEvolution of jaws
Placoderms – first fish w jawsPlacoderms – first fish w jawsDunkleosteous (Dinichthys) a Devonian arthrodire
PlacodermPlacoderm - Bothryolepis - Bothryolepis
• Today we will examine another Placoderm
• Named Bothryolepis
• It’s armor is similar to that of modern South American catfishes that live in shallow, fast moving, jungle streams in South America
Acanthodian PlacodermAcanthodian Placoderm a more usual body plana more usual body plan
Climatius, a Lower Devonian acanthodian
Cladoselache Cladoselache fylerifyleri, a 3-foot , a 3-foot
shark, was one shark, was one of the top of the top
predators in the predators in the
Devonian seas.Devonian seas.
Cartilagenous fishes: Fossil SharkCartilagenous fishes: Fossil Sharkhttp://www.exhibits.lsa.umich.edu/New/Welcome.html
Ray-finned (Actinopterygians) and Lobe-finned (Sarcopterygians)Ray-finned (Actinopterygians) and Lobe-finned (Sarcopterygians)
Bony Fishes (Osteichthys)
Rhipidistian fishRhipidistian fish
(Crossopterigian)
Similar skulls, teeth,Bones in limbs.
Fish limbs not for walking
Field Trip Catskill fm.Bones of early Amphibians
Hyneria lindaeHyneria lindae from Hyner, PA from Hyner, PAhttp://www.lhup.edu/jway/rdhll/RedHill.htm
Amphibians -Amphibians -Vertebrates Invade the LandVertebrates Invade the Land
• The first vertebrates to live on land, preceded by plants, insects, and snails
• Barriers they had to deal with:– desiccation
– reproduction
– effects of gravity
– extraction of oxygen by lungs rather than gills
Early AmphibianEarly Amphibian
Late Devonian IchthyostegaSkull, teeth, backbone and tail are Rhiphidistian-like
Labyrinthodont amphibianLabyrinthodont amphibian
Eryops, a carnivorous amphibian, named for folds in teeth Pennsylvania to Early Permian
Middle Carboniferous - Evolution of Middle Carboniferous - Evolution of the Reptiles the Reptiles
The Land is ConqueredThe Land is Conquered• The evolution of the
amniote egg freed reptiles from the constraint of returning to water to reproduce– amnion - liquid filled sac
surrounding the embryo
– allantois - waste sac
– a tough shell protects the developing fetus
– reptiles were able to colonize all parts of the land
Evolution of the Reptiles Evolution of the Reptiles
• The earliest reptiles are from the Lower Pennsylvanian– called Captorhinomorphs,
they were small, agile, and probably fed on insects
– success due to advanced egg, more advanced jaws and teeth, and speed
– Later reptiles evolved from this group by Permian
Cool
Warm
Skull structure in reptiles, temporalis muscleSkull structure in reptiles, temporalis muscle
Early Therapsids
Function of Temporal Openings
Eury wideAn not, withoutSyn united, togetherDia double
PelycosaursPelycosaurs
herbivorous Edaphosaurus
carnivorous Dimetrodon
Discussion: Sail function
Thermoregulation
Armor
Courtship
Evolution of the ReptilesEvolution of the Reptiles• Therapsids succeeded the pelycosaurs during the
Permian– mammal-like reptiles that quickly evolved into herbivorous
and carnivorous forms– they displayed fewer bones in the skull, enlargement of the
lower jawbone, differentiation of the teeth, and a more vertical position of their legs
– therapsids may have been endothermic, which may help explain their distribution over wide latitudes
• End Permian extinction eliminated about 66% of all amphibians and reptiles
Late Permian therapsidsLate Permian therapsids
Land Plant Evolution - SilurianLand Plant Evolution - Silurian• Plants had the same water-to-land transition
problems that animals did– vascular land plants have a tissue system to move water– nonvascular plants do not have this system, and are usually
small and live in moist environments– seedless vascular plants such as ferns closely resemble
green algae in their pigmentation, metabolism, and reproductive cycle
– green algae have also been able to make the transition from salt water to fresh water, leading some to believe that modern terrestrial land plants evolved from them
Back to the early Paleozoic to consider plant evolution
Silurian and Devonian FlorasSilurian and Devonian Floras• The earliest land plants earliest land plants are from the Silurian
– small, simple leafless stalks with a spore-producing structure at the tip (Rhynia drawing and modern Psilotum pictured)
– a rhizome (the underground part of the stem) transferred water from the soil to the plant and anchored it
– leaves, roots, and secondary growth all followed during the Devonian
• The evolution of the first seed allowed land plants (“Seed Ferns”) to spread over all parts of the land
LepidodendronLepidodendron L Dev. – P L Dev. – Penn.enn.A lycopod tree 90 – 100 feet tallA lycopod tree 90 – 100 feet tall
An important coal-former
Calamites,Calamites, a huge horsetail rush a huge horsetail rush 10-14 meters tall (Pennsylvanian)10-14 meters tall (Pennsylvanian)
L. Dev – E. Penns. FlorasL. Dev – E. Penns. Floras
• Source of coal• Seedless vascular: Need
moisture to reproduce, vulnerable to insect attack
– Lycopsids to 30m branches at top; leaves similar to palm
– Sphenopsids jointed stem underground rhizomes
• First Seed Ferns Late Devonian West Virginia
seed ferns
Spenopsid (Horsetail Rush) Calamites shown
Lycopsid (club moss) Lepidodendron shown
L. Pennsylvanian – M. Permian L. Pennsylvanian – M. Permian FlorasFloras
• Seed-bearing vascular– Gymnosperm trees -
Cordaites, Glossopteris, and others were able to colonize large areas of land
– many of these became extinct in the Late Permian; those that survived were able to tolerate the warmer and drier climates
Insects and other land arthropodsInsects and other land arthropods
• Have a strong exoskeleton, impervious to water so good for osmoregulation.
• Predation on plant spores probably a strong selective pressure for seed coatings.
Petalia sp. YPM 29867 Late Jurassic, Kimmeridgian, Solnhofen Ls. Solnhofen, Bavaria, West Germany.
Permian Marine Extinction EventPermian Marine Extinction Event
• The greatest recorded mass extinction to affect Earth occurred at the end of the Permian– about 90% of all marine invertebrate species– fusulinids, rugose and tabulate corals, many bryozoan and
brachiopod orders, and trilobites did not survive the end of the Permian
– causes for this have been speculated to be:• reduction in marine shelf as Pangaea formed• global drop in sea level due to glaciation• reduction in marine shelf due to regression• climatic changes
Fusilinids, large forams
Permian Extinctions Permian Extinctions
S. A. Bowring, et. al. (1998) U/Pb Zircon Geochronology and Tempo of the End-Permian Mass Extinction. SCIENCE 280 :1039-1045
• The mass extinction at the end of the Permian was the most profound in the history of life.
• U/Pb zircon data from south China place the Permian-Triassic boundary at 251 mya.
• Strata intercalated with ash beds below the boundary: Changhsingian pulse of the end-Permian extinction (loss of 85 percent of marine species) lasted less than 1 my.
• At Meishan, a negative excursion in 13C at the boundary had a duration of 165,000 years or less, suggesting a catastrophic addition of light carbon. GLOBAL FIRE!
13C13C
• 12C and 13C are stable isotopes of Carbon12C 98.89% 13C 1.11% in today’s atmosphere
Negative excursions mean 13C down or 12C up.
13C13C• Standard carbon in calcite from belemnites Pee
Dee Formation (abbreviated as PDB).• The process of photosynthesis favors the lighter
form of carbon • “If you recall from the above brief discussion of
the soot found in the … clay layer, it appears that a significant portion of the land plants burned; this would have released a great deal of light carbon into the atmosphere”
Extinctions alignedExtinctions aligned
Extinction
Extinction
Extinction
Major mass-extinction eventsMajor mass-extinction events
Supposedly due to glaciationbut it doesn’t line up with low water
Asteroid Impact
Asteroid Impact
Asteroid Impact
Mention 26-30 my cycle of extinctions
Asteroid Impact
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