exam Flashcards
what is actualism
idea that the laws of nature now also applied in the past
What is different about the Carboniferous Trophic Structure
detritivores
occupy the level of
primary consumers
What is Autoecology
studying the ecology of the individual
organism
What is Synecology
studying the interactions between organisms
and their environment
What is an Ecotone
The unique environments that are formed in the transitional
areas between habitats
Is diversity diversity high or low in ecotones
low
What are Marsh foraminifera and why are they important
highly zoned in salt marsh
Salt marshso can reconstruct paleosea level
how deep is the photic zone
~200m but most photosynthesis in top 100m
what is Epifaunal
living on the substrate
What in infaunal
Living in the substrate
what is vagile
capable of locomotion
what is Tiering
verticl ecological structure
what is biocoenosis
the organisms truly lived
together and interacted while alive
what is thanatocoenosis
organisms found together after death and decay
what is taphocoenosis
fossils preserved together in a single horizon/locality
what is the fidelity of an assemblage
How well the death or fossil assemblage matches the
living assemblage
what were the major morphological changes from the Edicarian to the Ordivician
1.Ediacaran Fauna
2. Small Shelly Fauna
3. Cambrian Explosion
4. Great Ordovician biodiversification
5. Nekton Revolution
what is the Ediacaran Biota
The oldest assemblage of large
complex organisms
* Soft body, high surface to
volume ratios, radial or
bilateral symmetry
what was the Ediacaran Ecology
No infaunal, or pelagic -
Life restricted to the seabed
* Few predators, or
scavengers - food chains
were short, dominated by
suspension and deposit
feeders
* There was tiering of the
benthos (evolution of stalks)
what were the Small Shelly Fauna
first evidence of hard skeletonization
* Some thought to be worms, or worm-like
* Some evidence of predation, or scavenging
* likely mobile, and sessile forms
what happened in the Cambrian explosion
- Rapid appearance of new body plans
- Diversification of Bilateria
- increased tiering
- Increase predation, driven by sight
- Increased biomineralization, nutrient availability and
defense
what happened in the Great Ordovician Biodiversification
- No new phyla (except Bryzoa)
extensive radiation, many crown
groups emerge - Evolution of the plankton –
diversification of acritarchs,
development of feeding larvae - Diversification of predators
led to “evolutionary arms race” and increasingly complex food webs
what happened in the Nekton Revolution
evolution of nektonic forms
Primarily cephalopods and fish
Devonian
what is Liebig’s ‘Law of the Minimum’
growth of a plant is dependent on the amount of food stuff which is presented to it in minimum quantity
what is the Law of Limiting Factors
Biological or ecological processes that depend on multiple factors are limited by the slowest factor
what is the Law of Tolerance
An organism success or survival is dependent on a complex set of conditions with maximum, minimums and optimal ranges of environmental factors
Key limiting factors in marine settings are
- Light
- Oxygen levels
- Temperature
- Salinity
- Depth
- Substrate
what is the Carbonate Compensation Depth
Limit on the distribution of organisms with carbonate skeletons (Calcite 4-5km, Aragonite 1-2km)
when did porifer Diverged from other metazoans
700-800mya
What is the most basal metazoan
Porifera - lack differentiated tissues, cellular organization
What are the two major groups of sponges/prorifera
Demospongea (common) Hexactinellida (glass sponges)
what is the body of a sponge made of
spongin
what is the Skeletal structure made of a sponge made of
spicules
calcite or silica
how do sponges feed
- Pump water through their ostia
- Water moved by choanocytes
- Food digested by amoeboid cells
- Water is expelled from spongocel through the osculum
how do sponges reporduce
sexually: spawning
asexually: budding
what is the distribution of sponges
global, feshwater and marine
antartica, abyssal plane
sponge ecology
some can crawl
some carnivores
some trace fossils (clionia)
what is the oldest fossil sponge
~890mya
what do sponges appear in the fossil record
cambrain explosion
what is a Stromatoporoid
extinct type of porifora
Mound or sheet shape with calcareous skeletons
what was the Stromatoporoid Ecology
- shallow marine, carbonate rocks
- components of reef systems in the early Phanerozoic
- Grew together in bioherms, or biostromes
- Often “hosted” epibiont species
what was Stromatoporoid Morphology
- Densely layered calcite skeletons, most with no spicules
- Different morphologies reflected the environment: laminar, domical, bulbous
Upper surface of many have small bumps called mamelons - Branching “canals” leading to radiating cracks on the upper
surface called astrorhizae – likely for expelling water
“cross hatched” pattern of horizontal laminae, and vertical pillars, squares in between called
galleries
when did stromatoporids appear
cambrian
when did stromatoporids go extinct
devonian
what are Archeocyathids
extinct group of cup-shaped organisms thought to be poriferans
what was the Archaeocyathid Morphology
Cup-shaped, porous walls, no
spicules
* Outer wall, and inner wall, interior space called the intervallum
* Vertical septa that partition the
intervallum
* Holdfast which anchors to the
sediment
what was the Archaeocyathid Ecology
Shallow water, marine, tropical
* Filter feed like sponges
* Likely lived at depths of 20-30m
* Formed the first reefs
when did Archaeocyathid appear
early cambrain
when did Archaeocyathid disappear
late cambrian
what is the least complex metazoan
cnidarian
which phyla is radially symmetrical
cnidarian
What are the major groups of Cnidarian?
- Hydrozoa (Jelly Fish, Fire Corals)
- Scyphozoans (moon
jellies, compass jellies) - Anthozoa (sea anemones, sea fans, sea pens, corals)
what are Common Cnidarian Traits
- Carnivorous
- Stinging cells (cnidoblasts)
- Live as polyps (sessile or
attached) or medusae (free
swimming) - Often exist as both during their
life cycle
what is the general cnidarian body play
hydra
what is the enteron
the cnidarian single opening, mouth, anus, reproduction
what is the name of the tentacles with stinging cells surrounding mouth of cnidarian
nematocysts in
cnidoblasts
describe the cnidarian body
Body made of two “walls” endoderm and ectoderm, with
gelatinous substance in between called the mesoglea
* Endoderm folds inward, and septa are secreted
what kind of reporduction do corals have
sexual, asexual budding, fragmentation
when are the earliest cnidarians
cambrian, possible edicarian
what are the Important coral groups
- Rugosa (extinct)
- Tabulata (extinct)
- Scleractinia(extant)
which extinct coral was horn shaped
rugosa
what is the arrangment of rugosa coral septa
six primary and six secondary
arranged in four quadrants
are rugosa solitary or colonial
both
when did rugosa and tabula corals live
ordivican to permian
are tabulata coral solitary or colonial
colonial
describe the sept of tabulata coral
reduced, prominant tabluae
are Scleractinia solitary or colonial
both
describe the septa of Scleractinia corals
prominent, divisible by 6
when did Scleractinia evolve
triassic (to present)
what are Hermatypic corals
have symbiotic algae called zooxanthellae
where do Ahermatypic corals live
cold water, slow growth
what is the distribution of corals
tropical shallow marine
what is the most productive marine ecosystem
reef
what are the three types of modern reefs by growth
Keep-Up
Catch-Up
Give-Up
what are the main zones in a reef system
lagoon, back reef, reef crest, fore reef
what are the three types of modern reefs by layout
Fringing Reef.
Barrier Reef.
Atoll.
darwin’s theory on three types of reefs
subsidence
Daly’s alternate reef formation hypothesis
glacial control - banks of islands eroded when sea levels lower
types of reefs in the carribean
bank/barrier
only ~100m from shore
(pacific is 1000s)
type of coral in Fore Reef Escarpment
storm derived rubble
coral in lowermost part of the ‘Reef Crest
Elkhorn
coral on reef crest
mature coral colony
corals in back reef
coral knob supercolony
coral in the lagoon
fine mud, coralanous algae
groups in lophophorates
Brachiopods & Bryzoans (&
Phoronids)
are lophophorates protostoma or deuterostoma
protostoma
what are bryozoans
lophophorates, Colonial animals, made of individual zooids
what is the key bryzoan morphology
- zooids in a protective covering
- Skeleton mineralized with calcite (when mineralized called zooecia)
- Zooids connected by a funiculus which extends along the stolon
- lophophore
- u-shaped gut
what is a lophophore
a feeding structure with tentacles
how do bryozoans reproduce
sexually and budding
describe bryozoan reporduction
- zooids hermaphroditic
- release sperm into water, capture with lophophore
- free swimming larvae settles to form new colony
what is the bryozoan ecology
most sessile, benthic, sublittoral
some freshwater, some vagile, some deepwater
different body shapes in diff env:
branching, fan, dome, palm, fenestrate, bushy
when did bryozoans appear
ordivician
earliest bryozoan
cambrian
what is a brachiopod
shelled lophophorate
what are the two types of brachiopods
articulate and inarticulate
how are brachiopods bilatteral symmetrical
through the midline of shell, not each side of shell like a bivalve
what are the two sides of a brachiopod shell
pedicel and brachial
pedical ventral and larger
what does an articulate brachiopod have
interlocking teeth
cardinal process
describe brachiopod feeding
Draw water in from sides of shell,
expel through the front
* Lophophore capture food particles,
brought to mouth along the
brachial groove
* lophophore not retractable (unlike bryzoans)
articulate brachiopods have calcareous supports (brachidium)
* u-shaped or curved gut
how do brachiopods unclog feeding tentacles
brachiopod sneeze
describe Brachiopod Reproduction
- release eggs/sperm into the water for external fertilization
- Some have a “brood chamber” for a developing embryo
- Have distinct male and female individuals
- Lingulid larvae swim and filter feed as plankton
Brachiopod Ecology
- Suspension feeding benthos
- anchor to substrate using pedicle,
filter feed using lophophores - Some infaunal and unattached forms
- Coral-like forms
two theories of Brachiopod Origins
- fold hypothesis
- related to tommotiids
brachiopod evolution
cambrian
reduced numbers in big extinctions
what is the second most diverse animal phylum
molluscs
Major Mollusc groups
- Bivalves
- Cephalopods
- Gastropods
- Polyplacophora (chitons)
- Scaphopoda (tusk shells)
- Aplacophora (worm-like)
General Mollusc Traits
- unsegmented body
- mantle, head, foot and visceral mass
- radula in head
Mollusc Reproduction
- some hermaphraditic
- most sexual, some parthenogenesis
- internal and external fert.
- Eggs usually deposited on hard surfaces in jelly or leathery sacks
- Some parental care
- Aquatic forms usually develop into free swimming larvae (that can be feeding, or non-feeding)
when did molluscs originate
cambrian or before
what is a Monoplacophorans
Single shelled mollusc that inhabit deep water (once
thought extinct)
General Bivalve Morphology
- Shells hinged, interlocking
- dentition
- Adductor muscles keep shell closed
- Pallial line is scar where mantle attaches
- Beak/umbones is the earliest part of the shell to form (growth lines extend out from there)
Bivalve Reproduction
Most are either male or female, some hermaphroditic
* Most s release sperm/eggs into the water, larvae mature in the plankton (some feeding, some existing on a yolk sac)
* Hermaphroditic forms draw sperm in through siphon, incubate embryos in brood chamber
* Some freshwater bivalves have larvae that must attach to a
living fish host to mature!
Bivalve Feeding
- detritovores
- gills (ctenidia) have been modified into filter-feeding apparatus
- water-siphon-gills-ctenidia
bivalve ecology
Intertidal to deep marine, and freshwater. epifaunal or infaunal
* Different morphologies can reflect their different life strategies and ecologies
* Good facies fossils
Bivalve evolution
cambrian
maybe from Rostroconcha
two vlves but no hinge
advantages of bivalves over brachiopods
can move
long siphon
increased in size as a result
gastropod shell
Coiled, conical, aragonite
shells that are closed at the
apex
* Have developed a variety of
shell shapes
gastropod reporduction
variable, some hermaphrodites
some love darts
some courting with copulatory organ
marine have larvae
gastropod feeding
Use radula to feed
* Radula pushed outward over
odontophore
* Retracted pulling food particles along with it into the esophagus
* Some carnivorous forms have fewer modified “teeth” that can inject venom (have been known to kill humans)
Can be grazers, scavengers, parasites, or carnivores
Gastropod Ecology
- Subclass Pulmatonata have a modified mantle cavity that
functions as a “lung” for living in terrestrial environments - Species in high energy marine environment usually have
thicker shells - Thin shells usually indicate freshwater, or terrestrial forms
gastropod evolution
cambrian
monoplacophoran-type
ancestor
most complex molluscs
cephalopod
what is a Hyponome
modified cephalopod foot for jet propulsion
cephalopod groups
- Nautiloidea (polyphyletic)
- Bactritida (extinct)
- Nautilus
- Ammonoidea (extinct)
- Coleoidea
- Belemnitida (extinct)
- Octopoda (octopus)
- Sepioidea (cuttlefish)
- Teutoidea (squid)
what a nautiloids
basel, shelled cephalopods
coiled shell
only living shelled cephalopod
Nautilus morphology
- Head, tentacles, foot, and
hyponome located towards
aperture (opening at large
end) - Visceral mass at rear of body
chamber - Mantle extends through
phragmocone as siphuncle
cord - Phragmocone separated by
septa into gas filled chambers - Septa attach to outer shell
wall at sutures
what is Bactritida
extinct cephalopods
devonian-triassic
straight shell
what are Ammonites
extinct cephalopod
devonian - end cretaceous
curved shell - planispiral with chambers
diverse shell types
what are Coleoids
cephalopods - octopus, squid and cuttlefish
what are Belemnites
extinct cephalopods
triassic-cretaceous
handle shaped, internal shell
mass accumulation in fossils - ‘battlefields’
what is the most diverse phyla of animals
arthropods
are arthropods protostomes or deuterostomes
protostomes
what are the main arthropod groups
- Trilobitomorpha (extinct)
- Chelicerata (Horseshoe crabs, “sea scorpions”,
- Myriapod (centi and millipedes)
- Hexapoda (ants, beetles, wasps, dragonflies, etc.)
- Crustacea (crabs, shrimp, lobsters)
What are the common Arthropod Traits
- segmented body
- compound eyes
- bilatterally symmetrical
- segmented/specialized legs
- exoskeleton of chitin
when did arthropods appear
cambrian (40% of burgess shale)
trace in edicarian
terrestrial in silurian
what are the restrictions to size of arthropods
gas exchange
strength of exoskeleton
vulnerability in ecdysis
Chelicerata Groups
- Pycnogondia (Sea Spiders)
- Xiphosura (Horseshoe Crabs)
- Eurypterids (Sea Scorpions)
- Arachnids (Scorpions,
Spiders, Ticks, Mites)
what is a Chelicerae
pincer appendage before the mouth
what are the only marine chelicerates
horseshoe crabs and sea spiders
Traits of Xiphosura - “Horseshoe Crabs”
- Large convex prosoma (fused head+thorax, cephalothorax)
- Opsithosoma (abdomen) 10 segments or less
- Telson (tail) long and spiny
Xiphosura Reproduction
gather on beach to spawn and lay eggs in sand
first confirmed Xiphosura in fossil record
ordivician
which animal Normally swim upside-down at
a 30 degree angle
horseshoe crab
what are Eurypterids
extinct marine arthropods
ordivician to permian
chelicerid not crustacean
carnivorous
maybe amphibous
Eurypterid Morphology
- Body divided into two sections (tagmata) like other Chelicerids
- The head (prosoma) was covered with a carapace
- Pre- and postabdomen combined had 12 segments
- The telson (tail) – telson usually pointed, flattened in some lineages
when did trilobites live
cambrian to permian
three body segments of trilobites
Cephalon * Thorax * Pygidium
what is a Hypostome
mouth (trilobite)
Three trilobite eye types
Holochroal * Schizochroal * Abathochroal
what is volvation
rolling up for defense (trilobite)
trilobite suture types
Proparian, Gonatoparian,
Opisthoparian, Lateral
what are Myriapoda
arthropods - milli/centipedes
when did myriapoda appear
silurian
what were the first terrestrial animals
myriapods
Crustacean Traits
- Hard crusty carapace
- Stalked compound eyes
- Possess mandibles
- 2 sets of antennae
when did crustaceans appear
cambrian
what are Ostracods
a small type of calcified crustacean
two types of hexapods
pterygotes = winged,
apterygotes=wingless
Hexapoda Morphology
- Uniramous appendages
- Pair of mandibles
- 6 limbs
- Single pair of antennae
when did hexapods appear
devonian
are echinoderms proterostomes or deuterostomes
deuterostomes
types of echinoderms
- Crinozoa
* Crinoidea (crinoids) - Blastozoa (extinct)
- Echinozoa
* Echinoidea (sea urchins, sand dollars)
* Holothuroidea (sea
cucumbers) - Asterozoa
* Asteroidea (starfish
* Ophiuroidea (brittle stars)
echinoderm traits
- Pentaradial symmetry
- Calcite skeletal plates (Mesodermal)
- Water vascular system (tube
feet)
Echinoderm Reproduction
mostly diff sexes
release sperm into water, lunar
some asexual
bilateral symm embryo
planktonic larvae (yolk)
when did echinoderms appear
cambrian
Echinoidea key traits
sand dollars and sea urchins
Ordovician to present
globular or heart shaped
aristotles lantern
5 genital plates
Irregular Echinozoans
infaunal
Periproct (anus opening)
migrated to face laterally
Asterozoa key traits
sea stars and brittle stars
ordivicain to present
detritovores or carniovres
light sensing cells at ends of arms
Which asterozoa has no anus
brittle star
what are Blastozoa
extinct echinoderms, no arms
silurian to permian
* Cystoids
* Blastoids
* Eocrinoids
what are Crinoidea
echinoderma
sea lilies and feather stars
crinoid morphology
Segmented stem composed of individual ossicles
* Rooted to substrate by a holdfast
* Cup shaped central body called the theca
* Plates at bottom of theca = calyx
crinoid feeding
- Suspension filter feeders
- Eat detritus and plankton,
- Tube feet put food into the ambulacaral groove, which transport it by cilia to the mouth
- No stomach, food transported/digested in intestines and expelled out the anus
crinoid reporduction
Gametes released from pinnules
floating larvae
when did crinoids appear
ordivician
what are Graptolithina
diverse group of colonial hemichordates, common in the Paleozoic
* Today represented by only one surviving genus, Rhabdopleura. others extinct by the end of the Carboniferous
graptolina traits
colonial, individuals are zooids
first zooid in a colony is
called the sicula, while later
zooids are called thecaecolony surrounded by chitin
what are Dendroidea
sessile Graptolites
two types of graptolites
sessile and planktonic
what are Graptoloidea
extinct planktonic graptolites
whats importanit about graptolites in fossil record
can pinpoint within 10kya
groups that originated in the Devonian
Hexapods
Ammonites and Bactrida
Groups that went extinct in the Devonian
Stromatoporid
Graptolite
Groups that appeared in the Cambrain
Porifera
Cnidarians
Lophophorates
Molluscs
Arthropod
Echinoderms
Groups the disappeared in the Permian
Trilobites
Blastoids
Eurypterids
Tabulate and Rugosa corals
Groups that appeared in the Ordivician
Rugosa and Tabulate corals
Bryozan
Xiphosura
Eurypterids
Hexapod
Echinodea
Groups that went extinct in the Ordivician
Most Graptolites