Natural history of Vertebrates Test 1
What are the two sister groups to chordates?
Hemichordates and echinoderms
In what group of animals is the notochord the primary support structure?
Jawless fishes
what class of tunicates retain larval traits and are swimming filter feeders
Appendicularia
what is the function of the ampullae of lorenzini
they detect electrical stimuli of muscle contractions
why are neural crest cells unique to verts?
they migrate to new locations and are pluripotent
lampreys use ___ ventilation
tidal
T/F: cephalochordata is the group that is most closely related to verts
true
t/f: lamprey adults die after reproducing
true
t/f: placoderms are a dead end
true
t/f: tissues in vertebrates form the endoskeleton
true
in mammals, the pharyngeal slit/pouches become what?
tubes, tonsils, and glands
what 3 subphyla are in the chordate phyla
tunicata, cephalochordata, and vertebrata
What are the 3 subphyla of the Chordata phylum?
tunicata, cephalochordate, and vertebrata
what is convergent evolution?
two taxa independently evolve similar features not due to a common ancestor
External egg development is called ___
Oviparity
Internal egg development that results in live birth and young receive NO nourishment from mother is __
Ovoviviparity
what protects enzymes from high urea concentrations
TMAO
lampreys are ___ meaning they move into smaller streams when breeding
anadromous
Vertebrates (are/are not) a monphyletic group
are
Holocephali have ____ jaws
autostylistic
In mammals, the pharyngeal slit/arches become what?
bone, ligaments, and cartilage
The nerve chord becomes what in humans?
brain and spinal cord
what vertebrate characters did conodonts have
calcium phosphate crystals, calcified cartilage, enamel, and dentine
What is the endostyle initially used for?
capturing/transporting food
what are the distinctive characteristics among chondrichthyes
cartilaginous skeleton, placoid scales, lipid liver, high urea concentrations, and ketone bodies
what class are lampreys in
cephalaspidomorphi
lampreys have a ___ circulatory system and a __ chambered hert
closed 2
where are the earliest teeth found
conodonts
what is a "species"
distinct populations, evolutionary cohesive and independent, and exists in nature
when was the first chondrichthyes diversification event
during the carboniferous, 359-299 mya
when was the second chondrichthyes diversification event
during the jurassic, 201-145 mya
when did the holocephalans and elasmobranchs diverge
during the silurian
The nerve chord forms from what?
ectoderm
the epidermis is derived from the ___ and the dermis is derived from ___
ectoderm mesoderm
hagfish have assumed ____
external fertilzation
True/False: "invertebrates" form a monophyletic group
false
t/f: elasmobranchi have gill covering
false
t/f: hagfish have a well developed eye that has a lens
false
t/f: lamprey teeth are supported by jays
false
t/f: lamprey teeth have dentine and enamel
false
t/f: the Ostracoderms are a clade
false
t/f:holocephali have spiracles in the adult
false
Jaws derived from what
first pair of visceral arches
what are the 2 extant taxa of the chondrichthyes
holocephali and elasmobranchii
elasmobranchii have pectoral fins that serve as ____ which provide lift when moving through water
hydrofoils
what type of jaws do elasmobranchi have
hyostylic
elasmobranchi body fluids are slightly ____ to the environment
hypertonic
phylogenetic trees are ___
hypotheses
why do chondrichthyes have placcoid scales
improves swimming and prevents bacterial growth
what is a paraphyletic group
includes MRCA but not all descendants
what is a polyphyletic group
includes all descendants but not mcra
holocephali have ___ fertilization
internal
what kind of fertilization do chondrichthyes have
internal
there are remnants of the notochord where in humans?
intervertebral disks
hagfish body fluids are ___ with the sea water
isosmotic
why do chondrichthyes have a lipid liver and high urea conc.
it helps with buoyancy control and osmoregulation
why do elasmobranchii have a spiral valve
it increases surface area for digestion and absorption
what are the major gnathostome diagnostic characters
jaws, calcified teeth, 3 semicircular canals, stomach spleen and pancreas, and paired fins with pectoral and pelvic girdles
Tunicates have all 5 chordate characteristics, but only in ___
larvae
when did placoderms go extinct
late devonian
what percent of animals are vertebrates?
less than 5
What is the primary function of the post anal tail?
locomotion
what is evolutionary reversal
loss of a feature
placoderms where primarily ___
marine
hagfish are ___ and ___ (habitat)
marine benthic burrowing
the muscular system is derived from the ___
mesoderm
rectal galnds help excrete __
nacl
what characters do lampreys share with gnathostomes
neural arches, lateral line system, 2 semicircular canals, pineal organ, mineralization of tissues, and support rays in fins
do hagfish have scales or paired fins?
no
do hagfish have vertebrae?
no
what type of feeding do hagfish do
scavenge and worm eaters
most adult tunicates are ___
sessile and filter feeders
what is a homologus trait
similar in structure due to shared ancestry; may differ in size and function
what is the phylogenetic species concept
smallest diagnosable group of individuals forming a clade
the only taxa that exists in nature is ___ all others are historical entities
species
what is the morphological species concept
species are ID by their physical features
since chondrichthyes don't have bone marrow, where are the RBCs
spleen
Vertebrata is a (class, phylum, subphylum)
subphylum
on phylogenetic trees, branches represent ___
taxa
why do some elasmobranchii have inter-uterine cannibalism
the babies that survive are strong and have high survival rates
Vertebrate diversity is dominated by which group of animals?
ray finned fishes
when did the ostracoderms live
550-250 mya (paleozoic)
how many species of extant sharks are there
556
hagfish have ___ barbels which are ___ and ___ receptors
6 chemo and touch
how many species of skates and rays are there
638
how many species of vertebrates are there?
65,000
how many species of echinoderms are there
7 thousand
how many species of hagfish are there
75
how many orders of placoderms were there
8
SC Holocephalii are the ___
ratfish
the jawless fish form SC __
Agnatha
How many species of hemiderms are there
130
how long does it take for the lamprey eggs to hatch
2-3 weeks
what percent of the brain in elsmaobranchii is dedicated to vision and chemoreception
20%
how many species of tunicates are there
2150
how many species of freshwater chondrichthyes are there
28
how many filter feeder chondrichthyes are there
3
how many harts do hagfish have
3
how long is the lamprey larval period
3-17 years
when did the Acanthodii go extinct
300 mya
how many species of lancelets are there
32
how many gill openings do holocephali have
4
how many species of lamprey are there
40
when did Chimaeriforms diverge from elasmobranchs
400 mya
when are the first definite chondrichthyes fossils dated
419-359 mya
how many pairs of gills do elasmobranchii have
5-7
how many species of chimaeriforme(ratfish) are there
50
when did myxini (hagfish) diverge from other verts
530 mya
when did the conodonts live
540-230 mya
what COULD have been the first super predator?
Dunkleosteus
what is a monophyletic group?
MRCA and all descendants united by one or more synapomorphy
what lamprey species entered the great lakes and caused collapse of lake trout industry
Peteromyzon marinus
chordata is a (class, phylum, subphylum)
Phylum
What are the 5 shared derived characteristics of chordates?
notochord, pharyngeal slits, dorsal hollow nerve chord, endostyle/thyroid, and post anal tail
hagfish have a ____ circulatory system, and ___ BP
open low
what type of birth do holocephali have (ovaparious, vivaparious)
ovaparious
when did the sharks skates and rays diverge
permian
what are the 2 extinct gnathostome classes
placoderms and acanthodians
The BSC says a species is a ___
population with the potential to interbreed in nature and produce viable offspring and are reproductively isolated
most placoderms where ____ or ____ (diet)
predators or scavengers
The notochord is (ventral or dorsal) to the nerve chord
ventral
"live birth" from gestation in "uterus" (body cavity) that receives nourishment from yolk sac is___
viviparity
do lampreys have a brain like other vertebrates (forebrain, midbrain, hindbrain)
yes