Anatomic Diversity Human anatomy is a typical anatomy of a member of Phylum Chordata. Human anatomy understood biologically within its comparative and developmental.
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Transcript Anatomic Diversity Human anatomy is a typical anatomy of a member of Phylum Chordata. Human anatomy understood biologically within its comparative and developmental.
Anatomic Diversity
Human anatomy is a typical anatomy
of a member of Phylum Chordata.
Human anatomy understood
biologically within its comparative and
developmental contexts.
Understanding the development of
vertebrate (in this case human)
anatomy is necessary to understand
the adult anatomy across vertebrates.
Phylum Chordata
Notochord = stiff connective tissue rod
Dorsal hollow nerve cord (neural
tube) = hollow nerve cord dorsal to
notochord (spinal cord + brain in us)
Endostyle/thyroid = gland involved in
iodine metabolism
Pharyngeal Openings (gill openings)
= openings into “throat,” behind mouth
Post-anal tail
Phylum Chordata
Phylum Chordata
Subphylum
Urochordata
Subphylum
Cephalochordata
Subphylum
Myxini
Subphylum
Vertebrata
notochord,
neural tube,
post-anal tail,
endostyle/thyroid,
pharyngeal openings
Subphylum Urochordata
Sea Squirts, Salps, & Larvaceans
Suspension feeders
Tadpole larva with
notochord in tail.
Sea Squirt Metamorphosis
Subphylum Cephalochordata
Lancelets (Amphioxus, Branchiostoma)
Suspension feeders
Notochord extends into head & includes
skeletal muscle cells.
Chordate derived characteristics obvious.
Chordate Synapomorphies
dorsal
nerve tube notochord
intestine anus
pharyngeal
basket (slits)
hepatic
diverticulum
post-anal
tail
Phylum Chordata
notochord
extends
into head
tadpole
larva
segmental
muscles
notochord,
neural tube,
post-anal tail,
endostyle/thyroid,
pharyngeal openings
Lancelet Musculature
Musculature
Lancelets, hagfishes, & vertebrates have
segmental muscles (myotomal muscles).
segmental muscles
(myotomal muscles)
Lancelet Tail Section
nerve tube
myotomal
muscles
notochord
Lancelet Structure
Sketch on board.
Craniata
Hagfishes and vertebrates.
SYNAPOMORPHIES
Cranium (cartilage or bone)
Liver
Calcium phosphate in skeleton
Neural crest tissue (Developmental)
Neurogenic placodes (Developmental)
Phylum Chordata
notochord
extends
into head
segmental
muscles
notochord,
neural tube,
post-anal tail,
endostyle/thyroid,
pharyngeal openings
Craniate Phylogeny
liver, CaPO4, neural crest, neuro. placodes
Hagfishes, Subphylum Myxini
43 species; marine
scavengers
no jaws
lack functional eyes,
tentacles, & one naris
serially
hermaphroditic
lack bone (cartilage)
secrete slime
Hagfish Anatomy
Cartilage under brain and in
mouth apparatus.
Keratinous tooth plates.
No real vertebrae.
Hagfishes, Subphylum Myxini
tentacles
mouth
pharyngeal
openings
caudal
fin
Hagfishes, Class Myxini
Hagfish Slime
Subphylum Vertebrata
Approximately 50,000 species.
Vertebrates arose in the marine enviro.
SYNAPOMORPHIES
Dorsal Fin with skeletal supports
Vertebrae – complete neural arches
Vertebrae
Craniate Phylogeny
dorsal fin,
complete neural arches
Lampreys
Class Petromyzontida
41 species
Oral disc with “teeth” & rasping “tongue”
Ammocoete larva - VERY similar to
cephalochordates in way of life
Larvae undergo metamorphosis.
Marine and freshwater ectoparasites
(adults) and suspension feeders (larvae)
Lampreys, Class Petromyzontida
oral
disc
1 narial opening
eye pharyngeal
openings
keratinous
“teeth”
dorsal
fins
Lampreys, Class Petromyzontida
ammocoete
larva
adult
Lamprey, ammocoete
neural tube
brain – spinal
cord notochord
intestine anus
pharyngeal
basket
(slits & bars)
endostyle
liver
heart
Sketch on board.
post-anal
tail
Lab Activity
Obtain a slide of a lamprey ammocoete
and a dissection microscope.
Examine the slide on the microscope.
If appropriate, date the page in your lab
notebook and sketch the ammocoete.
Label all the parts you labeled on the
previous slide.
Ask your instructor if you have difficulty.
Examine the whole preserved lampreys.
Lab Activity
Obtain a slide of a cross sectioned
ammocoete larva and a compound
microscope.
Find the section through the post-anal
tail and examine the slide on the
microscope.
Sketch the tail section. Label the
notochord, myotomal muscles, & neural
tube.
Ask your instructor if you have difficulty.
Gnathostomata
gnatho- = jaws; stoma = mouth
jawed vertebrates
pectoral & pelvic fins
Myelinated nerves
Craniate Phylogeny
jaws, myelin,
paired limbs
Sharks, Rays, Chimaeras, etc.
chondro- = cartilage; ichthys = fish
Sharks, rays, sawfishes, & chimaeras
Males have pelvic claspers.
marine (and freshwater) carnivores
Approx. 850 species
Class Chondrichthys
Osteichthys
osteo- = bone; ichthys = fish
“bony” vertebrates, NOT just FISHES
bony endoskeleton, lung(s)
ray-finned fishes, lungfishes, the
coelacanth, & terrestrial vertebrates
Craniate Phylogeny
bony endoskeleton,
lung(s)
Class Actinopterygii
actino- = ray; ptery = fin or wing
ray-finned fishes
marine and freshwater
24,500+ species
(= the number of species of all other vertebrates
put together)
Very diverse in habits and body form.
Class Actinopterygii
single, dorsal
lung
24,000 species+
Sarcopterygii
sarco- = flesh; ptery = fin or wing
fleshy & bony pectoral and pelvic axis
lobe “fins” (NOT just FISHES)
lungfishes, coelacanths, & terrestrial
vertebrates
Craniate Phylogeny
“lobes”
Coelacanths
2 species
deepwater marine
(East Africa &
Indonesia)
Lungfishes
6-9 species, Tropical
freshwaters
unique morphology
Paired ventral lungs
Tetrapoda
tetra- = four; poda = foot
“terrestrial” vertebrates
pectoral and pelvic limbs with digits
1
3
2
4
1
2
Craniate Phylogeny
limbs with digits
Amphibians
amphi = both/double, bios = life
frogs, toads, salamanders, caecilians
Usually distinct metamorphosis
Approx. 5,000 species
freshwater and terrestrial (none marine)
mucus covering skin
Amphibians
Amniota
Amnion = amniotic membrane
Amniotic membrane surrounds
embryo (in egg or in uterus)
amniotes = reptiles & mammals
Very distinct from other vertebrates
Craniate Phylogeny
amnion
Class Mammalia
Mammals
Named for
mammary
glands
Hair (no exceptions)
Approx. 4000
species
Most diverse =
rodents and
bats.
Theria
nipples
hair,
mammary glands
Monotremes
Platypus & Echidnas
Australia & New Guinea.
Lay eggs
Young lap up milk from nipple-less
mammary glands
Baby Platypus
Echidnas
Marsupials
Metatherians
Australia, New Guinea, & S. America
Morphologically diverse in Australia
Do not lay eggs, young develop in an
external pouch.
Milk from nipples
Eutherians
“Placental” mammals
Worldwide, Very diverse morphologically
Do not lay eggs; young do not develop
in an external pouch.
Milk from nipples.
Class Reptilia
Turtles, lizards,
snakes, tuataras,
crocodylians, &
birds
Birds ARE reptiles
Thick keratin
scales
Approx. 15,000
species
Many extinct
epidermal scales
of beta keratin
Turtles
Turtles, tortoises, & terrapins
Worldwide, <1000 species
Ribs and vertebrae form a
“shell” (test).
No teeth, keratinous “beak”
Lay eggs.
Lepidosaurs: Lizards & Snakes
Lizards, snakes, & tuataras
Worldwide
5000+ species
Subclass Archosauria
Crocodilians
Alligators, crocodiles, caimans,
and gavials
about approx. 40 species
Subclass Archosauria
Birds
Aves
9,000 species
Feathers, no teeth, keratin beak