Lecture 2 Flashcards
Where do come from?
Metazoa
Characteristics of the metazoan vertebrates?
Multicellular, heterotrophic, eukaryotic( contains nucleus and membrane protected organelles
Chordate evolution commences first with what?
Bilataria and Radiata
What is Bilataria?
where humans belong we have an anterior and posterior and 2 lateral sides are the same
What is Radiata?
Symmetrical all around
What is a Deuterostomes?
Blastopore becomes the anus ,radial cleavage and mesodermal skeleton, enteroceolic coelom
What is a Protostomes?
Blastapore becomes the mouth ,Spiral cleavage, ectodermal skeleton , schizocoelic coelom
What separates chordates from deuterostomes?
Pharyngeal slits, notochord, dorsal hollow nerve cord, endostyle and post anal tail.
What is the notochord?
arises from the mesoderm, hydrostatic flexible but resists compression and allows swimming motion
what is the dorsal hollow nerve cord?
hollow nerve cord, fluid filled, dorsal location, invagination (neural plate) Derived from ectoderm
what is the role of pharyngeal slits?
serve primarily in feeding. The opening allowed the one way flow of a water current
The role of Endostyle?
Glandular groove on pharynx (thyroid gland) involved in filter feeding , and the metabolism of iodine
The role of Post Anal tail?
a posterior elongation of the body extending beyond the anus.
All chordates have what?
they have a true endostyle and true thyroid gland
What are the first protochordates?
Hemichordates, Cephalochordates, Urochordates
what characterizes a hemichordate?
they are marine worms, deuterstomes, dorsal pharyngeal slits ( where pharyngeal slits developed, dorsal vessel which means that it has a forward blood flow )
what characterizes Cephalochordates?
fish like, has all five chordate characteristics, and amphioxus , posses cilia
what characterizes Urochordata ?
Sea squirts and at some point all 5 chordate characters were developed
what are some different characteristics to chordates compared to hemichordates ?
ventral pharyngeal slits and dorsal vessel with backward flow
What other characteristics do chordates share with some other taxa?
They have segmented body in some parts and myomeres which are sequential blocks of muscle
did chordates first evolve from annelids and arthropods?
not enough information to determine lack of evidence
What are some characteristics of echinoderms?
T hey are deuterostomes, similar larvae , sessile( organism sit in one place), filter feeders and share characteristics with hemichordates
What unique characteristic do echinoderms develop and why is that characteristic important?
They develop elongation that will help them swim better and the ability to suck more food. ( A more active lifestyle, and improved movement)
Are vertebrates diverse and complex?
yes
What characteristics are prevalent for the Vertebrates?
Vertebral column, cranium, and cephalization
Over the years what replaces the notochord ?
The vertebral column
what makes up the vertebral column?
Series of vertebrae with cartilage and bone
and defines the major body axis
What characterizes the cranium?
Bone or cartilage, encases brain and supports sensory organs
What characterizes cephalization?
contains embryonic characteristics such as Neural Crest and Epidermal Placodes
what characteristics distinguish vertebrates from other chordates?
The embryonic features which are the neural crest and epidermal placodes
How do prevertabretes feed?
They are suspension feeders such as cilia creating the current to move food into and across the pharynx
what evolutionary change did the prevertebrates make?
The development of the muscular pump ( able to consume big food) , muscles around the pharynx, cartilage in pharyngeal bars and gills with that being said vertebrates can’t bigger and have a. higher respiratory demand
What are Agnathans?
Jawless fishes they have a mouth with suction but no jaw
Why did filter feeding get replaced by the muscular pump?
because in larger animals this method became less effective in supplying their greater body mass.
What advantage was gained to to having muscle around the pharynx and cartilage in pharyngeal bars?
They were able to eat bigger. things
How did the development of gills help the early vertebrates?
they increase the resistance to fluid flow through the pharynx and helped push water to the newly evolving gills supporting the respiratory demands
Characteristics of Gnathostomes?
Jaw bearing fishes, raptorial feeding coupled with suction, larger food items need to be held, muscular jaws to open and close fast
predation
what are the classification of vertebrates?
Jaw based, “ footedness” and embryos
What does the jaw based vertebrate classification consist of ?
Agnathans and gnathostomes
What does the “Footedness” classification consist of?
Tetrapods meaning four footed like reptiles
What does Embryos consist of?
Amniotes : Sac like membrane
Anamniotes: not sac like membrane
What are Conodonts
These are extinct agnathans resembling eels
what is Ostracoderm
extinct Agnathans with shell skin
Most have a bony armor ( some structures similar to fins)
Myxiniformes:
Extinct agnathans that produced slime for escape
Lampreys:
extinct agnathans
for Gnathostomata how was the jaw formed?
from the anterior pharyngeal arches
what other characteristic was formed for the gnathostomata vertebrates?
Development of paired fins
Placoderm is under gnathostomata what are its characteristics?
Plate skin, dermal armor where we see bony plates, upper and lower jaw , paired appendages and diverse but extinct
What are Chondricthyes?
Cartilagenous skeletons
Elasmobrachs are knows as what ?
Sharks and Rays
Holocephali are known as what
Ratfishes
Teleostomi is another Gnathostomes
Teleostomi
Acanthoddi is part of teleostomi what are it characteristics?
small fish, prominent fin spines and sister taxa to bony fishes
Osteichthyes are bony fishes and what are they characterized in?
bone in the endoskeleton, bony operculum ( protection to the gills) , swim bladder, body covered by overlapping scales, terminal mouth and find ofter have lepidotrichia have spines or rays
Paleonischiformes
primitive ray finned fishes
Neopterygii:
derived ray finned fishes ( vTeleosts): circular scales, ossified vertebra, swim bladder, and complex jaw mobility
Sarcopeterygii :
internal nostrils, muscular fleshy paired lobe fins, heavy scales, they gave rise to terrestrial vertebrates ( able to sticks their head out to breath)
Actinopterygii consist of
paleonisciformeds and neopterigii
Actinopterygii consist of
paleonisciformes and neopterygii
Tetrapods have what characteristics:
lungs. for respiration and limbs for walking
What is chiridium ?
Muscular limbs with joints and digits
Lissamphibia:
modern amphibians with paired lungs require water moist skin no amnion metamorphic and poikilotherms ( can not regulates its temperature)
Caudata is a lissamphibian with what kind of characteristic
long body and tail, eternal and internal Fert, no tympanum (eardrum) , metamorphic
Anura is also an lissamphibian what are the characteristics
Adult with no tail, jumping morphology, extreme metaphorposis, eternal fertilization
Gymnophiona
burrowers, solid, not limbs and internal fertilization
what is amniotes?
sac like membrane around the embryo reptiles , birds and mammals
Temporal Fenestre
Anapsid: no temporal opening
Synapsid: singel
dips- paired
Temporal Fenestre
Anapsid: no temporal opening
Synapsid: single
dips- paired
Testudines
They are turtles and they did not take a huge genetic change and be anapsid or diapsid
What are the shells of the turtle?
Carapace: Dorsal
Plastron_ ventral and how genes
Lepidosauria is what
modern lizards and snakes they a scaly reptiles with complete temporal bars, quadrate not movable compared to braincase and teeth fused jaw
Lepidosauria squamates
they lose the lower temporal bar and quadratojugal
quadrate bone is now movable
what are some examples of squamates?
lizards: imbed or limbless , movable eyelids
snakes: limbless and extreme skull flexibility
amphibaenians liblmess burrowers thick skulls to push trough dirt
Aves
most closely related to crocodilians they have feathers, try flight, light with bones, air sacs, endothermic, teeth absent and lack urninarry bladder
Synapsida:
mammal like
Mammalia:
3 earbones and one bone makes up the lower jaw, mammary glands, hair, sweat glands , red blood cells
what are the mammal classifications?
platypus, their, matatheria, and eutheria
platypus is what ?
they lay eggs , poorly developed , mamary glands and poor ability to maintain. temperature, cloaca
Theria
bear live young , well developed mammary glands
Metatheria:
no true placenta and short uterine development
Eutheria:
true/ placental mammals rodents
