Lectures for Test 1 Flashcards
sagittal
any line that divides body into right and left
transverse
any line that divides body into front and back parts
frontal
any line that divides body into top and bottom parts
vertebrates belong to this clade
chordata
largest clade of chordata
craniata
how are groups defined and characterized?
groups defined based on ancestry, traits used to characterize group
chordates + hemichordates =
pharyngotremata
informal name referring to early and non complex craniates
protochordates
5 characters important in vertebrate evolutionary history
pharyngeal slits, notochord, dorsal hollow nerve cord, endotyle, post-anal tail
urochordata means
chordates with tails
example of urochordate
tunicate
what chordate characters does the tunicate have?
pharyngeal slits, endostyle, postanal tail with notochord and nerve chord in larval stage
cephalochordata means
chordates with heads
example of cephalochordate
amphioxus or branchiostoma or lancelet
habitat of amphioxus
in sand, half buried with head poking out
chordate characters present in amphioxus
notochord, dorsal hollow nerve cord, post-anal tail, pharyngeal slits
amphioxus feeding method is called
filter or suspension feeding
difference between amphioxus pharyngeal slits and more derived versions
amphioxus slits are for getting rid of water ingested during feeding not gas exchanged
informal group characterized by lack of jaws
agnathans
groups/species considered agnathans
myxinoidea, petromyzontoidea/hagfish, lamprey
characteristics of agnathans
lack jaws and paired appendages, now represented only by cyclostomes
earlier, diverse group of agnathans (now extinct)
ostracoderms
types of ostracoderms
osteostracans, anapsids, heterostracans
characteristics of cyclostomes
parasitic, no bone, long thin bodies, single median nostril, rasping tongue