Deuterostomes Flashcards
Two main groups of deuterostomes
Echinodermata, Chordata
Shared characteristics of Deuterostomes?
formation of anus from blastopore, enterocoelus, indeterminate fate of early blastopore, radial cleavage
Echinodermata body type?
larvae bilateral, adult is five-sided radial symmetry
Body features of echinodermata?
calcium carbonate endoskeleton, and water vascular system
five living echinoderm lineages?
crinoidea, asteroidea, ophiuroidea, echinoidea, holothuroidea
Traits of embryonic development in chordata
notochord, dorsal hollow nerve cord, pharyngeal slits, muscular post-anal tail
three major lineages of chordata
cephalochordates, urochordates, craniates(vertebrates)
Role pharyngeal slits?
suspension feeding devices for invertebrates, gas exchange in vertebrates(non tetrapods) aka gills, for tetrapods it is part of ear neck head
dorsal hollow nerve cord becomes what in chordates?
like a CNS
Cephalochordata are also known as?
lancelets or amphioxus
traits of cephalochordata?
most basal group, mobile but can be suspension feeders, marine, external fertilization
traits of urochordata(tunicates)?
marine, retained only pharyngeal slits as adults, two siphons, U-shaped gut, exoskeletal tunic, sexual/asexual/e or i
traits of craniates?
vertebrates with skull, can have brain other sensory organs, higher metabolism, heart with 2 or more chambers, RBC w hemoglobin, kidneys
monophyletic vertebrates distinguished by what..?
spinal column(cartilage or bone), cranium, fin rays(in aquatic forms)
myxini(hagfish) key traits
marine bottom dwellers, cartilage, no true vertebrae, lack jaws, small brain/eyes/ears,tooth
petromyzontids(lampreys) key traits
lack jaws, ectoparasites of fish, fresh/salt water, lack true vertebrae as well
burgess shale show what ancient chordates?
conodonts and other fossil chordates even some echinoderm
traits of conodonts
soft-bodied, lacking jaws , made mainly of cartilage, dental elements make them good index fossil
key vertebrate innovations in order?
bony exoskeleton, jaws, bony endoskeleton, limbs for land, amniotic egg
what are ostracoderms?
extinct jawless fishesm armored scale plates
derived characters of gnathostomes?
have jaws, enlarged forebrain, lateral line system(for aquatic forms), most diverse vertebrates
name the two ancient extinct gnathostomes
placoderms(no teeth, sister group), acanthodians(sister to bony fish)
chondrichthyes body type?
cartilage, also have cloaca
features of chondrichthyes?
predatory, acute senses, internal fertilization via claspers on fins
two majors groups of chondrichthyes?
elasmobranchi and holocephalians
traits of elasmobranchi?
spiral valve, apullae of lorenzini, diverse
traits of holocephalians?
venomous spine/operculum, single gill opening and no cloaca
three clades of amphibians
AAU– anura, apoda, uredela
anura consists of?
tailess ones, frogs toads
apoda?
legless ones, caecilians
uredela?
tailed ones– salamanders
amphibian characters?
lungs and skin for respiration as adults, used gills as larvae, moist skin, cloaca, metamorphosis
3 clades of amniotes?
anapsida, synapsida, diapsida
4 extra-embryonic layers in amniotic egg?
amnion, yolk sac, allantois, chorion
four major lineages of reptiles?
squamates, chelonians, crocodilians, aves
two groups of reptiles?
lepidosaurs and archosaurs
squamata characters?
cranial kinesis, vomernasal organ, usually lizards and snakes
birds descended from ____ dinosaurs
theropod
birds are part of monophyletic group called?
dinosauria
features that aid birds in flight?
lack of urinary bladder, one ovary(lighter), large pectoral muscles anchored to keel on sternum
two groups of birds today are?
neornithes and ratites
