Practicle #6 Flashcards
Euchordata Apomorphies
Urochordata and vertebrata.
- have neural crest
Nueral crest
Group of cells near dorsal margin of neural tube in embryo, dispenses cells to form cranial tissues.
Vertebrata
Fishes, amphibians, mammals, reptiles, birds.
- cranium
- tripartite brain
- sensory organs
- lateral line system
- 2 chambered heart
- liver
- kidney
- hemoglobin compounds
Cranium
Made of cartilage, becomes ossified, fuses to form skull, houses brain and sensory organs.
Tripartite brain
Larger than in invertebrates, has 3 parts, helps to deal with information and form sensory organs
Olfactory organs
Chemoreception for smell
Lateral line
Senses water movements, receptors embedded under skin.
Pineal organ
Detects presence/absence of light, under skin on top of head, regulates behaviors and hormones.
2 chambered heart
Derived from part of ventral aorta, evolved to accommodate the evolution of dense capillaries in gills
Hemoglobin compounds
Hemoglobin molecule binds with oxygen to increase oxygen content of blood, gives bloods its red color.
Liver
Produces proteins and digestive juices, stores energy, filters waste like dead blood cells.
Kidney
Maintains various bodily fluid solute concentrations, removes wastes like urea, especially important in marine life.
Vertebrae
Bony disks that form column, surrounds and protects the dorsal nerve, derived from notochord.
Cyclostomata
Jawless fish.
- circle mouths
- keratinized teeth
- rudimentary cartilaginous blocks (rather than vertebrae)
Myxini
Hagfish.
- scavengers
- no larval stage (direct development)
- oral tentacles for sensing and feeding
- oral plates
- threads from mucus glands
Petryomyzontida
Lampreys.
- parasitic fish
- anadromous
- eventually metamorphose
Gnathostomes
Jawed vertabrates.
- jaws
- calcified teeth
- vertebral column
- heterocercal tail
- paired fins
- stomach
- pancreas
- spleen
Jaws
Formed from first set of pharyngeal bars, allow for enlarged feeding gape.
Calcified teeth
Derivatives of calcium phosphate skeleton, important for biting/chewing.
Vertebral column
Calcified vertebrae replace notochord, surrounds and protects dorsal nerve.
Heterocercal tail
Allows for rapid acceleration and burst swimming.
Paired fins
Allow for greater conrol and stability while swimming, evolve into arms and legs
- pectoral + pelvic
Stomach
Expansion of foregut, wrinkles cause greater surface area, hydrochloric acid and muscular contraction help with digestion.
Pancreas
Produces enzymes for digestion.
Spleen
Filters and helps produce blood, stores immune system cells.
Chondrichthyes
Sharks, skates, rays, ratfish.
- male pelvic claspers
- placoid scales
- skeleton mostly cartilaginous
Holocephali
Ratfish.
- diffuse placoid scales
- pre-pelvic and cephalic claspers
- fused tooth plates
Osteichthyes
Ray-finned fishes, lungfish, coelacanths, tetrapods.
- swim bladder or lung for buoyancy
- adenticulate scales
- bony operculum
Actinopterygii
Ray-finned fishes.
- homoceral tail
- highly mobile
- specialized fins with bony spines
- spines in dorsal fin
- ganoine on scales
Sarcopterygii
Lobe-finned fishes
- muscular and lobed fins
- teeth have enamel
Actinistia
Coelacanths.
- ossified gas bladder
- 3 lobed tail
Chonata
Lungfish and tetrapods.
- bile sats for digestions
- choana: internal nostril for nose breathing
Tetrapods
Mammals, amphibians, reptiles.
- eyelids
- stapes
- atlas
- 4 legs, 5 digits per limb
Eyelids
Prevent cornea from drying out.
Stapes
Hyomandibular bone –> rod-like inner ear bone, attaches to eardrum, picks up vibrations, passes ear fliuds to brain.
Atlas
Anterior vertebrae connecting head to skull, increases movement.
Amphibians
Caucilians, salamanders, frogs.
- respirate through skin with sac lungs
- reduced digits on front limbs
- skin has poison glands and mucus glands (for defense and to prevent desiccation)
Apoda
Caecilians.
- legless, segmented amphibians
- osteoderms embedded in skin
- no pelvic girdle
- 2 teeth rows
- tenctacle sense organ on mouth
Urodela
Salamanders.
- live in wet environments
- have gills
- suscepticle to drought/toxins (indicators of healthy ecosystem)
Anura
Frogs and toads.
- limbless larvae with internal gills
- no true teeth
- lack tail as adults
- hindlimbs are longer than forearms
- ribs lost and pelvic girdle elongated
Frog habitats based on morphology
- pond dwellers: long legs, hind feet have lots of webbing
- Burrower: short and stubby, hindlimbs short, spade of foot, feet highly webbed
- climber: small body, long legs, slender toes with round pads
Amniota
Mammals and reptiles.
- reproduce out of water, amniote egg
- internal fertilization
- hard keratin covering
Amniote egg
Can be laid on land, inner protecting lining for gas exchange, surrounded by fluid filled sac, large nutritive yolk with nutrients.
Reptilia
Turtles, snakes, lizards, crocodiles, dinosaurs, birds.
- uric acid
- scales with beta-keratin
Testudines
Turtles and tortoises.
- marine/freshwater/terrestrial
- shell bone overlaid with epidermal scutes made of keratin
Squamata
Lizards and snakes.
- paired hemipenes in males
- enlarged Jacobson’s organ
Lizard morphological adaptations
- sand dweller: fringes on toes for running on sand, flat body, wedge shaped head
- burrower: lack limbs, elongated
- semiaquatic: enlarged tail for swimming
- arboreal: compressed body, rounded toe pads
- generalized: “normal” proportions, no specialization
Archosauria
Crocodylia and dinosauria.
- 4 chambered heart
- parental care
- facultative bipedalism
- nest building
Crocodylia
Crocodiles, alligators, gavials.
- flat skull with conical teeth
- laterally compressed tail for swimming
- webbed feet
Crocs = V-shaped snout
Alligator = U-shaped snout
Aves
Birds.
- collar bones fused into furcula (wishbone)
- sternum has keep for muscle attachment
- hollow bones
- semi-lunate carpal
- feathers
- powered flight
- shortened tails
- loss of teeth
- vertabrae fused
Hollow bones
Lungs extent into bones (increased O2 consumption to support flight)
Semi-lunate carpel
Crescent shaped wrist bone, increased flexibility.
Feathers
High modified scales, central axis is rachis, branching structure (vanes –> bards –> barbules –> hooks)
Bird morphological adaptations
- sand prober: long thin beak, legs for wading
- insect eater: beak long and pointed
- insect netter: short and flat beak, hairs on beak detet insects, catch insects in flight
- water strainer: short and flat beak, frills to hold food/water
- raptor: short hooks beak with sharp edges
- fish eater: long and spear-like beak
- seed cracker: sorth and stubby beak with sharp edges
