Zoology Lecture Notes - PDF

ZOOLOGY – LECTURE FOR REVIEW PURPOSES ONLY | NOTES BY: HONEY VAZQUEZ ​ secretes mucus used in filter feeding...

ZOOLOGY – LECTURE FOR REVIEW PURPOSES ONLY | NOTES BY: HONEY VAZQUEZ ​ secretes mucus used in filter feeding Endostyle or ​ transformed into thyroid gland in adult lampreys Chordata: Urochordata, Thyroid Gland and other chordates Cephalochordata, and Craniata Subphylum Urochordata Evolutionary Perspective Subphylum Urochordata Evolutionary Perspective General Characteristics ​ share deuterostome characteristics with echinoderms and hemichordates ​ common deuterostome ancestor gave rise to Phylogenetic ancestral representatives of: Relationships ○​ chordates Illustration ○​ echinoderms ○​ hemichordates ​ bilaterally symmetrical deuterostomes ​ has unique combination of five characteristics: ​ tunicates or sea squirts ○​ notochord (spinal column for support) ​ invertebrates characterized by an outer exoskeleton ○​ pharyngeal slits or pouches (gills) called tunic (defining characteristic) Characteristic ○​ dorsal tubular nerve cord (neural tube; brain and General Info ​ divided into three classes: s spinal cord) ○​ ascidians - sea squirts ○​ postanal tail ○​ appendicularians ○​ endostyle or thyroid gland ○​ thaliaceans ​ complete digestive tract ​ ventral, contractile blood vessel (heart) ​ sessile as adults ○​ ascidians (sea squirts) Development ​ planktonic as adults ○​ appendicularians (larvaceans) ○​ thaliaceans (thaliacea) Nerve Tube Formation Chordata Body Parts and Plan Metamorphosis Body Plan 1. endostyle – secrete mucus for food 2. pharynx with stigmas – mucus secreted is brought here Process of to entrap food Food 3. stomach Digestion 4. intestine 5. atrial (excurrent) siphon ​ supportive, flexible rod dorsal to body cavity ​ ciliary-mucous mechanism Notochord Feeding & ​ connective tissue sheath enclosing vacuolated cells ​ endostyle secretes mucus sheet Digestion ​ digestive waste exits with excurrent water ​ openings between digestive tract and outside of body ​ nervous system Pharyngeal ​ may be in form of pouches ○​ nerve plexus in body wall Slits ​ filter feeding or, in some, gills develop for gas ○​ single ganglion on pharynx exchange ​ no complex sensory organs Maintenance ​ uses pharynx for gas exchange Function Tubular Nerve ​ dorsal to notochord ​ open circulation Cord ​ expanded anteriorly into brain ○​ heart is at the base of pharynx ​ excretion Postanal tail ​ extends posteriorly beyond anal opening ○​ diffuses and releases with excurrent water  ZOOLOGY – LECTURE FOR REVIEW PURPOSES ONLY | NOTES BY: HONEY VAZQUEZ ​ monoecious Subphylum Craniata: Fishes Reproduction ○​ cross-fertilization is the rule and ​ external fertilization or within atrium ​ Fishes are not just a class, they’re a clade. Development ​ tadpole-like larva settles and undergoes metamorphosis Evolutionary Perspective Evolutionary Perspective Subphylum Cephalochordata ​ subphylum craniata Subphylum Cephalochordata ○​ skull surrounds brain, olfactory organs, eyes, and inner ear Phylogenetic General Characteristics ○​ infraphylum hyperotreti (hagfish) Relationships ○​ infraphylum vertebrata ​ fossil records ○​ craniates and bone date earlier than 500 mya. Illustration infraphylum – taxon below subphylum but above superclass ​ lancelets Subphylum Craniata ​ shallow marine substrates ​ partially buried filter feeders Subphylum Craniata ​ notochord extends into head ○​ gives this group their name ​ skull surrounds the three-part brain, olfactory General ○​ most of the cells are muscle cells organs, eyes, and inner ear Information ○​ notochord is somewhat contractile ​ unique embryonic tissue and neural crest ​ segmentally arranged muscles on either side of contributes to a variety of adult structures, Composition notochord including: ○​ allows for burrowing ○​ sensory nerve cells ​ has oral hood with cirri ○​ some skeletal structures ○​ other connective tissue structures. ​ filter feeding ○​ ciliated gill bars create water currents Feeding and ○​ oral cirri sorts food Infraphylum Hyperotreti Digestion ○​ endostyle secretes mucus that traps food on gill bars Infraphylum Hyperotreti ○​ transported to gut General ​ example: hagfishes ​ circulation Information ​ fishlike ○​ contractile waves in vessels propel blood Maintenance ​ skull consisting of cartilaginous bars; jawless; no ​ excretion Functions paired appendages ○​ excretory tubules receive waste from blood ​ coelom reduced ​ mouth with four pairs of tentacles Composition ​ olfactory sacs open to mouth cavity ​ dioecious ​ 5 to 15 pairs of pharyngeal slits ○​ gametes shed into atrium and exit via atriopore ​ ventrolateral slime glands Reproduction (or the opening in the body of a lancelet) and Class Myxini ○​ external fertilization Development ​ free-swimming larvae settle and metamorphose to Habitat marine adults General Info ​ likely most primitive group of craniates Subphylum Craniata ​ head supported by cartilaginous bars ​ lack vertebrae and retain notochord for axial Subphylum Cephalochordata Composition support ​ 4 pairs of sensory tentacles around mouth General Characteristics ​ ventrolateral slime glands ​ infraphylum vertebrata – monophyletic group of Food ​ scavenge dead and dying fish animals with backbones, gills, and a CNS. ○​ largest and most successful chordates General ○​ bony or cartilaginous vertebrae completely or Information partially replace notochord ○​ three-part brain ○​ skeleton modified into skull or cranium ○​ abundant fossil record  ZOOLOGY – LECTURE FOR REVIEW PURPOSES ONLY | NOTES BY: HONEY VAZQUEZ Illustration Life History Infraphylum Vertebrata Superclass Gnathostomata Superclass Gnathostomata Infraphylum Vertebrata General ​ jaws developed from anterior pharyngeal arches ​ vertebrae surround nerve cord and serve as primary Composition Information ​ vertebral column may have replaced notochord axial support ​ have hinged jaws and paired appendages ​ ostracoderms Composition ​ three semicircular canals ○​ extinct agnathans Examples ○​ bony armor ​ cartilaginous ○​ bottom dwellers ○​ chondrichthyes Classes ​ bony ○​ actinopterygii ○​ sarcopterygii Class Chondrichthyes, Subclass Elasmobranchii, and Subclass Illustration Holocephali Class Chondrichthyes Examples sharks, skates, rays, ratfishes ​ heterocercal tail – tail fin with large upper lobe Superclass Petromyzontomorphi ​ has placoid scales Composition ​ has cartilaginous skeleton Superclass Petromyzontomorphi ​ lack opercula and a swim bladder or lungs General ​ a large, sucker-like mouth, reinforced by cartilage Information ​ gill arches with spine-shaped processes Class Petromyzontida Illustration Class Petromyzontida Example ​ example: lampreys, brook lampreys ​ sucking mouth with teeth and rasping tongue ​ most are predators as adults, filter-feeders as larvae Subclass Elasmobranchii General Characteristic ​ for brook lampreys, adults do not feed Example sharks, skates, rays s ​ life cycle: involve open water adult stages and stream or river larval stages ​ cartilaginous skeleton may be partially ossified; Composition ​ placoid scales or no scales Habitat marine and freshwater Scales and Teeth of Sharks ​ seven pairs of pharyngeal slits Composition ​ blind olfactory sacs Illustration Illustration Subclass Holocephali Example ratfishes Composition ​ operculum covers pharyngeal slits  ZOOLOGY – LECTURE FOR REVIEW PURPOSES ONLY | NOTES BY: HONEY VAZQUEZ ​ lack scales ​ atria and ventricles at least partly divided ​ teeth modified into crushing plates ​ lateral-line receptors in an open groove Gas exchange lungs used in gas exchange Class Actinopterygii Class Actinopterygii ​ chondrosteans Illustration Examples ○​ sturgeons and paddlefish ○​ have cartilaginous skeletons ​ ray-finned fishes ○​ fins lack muscular lobes ○​ basal portions of paired fins not especially muscular Evolutionary Pressures ​ swim bladders Composition ​ paired fins supported by dermal rays Evolutionary Pressures ​ tail fin with approximately equal upper and lower lobes (homocercal tail) ​ closed circulatory system ​ blind olfactory sacs ​ heart ​ pneumatic sacs function as swim bladders ○​ 4 embryological enlargements of ventral aorta ○​ sinus venosus ​ neopterygii ○​ atrium Specific ○​ garpike (Lepisosteus) and dogfish or bowfin ○​ ventricle Information (Amia) ○​ conus arteriosus ○​ modern bony fishes – the teleosts ​ most fish have a single circuit ​ lungfish ○​ pulmonary circulation ○​ pulmonary and systemic circuits Circulation Illustration Class Sarcopterygii Class Sarcopterygii ​ water movement over gills ○​ opercular and pharyngeal muscles pump water ​ lungfishes, coelacanths, and tetrapodomorpha, in most fishes Examples including all tetrapods ○​ ram ventilation in elasmobranchs and open-ocean bony fish ​ lungfish ○​ ram ventilation is simply swimming with the Gas Exchange ○​ 3 genera fish’s mouth open ○​ found in: australia, africa, south america ​ gas exchange surfaces Specific ​ coelacanths ○​ gill (visceral) arches support gills Characteristic ○​ 2 species ○​ gill filaments and pharyngeal lamellae s ○​ found in: african and indonesian coasts ​ tetrapodomorpha countercurrent exchange mechanism ○​ extinct ancestors of ancient amphibians and all tetrapods ​ lobe-finned fishes Description ○​ fins with muscular lobes ​ paired fins with muscular lobes Composition ​ pneumatic sacs function as lungs  ZOOLOGY – LECTURE FOR REVIEW PURPOSES ONLY | NOTES BY: HONEY VAZQUEZ ○​ migrate between freshwater and marine environments ○​ gills cope with both uptake and excretion of ions ​ nitrogen wastes ○​ 90% ammonia (diffusion across gill surfaces) ○​ 10% urea, creatine, or creatinine (excreted by kidneys) ​ most oviparous ○​ some elasmobranchs are ovoviviparous whilst others are viviparous ​ fertilization Reproduction ○​ most external and ○​ copulatory structures (claspers in elasmobranch Development males) ​ development ○​ usually little or no parental care ○​ some tend nests or brood young ​ have brain and spinal cord ​ sensory receptors Further Phylogenetic Considerations ○​ external nares ○​ eyes (lidless and round lens) Terrestrialism ○​ inner ears (for equilibrium, balance, and hearing) ​ osteolepiform sarcopterygians ○​ lateral line system (sensory pits in skin detect ○​ common features with amphibians water movements) ○​ jaws, teeth, vertebrae, limbs ​ electroreception ​ Tiktaalik (the “fishapod”) ○​ prey detection by chondrichthyans (ampullae of ○​ fins, gills, scales Tetradomorpha Lorenzini) ○​ dorsoventrally compressed and widened skull ○​ Gymnarchus ○​ tetrapod-like forelimbs ○​ Electrophorus ○​ lacked opercular supports and dorsal and anal fins ○​ pectoral girdle and freely moveable neck Nervous and Sensory Functions Evolution of Tetrapod Limbs ​ kidneys ○​ filter nitrogenous wastes, ions, water, and small Amphibians organic compounds at nephrons ○​ glomerulus is a filtering capillary network Evolutionary Perspective ○​ tubule system promotes reabsorption ​ freshwater fishes Phylogenetic ​ tetrapodomorpha includes lobe-finned fishes ○​ excess water must be excreted Relationships ​ class sarcopterygii is monophyletic Excretion and ○​ ions and organic compounds are selectively ​ “double life” Osmoregulation reabsorbed ​ examples: frogs, toads, salamanders, caecilians ​ marine fishes Amphibia ​ early amphibians ○​ water must be conserved ○​ stegocephalian lineage including Ichthyostega ○​ excess ions excreted (365 mya) ​ elasmobranchs ○​ sequester urea in body tissues ​ all sarcopterygian descendants that possess ○​ rectal gland Tetrapods well-formed forelimbs and hindlimbs ​ diadromous fishes  ZOOLOGY – LECTURE FOR REVIEW PURPOSES ONLY | NOTES BY: HONEY VAZQUEZ Class Amphibia Class Amphibia ​ skin with mucoid secretions and lacking epidermal General scales, feathers, or hair; Illustration Characteristic ​ two atrial chambers in the heart; one cervical and one sacral vertebra ​ larvae usually aquatic and undergo metamorphosis Composition to the adult Order Gymnophiona Order Anura / Salientia Order Gymnophiona Order Anura or Salientia ​ example: caecilian or “blind snakes ​ examples: frogs and toads General ​ elongated, limbless ​ tailless; elongated hindlimbs modified for jumping Information ​ tropical burrowers feeding on soil invertebrates General and swimming ​ appear segmented because of skin folds Characteristic ​ adults lack tails ​ caudal vertebrae fuse into: urostyle, hindlimbs long, ​ segmented by annular grooves muscular and end in webbed feet ​ specialized for burrowing Composition ​ short and pointed tail ​ have five to nine presacral vertebrae with transverse ​ rudimentary left lung processes (except the first); Composition ​ post-sacral vertebrae fused into rod-like urostyle ​ fertilization internal ​ tympanum and larynx well developed Reproduction ​ larval stages within oviducts ​ fertilization external Reproduction ○​ eggs and larvae (tadpole) aquatic ○​ larvae are herbivores Illustration Illustration Order Caudata Order Caudata ​ example: salamanders, newts, sirens, amphiumas Evolutionary Pressures General ​ tail throughout life, unspecialized legs Information ​ Evolutionary Pressures ​ terrestrial ​ skin ○​ lives in moist forest floor litter with aquatic ○​ keratin deposits may produce warts, claws, or larvae (except in Plethodontidae) other hardened structures External aquatic ​ glands Habitat ​ Structure and ○​ newts (salamandridae) ○​ granular glands – noxious or toxic secretions Locomotion ○​ most of their lives in water, may retain caudal ○​ mucous glands – prevent drying fin ​ chromatophores ○​ color and color changes ​ long tail two pairs of limbs ​ skull Composition ​ ​ lack middle ear ○​ flattened and has fewer bony elements than fish ○​ jaw structure and musculature modified for ​ internal fertilization using spermatophore capturing and holding prey ○​ larvae with external gills, tail fin, larval ​ vertebral column – provides support & flexibility on Reproduction land dentition, and a rudimentary tongue ○​ some paedomorphic (e.g. Necturus) ○​ zygapophyses on vertebrae prevent twisting Support and ○​ single cervical vertebra Movement ○​ single sacral vertebra ​ sternum ○​ supports forelimbs and protect internal organs ​ pelvic girdle ○​ illium, ischium, pubis ○​ supports hindlimbs  ZOOLOGY – LECTURE FOR REVIEW PURPOSES ONLY | NOTES BY: HONEY VAZQUEZ ​ nitrogenous wastes ○​ ammonia and urea ​ in water – excrete excess water and conserve ions ○​ kidneys and urinary bladder ​ on land – conserve water with behaviors that prevent loss Osmoregulation ○​ nocturnal ○​ body posture ○​ cocoons Nutrition and ​ carnivores as adults ○​ cutaneous absorption the Digestive ​ herbivores as larvae ○​ storage in lymph sacs and urinary bladder System ​ prey capture via flip-and-grab ​ dioecious ​ adaptations for life divided between aquatic and ​ fertilization usually external terrestrial habitats ​ development usually in water ○​ similar separation of pulmonary and systemic Reproduction ​ courtship circuits to what was described in the lungfishes ○​ salamanders (olfactory and visual cues) ○​ cutaneous gas exchange results in blood ○​ anurans (tactile and auditory cues) returning to heart being highly oxygenated ​ well developed lymphatic system ​ male anurans ○​ lymphatic hearts and spaces ○​ attract females to breeding areas Circulation Vocalization ○​ establish breeding territories ○​ species specific ​ attendance at egg clutch by either parent Parental Care ​ egg transport ​ controlled by neurosecretions of hypothalamus, anterior pituitary gland, and thyroid gland. ​ salamanders and caecilians ○​ relatively minor changes ​ cutaneous respiration Metamorphosis ​ anurans (tadpole to frog) ○​ highly vascular skin promotes gas exchange ○​ limbs and lungs develop (30% to 90% of salamander respiration) ○​ tail is reabsorbed ​ buccopharyngeal respiration ○​ skin thickens ○​ moist surfaces of mouth and pharynx (1% to 7%) ○​ changes in head and digestive tract ​ pulmonary ○​ buccal pump mechanism creates positive Gas Exchange pressure Amphibians in Peril ​ larvae and some adults use external gills One-third of amphibian species are threatened with extinction. Water- and airborne pollutants quickly penetrate thin permeable skin. ​ threats ○​ clear-cutting forests and development ​ ectothermic (cannot generate own body heat) ○​ chytrid fungus Temperature ​ behavioral temperature regulation ○​ climate change Regulation ○​ for cooling (nocturnal, burrowing) ​ conservation ○​ for warmth (basking) ○​ population monitoring Nervous ​ vertebrate brain from three embryological ○​ collecting restrictions System subdivisions ○​ wetland conservation ​ skin receptors ○​ climate change reversal ​ lateral line system ​ chemoreception (nasal epithelium, mouth, skin) Further Phylogenetic Considerations ​ vision ○​ binocular vision ​ Lissamphibia are monophyletic ○​ nictitating membrane lubricates and washes Sensory eye (accomodation by lens movement) movement of sarcopterygians onto land Functions ​ hearing (air-borne vibrations) 1.​ skeletal and muscular changes that allowed greater ○​ tympanic membrane mobility on land ○​ stapes (columella) ​ hearing (substrate-borne vibrations) 2.​ jaw mechanism and moveable head permitted ○​ transmitted through front appendages and exploitation of insect resources on land pectoral girdle 3.​ development of amniotic egg ○​ operculum ○​ protects embryo from desiccation ​ kidneys ○​ amniotic lineage only Excretion ○​ dorsal body wall  ZOOLOGY – LECTURE FOR REVIEW PURPOSES ONLY | NOTES BY: HONEY VAZQUEZ Nonavian Reptiles: Diapsid Amniotes Evolutionary Perspective Amniote Lineage ​ a clade/group ​ monophyletic lineage including reptiles, birds, and Amniote Skull mammals Characteristic ​ have amniotic eggs (distinguishing characteristic) s with extraembryonic membranes that: ○​ protect embryo from desiccation ○​ cushion embryo Amniota ○​ promote gas transfer ○​ store waste ​ other terrestrial adaptations ○​ impervious skin ○​ horny nails ○​ water-conserving kidneys ○​ enlarged lungs Survey of the Reptiles ​ amnion – amniotic sac containing the fluid; ○​ for protection & cushioning Order Testudines ​ chorion – ​ allantois – function to transfer waste and nutrients; Order Testudines ○​ for gas exchange as well ​ yolk stalk – for yolk nourishment needed for an ​ turtles embryo to grow ○​ all tortoise are turtles, but not all turtles are ​ yolk sac – tortoise ​ characterized by: General ○​ bony shell The Amniotic Characteristic ○​ limbs articulate internally to ribs Egg ○​ keratinized beak (for gnawing food) rather than teeth ​ shell ○​ carapace (dorsal) and plastron (ventral) Reproduction oviparous ​ turtles ○​ habitat: life spent in water ○​ diet: feeds on plants and animals ​ Mammals ○​ shell: slim, heart-shaped ○​ most closely related to ancestral amniotes Cladistic Turtles vs. ○​ limbs: flippers for swimming ○​ reptilian lineage (birds, dinosaurs, other Interpretation Tortoise ​ tortoise reptiles) ○​ habitat: life spent on land ○​ traditional class “reptilia” is paraphyletic ○​ diet: mostly plants ○​ shell: round dome Amniote fossils document the divergence of two lineages ○​ limbs: sturdier legs for walking ​ Synapsids ○​ mammals ​ pleuradines – cannot elongate their necks ○​ single opening (fenestra; hole) in temporal Orders ​ cryptodines – can elongate their necks Early Amniote region of skull Evolution and ​ Diapsida Skull ○​ two fenestrae Structure ○​ all living reptiles (including birds; aves) and numerous extinct lineages Skeleton of a ○​ diapsid has debatable function but it is possible Turtle that it is to accommodate the elongation of the brain Order Crocodylia Order Crocodylia ​ examples: alligators, crocodiles, gavials, caimans ​ archosaur lineage General ​ skull characteristics: Characteristic ○​ openings in front of the eyes ○​ triangular eye orbits  ZOOLOGY – LECTURE FOR REVIEW PURPOSES ONLY | NOTES BY: HONEY VAZQUEZ ○​ laterally compressed teeth ○​ scales may be modified ​ has secondary palate which separates the nasal and ○​ epidermal layers shed through ecdysis mouth passageways ​ Support and movement ○​ nonexistent with frogs who have ○​ skeleton highly ossified buccopharyngeal cavity ○​ skull with secondary palate ○​ additional cervical vertebrae (including atlas Reproduction oviparous with parental care and axis) ○​ two or more sacral vertebrae attach the pelvic girdle to the vertebral column secondary palate: Illustration Order Sphenodontia ​ Most are carnivores Order Sphenodontia ○​ turtles can be carnivores, herbivores, or omnivores depending on the species ​ tuataras ​ Tongues ​ distinguished by skull features: ○​ non-protrusible - cannot extend, thrust ○​ akinetic jaw – lower firmly attached to upper forward, or opened out (for turtles and General ○​ two rows of teeth on upper jaw Characteristic crocodilians) ○​ single row of teeth in lower jaw ○​ protrusible - for lizards (squamata) and tuatara ○​ third eye above the head ​ Feeding adaptations of snakes ​ found in new zealand ○​ bones of the skull and upper jaw are moveable (upper jaw is also moveable on skull) ​ oviparous Nutrition and ○​ ligaments loosely join the halves of upper and Reproduction ​ dioecious the Digestive lower jaws anteriorly ​ mating by rubbing of cloaca System ○​ porterior pointing teeth ○​ glottis opens forward in mouth ○​ hinged maxillary bones in vipers ○​ venom glands in some (modified salivary glands) Illustration Order Squamata ​ HEART ○​ sinus venosus reduced to pacemaker (except Order Squamata turtles) ○​ two atria and incompletely divided ventricle ​ kinetic skull (except crocodilians) ○​ moveable jaws to engulf food General ○​ conus arteriosus and ventral aorta divided ○​ moveable quadrate bones and other skull Characteristic embryologically intro three major arteries modifications leaving heart ○​ increases skull flexibility ​ Illustration of the Heart ​ Suborder Sauria – Lizards ○​ usually two pairs of legs ○​ upper and lower jaws unite anteriorly Circulation ○​ oviparous, ovoviviparous, or viviparous Orders ○​ includes legless amphisbaenians ​ Suborder Serpentes – Snakes ○​ legless ○​ skull adaptations for swallowing large prey ​ Process of Circulation ○​ most oviparous, some give birth to live young ○​ synchronous contraction and relaxation of atrium and ventricle ○​ atrium pumps blood towards the ventricle → Evolutionary Pressures ○​ ventricle pumps blood outside the aorta → ○​ aorta delivers to the lungs, head and other parts Evolutionary Pressures of the body → then repeat back to atrium External ​ Skin Structure and ○​ distinguishing characteristic Locomotion ○​ thick, dry, keratinized; no respiratory functions  ZOOLOGY – LECTURE FOR REVIEW PURPOSES ONLY | NOTES BY: HONEY VAZQUEZ ○​ a few lizards and snakes ​ courtship behaviors are common ​ eggs usually develop unattended by a parent ○​ american alligator and a few others are exceptions Definition of Terms ​ Internal respiratory surfaces ○​ sponge-like lungs – provides large surface area ectothermic – organisms that cannot generate their own for gas exchange heat ​ Negative pressure ventilation Gas Exchange endothermic – organisms that can generate their own heat ○​ posterior movement of ribs and body wall hibernacula – area where organisms can hibernate expands body cavity intromittent organ – structure in a male organism that ○​ decreased body cavity pressure draws air into lungs delivers sperm into a female during copulation slotting (in birds) – the gap between the outer primary ​ most are ectotherms feathers of a bird's wing, where the feathers split and spread ○​ except brooding Indian pythons vertically ​ behavioral regulation turbulence – caused by changes in the characteristics of ○​ orientation at right angles to sun’s rays the air such as pressure and temperature ○​ warming by conduction from warm surfaces ○​ cooling by seeking shade or burrows, assuming erect posture and nocturnal habits ​ physiological regulation Birds: The Avian Reptiles Temperature ○​ panting Regulation ○​ diverting blood to skin while basking (specific Class Aves to marine iguanas) ​ torpor ​ dozens of shared characteristics with (other) reptiles ○​ temporary halt of metabolic activity ​ have: ○​ occurs in temperate climates ○​ single occipital condyle (called columella) ○​ enter hibernacula ○​ single ear ossicle ○​ different from hibernation (because body ○​ other skeletal characters temperature is not regulated) General ○​ nucleated red blood cells Characteristic ○​ nesting behavior ​ brain is similar to other vertebrates s ○​ endothermy (dinosaur lineages) Nervous ○​ cerebral hemispheres, optic lobes, and ​ archosaur lineage System cerebellum enlarged. ○​ saurischian lineage called the Theropods (aka ancient birds) ​ vision ○​ feathered theropod dinosaurs support this ○​ dominant sense lineage ○​ eyes focus by lens movement (such as in snakes) or changing lens shape (in other reptiles) ○​ have upper and lower eyelids as well as Evolutionary Perspective nictitating membrane Sensory ○​ nictitating membrane - for moisture and vision Evolutionary Perspective Functions underwater ​ median (parietal eye) ​ archaeopteryx ○​ outgrowth of roof of forebrain ○​ 150 mya (Germany) ​ hearing ○​ reptilian tail and clawed fingers ○​ airborne Ancient Birds ○​ imprint of feathers on tail and wings (from and the ○​ substrate borne vibrations – vibration felt by the fossils indicating flight capability) Evolution of limbs) ​ eoalulavis Flight ○​ 125 mya (Spain) ​ metanephric kidneys ○​ wings have alula (the thumb in the end of the ○​ for filtering waste (uric acid) wing) ​ water conserving behaviors Excretion and ○​ nocturnal habits ​ ancient birds aren’t necessarily dinosaurs Osmoregulation ○​ avoidance of high temperatures by burrowing ​ most bird lineages are represented by early fossils ​ water storage became extinct along with dinosaurs ○​ lymphatic spaces (to retain water) ​ modern birds, diverged from a few lineages, ○​ urinary bladder survived into the Tertiary period. Diversity of ○​ numerous species ​ internal fertilization and amniotic egg make Modern Birds ○​ 35 orders development apart from external water sources ​ dinosaurs’ sizes are because of evolutionary possible pressures during that period Reproduction ​ intromittent organ ○​ also related to the great oxidation event (when and ○​ hemipenes (reproductive organ in males) cyanobacteria released oxygen into the Development ​ parthenogenesis atmosphere) ○​ females only ○​ naha-hatch kahit walang DNA ng males  ZOOLOGY – LECTURE FOR REVIEW PURPOSES ONLY | NOTES BY: HONEY VAZQUEZ Evolutionary Pressures Evolutionary Pressures FEATHERS ​ functions for: ○​ flight ○​ insulation ○​ courtship ​ Muscles ○​ incubation ○​ flight adaptations ○​ waterproofing ​ Flight ○​ form airfoil wherein the gradient of pressure Two shafts of feathers: causes the plane to move upward (basically, ​ pennaceous – prominent shaft; hard feather ↑pressure ↓speed) ○​ flight feathers (asymmetrical) – for tails and ○​ slotting and alula reduce turbulence wings of birds ​ Tail ○​ contour feathers (symmetrical) – found in the ○​ functions for: balancing, steering, braking body; for waterproofing, insulation, and ○​ can be extended to control air resistance streamlining ​ Kinds of Flight ​ plumulaceous – rudimentary shaft; soft feather ○​ gliding ○​ for additional insulation ○​ flapping ○​ downward direction ○​ soaring ​ developmental feather anatomy: ○​ hovering ​ high rates of food consumption support rapid metabolic rates ​ bill modifications ○​ depending on lifestyle or type of food that they eat ​ digestive tract has crop for storage ​ stomach – they don’t have actual stomach, but they have a similar structure that is separated into two: ○​ proventriculus - secretes gastric juices ○​ ventriculus (gizzard) – muscular; contracts for grinding ((mechanical digestion) Nutrition and External the Digestive Structure and System Locomotion SKELETON ​ lightweight and strong – so they can fly ○​ has large air spaces and internal strutting ○​ reduced number of skull bones ○​ bill replaces teeth (some still have teeth but mostly only uses bills) ​ bill and flexible neck are used in nesting and feeding their young ​ pelvic girdle and vertebral column and ribs strengthened for flight ○​ synsacrum – fused sacral, lumbrical, and partial thoracic ​ completely separated atria and ventricles result in ○​ pygostyle – fused tail bones which holds the separate pulmonary and systemic circuits birds’ tail feathers and muscles ​ sinus venosus serves as pacemaker ​ Flight muscle attachment ​ very rapid heart rates and separate pulmonary and ○​ keeled sternum – extension of the sternum systemic circuits support flight and endothermy (breastbone) that runs axially along the midline ○​ heart is not dependent on the brain of the sternum ​ HEART ANATOMY Circulation ○​ furcula – wishbone of the bird at the end of their abdomen (beginning at the bottom of their neck) ​ Appendages ○​ fusion of bones ○​ perching tendons  ZOOLOGY – LECTURE FOR REVIEW PURPOSES ONLY | NOTES BY: HONEY VAZQUEZ ​ oviparous ○​ testes paired ○​ left ovary develops and releases eggs to large ostium ○​ albumen secreted by oviduct ○​ shell gland secretes shell around fertilized egg ​ territories and courtship common ​ mating ○​ monogamous ​ Syrinx Reproduction ○​ polygynous and ○​ polyandrous ○​ vocalizations Development ​ urogenital system of a female pigeon Gas Exchange ​ Bronchi lead to air sacs ○​ occupy much of body ○​ extend into bones ​ Lungs ○​ parabronchi – small air tubes that function in gas exchange; unique characteristics ​ respiratory cycles ○​ two cycles move each volume of air through the lungs ○​ uninterrupted airflow through parabronchi with both inspiration and expiration promotes ​ clutch size variables efficient gas exchange Nesting ​ most incubate eggs Activities ​ altricial – entirely dependent on parents at hatching ​ body temperature ​ precocial – relatively independent at hatching ○​ between 38 and 45ºC ​ heat conservation ​ periodic round trips between breeding and ○​ fluffing feathers decreases heat loss nonbreeding areas Thermoregulation ○​ tucking bill into feathers ○​ most annual and north/south ○​ countercurrent heat exchange in legs ○​ breeding area resource abundance varies from ​ heat generation season to season (abundant in spring/summer ○​ shivering Migration breeding season) ○​ muscular activity in flight ​ response to species-specific physiological conditions ​ enlarged forebrain ○​ innate clocks ○​ corpus striatum – for visual learning, feeding, ○​ environmental factors courtship, and nesting ○​ pineal body – ovarian development and ​ route-based navigation – landmarks on outward Nervous responses to light and dark periods journey used to guide return trip System ​ midbrain Navigation ​ location-based navigation – sun compasses, other ○​ sensory input for visual processing celestial cues, and the earth’s magnetic field ​ hindbrain ○​ motor coordination ○​ regulation of heart and respiratory rates Mammals: Synapsid Amniotes Seeing / Vision ​ has double-focusing mechanisms: ○​ curvature of lens Definition of Terms ○​ curvature of cornea ​ monocular vs. binocular vision obsoleted – no longer officially a subclass of the mammals but are still considered under them because of certain characteristics homologous – similar structure Sensory right chambers – right atrium and right ventricle System left chambers – left atrium and left ventricle gestation period – the period of time between conception and birth when a baby develops in the mother's womb proliferation – rapid increase or growth Smelling / Olfaction ​ minor importance except in vultures Hearing / Auditory Evolutionary Perspective ​ well developed Evolutionary Perspective ​ excretes uric acid stored in cloaca ○​ promotes water conservation and embryo ​ 70 mya development in terrestrial environments ​ extinction of many reptilian lineages led to adaptive Excretion and Age of Osmoregulation ​ supraorbital salt glands radiation of mammals Mammals ○​ marine birds secrete excess salt through nasal ​ synapsid branch (320 mya) openings ○​ first amniote lineage  ZOOLOGY – LECTURE FOR REVIEW PURPOSES ONLY | NOTES BY: HONEY VAZQUEZ ○​ mammalian characteristics evolved gradually ○​ incus over 200 million years ○​ stapes ○​ Therapsid subgroup ​ secondary palate ​ Characteristics of Therapsid: ○​ most developed compared to reptiles but have ○​ mammal-like teeth (omnivores; so their teeth similar function (separates oral and nasal cavity) varies) ○​ not homologous to archosaur secondary palate ○​ hindlimbs directly beneath body ​ teeth ○​ separation of thoracic and abdominal regions ○​ teeth specialization varies per organism ○​ survived nocturnally during archosaur ○​ diastema – space between teeth dominance. ○​ homodont ​ modern mammal radiation ​ uniformly conical – one type of teeth only ○​ mass extinction of dinosaurs and many other ​ usually for herbivores because they only eat taxa (65 mya) one type of food (grass, etc.) ○​ tertiary period “age of the mammals” ​ common in reptiles ○​ heterodont TWO LINEAGES ​ specialized for different functions ​ Subclass Prototheria (Obsoleted) ○​ deciduous (milk teeth) and permanent ○​ cloaca ​ single replacement of teeth is the ○​ oviparous diphyodont condition; polyphyodont in ○​ monotremata [platypus (ovi) & anteater (vivi)] reptiles ​ Subclass Theria – have infraclasses: ​ diphyodont – animal that has two sets of teeth, ○​ metatheria first a deciduous set, then a permanent set ​ marsupials – distinguishing feature is ​ polyphyodont – teeth are constantly replaced abdominal pouch ​ example: kangaroos, wombats, tasmanian ​ vertebral column – have more vertebra devil, koalas ○​ cervical ○​ eutheria ○​ thoracic ​ placental mammals – animals that do not ○​ lumbar Diversity of have pouches ○​ sacral Mammals ​ viviparous but offsprings have placenta (with Vertebral ○​ caudal regions Column, different composition) ​ appendicular skeleton – helps rotate the body Appendicular ○​ rotates under body Skeleton, and GEOLOGICAL INFLUENCES ○​ appendages move in an anteroposterior (up and Muscles ​ Continental movements isolated ancestors of four down) plane mammalian clades (superorders) such as Pangaea ​ muscles ​ Pangaea (100 mya) ○​ concentrated in upper portion of appendages ○​ subcontinents subdivided by later continental and in girdles movements ○​ facilitates movement ​ afrotheria and xenarthra – Africa, South America, and Antarctica ​ diverse feeding habits that reflect ecological ​ laurasiatheria and euarchontoglires – specializations North America, Europe, Asia ​ digestive tracts of herbivores: ○​ cecum ○​ ruminant stomach chambers Evolutionary Pressures ​ rumen – largest stomach compartment; acts Nutrition and as fermentation vat Evolutionary Pressures the Digestive ​ reticulum – filters large object; also System considered as “tuwalya” ng baka SKIN ​ reticulorumen – reticulum + rumen ​ Hair ​ omasum – absorbs fluid and bring them back ○​ epidermal for circulation ○​ periodically molded ​ abomasum – secretes acid (HCl) and ○​ sense of touch digestive system; fourth and final ○​ insulating layer compartment ​ Claws ○​ epidermal ​ complete separation of pulmonary and systemic ○​ offensive and defensive circuits ○​ specialized to form nails or hooves ○​ similarities with bird hearts result from External ​ Glands convergence within synapsid and archosaur Structure and ○​ epidermal – protection, for skin color lineages Locomotion ○​ sebaceous – for lubrication ​ adaptations to active lifestyle ○​ sudoriferous – for temperature regulation and ​ process of circulation Circulation removal of waste products ○​ right chambers are responsible for collecting ○​ scent (musk) – to produce pheromones deoxygenated blood → ○​ mammary – produce, store, and release milk ○​ transports it to the lungs for oxygenation → ​ cistern – mammary gland of cows where ○​ left chambers collect oxygenated blood from milk is stored; nonexistent in humans the lungs → transports it to the aorta → ○​ aorta will deliver it to the other parts of the SKULL AND TEETH body ​ Three middle ear ossicles ○​ malleus  ZOOLOGY – LECTURE FOR REVIEW PURPOSES ONLY