Comparative origin vertebratesWaristha Angsirijinda ,2015

The vertebrates PhylumClass

SubclassOrder

FamilyGenus

Species

Hemichordates: acorn worm

Phylum Chordata Phylum Chordata

Subphylum Urochordata Subphylum Cephalochordata Subphylum Craniata

Hagfish (Craniata withoutvertebrae)

Vertebrata(Craniata withvertebrae)

Subphylum Urochordata

Subphylum CephalochordataTentacle

Mouth

Pharyngeal slitsAtrium

Digestive tract

AtrioporeSegmentalmuscles

Anus

Notochord

Dorsal, hollownerve cord

Tail

2 cm

Subphylum Cephalochordata

Cephalochordata

Nervous system Central nervous system : hollow brain, dorsalnerve cord

Ependyma Cranial nerve 7 pairs

Circulatorysystem

Phylogennetictree

Class Agnatha (Jawless fishes)-Ostracoderms +-Cyclostomes () lamprays, hagfishes

1. 2. 3. parasite4. semicircular duct 2

Class Agnatha Hagfishes Lampreys

Primitive No jaws

Placoderm +

Class Chondrichthyes Elasmobranch : Cartilaginous skeleton

Class Chondrichthyes: 3 Cladoselachii + Selachii (

) Batoideo ray, skate

pelvic fin (male) clasper

Placoid

Shark

Class Chondrichthyes The members are called cartilaginous fishes, as theirendoskeleton is made of cartilage only. Bone isabsent, (Gk. Chondros = cartilage; ichthyes = fishes. Mostly marine fishes Body wall consists of placoid scales Mouth ventral Heterocercal type of caudal fin Five pairs of gill slits present, without operculum.Gills are lamellar type No air bladder Conus arteriosus with several rows of valves Males have a pair of claspers Fertilization is internal

Claspers shark

Semicircular canals

Conus arteriosus

Class Osteichythyes This class comprises the bony fishes whichform the majority of living fishes.

The members are called bony fishes, becausethe endoskeleton is made chiefly of bone(Gr .Osteon = bone; ichthyes = fish).

Inhabit all types of water lake, pond, river,salt water.

Fins are supported by finrays of cartilage orbone.

Class Osteichythyes Skin contains mucous glands.It consists of cycloid, ctenoidor ganoid scales. Mouth terminal Upper and lower jaws withteeth. Four pairs of gills present. Gill slits are covered by anoperculum. Gills are filamentary type. An air bladder or swimbladder is often present.

Scales

Class Osteichythyes

Osteichthyans

Cladistian

bichir

Chondrostean

sturgeon

gar

Halecomorph

bowfin

Teleosts

Class Amphibia Phylum Chordata

Subphylum VertebrataClass Amphibia

Order AnuraFamily Ranidae

Genus Rana

Class Amphibia Apoda : caecilians Urodela : necturus, siran Anura : toad, frog

Eggs - hatched in water , lack shell.First part of life in water ,move to land.

Apoda This order includes snake like, limbless amphibians. The name Apoda refers to limbless forms (Gr. A=without;

podos=foot). Primitive, burrowing amphibians. Body elongated, worm like. Limbs and limb girdles are absent. Skin appears wrinkled Tail is much reduced or absent. Eyes are rudimentary and functionless. Fertilization is internal. Parental care is exhibited by the females in some species by

coiling around the eggs until hatching.

Apoda

Caecilians

Anura Common amphibians, the frogs and toads are includedin this order. The name Anura refers to the absence of tail in adults(Gr. An=without; aura=tail). Body is divisible into head and trunk. A distinct neckregion is absent. Tail is absent in adults. Skin is soft and loosely attached. Scales are absent.Mucous glands are present in some species. Fore limbs are short and hind limbs are long, anadaptive modification for jumping. Hind limbs withwebbed toes, for swimming. Vertebral column is well developed. Vertebrae of different types are present.

Anura Gills and gill slits are absent in adults. Lungs are the respiratory organs. Skin and buccal cavity also have a role in respiration inmany species of frogs. Eyelids are present. A middle ear consisting of a tympanic membrane and acolumella is present. The inner ear contains 3semicircular canals. Fertilization is external. Adults return to water for egglaying. Larva undergoes metamorphosis and develops into anadult. This order includes about 2,200 species.

Columella

Anura

UrodelaNecturus

Siran

Retile Reptiles are the first true terrestrial vertebrates leading lifeon land successfully. The name Reptilia refers to the creeping mode of theirlocomotion on land, (L. repere or reptum = creep or crawl). Reptiles are the first vertebrates to lay eggs on land. These eggs are called amniote eggs. The development occurs completely on land. During development, the extra embryonic membranesnamely amnion, allantois and yolk sac are formed. This bag contains a fluid called amniotic fluid whichprotects the embryo from desiccation and against anyinjury. The vertebrates which have an amnion during theirdevelopment are grouped together as Amniota. The egg is externally protected by a leathery shell whichseparates the egg from its surroundings.

Retile Squamata:

-Turtle-Lizards-Snakes-Crocodilians

: Amniote egg with shell

Turtle

Lizards

Class Aves Birds are the first group of warm blooded vertebrates, (Homoiothermicanimals). They maintain a constant body temperature. Exoskeletal structures are epidermal derivatives. They include feathers, clawson toes, scales on legs and sheaths on beaks. Skin is dry. Cutaneous glands are absent. Oil glands or preen glands are present at the base of the tail and the oilysecretion is used for preening the feathers. Forelimbs are modified into wings for flying. Hind limbs are strong and modified to support and balance the body on theground. The feet are modified to carry out different functions like running,walking, perching, raptorial wading and swimming. Jaw bones are extended into a horny beak or bill. Teeth are absent in the beak. The shape of the beak varies in different birdsdepending upon their feeding habits. Body is spindle shaped, an adaptation for rapid flying. It is divisible into head,a long and flexible neck, trunk and a short tail. The bones are strong and pneumatic as a weight reducing adaptation. Fusionof bones and reduction in the number of bones are characteristic ex.synsacrum

Aves Warm blooded Hollow bones

Class Aves Skull bones are fused together and no indication of thesutures. Cranium is large, skull with a single occipital condyle. Mandible of the lower jaw articulates with the quadrate boneof the upper jaw and this is known as jaw suspension. Vertebral column is strong. The posterior thoracic, lumbar,sacral and anterior caudal vertebrae are united to form thesynsacrum. The last few vertebreae are fused to form pygostyle. Sternum is large and well developed with a mid ventral keelfor the attachment of the flight muscles or pectoral muscles. Clavicles of both sides are united to form a V-shaped , for themovement of the wings.

Class Aves Larynx has no role in sound production. Syrinx or voice boxis present for this purpose. Brain is large and well developed. Cerebral hemispheresare large. Eyes are large, with eyelids and nictitating membrane. Avascular pectin is concerned with lens accommodation,regulation of fluid pressure in the eye ball and perceptionof movements. Kidneys are metamorphic type. Uricotelic animals. Urinary bladder is absent. Fertilization is internal. Oviparous eggs large with moreyolk, with a protective calcareous shell. Eggs develop byincubation. During development, extra-embryonic membranes areformed. Exhibit parental care.

Class Aves Alimentary canal is well developed withspecialized regions such as crop, proventriculusand gizzard. Respiratory system is highly efficient. The pairedlungs are spongy, non-elastic and provided withair sacs. Heart is four chambered. Two auricles and twoventricles present with valves. No mixing of bloodoccurs. Sinus venousus and truncus arteriosus areabsent. Only right systemic is present.

Alimentarycanal

Pigeonskeleton

Class Mammalia Class Mammalia derives its name by the presence of the mammaryglands (L. Mamma = mammary glands). Mammary glands or milk glands are present in the females. Theseglands secrete milk for nourishing the young ones. Viviparous vertebrates which give birth to young ones, exceptmonotremes. These monotremes are egg laying mammals. Homoiothermic animals or warm blooded animals which maintain aconstant body temperature. Mostly terrestrial and some are secondarily aquatic. Body is covered by hairs. These hairs are epidermal in origin andprevent the loss of heat from the body. The hairs may be modifiedinto spines, spurs or scales. Two pairs of limbs are present. They are adapted for walking,running, burrowing, climbing, flying or swimming.

Class Mammalia Exoskeleton includes the hairs, spines, scales, claws,nails, hoofs and horns. Skin glands or cutaneous glands namely the sweatglands, oil or sebaceous glands are present. Diaphragm, a muscular partition that separates thethorax and the abdomen is present and has a role inrespiration. Endoskeleton is well developed. Cranium is large to accommodate a large brain. Lower jaw on each side is made of a single bone calleddentary. Cervical vertebrae, seven in number. Digits not more than five, often reduced in number.

Class Mammalia 2 1. Prototheria- reptile - (Cloaca)- - corpus callosum cerebralhemispher . Monotremata

2. Theria-

Class Mammalia Buccal cavity is separated from the nasal passage by apalate. Heterodont type of dentition, having different types ofteeth namely the incisors, canines, premolars and molars. Teeth are set in sockets and this type is called Thecodont.Milk teeth and permanent teeth appear. Three to four pairs of salivary glands are present. Alimentary canal ends in anus. Cloaca is absent. Heart is four chambered. Complete double circulation as inbirds. Only the left systemic arch is present. Renal portal system is absent. RBCs small and non-nucleated. Lungs are the respiratory organs.

Class Mammalia Glottis with a lid called epiglottis. Larynx contains vocal cords for sound production. Brain is well developed and highly evolved, withremarkable power of intelligence and memory. Sense organs well developed. External ear or pinna is present. Middle ear contains the ossicles namely themalleus, incus and stapes. Kidneys are metanephros type. Ureotelic animals,excreting urea as the nitrogenous waste product. Fertilization is internal.

Mammalia- Monotremata: platypus- Marsupialia:

kangaroo, wallbies, wombats, tasmanianwolves

Mammary glands Hair Differentiated teeth Warm blooded larger brains

Monotremata

platypus

Marsupialiawallbies

wombats

tasmanian wolves

Insectivora- allantois .moles, shrew- (plantigrade)- 5 - Cerebral hemishere - - - Organ snout

Insectivora

Dermoptera- flying lemurs

Chiroptera Patagium

Lagomorpha: rabbit

Rodentia : rat

Carnivora: dog, cat Pinnipedia: carnivores adapted for an aquaticlife ex. SEAL

(Ungulates: are mammal that walk on the tipsof their toes)

Perissodactyla: odd-toed ungulates ()ungulates in which of the body is borne onsingle toeex. horses, rhinoceros

Artiodactyla: ungulates in which of the bodyis borne on two toes: ex. Pig

Hyracoidea: hyrax

Proboscidea: ex.Elephants

Sirenia: ex.Dugongs

Cetacea: ex.whales, dolphins

Primates 1. Prosimians lemurs2. Anthropoids

3 2.1. ceboids -2.2 cercopitecoid - baboon, rhesus2.3 hominoid -apes

primates (grasping hand) (thumbs) nail Cerebral hemisphere Snout 2 5 clavicle

Ref Olmsted,D.D.2006. Frog Auditory System: TheInner Ear. http://geologyproject11.wordpress.com/geol-304/ http://www.corbisimages.com/stock-photo http://people.bethel.edu/~johgre/bio114d/LowerVerts.html http://www.brown.edu/Departments/EEB/EML/background/wing_anatomy.htm