ZOO301 Parade of Vertebrates

7/28/2014

Vertebrates

Comparative Vertebrate Anatomy

 ~60,000 known species

Parade of the

Vertebrates

 Most successful animal group in terms of survival  One of the largest group of taxa in animal kingdom  Found in various types of environments  Evolved for 590M years  Unique characteristics:  Presence of vertebral column  Formation of cranium

6. Amphibia 7. Reptilia 8. Aves 9. Mammalia

Ectotherms Endotherms

5. Osteichthyes

Anamniotes

4. Chondrichthyes

Amniotes

3. Placodermii

Fishes

2. Acanthodii

Tetrapods

1. Agnatha

Gnathostomes

The Geologic Time Scale

Agnathostomes

Vertebrate Classification

1

7/28/2014

The Vertebrates

 Agnathans

 Amphibians

 Ostracoderms

1

 Cysclostomes

2

 Placoderms

3

 Acanthodians

4

 Chondrichthyans  Elasmobranchs 5  Heterocephalans 6

 Osteichthyans  Actinopterygians 7  Sarcopterygians 8

                 

 Labyrinthodonts 9  Temnospondyls 10  Microsaurs  Lissamphibians 11

 Reptilians  Anapsids  Squamates  Crocodilians

12 13 14

 Avians  Archeornithes  Neornithes

Class Agnatha

 Mammals

15 16

Monotremata Marsupialia Insectivora Xenarthra Tubulidentata Pholidota Chiroptera Primates Lagomorpha Rodentia Carnivora Pinnepedia Perissodactyla Artiodactyla Hyracoidea Proboscidea Sirenia Cetacea

Ostracoderms  Oldest known vertebrates (Cambrian period)  Body covered with bony dermal armor (plates and tile-like scales) – armored fishes  Mostly 2-30 cm in length (longest: 2 m)

(Jawless fishes)

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

 Order: Heterostraci  Order: Osteostraci  Order: Anapsida  Order: Coelolepida  Order: Petromyzontiformes (lampreys)

 With sense organs (eyes) and pineal body (leads to olfactory sac)

eye); nostril

 Filter feeders

32 33 34

         

Cyclostomes

Living jawless fishes Notochord retained in adults Single median nostril No paired fin Naked skin (slime glands) With buccal funnel (adaptation to parasitic life) – with rasping tongue and horny denticles (lamprey) Seven gill slits Some marine, some freshwater Lampreys are anadromous organisms (marine but lay eggs in freshwater) Hagfishes: both gonads are present but only one is functional

Tentacles

Ostracoderm fossil from Canada (Silurian-Devonian Period)

Cyclostomes

 Order: Myxiniformes (hagfishes)

 Mostly freshwater habitat (few marine during Silurian period) (3rd

Ostracoderms

Myomyzon (Lamprey) Fossil dated during the Carboniferous period

Eptatretus (Hagfish)

Gill slits (twelve pairs)

Gill openings (seven pairs)

Mucous glands

Petromyzon (Lamprey)

2

7/28/2014

Class Chondrichthyes

 Subclass Elasmobranchii (naked gill slits)

 *Order Cladoselachii (primitive paleozoic sharks)  *Order Plueracanthodii (freshwater paleozoic sharks with lobed fins)  Order Squaliformes (sharks)  Order Rajiformes (sawfish, skates and rays)

 Subclass Holocephali (gills covered with operculum)  Order Chimaeriformes (Chimaeras)

Elasmobranchs        

Elasmobranchs

 Squaliformes with fusiform bodies (swift swimmers)  Rajiformes with dorsoventrally flattened body (bottom dwellers)  Long gestation period (2 yrs)  Cranium without sutures  Several sets of teeth  Large animals (20 m-whale shark)  Absence of swim bladder Heterocercal tail Large livers (bouyant oils) Pectoral fins as hydrofoils Absence of bones

Cartilaginous fishes Placoid scales Ventral mouth With claspers (internal fertilization) Macrolecithal egg Oviparous organism (eggs with horny leathery shell with tendrils) Presence of spiracle (1st gill slit) except chimeras Mostly marine

Class Osteichthyes

 Subclass Sarcopterygii (Choanichthyes) – lobe-finned fishes, fins attached to appendage (give rise to tetrapods)  Actinistians – mostly extinct except Latimeria  Rhipidistians – ancestors of amphibians  Dipnoans – lungfishes

 Subclass Actinopterygii – ray-finned fishes, modern fishes  Superorder Chondrostei – chiefly paleozoic  Superorder Holostei – dominant Mezoic fishes with ganoid scales  Superorder Teleostei – present forms of bony fishes

Chanos chanos

3

7/28/2014

Class Osteichthyes  Largest group of extant vertebrates  Bony fishes  With operculum  Terminal mouth  With swim bladders (air sacs)-neutral bouyancy  With cloaca  Overlapping scales (ganoid, ctenoid, cycloid,)  Fins stiffened by lepidotrichia

Chondrosteans

 Most primitive ray finned fishes  With ganoid scales  Largely cartilaginous  With spiracle  Ex. Sturgeon, paddlefish     

can reach 8 m marine and freshwater toothless (bottom feeders) can reach up to 100 years Roe (egg) – sold commercially as Russian caviar

   

Actinopterygii Ray-finned fishes Fin rays joined by membranes Absence of internal nares Main distinguishing characteristic: endoskeleton composition  Superorder Chondrostei-cartilaginous Superorder Holostei-cartilage & bones  Superorder Teleostei-bone

Holosteans  Intermediate form of ray-finned fishes  Freshwater  Ganoid scales; No spiracles  Single air bladder  Endoskeleton is ossified  Braincase is largely cartilaginous  Examples:  Bowfin  Garpike

4

7/28/2014

Teleosts

Teleosts

 Modern fishes

muscle segments fin supports

 Ossified skeleton

brain

 With cycloid or ctenoid scales (flexible and overlapping) olfactory bulb

 ~20,000 species  Found in any body of water

urinary bladde r

 With swim bladders

caudal fin

 Homocercal (equal lobe), protocercal (single lobe, vertebral column at center) or diphycercal tail (single lobe and vertebral column turns dorsally)  No spiracle

      

anus kidney swim bladder

heart liver gallbladder stomach intestine

dorsal fin

anal fin pelvic fin (one of two)

Sarcopterygii

pectoral fin (one of two)

Latimeria

Lobed-finned fishes Bony and fleshy lobe at the base of their paired fins With internal nares that open into oropharyngeal cavity Gill slits covered with operculum Give rise to the ancestors of tetrapods Some with cosmoid scales 2 major groups:  Actinistians – mostly extinct except Latimeria  Rhipidistians – ancestors of amphibians  Dipnoans – lungfishes

 Coelacanth  Only extant species discovered in Madagascar coast (originally believed to be extinct for more than 65 M years)  Skull and lower jaw architecture resembles of tetrapods (powerful jaw suspension)  Predatory

5

7/28/2014

Dipnoans

   

“True” lungfishes Only 3 living genera Non-functional gills Undergo aestivation during dry season  Similarity with amphibians:

Origin of tetrapod limbs

 Swim bladder connected to pharynx  Swim bladder supplied with blood via 6th aortic arch instead of dorsal aorta  Larvae with external gill slits  Presence of internal nares

Class Amphibia  Start of tetrapods  Anthracosaurs – ancestors of amniotes (mississippian to triassic period)  Cold blooded; Can live both in land and water  With lungs; can respire thru skin, mouth, pharynx, lungs

 Subclasses: Labyrinthodontia- Stegocephali – 1st tetrapods Lepospondyli Lissamphibiaa

Lissamphibians  Order: Anura (tailless)  Frogs (elongated urostyle)

 Order: Urodela (Tailed)  Salamander (perenibranchiate (retain larval gills); neotenous

 Order: Apoda (Legless)  Caecilians (borrowdwelling; short tail;~30 cm long)

6

7/28/2014

Class Reptilia  Cold blooded (aquatic, terrestrial)  Scaly; with claws  Breathe thru lungs  Developed long neck (cervical vertebrae)  Pelvic girdle articulates with 2 sacral vertebrae  Internal fertilization  Paired limbs usually pentadactyl  Heart with right and left atria  Cotylosaurs = stem reptiles

Class Reptilia  Subclasses (based on type of skull)

Euryapsids  With single dorsal temporal fossae; modification of diapsids  Descendants of birds (plesiosaurs, ichthyosaurs)  Synapsids  With single lateral temporal fossae; descendants of mammals  Heterodont dentition; dentary bone as the largest bone of the lower jaw  Therapsids

Class Reptilia  Subclasses (based on type of skull)  Anapsida  Absence of temporal arch  Cotylosaurs, turtles (chelonia)

 Lepidosauria  With 2 temporal fossae; Powerful jaw suspension  Sphenodon sp. or tuatara  Archosaurs  Diapsid skull (2 temporal arches); Extinct  Thecodonts (dinosaurs, crocodiles and alligators)

Order Chelonia

 Cyclenis amboinensis (land turtle)  Jaws lacks teeth  Covered with hard horny beaks

Tortoise  Enormous size  Large head shields  Limbs modified into swimming flippers

 Chelonia sp. (sea turtle)  Gopherus sp. (desert turtle)  Eretmochelis inbricata (hawksbill turtle)

7

7/28/2014

Order Squamata

Order Squamata

 Represent the most recent reptiles  Suborder Lacertilia (Lizards)  2 pairs of pentadactyl limbs  Upper and lower eyelids  Nictitating membrane  Hemiphyllodactylus sp. (House lizard)  Expanded digits for climbing walls and trees  Gecko gecko (tree lizard)  Nocturnal; eyes are large, pupils vertical  Eyelids are lost  Adhesive toe pads  Capable of loud vocalization  Varanus sp. (Giant or monitor lizard)  Large lizard with tail longer than head and body  Draco rizalis (flying lizard)  Lateral folds of the trunk

Order Crocodilia  Modified descendants of a group of bipedal archosaurs  Giants of the living reptiles  Crocodylus sp. (crocodiles)  Infest rivers and lakes in tropical region  Snout is narrow and pointed  4th tooth of the lower jaw is exposed when the mouth is closed  Aggressive  Alligator sp. (alligator)  Most abundant in the coastal regions of the southern US  Snout is broad and blunt  4th tooth of the lower jaw fits into a pit in the upper jaw  Passive

 Suborder Ophidia (Snakes)  Limbs are absent  Eyelids are immovably fused  Eyes are covered by transparent scales

 Ophidia sp. (snake)  Crawl by bending into a series of S-shaped curves  Some have fangs connected to poison sacs

 Cobra  Long cervical ribs that can be rotated outward  Has hollow non folding fangs connected to poison sacs venom gland

hollow fang

 Agnathans

The Vertebrates  Amphibians

 Ostracoderms

1

 Cysclostomes

2

 Placoderms

3

 Acanthodians

4

 Chondrichthyans  Elasmobranchs 5  Heterocephalans 6

 Osteichthyans  Actinopterygians 7  Sarcopterygians 8

 Mammals

 Labyrinthodonts 9  Temnospondyls 10  Microsaurs  Lissamphibians 11

 Reptilians  Anapsids  Squamates  Crocodilians

12 13 14

 Avians  Archeornithes  Neornithes

15 16

                 

Monotremata Marsupialia Insectivora Xenarthra Tubulidentata Pholidota Chiroptera Primates Lagomorpha Rodentia Carnivora Pinnepedia Perissodactyla Artiodactyla Hyracoidea Proboscidea Sirenia Cetacea

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

8

7/28/2014

Class Aves  Endothermic with feathers  Bipedal locomotion  Scales on their beak, legs and feet  Single occipital condyle and diapsid skull  Reduced body weight  Slender long bones with air cavities  No teeth  Has a large sternal keel (carina) for attachment of massive flight muscle  Presence of air sacs  Reduced wrist bones, palm digits  Fusion of bones (synsacrum)  Absence of urinary bladder

 Uropygial gland  Forelimbs for flying  Has a crop for storage of seeds and grain  Stomach is gizzard  Females with left ovary and left oviduct only  External incubation

Neornithes  Subclass: Neornithes (Modern Birds) Superorder: Odontognathae (with teeth) Superorder Neognathae (without teeth)  Ratites - can’t fly  Carinates – can fly

 Subclass:

Archeornithes

Archeonithes (Archeopteryx sp) oldest known bird had a long reptilian tail thecodont teeth on both jaws Forward nostrils Skull was more reptilian than avian absence of beaks unfused synsacrum had smaller wings

Class Mammalia Major Divisions: Oviparous Protheria (monotremes)  lays egg and with cloaca

Viviparous Metatheria (marsupials)  yolk sac as placenta

Eutheria (placentals)  with chorioallantoic placenta

 with mammary gland (except monotremes)  with hairs  Synapsid skull  1 dentary bone articulating with squamosal bone  3 middle ear bones  With diaphragm (separates thoracic from abdominal cavities  Sweat glands  Absence of cloaca (except oviparous mammals)  Heterodont dentition  2 sets of teeth  Biconcave, non-nucleated RBC  Ear with pinna  Specialized voice box  Developed cerebral cortex

9

7/28/2014

Mammalian Orders 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18.

Marsupialia Yolk sac serve as placenta Young nursed in marsupium Geographically isolated in Australia Ex. Kangaroo, koala, wallaby, opossum, phalanger, Tasmanian wolf

Monotremata Marsupialia Insectivora Xenarthra Tubulidentata Pholidota Chiroptera Primates Lagomorpha Rodentia Carnivora Pinnepedia Perissodactyla Artiodactyla Hyracoidea Proboscidea Sirenia Cetacea

Monotremes

Platypus (ductbill), Echidna (spiny anteater) Lay eggs Absence of nipples (modified sweat glands sucked by youngs) With cloaca Testes within abdomen (absence of scrotal sac) No pinna of ear

Insectivora Subsist on insects Plantigrade (flat footed) Absence of scrotal sac With shallow cloaca Sharp, pointed teeth with incisors Premolars poorly developed

Moles shrew

Tree shrew

hedgehog

Mole

Albino hedgehog

10

7/28/2014

Chiroptera

Ability to fly Presence of patagium Hindlimb digits with claws (clinging) With keel (sternum) With pinna Sanguinivorous

Primates

Primarily arboreal mammals Grasping hand Opposable thumb Presence of nails (instead of claws) Large cerebral hemisphere Duplex uterus One pair of nipples (thoracic region) Plantigrade Higher primates: Platyrrhine – nostrils open on sides Catarrhines – nostrils open anteriorly

Carnivora Flesh eaters Terrestrial Long sharp canines Powerful jaws Feet with tori

Pinnipedia Marine flesh-eaters No pinna of ears With flippers Anadromous organisms

Sea Lion

walrus

11

7/28/2014

Cetacea Aquatic marine mammals With tail fin similar to fishes (2 lobes) With flippers One nostril (dorsal side) Ex. Dolphin, whale, porpoise

Edentata Advance insectivorous Toothless Armored mammals (bony plates) Can roll into a ball (defense mechanism) Nocturnal Ex. armadillos

Peba (9-banded armadillo)

Pholidota

Tubulidentata Columnar teeth with tube-like pulp cavity anteaters Last surviving ancient line of hoofed mammals Derived from ancestral ungulate lineage Digitigrade Ex. Aadvark

 Toothless scaly anteaters  Overlapping horn scales  Ventral and inside extremities have exposed skin with hairs  Manus and pes with long curved claws  Skull is conical without a zygomatic arch.  Jaw muscles are weak.  Tongue sticky & long, vermiform, connected to long xiphisternum process of sternum  Muscular stomach wall.  Grinding of food assisted by pebbles (similar to gizzard of

Pangolin

birds)

12

7/28/2014

Rodentia

Largest group of mammals A pair of long curved incisors (knawing) No canines With diastema Can digest cellulose (due to commensals) With long coiled caecum Cellulose eaters Plantigrade gait Clawed feet Ex. mouse, hamster, guinea pig, squirrel

Perissodactyla Unguligrades (walks on the hoofed tips of 1 or 3 or 4 toes) most of the body weight is borne in a single digit has a mexasonic foot – walk on single digit (rhino and horses) Ex. horses, tapirs and rhinoceros, zebras

Lagomorpha Herbivores 2 pairs of incisors (on upper jaw) Split upper lip Strong hind legs Ex. Rabbits, hares, pikas

Artiodactyla Ungulates (walk using 2 toes – paraxonic foot) Most diverse Chambered stomach (at least 3) Ruminants (chew cud) Ex. pigs, hippopotamuses, cattles, camels, peccary, deer, antelopes, giraffe

13

7/28/2014

Proboscidea With proboscis Incisor form tusks Scanty hair on thick, wrinkled skin 5 toes ending hoof-like nails Molar are grinders Bulky animal Subungulates Ex. elephants and mastodons

Hyracoidea

 Hunchback when at rest  Harelip  Plantigrade  4 digits on forefeet and 3 digits on the hind feet  With small flat hoofs (except 1 digit)  Crowned teeth (similar to ungulates)  Ex. Hyrax

Sirenia

Freshwater or marine Strictly vegetarians Few hairs Paddle-like forelimbs Hindlimb absent (vestiges present internally – attached pelvic girdle) Naked skin Vestigial nails on flippers (manatee) Ex. Manatees, dugongs (sea cows)

14