Parade of the Craniates in Time and Taxa Flashcards
Major Developmental Synapomorphies of the Craniates
Neural crest
Neurogenic placodes
Major Nervous Synapomorphies of the Craniates
Skeletal braincase
Complex sense organs
Cranial nerves
Tripartite brain
Major Digestive Synapomorphies of the Craniates
Muscularization
Regionalization
Differentiated organs
Major Cardiovascular Synapomorphies of the Craniates
Heart
Hemoglobin
are separated from Vertebrata (Craniata) that have a skull
subphylum Protochordata
Vertebrates may be divided into
Agnatha (jawless) and Gnathostomata (having jaws)
Vertebrates are also divided into
Amniota, having an amnion
Anamniota lacking an amnion
having an amnion
Amniota
lacking an amnion
Anamniota
a thin membrane forming a closed sac about the embryo or fetus of a reptile, bird, or mammal and containing a watery fluid in which the embryo or fetus is immersed
amnion
Gnathostomata is subdivided into
Pisces with fins and Tetrapoda, usually with two pairs of limbs
Gnathostomata with fins
Pisces
Gnathostomata with two pairs of limbs
Tetrapoda
Many of these groupings of Chordates are described ass
paraphyletic
Some cladistic classifications exclude ____________ from the group Vertebrata because they lack vertebrae, although retaining them in Craniata since they do have a cranium
Myxini
Superclass Agnatha
classes
Class Myxini
Class Cephalaspidomorph
Superclass Gnathostomata
classes
Class Chondrichthyes
Class Sarcopterygii
Class Actinopterygii
Class Amphibia
Class Reptilia
Class Aves
Class Mammalia
are paraphyletic because they do not contain all of the descendants of recent common ancestor
Reptiles
Reptiles, birds and mammals compose a monophyletic clade called
Amniota
can only be grouped as amniotes that are not birds or mammals
Reptiles
No derived characters that group only ________ to the exclusion of birds and mammals
reptiles
Most common recent ancestor is also an ancestor of all remaining vertebrates
agnathans (hagfishes and lampreys)
__________ of a phylogenetic tree represent real lineages with geological information
branches
has many usages extending beyond what are actually considered fishes today
Fish
Aquatic vertebrate with gills, limbs (if present) in the form of fins, and usually with a skin covered in scales of dermal origin
modern fish
Do not form a monophyletic group
In an evolutionary sense, can be defined as all vertebrates that are not tetrapods
Fishes
Common ancestor of fishes is also an ancestor of __________
Therefore in pure cladistics, would make _______ “fish”- a nontraditional and awkward usage
land vertebrates
refers to one or more individuals of one species
Fish
refers to more than one species
Fishes
Includes the extinct heavily armored ostracoderms and the living hagfishes and lampreys
Superclass Agnatha
Until recently, earliest known vertebrate fossils were armored jawless fishes called
Small, heavily armored, jawless and lacked paired fins
ostracoderms
ostracoderms are found in the __________ deposits in United States, Bolivia and Australia
Late Cambrian
Fossil of an Early Chordate ae
Pikaia gracilens
Ostracoderms during the last 10 years, several 530-million-year-old fossils were discovered in the Chengjiang deposits beloning to one or two fishlike vertebrates:
Myllokunmingia and Haikouichthys
These fossils push back the origin of vertebrates to at least the Early Cambrian period
Ostracoderms
Ostracoderms show many vertebrate characteristics including
a heart, paired eyes, otic capsules and rudimentary vertebrae
______ is not considered to be a natural evolutionary assemblage
Earliest ostracoderms
Ostracoderms
Early group of ostracoderms
Extinct near end of Devonian
Heterostracans
Early group of ostracoderms
Represent an awkward design that probably filtered particles from the ocean floor
Sucked in water by muscular pumping
Some believe they may have been able to feed on soft-bodied animals
Heterostracans
Ostracoderms
Devonian saw a major diversification of ____________ producing numerous peculiar-looking forms, never evolved jaws or paired fins
heterostracans
Ostracoderms
Coexisted with heterostracans
Developed paired pectoral fins that stabilized movement
Jawless, toothless mouth
Sensory lateral line, paired eyes and inner ears with semicircular canals
Osteostracans
Ostracoderms
Head was well armored, but lacked axial skeleton or vertebrae
was Cephalapsis
Likely had a sophisticated nervous system and sense organs, similar to those of modern lampreys
Osteostracans
Small marine animal covered with a heavy, dermal armor of cellular bone, including a single-piece head shield
Cephalapsis
More streamlined than other Ostracoderms
Impressive diversification in Silurian and Devonian periods
Streamlined and more closely resembled modern lamprey
Osteostracans
All Ostracoderms became extinct by end of _________
Devonian period
For decades strange microscopic tooth-like fossils called __________ have been used to data paleozoic marine sediments without knowing what kind of creature originally possesed these elements
Conodonts
Complete ______ animals have been discovered (early 1980s)
Phosphatized toothlike elements, W-shaped myomeres, cranium, notochord, and paired eye and otic capsules
Exact position is not clear though
Important in understanding the evolution of early vertebrates
Conodonts
Conodonts clearly indicate they belong to ____________ clade
vertebrate clade
Include hagfishes (Class Myxini) and lampreys (Class Cephalaspidomorphi)
Members of both groups lacks jaws, internal ossification, scales or paired fins
Both groups share porelike gill openings and an eel-like body
Recent molecular analysis shows lampreys and hagfishes forming a monophyletic unit
Subclass Agnatha
Subclass Agnatha
Entirely marine
Scavengers and predators of annelids, molluscs, dead or drying fishes, etc.
Enters dead or dying animal through orifice or by digging inside using keratinized plates or tongue
Nearly blind and locate food by an acute sense of smell and touch
Special glands along body secrete fluid that becomes slimy in contact with seawater
Class Myxini
Class Myxini
To provide leverage, ties _____ and passes it forward to press against prey
knot in tail
Class Myxini
Body fluids are in __________ with seawater
osmotic equilibrium
Class Myxini
Circulatory system includes _________ in addition to a heart behind gills
three accessory hearts
class
Half of species belong to nonparasitic brook-dwelling species
Class Cephalaspidomorphi
All lampreys in Northern Hemisphere belong to the
family Petromyzontidae
Marine lamprey __________ occurs on both Atlantic coastlines and grows to a length of one meter
Petromyzon marinus
Eggs hatch in two weeks into ammoceotes larvae
Class Petromyzontida
Class Petromyzontida
Lives first on yolk supply and drifts downstream to burrow into sandy areas
Suspension-feeder until it metamorphoses into an adult
Change to an adult involves eruption of eyes, keratinized teeth replacing the hood, enlargement of fins, maturation of gonads and modification of gill openings
ammoceotes larvae
Class Petromyzontida
Other species remain in freshwater
Attach to a fish by a sucker-like mouth
Sharp teeth rasp through flesh as they suck fluids
Marine, ________ migrate to the sea (catadromous life cycle)
Parasitic Lampreys
Parasitic Lampreys Inject _______ into a wound
When, lamprey drops off but wound may be fatal to fish
anticoagulant
Class Petromyzontida life cycle
Parasitic freshwater adults live 1–2 years before spawning and dying
Anadromous forms live 2–3 years
lampreys that do not feed
Digestive tract degenerates as an adult
They spawn and die
Nonparasitic lampreys
Development of jaws in primitive fishes
Derived from the pharyngeal arches for prey-grasping and biting
Possess two paired fins or paired limbs
Enjoyed more active life
Gnathostomes
Gnathostomes class
Present during the Paleozoic
Represent the sister group to chondrichthyes and telosts which evolved from ostracoderms
Had paired pectoral and pelvic fins
Class Placodermi
Class Placodermi
Have heavy bony shields covering the head and gill region and another one for the trunk
Shields met in moveable joints
Body is either with small scales or naked
Appeared to be active predators
Arthrodires
Class Placodermi
Small armored placoderms with eyes on top of the head and a flattened belly
Suggested they are bottom feeders
Flourished up until the Devonian but diminished shortly thereafter
Antiarchs
Placoderm genus
arctolepsis
phyllolepsis
gemuendina
coccosteus
lunaspis
rhamphodopsis
bothriolepsis
About 970 living species
Smaller and more ancient group
Well-developed sense organs, powerful jaws, and predaceous habits helped them survive
True bone is completely absent throughout the class
Phosphatized mineral tissues retained in teeth, scales, and spines
Class Chondrichthyes
Subclass Elasmobrancii orders
Order Carcharhiniformes
Order Lamniformes
Order Squaliformes
Order Rajiformes
Order Myliobatiformes
Subclass Elasmobrancii
contains the coastal tiger and bull sharks and the hammerhead
Order Carcharhiniformes
Subclass Elasmobrancii
contains large, pelagic sharks such as the white and mako shark
Order Lamniformes
Subclass Elasmobrancii
contains dogfish sharks
Order Squaliformes
Subclass Elasmobrancii
contain skates
Order Rajiformes
Subclass Elasmobrancii
contains several groups of rays (stingrays, manta rays, etc.)
Order Myliobatiformes
Subclass Elasmobranchii
are among the most gracefully streamlined of fishes
Mouth opens into large pharynx, containing openings to gill slits and spiracles
Short esophagus runs to stomach
Liver and pancreas discharge into short, straight intestine
Fertilization is internal
Maternal support of embryo is variable
Sharks
shark body
Body is fusiform
shark Thrust and lift provided by an asymmetrical
heterocercal tail
shark Fins include
Paired pectoral and pelvic fins
One or two median dorsal fins
One median caudal fin
Sometimes a median anal fin
In male sharks, the medial part of the pelvic fin is modified to form a ________ used in copulation
clasper
sharks have ____________ are associated with olfaction
Paired nostrils
sharks have Lateral eyes are lidless and behind each eye is a ___________ - remnant of the first gill slit
spiracle
sharks have Tough, leathery skin with _______ - reduce water turbulence
placoid scales
Sharks Prey can also be located from long distances sensing low frequency vibrations in the _________ - consists of neuromasts in interconnected tubes and pores on side of body
lateral line
Electroreceptors, the_______, are located on the shark’s head
ampullae of Lorenzini
Sharks have Upper and lower jaws equipped with sharp, triangular teeth that are _______
constantly replaced
sharks have _________slows passage of food and increases absorptive area
Spiral valve in intestine
eggs hatch outside the mother’s body
Oviparous
the embryo develops within the uterus and is nourished by the egg yolk
Ovoviviparous
the embryo develops within the uterus and is nourished through a yolk sac placenta from the mother’s blood
Viviparous
Horny capsule encasing eggs laid by some oviparous species
Mermaid’s purse
Subclass Elasmobranchii
More than half of elasmobranchs are
Most specialized for
Respiratory water enters through large spiracles on top of the head
rays
rays have Teeth adapted for ______ prey
Molluscs, crustaceans, and sometimes small fish
crushing
Subclass Elasmobranchii
Have whiplike tail with spines and venom glands
Stingrays
Subclass Elasmobranchii
Have large electric organs on each side of head
Electric rays
subclass
Fossil chimaeras
Subclass Holocephali
Subclass Holocephali
First occurred in the Mississippian period, reached a zenith in the Cretaceous and early Tertiary, and then declined
Fossil chimaeras
Class chondrichthyes
Subclass
Mouth lacks teeth
Equipped with large flat plates for crushing food
Upper jaw fused to the cranium
Feed on molluscs, echinoderms, crustaceans, and fish
Scales are absent
Subclass Holocephali
class
Well represented in the Devonian
Became extinct by the lower Permian
Resemble bony fish but have heavy spines on all fins except the caudal fin
Probably the sister group of bony fishes
Class Acanthodii
class
Stout hollow spines were associated with the median and paired fins
Some species have additional paired spines extending along the lateral body wall
Body was covered with armor consisting of small scaled
The head is covered with dermal plates
Skeleton consisted of bone and cartilage
Class Acanthodii
Class Acanthodii
Have a large ___________ overlying the gill slits
Primitively consisting of elongate scaled with ancillary gill covered followed by a derived single opercular cover
operculum
Class Acanthodii
species
parexus
ischnacanthus
Bony Fishes
Specialization of jaw musculature improved feeding
Osteichthyes
In early to middle Silurian, a lineage of fishes with _________ gave rise to a clade that contains 96% of living fishes and all living tetrapods
bony endoskeletons
3 features unite bony fishes and tetrapod descendants
Endochondral bone replaces cartilage during development
Lung or swim bladder is present
Evolved as an extension of gut
Have several cranial and dental characters unique to clade
Evolved as an extension of gut if bony fish
swim bladder
Do not define a natural group and is a term of convenience rather than a valid taxon
Bony operculum and branchiostegal rays associate them with acanthodians
Operculum increased respiratory efficiency
Helped draw water across gills
Bony Fishes
Bony Fishes have _________ off the esophagus
Helped in buoyancy and also in hypoxic waters
Gas-filled structure
In fishes that use these pouches for respiration - pouches are called
lungs
In fishes that use these pouches for buoyancy - pouches are called
swim bladders
By the middle Devonian, bony fishes developed into 2 major lineages
class Actinopterygii
class Sarcopterygii
Class
Ray-finned fishes
radiated to form modern bony fishes
class Actinopterygii
Class
Lobe-finned fishes
include lungfishes and the coelacanth
class Sarcopterygii
Consist ancient and modern bony fishes whose membranous fins are supported by slender fin rays radiating from basal skeletal elements within the body wall - fins are not lobed
Gill slits are covered by a bony operculum
Air sac or swim bladder is usually present
Internal nares are lacking
Class Actinopterygii
Class Actinopterygii, Paleozoic era
Bony dermal armor and scales were overlain with a form of enamel called
ganoin
Class Actinopterygii
Paleozoic era
Caudal fins are ___________ like sharks
heterocercal
Class Actinopterygii
Paleozoic era
Bony dermal armor and scales were overlain with a form of enamel called
ganoin
Both traits have disappeared in more recent species in Class Actinopterygii, which are
ganoin
heterocercal tail
Class Actinopterygii
Can be divided into basal group and Neopterygii
Class Actinopterygii
Earliest forms
Small, had large eyes, a heterocercal caudal tail, and interlocking scales with an outer layer of ganoin
Single dorsal fin and numerous bony rays derived from scales stacked end to end
Fossils have been found as early as the late Silurian
Flourished throughout the late Paleozoic
Distinct from lobe-finned fishes and saw the ostracoderms, etc. decline
Palaeoniscids
Class Actinopterygii
In the clade Cladista
Have lungs, heavy ganoid scales, and other characteristics similar to the palaeoniscids
16 species of which all live in the freshwaters of Africa
Bichirs
Class Actinopterygii
27 species of freshwater and anadromous sturgeons and paddlefishes
Dam construction, overfishing, and pollution have led to their decline
Chondrosteons
Class Actinopterygii
Appeared in late Permian and diversified extensively during the Mesozoic
One lineage gave rise to the modern bony fishes: Teleost
Neopterygians
modern bony fishes:
Teleost
3 surviving early neopterygians are the
all gulp air and use the vascularized swim bladder to supplement gills
bowfin, gars and Atractosteus
Class Actinopterygii
Order:
Dermal scales have become very thin and flexible
Dermal bones of the skull are generally thinner and more numerous that in other bony fishes
Jaws and palate have become more independently maneuverable
Pelvic fins is more forward
Teleosts
Teleosts example
Blue marlin
Mudskipper
Lionfish
Sharksucker
Have an internal nares that open into the oropharyngeal cavity
Retain a gas-filled air sac
Gill slits are covered by a bony operculum that grows caudad from the 2nd pharyngeal arch
The Pre-Devonian ancestors are unknown
Lobed fins
Class Sarcopterygians
Ancestor of tetrapods
Group of extinct sarcopterygian fishes called
rhipdistians
Class Sarcopterygians
Had lungs, gills, and a heterocercal-type tail
During the Paleozoic, tail became a symmetrical diphycercal tail
Had powerful jaws, heavy, enameled scales, and strong, fleshy, paired lobed fins
Early sarcopterygians
Sarcopterygians
Two major clades: represented by ____ that are living
8 fish species
Sarcopterygians: two major cladess and the speciess under it
Actinistia: coelocanths (2 species)
Rhipdistia: lungfishes (Dipnoi) (6 species)
Sarcopterygians
flourished in late Paleozoic and then became extinct
Include ancestors of tetrapods
Rhipidistians
Sarcopterygians
Rhipidistians and the coelacanth were termed ________: polyphyletic group no longer used
crossopterygian
Arose in the Devonian, radiated, reached a peak in the Mesozoic, and dramatically declined
Thought to be extinct 70 million years, a specimen was dredged up in 1938
More were caught off coast of the Comoro Islands and in Indonesia
Living ______ is a descendant of Devonian freshwater stock
Coelacanth
Tail is diphycercal with a small lobe between the upper and lower caudal lobes
Young ________ born fully formed after hatching from eggs up to 9 cm in diameter
Coelacanth
Sarcopterygians
Skeletal elements of fin lobes corresponds to proximal skeletal elements of early tetrapod limbs
Skull was similar with that of early amphibians
Had air sacs that are probably used occasionally as lungs
Most had internal nares
Rhipdistians
Sarcopterygians
unlike close relatives, rely on gill respiration and cannot survive long out of water
(lung fish)
Australian lungfishes
Sarcopterygians
can live out of water for long periods of time
(lung fish)
South American and African lungfish
class
are the only living vertebrates that have a transition from water to land in both their ontogeny and phylogeny
Class Amphibia
Class Amphibia
was the oldest and were swamp-dwelling animals
Had minute bony scales in the dermis of the skin
Fishlike tail is supported by dermal fin rays
Skulls similar to those of rhipidistian fishes
Ichthyostega
Subclass of Ichthyostega
Subclass Labyrinthodontia
Class Amphibia
subclass :
Has a sensory canal system or neuromast organs which monitors aquatic environment
Size can range from the size of a newt to ta crocodile
Other species lack limbs, and other with bizarre large triangular skulls
Subclass Labyrinthodontia
Subclass Labyrinthodontia
Have skeletal similarities to modern frogs and salamanders
Suggests that Lissamphibia evolved and the results of heterochronic processes
Skeletal features of lissamphibians can be explained by retention of juvenile characteristics
Temnospondyls
Subclass Labyrinthodontia
Diverse group from the Penssylvanian to the Lower Permian
Share skeletal features with caecilians
Can either be convergence
Close relationship
Microsaurs
Subclass
Includes three groups of extant species:
Apoda - caecilians
Urodela - tailed amphibians
Anura - frogs, toads and tree toads
Includes also Triassic and Jurassic anurans whose skeletons resemble toads and frogs
Subclass Lissamphibia
Subclass Lissamphibia
Includes three groups of extant species:
Apoda - caecilians
Urodela - tailed amphibians
Anura - frogs, toads and tree toads
Subclass Lissamphibia
Order
Caecilians
Elongate, limbless, burrowing animals in swampy locations
Bodies have many vertebrae, long ribs, no limbs, and terminal anus
Eyes are buried beneath the bones of the skull
Some species have minute scales in their dermis
Vent is almost at the end of the body
Feed primarily on worms and small underground invertebrates
Fertilization is internal
Male has a protrusible copulatory organ
Order Gymnophiona (Apoda)
Subclass Lissamphibia
Order
Salamanders
Most are small, under 15 cm long with the Japanese giant salamander being 1.5 meters long
Limbs usually at right angles to trunk
Forelimbs and hindlimbs about equal in length
Burrowing species and some aquatic forms may have lost their limbs
Ectotherms with a low metabolic rate
Some aquatic throughout life cycle
Most have aquatic larvae and terrestrial adults
Internal fertilization in most
Order Urodela (Caudata)
Order Urodela is ___________ as both larvae and adults
Feed on worms, small arthropods, and molluscs
Order Urodela (Caudata)
any so-called cold-blooded animal
ectotherm
Order Urodela
Female recovers in cloaca a _________ deposited on a leaf or stick
spermatophore
male reproductive structures that package sperm cells to aid in their transmission to females during mating in a variety of invertebrate animals
spermatophore
Subclass Lissamphibia
Order
Aquatic species lay eggs in clusters or stringy masses
Completely terrestrial species deposit eggs in small, grape-like clusters under logs or in soft earth
Terrestrial species undergo direct development
Hatch as miniature adults
Order Urodela (Caudata)
mudpuppy vs axolotl
Axolotls can change their colors as a form of camouflage, while the common mudpuppy has a brown coloration
Subclass Lissamphibia
Order
Frogs and toads
Dates from Triassic period, 250 million years ago
Must live near water source
Reproduction mode requires water
Skin is water-permeable skin
Ectothermy
All have a tailed larval stage and tailless, jumping adults (except for 1 species)
Order Anura (Salientia)
_____ prevents anurans from inhabiting polar and subarctic habitats
Ectothermy
Subclass Lissamphibia
Order
Eggs of most hatch into tadpoles with a long, finned tail, no legs, internal and external gills and specialized mouthparts for (usually) herbivorous feeding
Tadpoles look and act entirely different from adult frogs
Order Anura (Salientia)
condition never occurs in frogs and toads
Perennibranchiate
is the condition of an organism retaining branchae, or gills, through life. This condition is generally said of certain amphibia, such as the mudpuppy. The term is opposed to caducibranchiate.
Perennibranchiate
________ families of frogs and toads
44
Family
Contains the common larger frogs in North America
Family Ranidae
Family
Includes the tree frogs
Family Hylidae
Family
(true toads)
Contains toads with thicker skins and prominent warts
Family Bufonidae
Order Anura (Salientia) example species
bullfrog
green tree frog
American toad
Goliath frog
gray tree frog
African clawed frog
Order of extinct reptile-like amphibians
Include all non-amniote labyrinthodont reptile-like amphibians
Anthracosaurs
Single, monophyletic lineage of Paleozoic tetrapods
Nonavian reptiles, birds, and mammals
Amniotes
Developing young enclosed by extraembryonic membrane called the __________
Secretes fluid, amniotic fluid, in which embryo/fetus floats
amnion
Extraembryonic Membranes:
Amnion
Allantois
Yolk sac
Chorion
Extraembryonic Membranes:
Encloses the embryo in fluid-filled space
Cushions the embryo and provides an aqueous medium for growth
Amnion
Extraembryonic Membranes:
Stores metabolic wastes
Allantois
Extraembryonic Membranes:
Nutrient storage
Yolk sac
Extraembryonic Membranes:
Surrounds embryo and all other extraembryonic membranes
Lies just beneath shell
Highly vascularized
Respiratory surface
Chorion
Extraembryonic Membranes:
Allantois and chorion sometimes fuse to form respiratory structure:
chorioallantoic membrane
Amniotes arose from amphibian-like tetrapods, the _________, during the Carboniferous
anthracosaurs
By the late Carboniferous, skulls of amniotes could be separated into groups based on three patterns of openings (fenestra) in the temporal region: _____________
These openings are associated with large muscles that elevate the lower jaw
anapsids, diapsids and synapsids
Types of Amniote skull
anapsids
synapsid
diapsid
euryapsid
Members of the paraphyletic class __________ includes nearly 8000 species
The Age of Reptiles lasted over 165 million years and included the dinosaurs
A mass extinction occurred at the end of the Mesozoic
Ectotherms like the fishes and amphibians
Parapineal glands in other organisms for thermoregulation
Class Reptilia (Sauropsida)
Modern reptiles represent surviving lineages
Tuatara
Lizards and snakes
Class Reptilia
is the sole survivor of a group that otherwise disappeared 100 million years ago
Tuatara
Class
Body is covered with thick cornified epidermal cells in plaques, shields, or scales
Impervious to water resulting in water conservation
Pelvic girdle articulates with two sacral vertebrae
Digits are supplied with claws
Class Reptilia (Sauropsida)
new kidney of Class Reptilia
Metanephros
Class Reptilia
Heart is partially or completely divided into right and left chambers
Has _________ circuit
pulmonary and systemic
Class Reptilia
Clade ____________
Includes the birds, crocodilians, and the extinct dinosaurs and pterosaurs
Archosauria
Archosaurs along with their sister group the lepidosaurs (lizards and snakes), and turtles form a monophyletic group that cladists call __________
Reptilia
refers to a paraphyletic group that includes the living turtles, lizards, snakes, tuataras, and crocodilians, and a number of extinct groups including plesiosaurs, ichthyosaurs, pterosaurs, and dinosaurs
nonavian reptiles
Class Reptilia
Subclass _____________
Have a skull with no temporal opening behind the orbits
There is no temporal fossa but there is a deep cavitation on each side of the midline
Anapsida
Primitive condition exhibited by basal reptiles and __________
__________ which diverse from another anapsid are the sole living members of group
Chelonia (modern turtles), Turtles
Class Reptilia
Order ________________
Stem reptiles
Resemble the most primitive extinct amphibians
Captorhinida
Class Reptilia
Order ________________
Fossils appear in the Upper Triassic, 220 million years ago
Shells consist of a dorsal carapace and a ventral plastron
Outer horny layer of keratin and an inner layer of bone
Bony layer is a fusion of ribs, vertebrae, and dermally-ossified elements
Unique among vertebrates, limbs and limb girdles are located deep to the ribs
Lack teeth and use tough, horny plates for gripping food
Order Testudinata(Chelonia)
Order Testudinata(Chelonia) example species
common snapping turtle
Galapagos tortoise
alligator snapping turtle
green sea turtle
Class Reptilia
Gave rise to all other traditional “reptiles” (except turtles) and to birds
Skull has two temporal openings
Diapsids
Class Reptilia
Two clades of Diapsids
Lepidosauromorpha
Archosauromorpha
Diapsids
Lepidosauromorpha
Ichthyosaurs and living reptiles, including lizards and snakes
Lepidosauria
Diapsids
Lepidosauromorpha
includes extinct aquatic groups including the long-necked plesiosaurs
Sauropterygia
Diapsids
Archosauromorpha
includes dinosaurs, living crocodilians, and birds
Archosauria
Subclass
Contains two extant groups:
Rhynchocephalians
Squamates
Lepidosauria
Subclass Lepidosauria
primitive but with different type of scales, teeth and internal morphology
Retain the ancestral diapsid skull
Rhynchocephalians
Subclass Lepidosauria
modern lizards, snakes and amphisbaenians
Diapsid skull with adaptive modifications
Squamates
Subclass Lepidosauria
Order
Lizard-like and live in burrows often shared with sea birds called petrels
Slow growing and may live to 77 years of age
Skull nearly identical to diapsid skulls of 200 million years ago
Well-developed median parietal eye buried beneath skin
Order Rhynchocephalia
class reptilia
Order Rhynchocephalia
represents one of the slowest rates of evolution known among vertebrates
diversified modestly in the early Mesozoic but then declined
Once widespread across New Zealand, the 2 species are now restricted to small islands
Sphenodon /tuatara
Only _____ living species of tuatara in New Zealand represent this ancient lineage
2
class reptilia
Order Rhynchocephalia
Loss of the _________ populations caused by human introduction of nonnative species which preyed upon the __________
___________ are vulnerable because they have slow growth and reproductive rates
Sphenodon /tuatara
class reptilia
Order
Most recent and diverse of diaspids
Account for up 95% of living nonavian reptiles
Order Squamata
class reptilia
appeared in the fossil record in the Permian but did not diversify until the Cretaceous
Lizards
class reptilia
appeared in the late Cretaceous from a group whose descendants include monitor lizards
Snakes
class reptilia
Order
Diaspid skulls have lost dermal bone ventral and posterior to lower temporal opening
Allowed evolution in lizards of a kinetic skull with movable joints
The quadrate, fused to the skull in other nonavian reptiles, has a joint at the dorsal end and articulates with the lower jaw
Order Squamata
class reptilia
Order
Joints in palate and across roof of the skull allow snout to be tilted Allows _______ to seize and manipulate prey and effectively close the jaw with force
Some are blind, some have spectacles (transparent eyelid)
Nictitating membrane is present
Teeth are in sockets
Order Squamata
class reptilia
Suborder Sauria
Diverse group with terrestrial, burrowing, aquatic, arboreal, and some aerial members
Some have degenerate limbs
Lizards
class reptilia
Suborder Sauria:
Small, agile, nocturnal forms
Adhesive toe pads allow them to walk on ceilings
Geckos
class reptilia
Suborder Sauria:
Include many New World lizards as well as the marine iguana of the Galápagos
Iguanids
class reptilia
Suborder Sauria:
Arboreal lizards of Africa and Madagascar
Many have an extendible tongue
Chameleons
Movable eyelids whereas snakes have a __________ covering
transparent
Nocturnal geckos have retinas with only ________
rods
Day-active lizards have both ___________ in retinas
rods and cones
lizards Have an __________ that snakes lack
external ear
Geckos use __________ to announce territory and drive away males
vocal signals
class reptilia
Suborder Sauria:
highly specialized for a fossorial (burrowing) life
Until recently, were placed in a separate suborder, ___________ because they appeared to be so different from other lizards - morphological and molecular data show they are highly modified lizards
amphisbaenians or “worm lizards”
class reptilia
Suborder Sauria:
Have elongate, cylindrical bodies of nearly uniform diameter and lack any trace of limbs
Eyes are usually hidden below skin and there are no external ear openings
Skull is conical or spade-shaped to assist in tunneling
amphisbaenians or “worm lizards”
Suborder Sauria: Lizards examples
flat-headed rock agama
central bearded dragon
Jackson’s chameleon
gecko
Prognathodon
thorny devil
Komodo dragon
legless Rhineura
anoles
Suborder
Limbless and have lost pectoral and pelvic girdles (except in pythons)
The many vertebrae are shorter and wider than in other tetrapods, allowing undulation
Elevation of the neural spine gives the musculature more leverage
Skin is infolded between scales
When stretched by a large meal, the skin is unfolded
Serpentes: Snakes
Suborder Serpentes: Snakes
allows them to eat prey several times their own diameter
Two halves of lower jaw are loosely joined, allowing them to spread apart
Skull bones also loosely articulated so mouth can accommodate large prey
Highly kinetic skull
allows breathing in Suborder Serpentes: Snakes
tracheal opening is extended
Suborder Serpentes: Snakes
Pair of pits in the roof of the mouth
Lined with olfactory epithelium
Forked tongue collects scent particles and conveys them to this organ
Jacobson’s organs
Suborder Serpentes: Snakes
Eyeballs have reduced mobility and a permanent ___________ for protection
corneal membrane
Most snakes have poor vision
Can feel vibrations at low frequencies, especially vibrations carried in the ground
true
true
___________ snakes have highly developed vision
Arboreal
snakes Lack _________ and do not respond to most aerial sounds
external ears
Suborder Serpentes: Snakes example species
coast garter snake
Barbados snake
Indian cobra
snakes use __________ rather than vision or hearing are main senses used to hunt prey
Chemical senses
Red on Yellow kills a Fellow
coral snake
Red on Black friend of Jack
milk snake
class reptilia
Subclass
Marine reptiles that are contemporaries of the dinosaurs
Had a dorsal temporal fossa on each side of the skull
might have been a result of evolutionary convergence
Euryapsida
Subclass Euryapsida examples
ichthyosaurs
pleiosaurs
class reptilia
Subclass
Defined as the group of all descendants from the common ancestor for crocodiles and birds
Were the dominant land craniates during the Mesozoic
Modern crocodilians and birds are the only survivors of the archosaurian lineage
Subclass Archosauria
class reptilia
Order
The stem archosaurs
Teeth set in deep pockets
Had pneumatic bones
With long neck and tail
Extinct
Order Thecodontia
class reptilia
Order
Clade gave rise to the Mesozoic diversification of dinosaurs and to birds
Modern crocodilians differ little from primitive crocodilians of the early Mesozoic
All have long, well-reinforced skull and jaw musculature for a powerful bite
Have a complete secondary palate, a feature only shared with mammals
Four-chambered heart
Crocodilia
There are 3 families of modern crocodilians
Alligators and caimans
Crocodiles
gavial
There are 3 families of modern crocodilians
are found primarily in the New World and have a broader snout
Alligators and caimans
There are 3 families of modern crocodilians
are widely distributed
Crocodiles
There are 3 families of modern crocodilians
One species of _________ occurs in India and Burma and has a very narrow snout
gavial
Order Crocodilia
teeth are set in sockets
Thecodont dentition
Alligators and crocodiles are ______
Usually 20–50 eggs are laid in mass of vegetation
Unguarded nests are easily discovered and raided by predators
oviparous
Order Crocodilia
High nest temperatures produce ___________
Low temperatures produce ________
Can result in females outnumbering males 5 to 1
males
females
Crocodiles vs. Alligators
Only the teeth of the upper jaw are exposed along the lower jaw line
4th tooth is hidden
Alligators
Crocodiles vs. Alligators
The teeth are exposed all along the jaw line in an interlocking pattern - even when the mouth is closed
They also have an enormous 4th tooth on the lower jaw that is accommodated by depressions in the upper jaw just behind the nostrils
Crocodiles
class reptilia
Order
Extinct group of flying archosaurs
Had pneumatic bones like birds but wings are more like those of the bats
With an elongated fourth finger
Order Pterosauria
Dinosaurs are divided into two by the structure of their ___________
pelvic girdles
class reptilia
Suborder
Dinosaurs that are mostly predators
Saurischians
class reptilia
Suborder
Dinosaurs that are mostly herbivores
ornithischians
class reptilia
Subclass
Mammal-like reptiles
One lateral temporal fossa
has 2 orders
Synapsida
class reptilia
Subclass Synapsida
order
Early synapids
Order Pelycosauria
class reptilia
Subclass Synapsida
order
Late synapsids
Mammalian precursors
Order Therapsida
Class
Over 9,700 species have been described worldwide
Only fishes have more species among vertebrates
inhabit all biomes, from mountains to prairies, on all oceans, and from the North to the South Pole
Some live in dark caves, and some dive to 45 meters depth
Class Aves
Some live in dark caves, and some dive to 45 meters depth
“bee” hummingbird
is the unique and essential feature or hallmark of birds
feather
Some feathers were also present in some ___________ - these feathers were not capable of supporting flight
Obviously served in other capacities such as thermoregulation or mating behavior
Also serves as protective coloration in other species
theropod dinosaurs
Forelimbs are modified as wings, although not all are capable of flight
Hindlimbs are adapted for walking, swimming or perching
All have horny, keratinized beaks
All lay eggs
birds
birds and non-avian reptiles similarities
Skulls that abut the first neck vertebra by a single ball-and-socket joint
Single middle ear bone, the stapes
Lower jaw consisting of five or six bones
Excrete nitrogenous wastes as uric acid
Similar yolked eggs
Embryo develops on surface by shallow cleavage patterns
Adaptation for Flight
With feathers and wings
Bones lack ventral marrow or became hollow with extensions from the air sacs to become pneumatic
Skull has thinned but stayed durable
Bones of the wrist, palm and digits have decreased
No teeth
No urinary bladder to store urine
Large intestine has been shortened so that no feces will be stored
Class Aves
Subclass
Include a number of basal birds representing a paraphyletic assemblage
Skull resembled modern birds but had teeth rather than a beak
Skeleton was reptilian with clawed fingers, abdominal ribs, and a long bony tail
Feathers were unmistakably imprinted along wings
With saurischian pelvis which allowed flight
Archaeornithes
prompted the Subclass Archaeornithes
Discovery of the fossil of
Archaeopteryx lithographica in 1861
Class Aves
Subclass
Includes three subgroups
Include all extinct and living birds
Four-chambered heart
Tail feathers arranged in a fan-like manner around tail stump
Fused metacarpals
Epidermal scales on bill, legs, feet
Bill instead of teeth; teeth absent in modern forms
Modifications for flight include hollow bones, pectoral appendages modified as wings, air sacs, large eyes and large cerebellum
Modifications for vocalization
Subclass Neornithes
Subclass Neornithes three subgroups:
Odontognathae - toothed marine birds
Paleaognathae - ratites
Neognathae - all other birds
Class Aves
Subclass Neornithes
Superorder
Used land as base for marine operations
Includes:
Hesperornis
Ichthyornis
Superorder Odontognathae
Class Aves
Subclass Neornithes
Superorder Odontognathae
Covered with small, hairlike feathers
Had vestigial wings but had stout legs for wading
Diver of fishes
Hesperornis
Class Aves
Subclass Neornithes
Superorder Odontognathae
Active flier that can go offshore to feed
Ichthyornis
Class Aves
Subclass Neornithes
Superorder
Descendants of active fliers but now have small incompetent wings
Legs are powerful for running from predators
Extant species include rheas, ostriches, emus and cassowaries
Superorder Palaeognathae
Superorder Palaeognathae examples
Rhea
Dinornis
Struthio
Tinamus
Apteryx
Dromaius
Aepyornis
Casuarius
Pseudocrypturus
Class Aves
Subclass Neornithes
Superorder
Generally called carinates because of the presence of large carina to which large flight muscles attach
Migration is a behavioral adaptation due to climatic changes
Superorder Neognathae
_______ are neognaths even though they are not capable of flight - forelimbs have become flippers
Penguins
Class Aves
Subclass Neornithes
Superorder Neognathae
Orders
Order Columbiformes
Order Pelecaniformes
Order Anseriformes
Order Galliformes
Order Falconiformes
Order Psittaciformes
Order Passeriformes
Mammals evolved from ____________ that have a pair of temporal openings in the skull
were first amniotes to diversify widely into terrestrial habitats
synapsids
were transitional group between amphibians and synapids succeeded by therapsids (group from which mammals evolved)
two occipital condyles
Secondary palate
Heterodont dentition
Pelycosaurs
Class
Amniotes with a synapsid skull, hair and mammary glands with nipples (except monotremes)
Single dentary bone (mandible) articulating with the squamosal bone
Three bones in the middle ear cavity
Muscular diaphragm separating the pleuropericardial from the peritoneal cavity
Sweat glands
Absence of an adult cloaca (except in monotremes)
Biconcave, enucleate red blood cells except in camels and llamas
Pinna or auricle for sound-collection
Extensive development of the cerebral cortex
Class Mammalia
tooth shape differences along the tooth row—incisors and canines rostrally and cheek teeth (premolars and molars) caudally. These are the four tooth classes of mammals: incisors, canines, and premolars are replaced, they are deciduous teeth
Heterodont dentition
Class Mammalia
Subclass
Egg laying mammals
Mammary glands without nipples
Pectoral girdle with separate precoracoid, coracoid, and interclavicle
Scapula with spine
Oviducts separate
With cloaca
Subclass Prototheria
Class Mammalia
Subclass Prototheria
Order
Cloaca has a single opening to the exterior
All extant species are found in Australia, Tasmania and New Zealand
Have heavily yolked eggs
Have a ventral mesentery that extends the length of the abdominal cavity
Testes are confined in the abdominal cavity
Outer ear has no pinna and malleus and incus are larger than most mammals
Brain lacks the corpus callosum
Have no nipples but have fluid exudates from modified sweat glands
Endothermic but their body temperature is less stable
Monotremata
example order Monotremata
platypus, anteater
Class Mammalia
Subclass
Infraclass
Marsupial mammals
Yolk sac serves as placenta
With an abdominal skin pouch (marsupium) supported by 2 marsupial bones
Teats open into the marsupium
Precoracoid and interclavicle absent
Coracoid reduced
Scapula with spine
Clavicle present
Four molars on each side
Shallow or no cloaca
Smooth brain
Double vagina
Subclass Theria : Infraclass Metatheria
Class Mammalia
Subclass Theria
Infraclass Metatheria
Order
Fetal yolk sac serves as the placenta
Young are born in the larval stage and continues growth in the marsupium (has two epipubic bones)
Have shown parallel evolution with other mammals that shared the same environment
Marsupialia
Order Marsupialia example
kangarooo
marsupial mole
suagr glider
tasmanian devil
Class Mammalia
Subclass
Infraclass
The true placental mammals
Viviparous with chorioallantoic placenta
With0ut marsupium or marsupial bones
Shoulder girdle like marsupials
Mostly three molars on each side
One vagina
No cloaca
Subclass Theria: Infraclass Eutheria
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order
Form the basal mammalian group
Subsist on diet of insects, worms and other small invertebrates
Primitive traits:
Flat-footed (plantigrade) stance
Five toes
Smooth cerebral hemispheres
Small, sharp, pointed teeth
Large embryonic allantois and yolk sac
Shallow cloaca
Testes retained in abdominal cavity
Order Insectivora
Order Insectivora examples
hedgehog
solenodon
moles
white-tooth shrew
desman
forest shrew
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order
New world insectivorous mammals
None have incisor, canine or cheek teeth but if present are peglike and lack enamel
Anteaters are completely toothless
Front claws are for digging
Only mammals that develop a true bony dermal armor
Order Xenarthra
Order Xenarthra examples
three-toed sloth
pygmy sloth
anteaters
armadillo
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order
Central and South American insectivores
Elongated snout, long sticky tongue and strong claws on the front feet
Teeth are peglike, lack enamel and have shallow roots
Order Tubulidentata
Order Tubulidentata example
aardvark
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order
Toothless and peculiarly scaly
Scales are made of keratin and appear to be agglutinated hairs
Order Pholidota
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order
Only known craniates to achieve true flight
Patagium is made of double membrane stretched along the body
First digit of wings bears claws for climbing and all digits of hind limbs have claws for hanging
Sternum is keeled
Order Chiroptera
a membrane or fold of skin between the forelimbs and hind limbs on each side of a bat or gliding mammal.
Patagium
Order Chiroptera example
bats
Order Chiroptera nutritional diets
hematophagous
frugivorous
insectivorous
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order
Arboreal mammals which arose as an offshoot from Cretaceous insectivores
Grasping hands with opposable thumbs
Elaborately large cerebral hemispheres
Plantigrade with 5 digits
Large clavicle
Skull is set at right angles to the vertebral column
Eyes directed forward and are close together
Cerebral hemisphere are highly developed
32 teeth in the permanent set
Placenta is deciduate
Usually pregnancy produces 1 offspring
Order Primates
primates have ________ teeth in the permanent set
32
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order Primates
Suborder
Lemurs
Lorises
Tarsiers
Suborder Prosimii
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order Primates
Suborder Prosimii
have the long axis of the head in line with the vertebrate
Lemurs
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order Primates
Suborder Prosimii
have no tail and the index finger is vestigial
Lorises
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order Primates
Suborder Prosimii
resembles more anthropoids
All fingers have nails except 2nd and 3rd
Deciduate placenta
Tarsiers
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order Primates
Suborder
Platyrrhines, Catarrhines
Suborder Anthropoidea
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order Primates
Suborder Anthropoidea
New world monkeys
Have nostrils opening on the side
Platyrrhines
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order Primates
Suborder Anthropoidea
Cerpithecoids (old world monkeys), pongids (apes, chimps, gorillas) and hominids (humans)
Nostrils open downward
Have no tails
Catarrhines
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order
All are herbivores
Two pairs of incisors on the upper jaw and a small pair lying immediately behind
Two families
Order Lagomorpha
Two families of
pikas and hares and rabbits
difference of rabbits and hares and pikas
Rabbits are generally helpless when born while hares are active within an hour
Pikas have smaller bodies and limbs of equal length
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order
Largest mammalian order
Single pair of curved incisor teeth on each jaw
Teeth grow throughout life with canine teeth absent
Cellulose eaters thereby adapting the cecum to house cellulose-digesting microorganisms
Order Rodentia
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order
Have powerful jaws with sharp canine teeth
Have 42 teeth with premolars tricuspid and molars have four cusps
Clavicles are reduced, vestigial or absent
Cerebral cortex is unusually convoluted compared to most mammals
With 5 or 4 digits usually with retractable claws
Order Carnivora (Fissipedia)
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order
Carnivores adapted for aquatic life
Feed in fish, squid, molluscs and crustaceans
Leaves the water once a year to breed and young are born on land unable to swim
Webbed paddle-like limbs (flippers) without claws
Order Pinnipedia
Mammals that walk on the tips of the toes protected by hoofs
Have no more than 4 toes on each foot, others have only 1 such as horses
Herbivorous with the molar teeth adapted for grinding vegetation
Only mammals with horns
Ungulates
include elephants, hyraxes and manatees
Subungulates
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order
Walk on the hoofed tips of one, three or four toes
Body weight is borne on a single digit called the mesaxonic foot
Usually called odd-toed ungulates
Order Perissodactyla
Order Perissodactyla examples
horses. zebras, rhinos
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order
Ungulates in which the weight is born on two toes called the paraxonic foot
Had even number of toes on the foot
Most are ruminants except for pigs
Order Artiodactyla
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order
Flat-footed but all except one digits end on hoofs
Order Hyracoidea
Order Artiodactyla examples
giraffe, deer, camels
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order
Have a proboscis, scanty hair and thick, wrinkled skin
Incisor are elongated to form tusks, canine teeth are absent and molars are large
Five toes that end in hooflike nails with an elastic pad that supports the weight
Order Proboscidea
Order Proboscidea example
elephants
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order
Strictly vegetarian
Forelimbs are paddles with the hindlimb loss along evolution
The only completely aquatic mammals together with cetaceans
Order Sirenia
Order Sirenia examples
dugong. manetee, sea cow
Class Mammalia
Subclass Theria: Infraclass Eutheria
Order
Permanently marine mammals
Forelimbs are paddle-like with hindlimbs vestigial
Nostrils are on top of the head forming a blowhole
Most have teeth but others have baleen (whalebone)
Order Cetacea
example of Order Cetacea
dolphins, whales
