BIOL 432 LEC-Exam 1

herpetology

scientific study of amphibians and reptiles

herptile

reptile or amphibian(“herp”)

herpeton

“creeping” or “crawling thing”

Caudata (Urodela)

Caudata/tail, Salamanders (798 sp)

Amphibian

amphi=”dual” or “double” (Gr)

bios=”life” (Gr)

\

Reptile

reptilis=”to creep” or “crawl”

Anura

to be w/out tail

frogs

(7564 sp)

\-most successful group better than mammals

Gymnophobia (Apoda)

Caecillians

limbless amphibians

Apoda: w/out limbs

215 sp

Testudines(Chelonia)

Turtles

363 sp

\-whole body encased in bone (shell): unique in vertebrates

Crocodylia

Crocodilians

27 sp

Rhynchocephalia

Spenodontia: Tuatana

2 sp

\-was global but replaced by Squamata (outcompeted)

Squamata (Sauria & Serpentes)

Lizards and Snakes

11,348 sp

Amphibian

anamniotic tetrapods usually lacking the dermal scales found in fish or epidermal scales found in reptiles

reptile

amniotic tetrapods with epidermal scales but lacking hair or feathers

Why Herpetology

1. ecosystem function (community structure, energy flow, ecosystem engineer, biomass largest, community structure)
2. ecosystem services (pollinators, seed dispersers, habitat architects)
3. introduced species
4. apex predators
5. local resource (food, products, income)
6. biomedical research
7. pets/companion industry
8. source of mortality
9. myths & folklore
10. conservation

Phylogenetic systematics (Cladistics)

approach for grouping taxa based on homology.

\
Trees are based on shared derived characters (synapomorphies) and reflect genealogy.

Phylogenetic tree

graphic representation of the ancestor and descendent (genealogical) relationships between taxa.

Parisomy

the simplest explanation is likely the best:

i.e in tree the least number of character state changes is best

Tree Branch

line connecting a branch point to a terminal taxon in a phylogenetic tree

\
line represents a lineage.

Lineage

any continuous line of descent.

Node

line represents a speciation event on the tree (connects 2 or more branches).

Symplesiomorphy

shared ancestral character between two taxa.

Synapomorphy

a shared derived character between two taxa.

Apomorphy

uniquely derived trait; autapomorphy- unique trait in only one lineage).

Homology

shared traits inherited from a common ancestor.

Homoplasy

similar traits (analogy) due to convergence rather than common descent.

Convergent Evolution

an evolutionary change producing similar characteristics (homplasies) in two or more distantly related forms as a result of their independent adaptation to similar in ecological conditions.

Monophyletic group (clade)

group of organisms that includes the most recent common ancestor and all of its descendants (e.g. mammals).

Paraphyletic group

group of organisms that includes the most recent common ancestor but not all of its descendants (e.g. non-avian reptiles).

Polyphyletic group

group of organisms that does not include the most recent common \n ancestor of those organisms.

Taxon

any named group of organisms sharing the same name

Paleontology

study of prehistoric life (98% extinct)

Fossil

any trace of “ancient” life

>10-11 kya (Pleistocene-older)

Subfossil

any trace of “recent life”

Fossils

\-found where earth crust is exposed

\-remains of once living thing

Types of Fossils

1. impressions
2. structures
3. bromalites

Bromalite Types

1. coprolites(poop)
2. gastrolites(stomach contents)
3. regurgatillites (vomet)

Why Fossilization Rare

1. scavenged
2. decomposed
3. weathered

Why Fossilization Biased

1. aquatic system
2. hard tissues (easily petrified/fossilized)
3. large/familiar taxa

Fossilization-MODES

1. frozen
2. dehydrated
3. amber
4. petrification

stratigraphy

relative dating

(examining layers of sediment that have unique biota)

radiometric dating

\-absolute dating

(works by radioactive atoms and rate of decay)

silurian 445-410 mya

algae/cyanobacteria (produce O2)

devonian 410-360 mya

\-plants colonize land (produce O2 )

\-insects colonize land

\
\-TETRAPODS ORIGINATE (Sacopterygians-lob finned fish)

Why Colonize Land

1. food resources
2. predation/competition
3. respiration
4. basking
5. reproduction

challenges of life on land-support

\-water 8x dense as air, gravity→

vertebral column, ribs, pelvic, enclosed skull

challenges of life on land-locomotion

\-lateral undulation→ limbs, muscles (flexors: Ventral=lift body , extensors: dorsal=lift limbs)

\-digits, extra articulations

\-pelvic/pectoral girdles

\-veterbral column

challenges of life on land-feeding

\-suction feeding in water→ tongue protrusion (fleshy muscular tongue)

\-pectoral girdle free from skull

\-atlas (1st vertebrae)

\-skull flattens/broadens

challenges of life on land-desiccation(water balance)

\-skin


1. epidermis: stratum corneum-keratin
2. dermis: grandular-mucous

\-nasal passages (choana)


1. deliver air to lungs
2. behavioral adjustments (where to live, when active)

challenges of life on land-respiration

\-air 4-10x O2→ gills collapse

\-lungs

ventilation


1. thoracic compression
2. buccopharyngeal pumping

challenges of life on land-sensory systems

\-sight


1. lacrimal (tear) glands
2. eyelids

\-sound (99% reflects off body)


1. tympanum-ear drum
2. stapes-middle ear

\-smell


1. olfactory response

challenges of life on land-reproduction

\-biphasic lifestyle

transitional forms- eusthenopteron

1. bony limb elements
2. limb muscles
3. skull attached to pectoral girdle
4. no pelvic girdle

transitional forms- Tikaalik

1. limb elements larger
2. wrist/ankle bones
3. skull free from pectoral girlde
4. no pelvic girdle

Tetrapod Synapomorphies

1. 4 limbs
2. paired bones in forearm
3. hinged limb
4. digits

Temnospondyl (375-130 mya)

1. crocodile-like snout
2. diverse fish eater
3. aquatic and terrestrial

Lepospondyl (360-275 mya)

1. fewer skull bones
2. diverse body forms
3. mostly aquatic

Lissamphibia

Liss (Gr)=smooth amphibians


1. extant amphibians
2. sister to amniota
3. 8679 sp

Lissamphibia Synapomorphies

1. teeth: pedicellate/bicuspid
2. middle ear


1. stapes-airborne vibrations
2. operculum-ground-borne vibrations
3. inner ear


1. papilla basilaris-high freq
2. papilla *amphibiorum*-low freq
4. skull


1. fewer bones
2. open palate
3. fenestrations
4. 2 occipital condyles
5. ribs
6. atlas
7. levator bulbi


1. muscle-eye elevation
8. respiration


1. custaneous
9. glandular skin


1. muscous:mucoproteins
2. serous:pheremones,secondary sexual trait
3. poison
10. dichromates


1. red&greeen cones
11. skin


1. epidermis=thin outer layer
2. dermis=thick inner layer


1. muscous glands
2. granular glands
12. biphasic lifestyle


1. external fert.
2. aquatic eggs
3. aquatic larvae

\

Classification Order

Kingdom

phylum

class

order

family

genus

species

\-a

order+

\-oidea

super family

\-idae

family

\-inae

sub family

Gymnophiona-Oldest one?

Eocaecilla-dawn caecilian

Gymnophiona-Ecomorphic Diversity

\-fossil

\-semi-aquatic

\-aquatic

Caecilian Traits: BODY

1. limbless/elonagte
2. no pelvic/pectoral girdles
3. annulated “costal grooves”
4. dermal scales(some)
5. tail reduced/absent
6. eyes reduced
7. eyes covered by skin or bone
8. tentacle


1. chemosensory organ
2. VNP
3. protrusible (Some)
9. lungs (left reduced)
10. cutaneous
11. external gills (larvae)

Caecilian Traits: Skull

1. compact
2. ossified
3. akinetic
4. completely roofed (most)
5. teeth curved/long
6. long retroarticular
7. strong jaw muscles
8. dual jaw closing mechanism

Caecilian Traits:Diet

1. invertebrates (worms)
2. vertebrates (small)


1. lizard
2. termites

Caecilian Traits: Akinetic Terrestrial Feeding

spin & shear feeding

Caecilian locomotion

Concertina

Caecilian Traits:Reproduction Fertilization

1. internal


1. phallodeum (male copulatory organ: part of cloaca)

Caecilian Traits:Reproduction Modes

1. oviparous


1. eggs→aquatic larvae
2. terrestrial eggs→direct development
2. viviparous


1. eggs (oophagy)
2. oviductal secretions (“uterine milk”)

Parental Care

behavior involving PI that improves offspring survival


1. postnatal
2. maternal/paternal/allopaternal


1. costly to parent

Caecilian Traits:Reproduction PI

1. egg guarding
2. cloacal secretions: caecilian milk
3. dermatophagy: nutritious skin

Caudata Oldest

Karaurus

\-mid jurassic

\-aquatic

Caudata Habitats

1. forest/jungle
2. woodland
3. grassland
4. caves
5. rock outcrops


1. freshwater

Caudata Ecomorphic Diversity

1. terrestrial
2. semi-fossorial
3. semi-arboreal/arboreal
4. cave dwelling
5. aquatic/semi-aquatic

Salamander Traits-Body

1. robust limbs
2. well-developed tail


1. locomotion
2. energy storage
3. costal grooves

Salamander Traits-Skull

1. maxilla incomplete
2. palate incomplete
3. teeth maxilla/vomer

Salamander Traits: Genomes

largest of tetrapods

\-30-120 Gb

Salamander Traits: Regeneration

1. tails/limbs/organs


1. stem cells?

Salamander Traits: Respiration

1. cutaneous skin


2. external gills


1. lungs

Salamander Traits: lunglessness

\-Plethodontidae

\-Rhyacotritonidae

\-Salamandridae

\-Crypobranchidae

Salamander Traits: Locomotion

1. aquatic
2. terrestrial
3. arboreal

Salamander Traits: Diets

\-insectivores

\-invertebrates

\-carnivores

Salamander Traits: Feeding

1. suction feeding
2. tongue projection (simple)


1. muscular stick tongue pad (mucous)
2. attached to floor of mouth
3. hyoglossus extends/retracts
3. tongue projection (advanced)


1. muscular sticky tongue
2. attached to hyoid
3. subarcualis muscle squeeze hyoid
4. abdominal muscles retract

Salamander Traits: Defense

1. chemical defenses


1. caudal anatomy (drop tail)

Salamander Traits: communication

1. chemical/tactile


1. nose (volatile)
2. VNO (non-volatile)
3. nasolabial groove
4. clocoa
2. visual

Salamander Traits: Courtship

1. chemical


1. pheromones
2. tactile


1. pheromones/touch
3. visual


1. semaphores/displays

Salamander Traits: Fertilization

1. internal


1. male→spermatophore
2. female→spermathecae

Salamander Traits: Modes

1. oviparity- laying eggs


1. pond (small eggs)
2. stream (larger eggs)
3. terrestrial (50%)
2. viviparity-eggs retained in body

oviparity

laying eggs

viviparity

eggs retained in body

Salamander Traits: Development

\-metamorphosis

\-direct development

\-neoteny

\-obligate

\-facultative

metamorphosis

eggs→lavae→juvenile

direct development

egg→ juvenile

neoteny

sexual maturity reached while in larval form

obligate

metamorphosis not inducible

facultative

conditions dictate neoteny