Herpetology Lab Practical 1

Ranidae - True frogs

CO genus - Lithobates
-extensive toe webbing
-pointed snout
-some species shave dorsolateral folds
-robust, muscular hind limbs for jumping & swimming

Hylidae - Tree Frogs

CO genus - Pseudacris, Acris, Hyla
-Subdigital toepads
-Extra jointed digits
-Elongate limbs

Microhylidae

CO Genus -Gastrophryne
-Narrow mouth
-Small, round body
-Many species have fold of skin over eyes
-Very small tympanum

Dendrobatidae - Poison frogs

-Small body size
-Enlarged toe tips
-Diverse aposematic coloration
-Smooth skin
-No webbing
-Proportionally long forelimbs

Pipidae - Aquatic tongueless frogs

-Narrow, flattened skulls
-Many species have claws
-Full webbing on hind feet
-Extremely long fore foot digits for feeding

Ascaphidae - Tailed frogs

-Earless frogs
-Males have a tail
-Do not vocalize
-No tympanum

Bufonidae - True toads

CO genus - Anaxyrus
-blunt head, rounded mouth
-paratoid glands
-many species have cranial crests
-most have dry & warty skin

Scaphiopodidae - Spade foot toads

CO Genus - Spea, Scaphiopus
- Keratin-based spade on hindfoot
-Smooth skin
-Some species have a boss
-Hind foot webbing

Bominatoridae - Fire-bellied toads

-Blunt head, rounded mouth
-Aposematic coloration
-One species is completely lungless - only lungless frog
-Rough skin
-No tympanum

Frogs

Class Amphibia

Order Anura

Salamanders

Class Amphibia

Order Caudata

Ambystomatidae

CO Genera - Ambystoma

Biphasic, some paedomorphic

Key traits for family

- Blunt head, rounded mouth

- Costal grooves – very prominent

- Rounded tails

Dicamptodontidae

Biphasic, some paedomorphic

Key traits for family

- Large head, triangular snout

- Huge body size

- Costal grooves – not prominent

- Keeled tail

Plethodontidae

Direct developing, biphasic, paedomorphic

Key traits for family

- Nasolabial grooves

- Costal grooves

- Often rounded tail, but diverse morphology

- Lungless!

- Small size

Salamandridae

Biphasic, or triphasic!

Key traits for family

- Rough skin

- No costal grooves

- Paddle tail

- Danger-mander

Rhyacotritonidae

Biphasic – specialized for torrent streams

Key traits for family

- Costal grooves

- Short tail

- Males have cloacal flaps

- Small body, rounded and blunt head

- Prominent eyes

Hynobiidae

Biphasic, some paedomorphs

Key traits for family

- Costal grooves

- Rounded or slightly keeled tail

- Some are lungless!

Cryptobranchidae

Paedomorphic, fully aquatic

Key traits for family

- Paddle-tail

- Broad, flattened head

- Gill slits

- Lateral folds

- HUGE!

Sirenidae

Paedomorphic, fully aquatic

Key traits for family

- Gills as adults

- Elongate body

- Only has forelimbs = 2 limbs

- Reduced limb size

Amphiumidae

Paedomorphic, fully aquatic

Key traits for family

- Gill slits

- Extremely elongate body

- Four vestigial limbs

- Reduced number of digits (most salamanders have 4 / 5)

Proteidae

Paedomorphic, fully aquatic

Key traits for family

- Proportional limbs

- External gills

- Paddle-like tail

- Elongate snout - interesting trait

Gymnophiona

- Limbless

- Presence of sensory tentacles

- Annuli

- Eye morphology; vestigial eyes

- Presence/absence of tail

Lizards

Class Reptilia

Order Squamata

CO Families

Teiidae –Whiptails (Aspidoscelis)

Phrynosomatidae – Horned lizards, fence lizards,earless lizards,etc.

Scincidae – Skinks (Plestiodon)

Crotaphytidae – Collard lizards

Family Phrynosomatidae

CO Genera - Holbrookia, Phrynosoma, Sceloporus, Uta, Urosaurus

Morphological diverse family!

Key traits for family

- Labial scales

- Eyelids

- Distinct head

Genus: Phrynosoma

CO species (3): P. hernandesi, P. cornutum, P.modestum

Key traits

- Robust body, short limbs / tail, horned scales

- distinct eye lids

- labial scale

Genus: Holbrookia

CO species (1): H. maculata

Key traits

- Granular scales, short tail, no ears, paired ventrolateral blotches

- distinct eyelids

- labial scales

Genus: Sceloporus

CO species (3): S. undulatus, S. magister, S. graciosus

Key traits

- mucronate scales, ventralateral blue blotches

- distinct eyelids

- labial scales

Genus: Uta

CO species (1): U. stansburiana

Key traits

- Angular head, granular scale, side blotch, horn

- distinct eyelids

- labial scales

Genus: Urosaurus

CO species (1): U. ornatus

Key traits

- Angular head, granular scale, barred pattern, horn-like scales

- distinct eyelids

- labial scales

Crotaphytidae

Crota – side ; phyte – head

(they have big heads)

CO Genera - Crotaphytus, Gambelia

Key traits for family

- Enlarged musculature on head

- Long tail, muscular legs

Genus: Crotaphytus

CO species (1): C. collaris

Key traits

- collar pattern, robust head, blue/yellow coloration

- Broad head

- long tail

- muscular limbs

Genus: Gambelia

CO species (1): G. wislizenii

Key traits

- spotted pattern, lacks collar, more elongated rostrum

- Broad head

- long tail

- muscular limbs

Scincidae

Genus: Plestiodon

CO species(2): P. multivirgatus, P. obsoletus

Key traits for family

- Lack of gular fold

- Cycloid (fish-like)scales

- Attenuate limbs

Teiidae

Genus: Aspidoscelis

CO species (5): A. sexlineata,A. tigris, A. tesselata, A. neotesselata, A. velox

Key traits for family

- Plate-like scales on head

- Granular scales on body

- No distinct neck

- Narrow head

Lizard families in the Clade Iguania

Chamaeleonidae – Chameleons‘

Agamidae– Assorted dragons

Iguanidae – Iguanas

Dactyloidae – Anoles

Chamaeleonidae

Old World lizards

Key traits:

– Paw-like hands& feet (zygodactyl)

– Horns and/or crests

– Protruding eyes

– Laterally flattened bodies

– Extensile tongue

– Granularscales

Iguanidae

Key traits:

– Large bodied lizards, often football shaped with robust head

– Can have crest on the back and tail

– Variable scales throughout body

– Can have a dewlap

Agamidae

Old World iguanids

Morphologically diverse

Key traits:

– Well developed limbs

– Diverse color patterns

– Unique adaptations(frills, wings)

Dactyloidae

Key traits:

– Tails are longer than body

– Most species exhibit sexual dimorphism – males have dewlaps

– Pointed snouts

– Can have dorsal crests

– Granular scales

Lizard families in the Clade Anguimorpha

Varanidae– Monitorlizards, Komodo dragons

Anguidae – Glasslizards, legless lizards

Helodermatidae – Gila monsters

Varanidae

Key traits:

– Elongated neck (due to an extra vertebra)

– Long forked tongues

– Large lizards – up to 9 feet

– Huge claws

Anguidae

Key traits:

– Lateral fold

– Rectangularscales

– Morphologically diverse in terms of presence/absence of limbs and body size

Helodermatidae

Key traits:

– Short tails

– Max length of 3 feet

– Short, broad, rounded snout

– Large granularscales

– Ossified dermalscales

– Venomous!!But generally passive lizards and not excessively toxic

More Lizard Families

Amphisbaenidae – worm lizards

Lacertidae – wall lizards

Gekkota* (infraorder) – geckos

Xantusiidae – night lizards›

Gekkota

Key traits:

– Extremelydiverse group

– Many specieslack eyelids

– Typically have granular scales

– Diverse toe morphology – toe pads

Rhineuridae

Key traits:

– Shovel-like snout

– Limbless

– Annular (ring-like)scale pattern

– Reduced/vestigial eyes

– Elongate body,truncated tail

Lacertidae

Key traits:

– Granular scales on most of body, rectangular scales onstomach

– Small lizards with slender bodies and long tails

– Back legs typically largerthan front

– Wide range of colors

Xantusiidae

Key traits:

– Moderately flat bodies and heads

– Granularscales on body, large plates on head

– No eyelids

– Elliptical pupils

Amphibian evolution

Snakes

Class Reptilia

Order Squamata

Turtles

Class Reptilia

Order Testudines

Salamander Common Traits

Costal Grooves

- Located on the sides of the salamander body

- Look like rolls, bumps, or ribs poking out under the skin

- Evenly spaced bumps with a crease in between each segment

Tail Shape (2 types)

Rounded

- All or most of the tail is circular or tubelike in shape

- Would appear as a circle if a cross section cut was made

Keeled/Paddle

- All or most of the tail is vertically flattened

- Widest part of the tail is in the middle, becoming thinner at the top and bottom

- Would appear as an oval if a cross section cut was made

Nasolabial Groove

- Located in the space between the nose and mouth

- Grooves, that are channel-like which run from the nose down to the mouth

- One groove under each nostril, making 2 total on the face

Gills

- Located behind the head on either side of the body

- Leafy, frill-like, or branched structures that are in place of lungs

- On the juvenile form of aquatic salamanders

Frog Common Traits

Tympanum

- Located on the sides of the head, behind eyes

- Large round circles that range in color but are usually green or brown

Parotoid Glands

- Located on the sides of the head, behind eyes or behind tympanum

- Large raised bumps that are distinct from warts (if present)

- Can be oval or circular

- Can be the same color or different color that the rest of the skin

Dorsolateral Folds

- Located on the back, slightly to sides of the body

- Two long folds of skin that run in one line from the back of

the head to the end of the back

- Can be the same color or different color that the rest of the

skin

Boss

- Located on top of the head between the eyes

- Hard raised bump, (as if a cartoon was bonked on top of

the head)

- Feels like a round bone under the skin

Snakes Common Traits

Labial Scales

- Located around the mouth on the upper and lower "lips"

- Starts from nose and goes toward the back of the mouth

- Upper scales are large and distinctly shaped

- May have dark markings (bars) running vertically between each scale

Scale Types

Smooth

- Cover the whole body of the snake

- Smooth and soft to the touch

- Often diamond shaped and appear to not be overlapping

Keeled

- Cover the dorsum and sides of the body

- Rough to the touch

- A small raised line runs down the middle of each scale

- Individual scales often pointed at the tips

- May appear to be overlapping a little

Anal Scale (2 types)

Single

- Located on the ventrum or belly

- Separates the body from the tail

- Last belly scale (long, horizontal smooth scale)

- One single scale

Divided

- Located on the ventrum or belly

- Separates the body from the tail

- Last belly scale (long, horizontal smooth scale)

- Divided diagonally into two scales, one scale overlaps the other

Hemipenes

- Located on the ventrum or belly

- Between the torso and the tail

- 2 white phallic structures with frills at their ends splaying out from the last belly scale

- Often seen on preserved specimens in pairs

Lizards Common Traits

Gular fold

- Located on the ventral side of body

- Between head and torso

- Horizontal fold of skin that defines the neck area

Scale type

Mucronate

- Pointed, sharp

- Often keeled

- Rough to the touch

Cycloid

- Rounded

- Like fish scales

- Smooth to the touch

Granular/beaded

- Small, round

- Like lizard is covered in very small individual beads

- Bumpy but smooth to the touch

Dewlap

- Located on the ventral side of body

- Between head and torso

- Vertical fold of skin that expands perpendicular to the body

- Can expand or fold down (retract)

- Can be the same color as the body or different

Dorsal Crest

- Located on the dorsal side of body

- Can start on head and continue down body, sometimes to tail or...

- Can start behind head and continue down the body, sometimes to tail

- Can be covered in scales that cover the body or be uniquely spikey scales

- Can be the same color as the body or different

Turtle Common Traits

Carapace

- Located on/is the dorsum

- Often hard and slightly rounded structure with unique patterns

- Can have smooth or spiked edges

- Attached to the rest of the turtle

- Spine is fused to underside

Plastron

- Located on/is the ventrum

- Often hard

- Can have unique coloration or patterns

- Often large and covering most of ventrum

- Attached to the rest of the turtle

Scutes

- Located on dorsum (on top of carapace)

- Not all carapaces have scutes!

- Smooth, hard/durable scale-like structures

- Can have unique patterns or colors

Tubercules

- Located on neck, sometimes under chin

- Small protrusions

- Can be tentacle-like or spikey

- Often the same color as turtle skin