Zoo_BI,_Carts,_Komodo_Dragon Flashcards
Q: When do Komodo dragons stop growing?
Like other reptiles, Komodo dragons continue to grow throughout their lifetime. This growth slows after 6 years when dragons reach their average adult size.
Q: Komodo dragon diet?
Predators and scavengers.
Strictly carnivorous.
Birds, mammals (deer, pigs), smaller dragons, invertebrates, carrion.
As juveniles, small animals. As adults, larger prey, as large as water buffalo.
Q: Reptile teeth, ingestion, waste
Generally simple and conical (peg-like).
Uniform in shape and size throughout jaw (homodont). Vary slightly in size.
Upper and lower tooth rows do not contact one another.
Continuously shed and replaced throughout life.
Used for killing and holding.
Swallow food whole.
Waste is uric acid, which is low in water content, reducing water loss.
[duplicate card: Reptiles, BI Komodo dragon]
Q: Skull identification, reptile vs mammal
Reptiles are homodonts; all teeth are similar. Usually long, conical. (Turtles lack teeth.)
Reptiles have proportionately smaller brains than mammals.
Reptiles have two nasal openings in their skull. Mammals have one.
Reptiles have a single point of attachment between skull and spinal column. Mammals have two.
Lower jaw of reptile is comprised of several different bones and is hinged to the upper jaw and skull through the quadrate bone. Mammal lower jaw connects directly to skull.
The tuatara and most lizards also have a small hole at the top skull due to the parietal eye.
[duplicate card: Skulls, BI Komodo dragon]
Q: Something crocodilian teeth have in common with mammal teeth?
They are socketed. Other reptiles do not have socketed teeth.
Q: Discuss a some differences between alligator and iguana teeth.
Alligator: socketed with deep roots like that of humans (crocodilians are only reptiles with socketed teeth.
Iguanas: sharp, jagged teeth that are capable of shredding leafy foods.
Q: Burmese python teeth
Back curving teeth that grab prey and don’t let it escape.
Q: How many teeth do Komodo dragons have?
About 60
Q: Komodo dragon teeth
Serrated.
About one inch long.
Frequently replaced. Further rows of replacement teeth lie behind.
Also have rear facing teeth to help grab on to prey.
Q: How many sets of teeth will a Komodo dragon go through?
Four or five sets of teeth in a lifetime.
Q: Are Komodo dragons venomous?
Yes.
They have a venom gland in their lower jaw. Venom prevents blood from clotting and decreases blood pressure, causing massive blood loss and inducing shock. [link below]
ALSO: Harmful bacteria lives in their saliva. Bits of rotten flesh get stuck in serrated teeth, “turning their saliva into a mini-habitat for harmful bacteria that can cause untreated bite wounds to become septic.” [link below]
https://nationalzoo.si.edu/animals/news/how-dangerous-are-komodo-dragons-and-other-komodo-dragon-facts#:~:text=Researchers%20have%20also%20documented%20a,blood%20loss%20and%20induces%20shock.
Q: Unique/surprising Komodo dragon senses?
Jacobson’s organ (details on other cards)
Parietal eye (details on other cards)
Strong sense of smell: can detect rotting carcasses from 10 kilometers away.
Q: Other term for a Jacobson’s organ?
Vomeronasal organ (VMO)
Q: What is a Jacobson’s Organ?
-Some animals have auxiliary olfactory sense organ (the VMO or Jacobson’s Organ) at the roof of the animal’s mouth
-Chemical receptor used to detect chemical stimuli.
-Can be found in all vertebrates, but is only enhanced in a few: snakes and lizards (squamata order), cats, wolves, ungulates, and lemurs.
-In some mammals (i.e. cats and hooved animals), organ is involved in the flehmen response (lifting upper lip, grimace), and is used to detect pheromones, chemical messengers carrying info between individuals of same species.
[card duplicated: biofacts-skulls, Komodo dragon cart]
Q: What is a benefit of snake/lizard tongues being forked?
Reptiles smell using the tip of their tongue.
Tongue picks up airborne molecules and is withdrawn into mouth where scents are interpreted by Jacobson’s organ (details on other card), which has two opening ducts.
Forked tongue allows them to sense direction of smell.
Also provides more surface area.
Q: What can we learn about a reptile by looking at its tongue?
The degree of the tongue’s fork indicates the use of the Jacobson’s organ.
Reptiles with deeply forked tongues have a more developed Jacobson’s organ.
E.g., common green iguana has very shallow fork and doesn’t use its Jacobson’s organ as much as a Komodo dragon, which has a deeply forked tongue.
Q: Can we directly observe anything related to the Jacobson’s organ on the Komodo dragon biofacts cart?
You can see the receptor pits on the Burmese python skull.
Q: Parietal eye
(pineal eye)
Light sensitive (photoreceptive) organ on top of the head which looks like a clear scale.
Associated with the pineal gland, regulating circadian rhythmicity and hormone production for thermoregulation
Also acts as defensive measure, since approaching predator will cause the light to change.
Found in some reptiles, some amphibians, and some fish.
Note: the parietal eye is especially visible on the common green iguana skull but not on the alligator skull on the komodo dragon biofact cart. Crocodilians lost this adaptation as have birds and mammals.
Note: the parietal eye is why proper UV lighting in the Komodo dragon exhibit is important.
[duplicate card: reptiles, komodo dragon cart]
Q: By what characteristic are modern reptiles split into subclasses? What is notable about the evolution of these characteristics?
-Modern reptiles: four subclasses based on number and position of temporal fenestrae, openings in the sides of the skull behind the eyes. [TODO needs clarification: all modern reptiles have either 0 or 2 fenestrae, so positioning must distinguish further? Early amniotes (some of which evolved into mammals) are divided into 3 groups based on fenestrae.]
-Early in reptile history, changes occurred in muscle attachment to the lower jaws and the skull in amniotes having to do w/ development of stronger and more efficient jaw muscles and a diversification in what they ate. Allowed more powerful and faster bites.
–Three patterns of holes (fenestrae) in the temporal region of the skull, just behind the eye. (details on separate card)
–Provided space for the large muscles needed for feeding when shifting from an aquatic environment to a terrestrial one where the vegetation was more coarse.
[duplicate card: Reptiles, Komodo dragon cart]
Q: Fenestrae
a small opening in the bone
[duplicate card: Reptiles, Komodo dragon cart]
Q: Three patterns of holes that developed in skulls of early amniotes.
-Different patterns of fenestrae in temporal region of skull behind eye
-0 temporal fenestrae: anapsids- turtles, tortoises and terrapins
-1 temporal fenestrae: synapsids- evolved into mammals
-2 temporal fenestrae: diapsids- birds and major reptiles (lizards and snakes, tuatara, alligators and crocodiles, dinosaurs)
[duplicate card: Reptiles, Komodo dragon cart]
Q: How are modern reptiles classified?
Temporal fenestrae, or lack thereof.
Most have two fenestrae with the exception of the turtles, tortoises, and terrapins, who lack fenestrae.
[duplicate card: Reptiles, Komodo dragon cart]
Q: Common green iguana diet?
Herbivore
Leaves, flowers, fruit
Q: Common green iguana habitat?
Rain forests of northern Mexico, Central America, the Caribbean Islands, and southern Brazil. They spend most of their lives in the canopy, descending only infrequently to mate, lay eggs, or change trees.
