ReptilesReptiles

Shaleva, Teodora Shaleva, Ekaterina

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Reptilia Class• Chordata Phylum – includes fishes, amphibians, birds,

reptiles and mammals (1)• Orders – Crocodilia (crocodiles, gavials, caimans, alligators)

(1) - Rhynchocephalia (tuataras from New Zealand)

(1) - Squamata (lizards, snakes, worm lizards) (1)

- Testudines (turtles, tortoises) (1)

• Reptilia Class – includes all amniotes except birds and mammals (7)

• Reptiles are a paraphyletic group – if birds were included it would be a monophyletic group (that includes all descendants of a particular form) (7)

• The claws of the reptiles and birds contain the same protein to the one in human hair and nails (8)

• The origins of hair date back to 310-330 million years ago to the last common ancestor of mammals, birds and reptiles (8)

Common ancestor with mammals (humans)

General Information• Scientific name – Reptilia (Latin : repere – “to creep”)

(7)• Derived characteristics:

– “cold-blooded” – have body temperature that varies with that of the surroundings (3)- have scales that cover their body (3)

• Bilateral symmetry – their body has two equal parts that are symmetrical (3)

Facts: - Reptiles are found on every continent except Antarctica (2)- They have existed for more than 300 million years (3)- There are more than 8000 reptile species (3)- They don’t have fur of feathers (3)

- Three-chambered hearts (3)- Most of them lay eggs,

which are protected by a leathery shell – amnion (3)

- Waterproof skin (3)- The extinct dinosaurs were

reptiles (3)- They are among the longest

living species on Earth (3)

How do they move?• Similar to mammalian walk – front and back

legs move in opposition (5)• As it walks, a reptile bends its torso into a

curve to help push the feet along (5)• Despite the awkward motion, some reptiles

are capable of moderate speeds (5)• Snakes don’t have limbs – they move by

slithering along the ground (4)• Some lizards can lift their front legs off the

ground when running (5)

How do they reproduce?

• Most reptiles reproduce sexually, though some are capable of asexual reproduction (7)

• Sexual reproduction - the female’s eggs are being fertilized by the male internally (4)

• The eggs, are then carefully deposited (4)• Asexual reproduction (parthenogenesis) – identified in six

families of lizards and one snake (7)• Reptiles can be oviparous (that lay eggs) and viviparous

(that bear live young) (4)• A female that lay eggs is called gravid (otherwise pregnant)

(4)

How do they obtain food?

• Most are carnivorous – hunt down their food (7)

• Digestion is slower than in mammals (7)

• Large reptiles like crocodiles can live from a single large meal for months, digesting it slowly (7)

• Today turtles are the only herbivorous reptile group (7)

• Most snakes can dislocate their jaw allowing them to swallow prey much larger than themselves (3)

Some Representatives

Anaconda – heaviest snake (3)

Galapagos Tortoise – longest living tortoise (15)

Komodo dragon – the largest lizard (3)

King Cobra

• Ophiophagus hannah – ophiophagus means “snake-eater” (10)

• The longest venomous snake in the world (can reach 5.4 m) (10)• They can lift 1/3 of their body (10)• Depending on where they live, they vary in color – brown,

yellow, black, green (10)• They shed their skin 4-6 times a year (every month for juveniles)

(10)• They are more intelligent than other cobras and can distinguish

between their caretakers from strangers (10)• Live for 20 years (10)• Habitat – found throughout southeast Asia, in rainforests,

swamps, savannas, and even around human settlements (10)• Excellent swimmers (10)

• Food – usually non-venomous snakes and lizards (10)• Hunt their food by smelling the air with their forked

tongue (10)• Importance

– Negative – its venom is very strong – death occurs very shortly from respiratory arrest and cardiac failure (9)

- Positive – they are among the most attractive highlights in zoos (9)

http://www.youtube.com/watch?v=x7XY3dMVNhg

Green Sea Turtle

• Chelonia mydas (11)• The largest hard-shelled sea turtle in the

world – ranges in length from 2 to 6 feet (11)• They are called Green Sea Turtles because of

the color of their flesh, which is green from the algae they eat (12)

• Reach sexual maturity slowly – between 10 and 50 years (12)

• Habitat – warm tropical oceans, in warm, shallow water, where they spend all of their lives (most common in Hawaii) (11)

• The only time they leave the water is when females come on shore to nest (11)

• Food – sea grasses, algae and crabs• Considered a threatened species in the

United States (11)

American Alligator

• Alligator mississippiensis (6)• The largest reptile in North America (6)• Reach 4 to 4.5 meters (6)• Habitat – primarily freshwater swamps,

but also in rivers and lakes (6)• Food - juveniles eat small

invertebrates; large adults can attack almost all prey within range (6)

• They rarely attack children and adults – only when provoked or mistaken (6)

• In some areas growing alligator population causes problems with human population (6)

• Start to breed in spring (6)

Human uses and interactions

• Negative (for humans)- Poisonous snakes – in USA 12 people a

year die from snake bites (12)- Crocodiles and alligators are also

dangerous for humans (6)• Positive- Lizards and snakes are used as pets

(14)- Reptiles are used as attractions in

zoos (9)- Delicacies in some cultures – snakes in

China, “turtle soup” in Asia, iguanas are called “tree chickens” and are eaten in the Yucatan Peninsula (14)

Interesting Facts

• If a snake is born with two heads, its both heads fight each other for food (3)

• The Egyptians used crocodile dung as the first contraceptive in human history in 2000 B.C. (3)

• The distance between an alligator’s eyes, in inches, is directly proportional to the length of the alligator in feet (3)

• Turtles were present on earth before the dinosaurs (3)

• More Americans die each year from bee stings than from snake bites (4)

What percent of snakes are harmful to humans? (4)

Less than 2 %Less than 2 %

Works Cited• Myers, P. 2001. "Reptilia" (On-line), Animal Diversity Web. Accessed March 22, 2010 <

http://animaldiversity.ummz.umich.edu/site/accounts/information/Reptilia.html>. [Class Reptilia] (1)• Cornett, Brandon. “21 Interesting Facts About Reptiles”. ReptileKnowledge.com. 2009. March 22, 2010 <

http://www.reptileknowledge.com/articles/article19.php>. [General Information and Interesting Facts] (2)• “Facts About Reptiles”. Buzzle.com. 2010. March 22, 2010 <

http://www.buzzle.com/articles/facts-about-reptiles.html>. [Interesting Facts] (3)• Wissman, Margaret A. “Reptiles Reproduction: From Egg to Adult”. Exoticpetvet.net. 2006. March 22, 2010

<http://www.exoticpetvet.net/reptile/rerepro.html>. [Reproduction] (4)• Maestri, George. “Reptile Walks”. Informit.com. 2010. March 22, 2010 <http://

www.informit.com/articles/article.aspx?p=22802&seqNum=3>. [Movement] (5)• Britton, Adam. “Alligator mississippiensis”. Crocodilian Species List. 1995-2009. March 22, 2010 <http://

www.flmnh.ufl.edu/cnhc/csp_amis.htm>. [Representatives: American Alligator] (6)• “Reptilia”. ZipCodeZoo.com. 2004-2009. March 28, 2010 <http://zipcodezoo.com/Key/Animalia/Reptilia_

Class.asp>. [Digestive System and Reproduction] (7)• “Human Common Ancestors with Reptiles”. Abovetopsecret.com. November 16, 2008. March 28, 2010

http://www.abovetopsecret.com/forum/thread412119/pg1>. [Common Ancestor] (8)• Young, D. 1999. "Ophiophagus hannah" (On-line), Animal Diversity Web. March 28, 2010

<http://animaldiversity.ummz.umich.edu/site/accounts/information/Ophiophagus_hannah.html>. [Representative: King Cobra] (9)

• “King Cobra”. Angelfire.com. March 28, 2010 <http://www.angelfire.com/mo2/animals1/snake/kingcobra.html>. [King Cobra] (10)

• Hibbard-Rode, Karen, Klostermann, Matt. “Green Sea Turtle”. Biological Diversity 2001.November 27, 2001. March 28, 2010 <http://www.earlham.edu/~klostma/greenseaturtle.htm>. [Representative: Green Sea Turtle] (11)

• “Green Sea Turtles”. Earthtrust.org. March 28, 2010 <http://earthtrust.org/wlcurric/turtles.html>. [Green Sea Turtle] (12)

• Auerbach, Paul. “Snake Bites”. Surviveoutdoors. 2000-2010. March 28, 2010 <http://www.surviveoutdoors.com/reference/snakes/snake-bites.asp>. [Snake Bites] (13)

• Vogt, Josh. “What are Reptiles Used for Food?”. eHow. 1999-2010. March 28, 2010 <http://www.ehow.com/list_6008787_reptiles-used-food_.html>. [Delicacies] (14)

• Raymond, Claire. “Exclusive: The Oldest Creature on Earth”.mirror.co.uk. 2005 March 28, 2010 < http://www.mirror.co.uk/news/top-stories/2005/10/19/exclusive-the-oldest-creature-on-earth-115875-16265479/> [Galapagos Tortoises] (15)

Works Cited

Images: http://shanghaishakedown.typepad.com/shanghaishakedown/images/p1290107.jpg -

Turtle Souphttp://www.digitalscryer.com/Pics/Hulk/komodo.jpg - Komodo Dragonhttp://brianlean.files.wordpress.com/2007/12/ga.jpg - Galapagos Tortoisehttp://plaza.ufl.edu/jessmel/jessica/anaconda.jpg - Anacondahttp://susty.com/image/american-alligator-teeth-scales-tail-mud-species-spotlight-reptile-habitat-loss-endangered-sustainability-new-wave-environmentalism-go-green-susty-photo-357x500.jpg

-American Alligatorhttp://www.earlham.edu/~klostma/greenseaturtle.htm - Green Sea Turtlehttp://www.k12.nf.ca/acreman/learning_logs/king_cobra.JPG - King Cobrahttp://kentsimmons.uwinnipeg.ca/16cm05/1116/34-24-ExtantReptilesCollage.jpg - Some

Representativeshttp://www.nap.edu/books/11876/xhtml/images/p20013a49g8002.jpg - Cladogram