3. Cold blooded.
Can survive both on land and in water.
Mostly lay eggs.
Most lay eggs, none have hair or fur.
All lack external ears.
Four main group of reptiles:
Turtles
Snakes
Lizards
Crocodiles
Introduction of Reptiles
3
4. AMNIOTIC EGG
Amnion:
The innermost membrane of the fetal
membranes of amniotes; the sac in which the
embryo is suspended; protects the embryo from
shock and carries out hydration.
Chorion:
Allows exchange of oxygen and carbon
dioxide between the embryo and the egg’s
external environment
Allantois:
Membrane in an egg that stores
nitrogenous wastes produced by the embryo and
facilitates respiration.
Source:
https://www.google.com/imgres?imgurl=https%3A%2F%2Fi.ytimg.com%2Fvi%2FdYND5LZ7KiQ%2Fmaxresdefault.jpg&imgrefurl
=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DdYND5LZ7KiQ&tbnid=FUZNkIFlRpqeKM&vet=12ahUKEwiq8MPj8qL4A
hVD0YUKHS5oBBwQMygCegUIARDcAQ..i&docid=L0CgY4qF-
Zn9PM&w=1280&h=720&q=AMNIOTIC%20EGG&ved=2ahUKEwiq8MPj8qL4AhVD0YUKHS5oBBwQMygCegUIARDcAQ
5
5. Fertilization
Most reptiles reproduce sexually and have internal fertilization.
Males have one or two penises that pass sperm from their cloaca to
the cloaca of a female.
Fertilization occurs within the cloaca, and fertilized eggs leave the
female’s body through the opening in the cloaca.
In a minority of species, the eggs are retained inside the female’s body
until they hatch. Then the offspring leave the mother’s body through
the cloaca opening.
5
6. Reproduction Methods
Oviparous – egg layers
Viviparous – live birth
Ovoviviparous – eggs stay inside of mother until they
are ready to hatch, then the eggs hatch inside of the
mother and babies come out like live birth.
6
7. 7
Parthenogenesis
Identified in 6 females, mostly in geckos.
In this growth and development of an egg into an embryo occurs
without fertilization by males or sperm.
All are females
Low genetic diversity
E.g. Mexico whiptail Lizard
Sourcee: https://www.google.com/imgres?imgurl=https%3A%2F%2Fmedia.nationalgeographic.org%2Fassets%2Fphotos%2F227%2F611%2Fab3c5d5b-534a-44be-b7f1-6376db25f778.jpg&imgrefurl=https%3A%2F%2Fwww.nationalgeographic.org%2Farticle%2Fhow-asexual-lizard-procreates-alone%2F9th-
grade%2F&tbnid=N4aMCzrHwoFCyM&vet=12ahUKEwie1a2S9KX4AhVE4oUKHSQOD84QMygBegUIARCxAQ..i&docid=k5x_X0NuAVyv8M&w=2000&h=1325&q=mexico%20whiptail%20lizard&ved=2ahUKEwie1a2S9KX4AhVE4oUKHSQOD84QMygBegUIARCxAQ
8. Parental care
Female turtle lay their eggs on
beaches and return to sea having
nothing to do with their young.
Female Crocodile are protective of
their nest.
8
Source:
https://www.google.com/imgres?imgurl=https%3A%2F%2Fdr282zn36sxxg.cloudfront.net%2Fdatastreams%2Ff-
d%253Aca1fb4e21332f77edf7bfa929a3c243e5116775ec4247afd7ea00911%252BIMAGE_TINY%252BIMAGE_TINY.1&imgref
url=https%3A%2F%2Fwww.ck12.org%2Fbook%2Fck-12-biology-advanced-concepts%2Fsection%2F16.22%2F&tbnid=-
Qwlc9W3OowyRM&vet=12ahUKEwihi_Pn9aX4AhUBZvEDHVb1C6EQMygJegUIARDVAQ..i&docid=COqDNAoy0r1SUM&w=10
24&h=678&q=hatching%20of%20reptile%20egg&ved=2ahUKEwihi_Pn9aX4AhUBZvEDHVb1C6EQMygJegUIARDVAQ
Source
https://www.google.com/imgres?imgurl=https%3A%2F%2Fimages.ctfassets.net%2Fx2t7lek2vf7h%2F4bEaIKThaGdXihCumh
2BjJ%2Faa9e56b299274a4b73efbf7f9eae685f%2F9246590097_4c4384570f_o_copy.png%3Fw%3D960%26h%3D540%26q%3D50
%26fm%3Dpng&imgrefurl=https%3A%2F%2Fnew.smm.org%2Flearn%2Fbuild-an-alligator-nest&tbnid=-
zbv5_ks0Bo85M&vet=12ahUKEwiSuvHj9qX4AhUHBRoKHdMlAp8QMygKegUIARDJAQ..i&docid=n9eGXEiMufjp_M&w=960&h=5
40&q=protection%20of%20nest%20in%20female%20crocodile%20&ved=2ahUKEwiSuvHj9qX4AhUHBRoKHdMlAp8QMygKegUIA
RDJAQ
9. Turtles
Turtles are oviparous.
Female turtles lay eggs in a nest that they dig (usually in
sand).
The females leave after laying eggs, no parental care.
Source
https://www.google.com/imgres?imgurl=https%3A%2F%2Fak.picdn.net%2Fshutterstock%2Fvideos%2F2
5694369%2Fthumb%2F1.jpg&imgrefurl=https%3A%2F%2Fwww.shutterstock.com%2Fvideo%2Fclip-
25694369-turtle-egg-concept-digging-hole-out-
eggs&tbnid=ufEF0jtWU2jVHM&vet=12ahUKEwiEp_jX86L4AhVGhc4BHfcHD4oQMygCegUIARC3AQ..i&doci
d=oF_Ag41fLY7BDM&w=852&h=480&q=turtle%20digging%20hole%20AND%20LAY%20EGGS&ved=2ahU
KEwiEp_jX86L4AhVGhc4BHfcHD4oQMygCegUIARC3AQ
9
10. Turtle Eggs
Eggs vary in size and amount.
Turtles Eggs:
Avg. 50 eggs
soft and hard shells
avg. 60 day incubation
Soft shell 30 day
Hard shell 18 months
Source
https://www.google.com/imgres?imgurl=https%3A%2F%2Fi.ytimg.com%2Fvi%2FRWQURc4
yhpo%2Fmaxresdefault.jpg&imgrefurl=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv
%3DRWQURc4yhpo&tbnid=hzVvissIxuXkUM&vet=12ahUKEwiOpuCc9KL4AhW8hM4BHeNpB
YQQMygDegUIARDXAQ..i&docid=4DN6dVHAE_LZdM&w=1280&h=720&q=EGG%20OF%20T
URTLE&ved=2ahUKEwiOpuCc9KL4AhW8hM4BHeNpBYQQMygDegUIARDXAQ
10
11. Turtle Mating
Males plastron are usually concaved, so the male can
climb on the back of the female.
Males uses his claws on the front limbs to grasp the
front edge of the females carapace.
Source
https://www.google.com/imgres?imgurl=https%3A%2F%2Fupload.wikimedia.org%2Fwik
ipedia%2Fcommons%2Fe%2Feb%2FTurtles_mating.jpg&imgrefurl=https%3A%2F%2Fco
mmons.wikimedia.org%2Fwiki%2FFile%3ATurtles_mating.jpg&tbnid=5SXHonGibjo8HM&
vet=12ahUKEwiz8bzy9KL4AhUaw4UKHQf0AlkQMygBegUIARDJAQ..i&docid=1fNsMOwbv
QDp2M&w=3038&h=2019&q=MATING%20OF%20TURTLE&ved=2ahUKEwiz8bzy9KL4Ah
Uaw4UKHQf0AlkQMygBegUIARDJAQ
1
1
12. Snakes
Snakes may be oviparous, ovoviviparous, or viviparous.
Most snakes are oviparous
Snakes lay there eggs under rocks, hollow logs, in the ground, or
anywhere warm.
Snakes also do not provide parental care.
12
Source:
https://www.google.com/imgres?imgurl=https%3A%2F%2Fi.pinimg.com%2
F736x%2Fcf%2F77%2F8b%2Fcf778ba17b774f418b036df95cf4a6ce.jpg&imgr
efurl=https%3A%2F%2Fwww.pinterest.com%2Fpin%2F762656518125082820
%2F&tbnid=IO9zEIzc_AQiJM&vet=12ahUKEwj85fTCzan4AhUZNxoKHZLEAgU
QMygMegUIARDPAQ..i&docid=1BJq837R8wIyMM&w=736&h=1308&q=eggs%20of%20snakes&ved=2ahUKEwj85fTCzan4AhUZNxoKHZLEAgUQMygMegUIA RDPAQ
13. Mating
The male and female will wrap around each other
until their cloacae are together.
Females may hold the sperm for months until they
fertilize the egg.
13
Source:
https://www.google.com/imgres?imgurl=https%3A%2F%2Fi.pinimg.com%2Foriginals%2Ff3
%2F1e%2F20%2Ff31e20e7fcdfb1edf5ff129947866de9.jpg&imgrefurl=https%3A%2F%2Fwww.
pinterest.com%2Fpin%2F403283341603084904%2F&tbnid=DDctg8k82EMxyM&vet=12ahUKE
wiW2ru4zqn4AhWAhc4BHTRQDrEQMygKegUIARC5AQ..i&docid=bokv9efeib8uHM&w=640&h
=383&q=mating%20of%20snakes&ved=2ahUKEwiW2ru4zqn4AhWAhc4BHTRQDrEQMygKegUI
ARC5AQ
14. Incubation
The temperature of the environment controls how fast the
babies develop.
Egg layers:
30-50 days after mating
lay 5 to 60 eggs
10 to 100 babies
Snakes get out of their eggs using a tooth on their snout to slice
the egg open called?
Egg Tooth
14
15. Lizards
Lizards are also OV, OVOV, and VIVI, but most are OV.
Lizards lay eggs in holes dug in the soil.
Dimorphism
Definite difference you can see between the male and females.
15
Source
https://www.google.com/imgres?imgurl=https%3A%2F%2Fthumbs.dreamstime.com%2Fb%2Flizard-eggs-
lizard-eggs-bao-bolong-wetland-reserve-national-park-gambia-africa-
186109978.jpg&imgrefurl=https%3A%2F%2Fwww.dreamstime.com%2Fphotos-images%2Flizard-
eggs.html&tbnid=VrqAXsksqLa2fM&vet=12ahUKEwiIxcOQz6n4AhVEYxoKHYpdDQ4QMygBegUIARC-
AQ..i&docid=LFP5bgbj-Ccq-
M&w=800&h=450&q=lizards%20digging%20eggs&ved=2ahUKEwiIxcOQz6n4AhVEYxoKHYpdDQ4QMygBegUIAR
C-AQ
16. Mating
Males attract females by displaying bright body colors, engage in
bobbing or body movements to attract the female.
Once accepted by a female the male will grasp and bite the
female’s neck to hold her down.
Females may hold or store sperm for long periods before
fertilization.
16
Source
https://www.google.com/imgres?imgurl=https%3A%2F%2Fimage.shutterstock.com%2Fz%2Fstock-photo-
house-lizards-mating-on-a-white-wall-slight-noise-due-to-high-iso-shallow-depth-of-field-
628507703.jpg&imgrefurl=https%3A%2F%2Fwww.shutterstock.com%2Fimage-photo%2Fhouse-lizards-
mating-on-white-wall-628507703&tbnid=h59fWGUPwPB8OM&vet=12ahUKEwiHgZ7qz6n4AhVM-
YUKHRJHAI0QMygJegUIARD1AQ..i&docid=xY5NzOEl8rma3M&w=1500&h=1101&q=lizards%20MATING&ved
=2ahUKEwiHgZ7qz6n4AhVM-YUKHRJHAI0QMygJegUIARD1AQ
17. Lizard Incubation
Small lizards (geckos and anoles):
30 days
lay 1-2 eggs
Large Lizards (monitors)
120 days
50 eggs
Lizards also have an egg tooth
17
18. Crocodilians
Crocodilians are only oviparous
Crocodilians court females like lizards, but they mate in the
water.
Females build nest out of water
Eggs are laid in nest and then covered up by the mother.
18
SOURCE
ttps://www.google.com/imgres?imgurl=https%3A%2F%2Fingwelala.co.za%2Fimages%2Farticles%2Farticle_nesting_crocodile_02.jpg&imgrefurl=https%3A%2F%2Fingwelala.co.za%2Farchives%2Ffauna-
flora%2Fnesting-
crocodiles.html&tbnid=iQrUsdIiOZa3DM&vet=12ahUKEwii3azA0Kn4AhUTShoKHWodDOwQMyguegUIARCpAg..i&docid=FUhZR2iv7dLIcM&w=750&h=500&q=crocodiles%20nest%20in%20water&ved=2ahUKEwii3
azA0Kn4AhUTShoKHWodDOwQMyguegUIARCpAg
19. Incubations
All crocodilians lay hard shell eggs.
The amount of eggs laid depends on the age and size of the
female.
Alligators:
lay 20-30 eggs female.
Crocs:
lay 60-100 eggs
Gharials:
lay 40 eggs
Youtube link:
https://youtu.be/x2iQfPRseyg 19
20. 20
• Gauthier J.A. (1994): The diversification of the amniotes. In: D.R. Prothero and R.M. Schoch (ed.) Major
Features of Vertebrate Evolution: 129–159. Knoxville, Tennessee: The Paleontological Society.
• "Reptile Database News". www.reptile-database.org. Retrieved 2022-05-25.
• Ezcurra, M. D.; Scheyer, T. M.; Butler, R. J. (2014). "The origin and early evolution of Sauria: reassessing the
Permian saurian fossil record and the timing of the crocodile-lizard divergence". PLOS ONE. 9 (2):
e89165. Bibcode:2014PLoSO...989165E. doi:10.1371/journal.pone.0089165. PMC 3937355. PMID 24586565.
• Sander, P. Martin (2012). "Reproduction in early amniotes". Science. 337 (6096): 806–
808. Bibcode:2012Sci...337..806S. doi:10.1126/science.1224301. PMID 22904001. S2CID 7041966.
• Franklin-Brown, Mary (2012). Reading the world : encyclopedic writing in the scholastic age. Chicago
London: The University of Chicago Press. p. 223;377. ISBN 9780226260709.
Websites links
• https://www.nwf.org/Educational-Resources/Wildlife-
Guide/Reptiles#:~:text=Reptiles%20are%20a%20class%20of,give%20birth%20to%20live%20young.
• https://www.britannica.com/animal/reptile
• https://www.nationalgeographic.com/animals/reptile.
Articles
References