Comparative Anatomy Vertebrate Classification: Amphibians and Reptiles

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Comparative AnatomyVertebrate Classification
Amphibians and Reptiles
Note Set 3 Chapter 3
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Reptiles

• Mesozoic Era (Jurassic Period)- Age of Reptiles
• Extinction took place at end of Paleozoic era
  with placoderms

Figure 5.1 Carboniferous Period.
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Figure 5.2 Cotylosuars, stem reptiles.

• Labyrinthodont amphibians led to stem reptiles-
  cotylosaurs
• Which gave rise to all reptiles and mammals

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Phylogeny of Amniote Groups
Figure 5.3
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Reptile Characteristics

• True claws
• Amniotic eggs
• No metamorphosis
• 12 pairs of cranial nerves
• Single occipital condyle

Figure 5.4 Dragon
Figure 5.5 Reptile egg.
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Reptile Oral Cavity

• Tooth type
• Acrodont
• Tooth on surface of jaw
• Ex fish and Sphenodon (tuatara)
• Pleurodont
• Tooth attached on medial surface of jaw
• Ex lizards and snakes
• Thecodont
• Teeth embedded in socket in jaw bone
• Ex crocodile

Figure 5.6 Jaw cross section .
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Skull Type
Figure 5.7

• Reptiles are diversified by skull type
• Anapsid- lack temporal fossa
• Diapsid- two temporal fossa
• One dorsal and one ventral
• Synapsid- single, lower temporal fossa
• Gives rise to mammal-like reptiles

Figure 5.8 Sarcopterygii scull.
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Reptilian Subclasses

• Anapsida
• Order Testudines (Chelodina)
• Ex turtles
• Diapsida
• Major reptiles
• Order Squamata
• Ex lizards and snakes
• Suborder Serpentes Sauria
• Order Sphenodon
• Ex tuatara
• Order Crocodillia
• Synapsida
• Mammal-like reptiles
• Suborder Pelycosauria
• Suborder Therapsida

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Stem Reptiles
Figure 5.10
Figure 5.9.
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Dinosaur Groups

• Morphological character of pelvis
• makes distinction
• Saurischians
• Triradiate pelvis
• Lizard-like
• Omithischians
• Tetraradiate pelvis
• Bird-like

Figure 5.11 Pelvic of two dinosaur groups.
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Dinosaur Groups (cont.)

• Saurischians
• Gives rise to dominant
• reptiles
• Birds evolved
• Parallel convergence

Figure 5.12 Reptilia Cladogram.
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Birds

• Archeopteryx- bird fossil record
• Feathers and teeth present

Figure 5.13 Archeopteryx fossil.
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Birds (cont.)

• Keeled sternum in birds that fly

Figure 5.14 (a) Archaeopteryx (b) pigeon.
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Literature Cited

• Figure 5.1- http//www.geocraft.com/WVFossils/Carb
  onifPeriod.html
• Figure 5.2- http//departments.umw.edu/biol/www/Wi
  eland/Biol425/Reptile_Phylogeny.gif
• Figure 5.3- http//www.mun.ca/biology/scarr/Phylog
  eny_of_Amniota.htm
• Figure 5.4- http//www.tucan.net/ImageGallery/gall
  ery.php?id14
• Figure 5.5- http//www.emc.maricopa.edu/faculty/fa
  rabee/BIOBK/BioBookDiversity_9.html
• Figure 5.6- http//www.peteducation.com/article.cf
  m?cls17cat1796articleid2812
• Figure 5.7- http//www-rohan.sdsu.edu/rhmiller/ch
  ordates1/Chordates1.htm
• Figure 5.8- http//www.palaeos.com/Vertebrates/Uni
  ts/140Sarcopterygii/140.400.html
• Figure 5.9, 5.11 5.14- Kent, George C. and
  Robert K. Carr. Comparative Anatomy of the
  Vertebrates. 9th ed. McGraw-Hill, 2001.
• Figure 5.10- http//pharyngula.org/pzmyers/MyersL
  ab/teaching/Bi104/l02/amniotelin.html
• Figure 5.12- http//www.enchantedlearning.com/subj
  ects/dinosaurs/dinoclassification/
• Figure 5.13- http//www.emc.maricopa.edu/faculty/f
  arabee/BIOBK/BioBookDiversity_9.html