Class Notes (808,494)
Canada (493,253)
Zoology (202)
ZOO 2090 (90)
Lecture 11

Lecture 11.docx

7 Pages
Unlock Document

University of Guelph
ZOO 2090
Fred Laberge

Lecture 11 ZOO*2090 October 21, 2013 Modern Amphibians – Lissamphibia Objectives - discuss different hypotheses about the origin of modern amphibiabs - contrast form and function of the three groups of living amphibians Skin - mucous glands secrete mucus, helps with cutaneous respiration - granular glands secrete poisonous alkaloid compounds involved in defense - skin is thin to allow gas exchange, but the more terrestrial the more keratinized it is, where it protects against desiccation - only some caecilians and toads have bone elements in the dermis Metamorphosis - direct development also occurs Padicellate Teeth - tooth has suture dividing base (pedicel) from tip (crown) - unique to amphibians in modern forms, but also seen in some temnospondyls Lecture 11 ZOO*2090 October 21, 2013 Anurans (Salientia) - frogs Tailed frogs Fire-bellied toads Tongueless frogs Spadefoot toads True toads Tree frogs Dart-poison frogs True frogs Lecture 11 ZOO*2090 October 21, 2013 Anurans (Salientia) - frogs Main characters - absence of tail (adults) - jumpers - tympanum usually present - fertilization external, except in Ascaphus Skull - flattened, open, with big jaws - the palate is highly reduced, allowing the eyeballs drop into the oral cavity Axial Skeleton - Shortened vertebral column with 9 or fewer vertebrae - Atlas-skull junction forms a movable joint through two condyles  improved mobility of head in dorsoventral axis - Post sacral vertebrae fused into a rod-shaped urostyle lying between the two elongated illium bones of pelvic girdle Appendicular Skeleton - robust pectoral girdle and fused radius/ulna are used to absorb shock of landing - tibia/fibular and ankle bones are also fused for sturdiness, but note relative increase in length of hindlimb characteristic of jumpers Lecture 11 ZOO*2090 October 21, 2013 Urodeles (Caudata) – Salamander Newts and ‘true salamanders’ Mudpuppies Hellbenders Urodeles (Caudata) – Salamander Main Characteristics - Paired limbs and a long tail - Suction feeding in water and projectile tongue on land - No tympanum present - Fertilization can be external or internal by means of spermatophore transfer - Mostly found in North American forests, most are strictly terrestrial - Extensive radiation in American tropics  many fossorial and arboreal forms Lecture 11 ZOO*2090 October 21, 2013
More Less

Related notes for ZOO 2090

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.