CORRECT

You characterized the sphenodon as follows:

CLOSED CIRCULATORY SYSTEM
Hepatic portal system present

HEART IS MULTICHAMBERED
Eight or fewer aortic arches

CAUDAL AREA DRAINED BY RENAL PORTAL VEIN AND/OR OTHER VEINS


HEART CHAMBERS NOT IN SINGLE TANDEM SERIES
Lymphatic system present

VENTRICLE AT LEAST PARTIALLY DIVIDED
Posterior body parts drained by post caval only

AORTIC ARCH IV JOINS DORSAL AORTA ON RIGHT AND LEFT
Ventral aorta forms 2 aortic trunks and 1 pulmonary trunk

VENTRICLE WITH INCOMPLETE SEPTUM
Pulmonary and systemic circuits partially separate

BOTH DUCTUS ARTERIOSUS AND DUCTUS CAROTICUS PATENT IN ADULT


PHYLUM: Chordata
SUBPHYLUM: Vertebrata
CLASS:Reptilia
SUBCLASS:Lepidosauria
ORDER: Rhynchocephalia

If you have any questions, please contact Prof. Nancy Wall at *6742
or via e-mail at walln@lawrence.edu .

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Last updated: 11 August 2000
by Valeska S. Okragly (¹03)
for the LU Biology Department