EEB388H1 Quiz: quiz 1
7 Nov 2015
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Determination of maturity: heavily worn teeth, or missing teeth, fused sutures in braincase, height of sagittal crest and length of postorbital processes increases with age=adult, deciduous (milk teeth) present, teeth not fully erupted, poorly fused sutures=young. Metatheria: marsupium in which young are carried(lack of pouch is ancestral condition) # of incisors in the upper jaw is higher than in the lower jaw [except diprotodontia] max 5/4 i: primitive dental formula is 3/3 p 4/4 m (this is the reverse in eutherians) Jugal contributes to the mandibular fossa: hallux is clawless. Absent (because no heavy chewing) (because no heavy chewing) Narrow jaws with rubbery skin, to get into termite founds or ant. Short tail, doesn"t need holes: present epipubic bones. Didelphimorphia: species confined to neotropical region ( except didelphis virginiana which is in nearctic region, opossums, most omnivores. Large species often have marsupium but smaller species lose it: tail is prehensile (for grasping)
