Family Didelphidae Virginia opossum—Didelphis virginianagoheen/mammalogy course/lab_2.pdf ·...
Transcript of Family Didelphidae Virginia opossum—Didelphis virginianagoheen/mammalogy course/lab_2.pdf ·...
Order Didelphimorphia, Family Didelphidae—American opossums Virginia opossum—Didelphis virginiana
1) dental formula = I5/4 C1/1 P3/3 M4/4 2) prominent sagittal crest 3) fenestrated palatines 4) angular process medial from mandible
Order Soricomorpha, Family Soricidae—shrews
1) incomplete zygomatic arches 2) at least some teeth tipped with red or black 3) cheek teeth dilambdodont 4) bicuspid I1
pygmy shrew—Sorex (Microsorex) hoyi
1) only 3 unicuspids readily visible from side
1 2 4
water shrew—Sorex palustris
1) skull length > 19 mm (not in key) 2) rostrum short, relative to S. bendirii
Pacific water shrew—Sorex bendirii
1) skull length > 19 mm (not in key) 2) rostrum long, relative to S. palustris
Sorex bendirii
Sorex palustris
arctic shrew—Sorex arcticus masked shrew—Sorex cinereus tundra shrew—Sorex tundrensis
1 2 3 4
1) 3rd unicuspid not smaller than 4th
Sorex cinereus Sorex arcticus
Sorex tundrensis
dusky shrew—Sorex monticolus Trowbridge’s shrew—Sorex trowbridgii
vagrant shrew—Sorex vagrans
1) 3rd unicuspid smaller than 4th
4 3
Order Soricomorpha, Family Talpidae—moles
1) complete zygomatic arches 2) teeth entirely white
shrew-mole—Neurotrichus gibbsii
1) dentition: I3/3 C1/1 P2/2 M3/3 2) auditory bullae incompletely formed
coast mole—Scapanus orarius
1) dentition: I3/3 C1/1 P4/4 M3/3 2) auditory bullae completely formed 3) skull < 40 mm
coast mole—Scapanus orarius
Townsend’s mole—Scapanus townsendii
1) dentition: I3/3 C1/1 P4/4 M3/3 (usually) 2) auditory bullae completely formed 3) skull > 40 mm
Townsend’s mole—Scapanus townsendii