Insectivora and Marsupialia of Millennium Park

Meghan Maraia

Order Marsupialia

• 18 families, 250 species– Confidently monophyletic

• General Characters– 3 premolars 4 molars– Palatal fenestrae– Inflected angular process– Marsupium – Epipubic bones in both sexes

Characters

Characters

Epipubic bones of Didelphis virginiana

Didelphis virginiana

• Virginia Opossum• Distinguishing characters– Prehensile tail– Opposable big toe– 50 teeth– Pronounced sagittal crest

• Prefer woodland environments, found in prairies and marshes

Fossils of Millennium Park

Ischium

Fossils Cont’d• Thoracic, lumbar and

cervical vertebrae• Left mandible, edentulous• M1, lower left

Order Insectivora

• 4 families, 442 species

• Family Sorcidae-Shrews

- No zygomatic arch- Incisor #1 is large and

hooked- Strongly procumbent

lower incisors

• Family Talpidae- Moles

- complete zygomatic arch

- Pinnae is absent- Eimer’s organ –

sensory organ- Keeled sternum

Cryptotis parva

• Least Shrew• Distinguishing characters– Short tail– Long pointed snout– Chestnut colored cusps– 4 unicuspid teeth

• Most often occur in dry open grassland

Fossils of Millennium Park

• Molar, right lower• Sorcidae, but no species : -Upper incisor -Partial right mandible, edentulous

Scalopus aquaticus

• Eastern Mole• Distinguishing characters– Forelimb and pectoral girdle modified for

digging– Hinged fur• Permit backward and forward movement in

burrows– Thin zygomatic arch

• Prefer well-drained soil of open fields

Fossils of Millennium Park

• Right and Left humerus• Ulna• M1 or M2 lower molar