Chapter 10 starred

Ornithorhynchidae

Platypus family of egg-laying mammals.

Tachyglossidae

Echidna family

Monotremata

Order containing platypuses and echidnas; egg-laying mammals.

Epipubic bones

Bones extending from the pelvis; found in monotremes and marsupials.

Cloaca

One shared opening for digestive, urinary, and reproductive systems; found in monotremes.

Abdominal testes

Testes remain inside the abdomen rather than in a scrotum.

Scrotum

External sac that holds testes; monotremes do not have one.

Paired uteri

Marsupial females usually have two uteri.

Vaginal canals

Marsupial females usually have paired vaginal canals.

Medial vagina

The marsupial birth canal.

Bifurcated penis

A split or forked penis; common in male marsupials.

Precocial

Young born relatively developed and able to move or feed soon after birth.

Baculum

Penis bone; present in most mammals, including monotremes.

Cochlea

A monotreme ear characteristic; not coiled

Monotreme pectoral girdle

Attached to the head, resulting in little or no neck.

Platypus electroreception

Platypus bill detects electrical signals from aquatic prey while diving.