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Zoology
CLASSIFICATION OF MAMMALS: PROTOTHERIA
By BS MediaTwitter Profile | Updated: Saturday, 01 July 2017 21:01 UTC
Mammalia is divided into two subclasses. 1) Prototheria 2) Theria
GENERAL CHARECTERS OF PROTHERIA
- External pinnae are absent.
- In the young stage teeth are present and in the adults horny plates are formed.
- Mammary glands are present and tears are absent.
- Body is covered by hairs.
- Pelvic girdle shows epipubic bones.
- Vertebrae will not show epiphyses.
- Ribs are single headed. (Tuberculum is absent)
- Corpus callosum is absent in brain.
- Cochlea is simple and is not coiled.
- In the males the testis is abdominal.
- Females are egg laying. Hence prototherians are called egg laying Mammals.
This subclass includes only one order that is Monotremata.
Order Monotremata:
Thesemammals show prototherian characters. They can found in Australia, Tasmania and New-guinea.
Ex: 1. Echidna (Spiny ant eater), 2. Ornithorhyncus (Duck billed platypus)
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