2. Class Mammalia
Subclass Prototheria
‡ Order Triconodonta
Morganucodontidae
Amphilestidae
Triconodontidae
‡ Order Docodonta
Order Monotremata
‡ Subclass Allotheria
Order Haramiyoidea
Order Multituberculata
Subclass Theria
‡ Infraclass Trituberculata
Order Symmetrodonta
Kuehnoetheriidae
Order Eupantotheria
Dryolestidae
Infraclass Metatheria
Infraclass Eutheria
(After Carroll 1988)

3. ‡“Class” Mammaliformes
Order Morganucodontia
Morganucodontidae
Order Docodonta
Order Haramiyoidea
Class Mammalia
Subclass Prototheria
Order Platypoda
Order Tachyglossa
Subclass Theriiformes
‡ Infraclass Allotheria
Order Multituberculata
‡ Infraclass Triconodontia
Infraclass Holotheria
‡ Order Symmetrodontia
‡ Order Eupantotheria
Order Metatheria
Order Eutheria
(After McKenna & Bell 1997)

7. PROTOTHERIA – Order Triconodonta
Morganucodon (late Triassic)

8. PROTOTHERIA – Order Triconodonta
Morganucodon (late Triassic)

9. PROTOTHERIA – Order Triconodonta
Jurassic - Cretaceous

10. PROTOTHERIA – Order Docodontia
Haldanodon (mid-late Jurassic)

11. ALLOTHERIA – Order Multituberculata
Late Triassic-Oligocene (160 million yrs.)

12. ALLOTHERIA – Order Haramiyoidea
Late Triassic – Jurassic, Europe, Greenland & Africa

13. ALLOTHERIA – Order Multituberculata
Family: Eucosmodontidae
Kryptobaatar
late Cretaceous, Mongolia

14. ALLOTHERIA – Order Multituberculata
Ptilodus Paleocene N. America

15. PROTOTHERIA -- Order Monotremata Family Ornithorhynchidae
Ornithorhynchus anatinus

16. PROTOTHERIA -- Order Monotremata
Family Ornithorhynchidae (fossil history)
Deciduous teeth
Ornithorhynchus
Recent
Obdurodon
Miocene, Australia
Steropodon
Cretaceous, Australia
Monotrematum
Paleocene, South America
Kollikodon
Cretaceous, Australia

17. PROTOTHERIA -- Order Monotremata Family Tachyglossidae (echidnas)
Tachyglossus
Short-beaked echidna
(Australia, Tasmania, New Guinea)

18. PROTOTHERIA -- Order Monotremata Family Tachyglossidae (echidnas)
Zaglossus
Long-beaked echidna
(New Guinea)

20. ORDER SYMMETRODOTA earliest therians
Vincelestes
early Cretaceus, Argentina

21. PROTOTHERIAN - THERIAN CONTRASTS
PROTOTHERIANS THERIANS
(monotremes) (marsupials &
placentals)
Teeth
Deciduous teeth only Permanent dentition
multi-cusped molars tribosphenic molars
Skeleton
Therapsid features:
skull with “extra” bones fusion of skull bones
cervical ribs cervical ribs lost
“reptilian” shoulder girdle “mammalian” shoulder
sprawling limb posture upright limb posture
Reproduction
“reptilian” cloacal opening separate urogenital &
anal openings
oviparous viviparous
mammary glands not well-developed teats
forming teats

22. POSSIBLE SUB-ORDER RELATIONSHIPS
MAMMAL
POLYPHYLY
MONOTREMES PLUS
MULTITUBERCULATES
MARSUPIALS
PROTOTHERIA PLUS
THERIA
(prevailing view)