Class MammaliaSubclass Prototheria

‡ Order TriconodontaMorganucodontidaeAmphilestidaeTriconodontidae

‡ Order DocodontaOrder Monotremata

‡ Subclass AllotheriaOrder HaramiyoideaOrder Multituberculata

Subclass Theria‡ Infraclass Trituberculata

Order SymmetrodontaKuehnoetheriidae

Order EupantotheriaDryolestidae

Infraclass MetatheriaInfraclass Eutheria

(After Carroll 1988)

‡“Class” MammaliformesOrder Morganucodontia

MorganucodontidaeOrder DocodontaOrder Haramiyoidea

Class MammaliaSubclass Prototheria

Order PlatypodaOrder Tachyglossa

Subclass Theriiformes‡ Infraclass Allotheria

Order Multituberculata‡ Infraclass Triconodontia

Infraclass Holotheria‡ Order Symmetrodontia‡ Order Eupantotheria

Order MetatheriaOrder Eutheria

(After McKenna & Bell 1997)

PROTOTHERIA – Order TriconodontaMorganucodon (late Triassic)

PROTOTHERIA – Order TriconodontaMorganucodon (late Triassic)

PROTOTHERIA – Order TriconodontaTriconodon

Jurassic - Cretaceous

PROTOTHERIA – Order Docodontia

Haldanodon (mid-late Jurassic)

ALLOTHERIA – Order Multituberculata

Late Triassic-Oligocene (160 million yrs.)

ALLOTHERIA – Order HaramiyoideaLate Triassic – Jurassic, Europe, Greenland & Africa

ALLOTHERIA – Order MultituberculataFamily: Eucosmodontidae

Kryptobaatarlate Cretaceous, Mongolia

ALLOTHERIA – Order Multituberculata

Ptilodus Paleocene N. America

PROTOTHERIA -- Order MonotremataFamily Ornithorhynchidae

Ornithorhynchus anatinus

PROTOTHERIA -- Order MonotremataFamily Ornithorhynchidae (fossil history)

ObdurodonMiocene, Australia

OrnithorhynchusRecent

Deciduous teeth

SteropodonCretaceous, Australia

MonotrematumPaleocene, South America Kollikodon

Cretaceous, Australia

PROTOTHERIA -- Order MonotremataFamily Tachyglossidae (echidnas)

TachyglossusShort-beaked echidna

(Australia, Tasmania, New Guinea)

PROTOTHERIA -- Order MonotremataFamily Tachyglossidae (echidnas)

ZaglossusLong-beaked echidna

(New Guinea)

ORDER SYMMETRODOTA earliest therians

Vincelestesearly Cretaceus, Argentina

PROTOTHERIAN - THERIAN CONTRASTS

PROTOTHERIANS THERIANS(monotremes) (marsupials &

placentals)

TeethDeciduous teeth only Permanent dentition

multi-cusped molars tribosphenic molars

Skeleton Therapsid features:

skull with “extra” bones fusion of skull bonescervical ribs cervical ribs lost

“reptilian” shoulder girdle “mammalian” shoulder sprawling limb posture upright limb posture

Reproduction“reptilian” cloacal opening separate urogenital &

anal openingsoviparous viviparousmammary glands not well-developed teats

forming teats

POSSIBLE SUB-ORDER RELATIONSHIPS

MAMMALPOLYPHYLY

MONOTREMES PLUSMULTITUBERCULATES

MONOTREMES PLUSMARSUPIALS

PROTOTHERIA PLUSTHERIA(prevailing view)