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Prototheria

(class Mammalia) A subclass that comprises the extinct orders Docodonta, Triconodonta (although their inclusion in the subclass is controversial), and Multituberculata, as well ...

Prototheria

Prototheria   Quick reference

A Dictionary of Zoology (4 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
73 words

... (class Mammalia) A subclass that comprises the extinct orders Docodonta , Triconodonta (although their inclusion in the subclass is controversial), and Multituberculata , as well as the order Monotremata , members of which (platypus and echidnas) still survive. Prototherians are distinguished from therians mainly by the skull wall, which in prototherians has a small squamosal and alisphenoid , and by their teeth. The two subclasses began to diverge from a common stock during the late Triassic . ...

Prototheria

Prototheria   Quick reference

A Dictionary of Biology (7 ed.)

Reference type:
Subject Reference
Current Version:
2015
Subject:
Science and technology, Life Sciences
Length:
92 words

... A subclass of mammals—the monotremes—that lay large yolky eggs. It contains only the duckbilled platypus and the spiny anteater. After hatching, the young feed on milk from simple mammary glands inside a maternal abdominal pouch. In the anteater the eggs are also incubated in this pouch, while the platypus builds an underground nest. Adult monotremes have no true teeth. Their skeleton resembles that of a reptile, and although they are warm-blooded the body temperature is somewhat variable. They are believed to have originated at least 150 million...

Prototheria

Prototheria   Reference library

The New Oxford Dictionary for Scientific Writers and Editors (2 ed.)

Reference type:
Subject Reference
Current Version:
2009

... (cap. P) A subclass of primitive mammals containing a single order, *Monotremata . Individual name and adjectival form: prototherian (no...

Prototheria

Prototheria noun   Quick reference

Oxford Dictionary of English (3 ed.)

Reference type:
English Dictionary
Current Version:
2015
Subject:
English Dictionaries and Thesauri
Length:
58 words
Prototheria

Prototheria   Quick reference

New Oxford American Dictionary (3 ed.)

Reference type:
English Dictionary
Current Version:
2015
Subject:
English Dictionaries and Thesauri
Length:
54 words
Prototheria

Prototheria  

(class Mammalia)A subclass that comprises the extinct orders Docodonta, Triconodonta (although their inclusion in the subclass is controversial), and Multituberculata, as well as the order ...
Theria

Theria  

(superclass Gnathostomata, class Mammalia)A subclass that comprises the three infraclasses Pantotheria (extinct ancestral forms), Metatheria (marsupials), and Eutheria (placental mammals), ...
Metatheria

Metatheria  

(class Mammalia, subclass Theria)An infraclass that comprises the marsupials and their extinct relatives, sometimes included in the single order Marsupialia and now more usually divided into several ...
Docodonta

Docodonta  

(class Mammalia, subclass Prototheria)An extinct order of primitive mammals, known only from teeth found in Late Jurassic rocks. Their brains may have been larger than those of reptiles; probably ...
Tachyglossidae

Tachyglossidae  

; subclass Prototheria, order Monotremata)A family of insectivorous monotremes, now recognized as being more closely related to the placental mammals (see Eutheria) than to the platypus (see ...
Steropodon

Steropodon  

(subclass Prototheria, order Monotremata)The earliest Australian mammal and the only known Mesozoic representative of the monotremes. It is known only from opalized jaws and teeth found in Cretaceous ...
Multituberculata

Multituberculata  

(class Mammalia, subclass Prototheria)An extinct order of rather rodent-like mammals, which first appeared in the Late Jurassic in Europe, flourished during the Cretaceous and Palaeocene, but became ...
Ornithorhynchidae

Ornithorhynchidae  

; subclass Prototheria, order Monotremata)A monospecific family (Ornithorhynchus anatinus) of nocturnal monotremes that are highly adapted for aquatic life. They are now known to be related more ...
Eutheria

Eutheria  

(class Mammalia, subclass Theria)The infraclass that includes all of the placental mammals and which probably arose during the Cretaceous. The blastocyst develops an outer layer of cells which ...
Triconodonta

Triconodonta  

(class Mammalia, subclass Prototheria)An order that includes the earliest of all mammals, living from the Triassic until the Early Cretaceous and distributed over the northern continents. Typically ...
monophyletic

monophyletic  

In systematics, describing a group of organisms that contains all the descendants of a particular single common ancestor. In cladistics such a grouping is called a clade and is the only type of group ...
Monotremata

Monotremata  

(class Mammalia, subclass Prototheria)An order comprising the duck-billed platypus (Ornithorhynchus anatinus, see Ornithorhynchidae) and the echidnas or spiny ant-eaters (Tachyglossus and Zaglossus, ...
mammal

mammal  

A class of warm‐blooded vertebrate animals that breathe air, have hair, feed their young with the mother's milk, have four types of well‐developed teeth, and usually have four well‐developed limbs ...
Docodonta

Docodonta   Quick reference

A Dictionary of Zoology (4 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
61 words

... ( class Mammalia , subclass Prototheria ) An extinct order of primitive mammals, known only from teeth found in Late Jurassic rocks. Their brains may have been larger than those of reptiles; probably their young were fed with milk; possibly they were homoiotherms ; and perhaps they were insectivorous, arboreal, and nocturnal. They were about the size of, and must have resembled, shrews. ...

Theria

Theria   Quick reference

A Dictionary of Zoology (4 ed.)

Reference type:
Subject Reference
Current Version:
2014
Subject:
Science and technology, Life Sciences
Length:
50 words

... ( superclass Gnathostomata , class Mammalia ) A subclass that comprises the three infraclasses Pantotheria (extinct ancestral forms) , Metatheria (marsupials) , and Eutheria (placental mammals) , distinguished from the Prototheria principally by their teeth and by the structure of the sides of the skull, formed in therians by large squamosal and alisphenoid bones . ...

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