Monotreme

Monotremes; Temporal range: Late Triassic – Holocene, 210–0 Ma PreЄ Є O S D C P T J K Pg N
	A short-beaked echidna, a platypus, a Steropodon reconstruction, an a wastren lang-beaked echidna
Scientific classification
Kinrick:	Animalia
Phylum:	Chordata
Cless:	Mammalia
Subcless:	Prototheria
Order:	Monotremata; C.L. Bonaparte, 1837
Subgroups
	†Kryoryctes?; †Steropodontidae; Platypoda Ornithorhynchidae; ; Tachyglossa Tachyglossidae; ;

Monotremes (frae the Greek μονός monos "single" + τρῆμα trema "hole", referrin tae the cloaca) are mammals that lay eggs (Prototheria) insteid o givin birth tae live young lik marsupials (Metatheria) an placental mammals (Eutheria).

References

↑ Hugall, A. F.; et al. (2007). "Calibration choice, rate smoothing, and the pattern of tetrapod diversification according to the long nuclear gene RAG-1". Syst. Biol. 56 (4): 543–63. doi:10.1080/10635150701477825. PMID 17654361.
↑ Groves, C. P. (2005). Wilson, D. E.; Reeder, D. M (eds.). Mammal Species of the World (3rd ed.). Baltimore: Johns Hopkins University Press. pp. 1–2. OCLC 62265494. ISBN 0-801-88221-4.CS1 maint: ref=harv (link)
↑ Bonaparte, C. L. (1837). "A New Systematic Arrangement of Vertebrated Animals". Transactions of the Linnean Society of London. 18 (3): 258. doi:10.1111/j.1095-8339.1838.tb00177.x.

[1] Hugall, A. F.; et al. (2007). "Calibration choice, rate smoothing, and the pattern of tetrapod diversification according to the long nuclear gene RAG-1". Syst. Biol. 56 (4): 543–63. doi:10.1080/10635150701477825. PMID 17654361.

[msw3-2] Groves, C. P. (2005). Wilson, D. E.; Reeder, D. M (eds.). Mammal Species of the World (3rd ed.). Baltimore: Johns Hopkins University Press. pp. 1–2. OCLC 62265494. ISBN 0-801-88221-4.CS1 maint: ref=harv (link)

[3] Bonaparte, C. L. (1837). "A New Systematic Arrangement of Vertebrated Animals". Transactions of the Linnean Society of London. 18 (3): 258. doi:10.1111/j.1095-8339.1838.tb00177.x.

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