Boreoeutheria: Perbedaan antara revisi

* [[Euarchontoglires]]

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Fosil yang paling awal diketahui sekitar 65&nbsp;juta tahun lalu, segera setelah [[Peristiwa kepunahan Kapur–Paleogen]], meskipun data molekul memperkirakan kelompok hewan ini mungkin lebih awal dari itu, yaitu saat zaman [[Cretaceous]].<ref name=placental_radiation>{{cite journal |last1=O'Leary |first1=M. A. |last2=Bloch |first2=J. I. |last3=Flynn |first3=J. J. |last4=Gaudin |first4=T. J. |last5=Giallombardo |first5=A. |last6=Giannini |first6=N. P. |last7=Cirranello |first7=A. L. |year=2013 |title=The placental mammal ancestor and the post–K-Pg radiation of placentals |journal=Science |volume=339 |issue=6120 |pages=662–667 |doi=10.1126/science.1229237 |pmid=23393258}}</ref> Dengan beberapa pengecualian <ref>Klad boreoeutherian yang tidak memiliki [[skrotum]] adalah [[tikus tanah]], [[landak]], [[anteater]], beberapa [[anjing laut]] dan [[badak]], [[tapir]], [[kuda nil]], dan [[ikan paus]].</ref> Hewan jantan memiliki [[skrotum]].<ref name="MillsMarchant-Forde2010">{{cite book|last1=Mills|first1=D. S. |last2=Marchant-Forde|first2=Jeremy N. |title=The Encyclopedia of Applied Animal Behaviour and Welfare|url=https://books.google.com/books?id=vrueZDfPUzoC&pg=PA293|accessdate=20 June 2019 |year=2010 |publisher=CABI |isbn=978-0-85199-724-7 |pages=293– }}</ref><ref>{{cite web |url=http://www.slate.com/articles/health_and_science/science/2013/07/are_testicles_external_for_cooling_galloping_display_or_something_else.html |title=Why are testicles kept in a vulnerable dangling sac? |last=Drew |first=Liam |date=8 July 2013 |website=slate.com |quote=Between these branches, however, is where it gets interesting, for there are numerous groups, our descended but a-scrotal cousins, whose testes drop down away from the kidneys but don't exit the abdomen. Almost certainly, these animals evolved from ancestors whose testes were external, which means at some point they backtracked ...&nbsp;, evolving anew gonads inside the abdomen. They are a ragtag bunch including hedgehogs, moles, rhinos and tapirs, hippopotamuses, dolphins and whales, some seals and walruses, and scaly anteaters.}}</ref> Sub-klad [[Scrotifera]] dinamai karena hal ini.<ref>{{cite journal |author=Waddell |year=1999 |title=Using novel phylogenetic methods to evaluate mammalian mtDNA, including amino acid-invariant sites-LogDet plus site stripping, to detect internal conflicts in the data, with special reference to the positions of hedgehog, armadillo, and elephant |journal=[[Systematic Biology]] |volume=48 |issue=1 |pages=31–53 |doi=10.1080/106351599260427 |url=http://sysbio.oxfordjournals.org/content/48/1/31.abstract |accessdate=4 October 2011 |display-authors=etal |quote=The name comes from the word [[scrotum]], a pouch in which the testes permanently reside in the adult male. All members of the group have a postpenile scrotum, often prominently displayed, except for some aquatic forms and pangolins (which have the testes just below the skin). It appears to be an ancestral character for this group, yet other orders generally lack this as an ancestral feature, with the probable exception of [[Primate]]s.}}</ref>