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|WikiProject Mammals / Monotremes and Marsupials||(Rated C-class, High-importance)|
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|This article contains a translation of Beutelsäuger#Entwicklungsgeschichte from de.wikipedia.|
- 1 Range Map Incomplete
- 2 Metatheria/Marsupialia
- 3 Which taxon
- 4 Taxonomy
- 5 Pouch Clarification
- 6 References
- 7 Number of species
- 8 Infraclass, not subclass
- 9 Marsupial Frogs
- 10 ancestral homeland?
- 11 more info?
- 12 Macropods
- 13 south-east asian origin
- 14 Marsupial neurology
- 15 Please clarify the cloaca bit
- 16 Classification of a species known only thru fossil record
- 17 Merge 'Joey' into this article
- 18 Multiple vaginas
- 19 Petrosal
- 20 Helpful paper for marsupials
- 21 New maps
- 22 Marsupials Displacing Australian Placentals
- 23 What this article doesn't mention is if males have pouches
- 24 North America / Mexico
- 25 Deleted misleading and antiquated 1924 reference to migration of marsupials
- 26 Jelly beans
- 27 Insert etymology
- 28 Sparassodonta & Marsupials
- 29 Citations Needed
- 30 Sentence Structure
- 31 Direction of the Marsupial migration
- 32 Regarding dryolestoid affinity
- 33 Citation 45 incomplete
- 34 Grammatical errors in automatically translated text
Range Map Incomplete
I work for a pest control company in Riverside County, California (southern California), and we catch Virginia opossums quite often. The "introduced range" on the map is in need of an update. — Preceding unsigned comment added by 184.108.40.206 (talk) 02:39, 7 November 2011 (UTC)
Opossums (delphimorphia) are also common in San Francisco, California. The map, "Present day distribution of marsupials", needs to be updated to show the range of introduced Marsupials to California. --NoahSpurrier (talk) 16:29, 7 April 2012 (UTC)
Should we be using this for the Scientific classification tables or the Metatheria subclass? The Metatheria page seems to say that it is a more modern classification. The University of Michigan Museum of Biology uses Metatheria. I will not change it because I am not an animal scientist. -- PlatinumX 02:36, 16 Mar 2004 (UTC)
To me, I think use of the Metatheria makes sense, but I think the question should be posted to users before a change is made, so I'm adding an article where the poll can be taken. --220.127.116.11 01:01, 30 May 2004 (UTC)
- This article contradicts with Mammalia and many others, because of Marsupialia / Metatheria. I think it must be fixed as soon as possible, but - no changes since 30 May 2004. On the other hand, if the infraclass is Metatheria, then what is Marsupialia - just some abstract group within Metatheria? Or has it scientific taxonomic name too? --18.104.22.168 13:25, 7 July 2007 (UTC) (Nomad)
- In simple terms (although I am not a scientist) mammals are raising their young with the help of their mammalian glands, whether in a pouch or outside. Marsupials are born in an embryo like state and then develop in the pouch. There is no placenta. Animals that have a placenta (and larger womb) are also mammals and these are the ones we think of usually.
Because we cannot see the mammalian glands which are in pouches, we tend to think marsupials are not mammals. Just goes to show, if you do not see it, that does not mean it does not exist. 22.214.171.124 (talk) 06:38, 3 October 2014 (UTC)
Should we maybe use superorder instead of magnorder?--Ingoolemo 01:09, 2004 Jun 6 (UTC)
I don't think this classification (McKenna & Bell's, apparently) is a good one. The Ameridelphia is probably paraphyletic. I think my own classification (Mammal Taxonomy is better and the Metatheria and Marsupialia pages should be merged. Ucucha 14:28, 10 Apr 2005 (UTC)
In the opening line of the article, it says that marsupials are characterized by a pouch. This is untrue. The true defining characteristic of a marsupial is that it gives birth to its offspring at a young, undeveloped age (prematurely). This is the biological taxonomically correct reason for their classification.126.96.36.199 (talk) 14:53, 17 May 2009 (UTC)
This article assumes that the reader knows that nipples are inside the pouch. It would be nice if this could be worded to make that more clear. And, along those same lines, I followed the Pouch link to see if it clarified this. Unfortunately, it gets redirected to Ileo-anal pouch. I'm not sure that should happen, but it is definately not related to this topic. But I enjoyed the page otherwise! :-) PerlKnitter 14:34, 11 August 2005 (UTC)
not all marsupials have true pouches. The article should mention this. References: http://www.arkive.org/brush-tailed-phascogale/phascogale-tapoatafa/ http://www.marsupialsociety.org.au/keeping-marsupials-dasyurids.html http://jeb.biologists.org/content/205/24/3775.full.pdf http://blogs.scientificamerican.com/tetrapod-zoology/2012/07/12/meet-the-borhyaenoids-2012/ — Preceding unsigned comment added by 188.8.131.52 (talk) 05:18, 5 December 2013 (UTC)
There appear to be a few footnotes, but they aren't referenced at the bottom of the article. Shouldn't they be? Also, the author references "M.J. Spechtt" with respect to the Marsupials and Placentials evolving independently. That's an interesting fact, and I would love to read the reference. But if the reference is not well accepted, I'd like to know that. OrangeMarlin 19:31, 27 December 2005 (UTC)
- I can't find any online reference to an MJ Spechtt - not on google, not at pubmed. The only place it appears is in mirrors of wikipedia. The closest I could find were: a JM Specht who works in cancer; an RL Specht who has done some research into the plants that marsupials eat; a Chelsea Specht who works in plant evolution. I think this reference is fraudulent and should be removed. google "Spechtt marsupial -1982" or "Spechtt evolution -1982" (the last flag removes nearly all the wikipedia mirrors). If there were a biologist/paleontologist named spechtt or specht who worked in this area, these searches would not come up empty. Flies 1 (talk) 22:54, 7 May 2010 (UTC)
Number of species
The first part of the article says that there are between 260 and 280 species of marsupials, but in the second part of the article the sum of the numbers of species in the orders is 334!? —The preceding unsigned comment was added by 184.108.40.206 (talk • contribs) .
- Fixed. The lower section numbers wer updated, but the upper seciton had not been. - UtherSRG (talk) 00:40, 20 April 2006 (UTC)
Infraclass, not subclass
- I have mostly encountered Metatheria as a monotypic (for present times) infraclass, not marsupialia (most times treated as a class or superclass by older and propably not very accurate literature). Even in wikipedia it is stated that metatheria and marsupialia are not completely synonymous while they are both treated as infraclasses. Can we have an experts' opinion on that please?--220.127.116.11 (talk) 02:15, 22 November 2008 (UTC)
I added marsupial frogs but UtherSRG removed them. Why? Are not marsupial frogs marsupial? Is convergent evolution a reason why marsupial frogs are not marsupial enough to appear on the marsupial page? --SafeLibraries 17:45, 16 August 2006 (UTC)
- Because they already have an article, marsupial frog, which I put a link to at the top of the article where it belongs. In addition "marsupial frog" is unique, while "marsupial mammal" is redundant - the frogs are named for the mammal. "Marsupial" by itself with no context refers to the mammal; it only refers to the frogs in the context of the frogs. - UtherSRG (talk) 18:22, 16 August 2006 (UTC)
- I see now. I missed before that "This article is about mammal. For the frogs, see marsupial frog" was added to the top of the page. That's a great solution. Thanks. --SafeLibraries 18:35, 16 August 2006 (UTC)
I'd like to see a little more about (or links to) the continental drift theories explaining why there are marsupials in Australia and South America but not in Africa. Were there marsupials in Antarctica, Madagasgar and India? I'd love to see a map showing the pre-drifted continents with a hypothetical "homeland" of the marsupials shaded in. User:bigfun 21:36, 30 March 2007 (UTC)
- Marsupials probably originated in North America and - in contrast to most placentals - reached both South America and Australia. They survived in Eurasia and North America (I'm not sure about Africa) until sometime in the Miocene; their extinction was probably caused by climatic changes. Ucucha 18:55, 31 March 2007 (UTC)
The references used(Harrison1924) is incorrect, it is not a recognised source or a published paper that has gone through peer review. The age given in the article is also incorrect. Marsupial diversity originates in south america. despite the most prominent appearing in australia. According to biogeographic theory, the area of highest diversity is also the point of highest radiation of species to elsewhere on the planet. This is also backed up with the fact that the most primitive marsupials (which exhibit the most basic pouch structure) are also found in south america. the date 124 million years ago cannot then be used as an acceptable date, as south america had no contact (or ever has since pangaea) with china, and maintained geographic isolation since it left Gondwana (the southern supercontinent) AFTER 124mya. Other species left behind to colonise australia (since africa and india had already departed the supercontinent) and flee the ice sheets and the cold, were left to diversify in to the megafauna of australia. The fossil in china is merely the furthest extent of the "wallace line" A line drawn by biologist Alfred wallace to indicate the barrier, where australian/oceanean and eurasian species of plants and animals meet. While geological and radiological dating cannot lie, It could be surmised that this species is a relict taxa from before the split in the continents, A species which may have moved to south america. Or may have existed worldwide. The fossil record is unreliable as a source of absolutes. one this is not absolute, that the laurasian supercontinent is the homeland of the marsupial. —Preceding unsigned comment added by 18.104.22.168 (talk • contribs)
- I am unable to understand all that you are writing here, but you appear to be omitting the fact that there (to the best of my knowledge) are no Mesozoic marsupials anywhere in Gondwana. Instead, there is a large variety of Cretaceous North American marsupials, and there are also some from Asia. Ucucha 19:26, 27 April 2010 (UTC)
"Marsupial success over placental mammals in Australia has been attributed to their comparatively low metabolic rate, a trait which would prove helpful given Australia's characteristic low fertility and aridity. " This needs to be looked at by an expert as Australia only became arid at the holocene around 10-14 thousand years ago - and at the stated time of their spread to Australia (50mya) Australia was I think quite heavily forested. —Preceding unsigned comment added by 22.214.171.124 (talk) 21:51, 23 December 2010 (UTC)
south-east asian origin
The speculation that marsupials may have reached Australia via south-east Asia is so absurd that it shouldn't even be raised in this article. Marsupials have existed in Australia long before Australia drifted anywhere near Asia. The assertion that marsupials co-exist with "primates, hoofed mammals and other placentals" in Indonesia is false, as it overlooks the fact that they are separated by the Wallace Line, a deep channel in the sea within Indonesia that has insured that the eastern part (east of Lombok Strait) has never been connected by a land bridge to the western part during periods of low sea level. Thus only a few flying mammals and rodents (which presumably caught a ride on floating logs) have managed to cross. --126.96.36.199 (talk) 07:43, 30 December 2007 (UTC)
The opening paragraph suggests that the only major difference between marsupials and placentals is their respective reproductive systems. This is misleading. For one thing, marsupials and monotremes lack corpora callosa. Not sure where to mention this, as the opening paragraph of this article already seems a bit overlarge, but this is hardly enough data to justify a new section. 188.8.131.52 (talk) 13:24, 18 January 2008 (UTC)
- Do you have verifiable and reliable source that you can cite? - UtherSRG (talk) 14:56, 18 January 2008 (UTC)
- Walker's Mammals of the World, 6th Edition, Volume I, page 5.
"The brain of the marsupials, like that of the monotremes, lacks a corpus callosum [...]"
Please clarify the cloaca bit
Marsupials have a cloaca that is connected to a urogenital sac in both sexes.
Classification of a species known only thru fossil record
The distinction between a placental mammal and a marsupial one is soft tissue which wouldn't normally be fossilized. I presume there are female pelvic differences that are taken as evidence. Whatever the method it should be made clear. 184.108.40.206 (talk) 21:41, 29 December 2008 (UTC)
- Yes, there are distinct skeletal differences between marsupials and placental mammals - although it's not the pelvis that is crucial, and, indeed many marsupial fossils are known only from parts of the skull. I'll add something to the article to clarify the issue. Anaxial (talk) 21:56, 29 December 2008 (UTC)
Merge 'Joey' into this article
The Joey (marsupial) article is proposed for merging into this one.
- I agree, too, because the stub article really has no reason to be apart from the main topic --Cyndaquazy (talk) 21:05, 18 August 2009 (UTC)
The page is incorrect, or at least vague, about the details of the marsupial reproductive system. Here's the problematic statement:
"Females have two vaginas, both of which open externally through one orifice but lead to different compartments within the uterus."
Most sources describe marsupials as having two lateral vaginas (for mating), along with a median vagina (for birth). The latter can be transitory or permanent. (One of the documents the page refers to the median vagina as a "pseudovaginal canal", which I haven't seen anywhere else.) The two lateral vaginas open into two uteruses, or a "double-horned (bicornuate) uterus". Walker's Mammals of the World goes into some detail in chapter 1. MacDonald's Encyclopedia of Mammals is much briefer, but mentions the "double-horned (bicornuate) uterus". There are some illustrations of the internal reproductive organs in Stephen Jackson's Koala: Origins of an Icon. WorldAsWill (talk) 04:52, 9 April 2009 (UTC)
- Looks correct to me; I'm not aware of another meaning of the word "petrosal" - albeit it's a separate bone in marsupials, not a part of a fused temporal bone, as in humans. (Although I agree a link was needed!) Anaxial (talk) 21:02, 16 March 2010 (UTC)
Helpful paper for marsupials
http://www.biologia.ufrj.br/labs/labvert/Artigos/GEB13_439.pdf Andrew Colvin • Talk 21:58, 22 June 2010 (UTC)
The maps that were just added to the article are helpful, but there are a couple of problems. In File:Marsupial_biogeography_present_day_-_dymaxion_map.png, the introduced range of marsupials in New Zealand and on the U.S. West Coast is colored. I wouldn't do that, especially for a map where the focus is on biogeography. On the other hand, the map is missing the indigenous distribution of marsupials on Sulawesi, the Vogelkop peninsula, and New Britain, and (if introduced distributions are to be included) the feral populations of red-necked wallabies in the UK. I was also surprised to see the range of the Virginia opossum extending all the way north to the Hudson Bay.
File:Marsupial-biogeography-animation-map.gif is completely wrong, and I have removed it from the article for the present. There are, in fact, no known unambiguous records of marsupials from the southern continents during the Mesozoic (UA 8699 is one disputed record). The map starts at 170 MA, whereas the oldest known metatherian (not even marsupial) is Sinodelphys at 125 MA. Marsupials occurred commonly in Laurasia during the Cretaceous and survived in Europe (for example) into the Miocene; all that is missing from the map, which only shows them occurring on Gondwana. Ucucha 05:35, 23 June 2010 (UTC)
- Every single book I have read about the biogeography of marsupials explains it exactly as the animation showed.
- Jerry Coyne’s book Why Evolution is True
- Richard Dawkins book The Greatest Show on Earth
- and others.
- Also, maps online of the distribution showed the marsupials extending way up north in North America.
- Come to think of it, these books and source must be considering marsupial ancestors. If you say that there are no marsupial fossils in the Mesozoic, then that poses a problem with the distribution of them. If they were in Europe, then these sources are lying or omitting information. If this is the case, then how did they end up wherever they are today? The map can be remade to accommodate the correct information very easily. Andrew Colvin • Talk 20:59, 23 June 2010 (UTC)
- That marsupials spread to Australia via South America and Antarctica is undoubtedly true. That there are no undisputed records of marsupials anywhere in Gondwana during the Mesozoic (let alone during the Middle Jurassic, as your map suggests) is also true, however, and that metatherians (not necessarily marsupials—marsupials are the crown group that includes the last common ancestor of the living species and all its descendants, whereas metatherians are the total group that includes everything that shares a more recent common ancestor with marsupials than with placentals; I was imprecise with those terms in my previous post) first occurred in Asia and North America during the Cretaceous is also true. See, for example, Luo, Z.-X., Qiang, A., Wible, J. R. & Yuan, C. 2003 An early Cretaceous tribosphenic mammal and metatherian evolution. Science 302, 1934–1940. (doi:10.1126/science.1090718) Ucucha 21:09, 23 June 2010 (UTC)
- (After edit conflict) It matters whether we're talking about metatherians or marsupials, as I defined them in my previous post. Metatherians first appear in China at about 125 MA (Sinodelphys, see Luo et al., 2003) and a little later in North America. During the Cretaceous, they spread across North America and Eurasia. Herpetotheriid and/or peradectid marsupials survived in Europe until somewhere in the Miocene (20 MA or so), and also occurred in Africa and Asia (I don't know the details right now). Metatherians probably spread to South America around the early Paleocene. There are no undisputed records in the Mesozoic of Gondwana, though there are apparently some poorly dated or poorly determined things from the Cretaceous of South America (Krause, 2001, cited in UA 8699) and a possible record from the latest Cretaceous of Madagascar (UA 8699, which may also be from a placental). From South America, they spread on to Australia, where the earliest marsupial fossils occur in the early Eocene (Djarthia, see ). Ucucha 21:09, 23 June 2010 (UTC)
- If we're talking about marsupials in the strict sense, it becomes a little blurred. Herpetotheriids, peradectids, and co have traditionally been interpreted as closely related to modern opossums (and therefore as marsupials), but herpetotheriids at least may actually be outside the marsupial clade (see Sánchez-Villagra et al., 2007, doi:10.1098/rsbl.2007.0090). That may also turn out to be the case for other Laurasian metatherians like peradectids, and if that is the case, true marsupials may never have occurred outside South America, Antarctica, and Australia (except for the Virginia Opossum and the modern opossums of Central America). But I'm not sure whether that interpretation is supportable by sources or original synthesis. Ucucha 21:14, 23 June 2010 (UTC)
Marsupials Displacing Australian Placentals
According to the article, "In Australia, marsupials displaced any placental mammals entirely, and have since dominated the Australian ecosystem." The source is The Ancestor's Tale, by Richard Dawkins. I asked the good folks at http://www.askabiologist.org.uk/answers/viewtopic.php?id=5165 about this and someone said that nothing to this effect was in the book. Can anyone verify or refute this? Zhoulikan (talk) 03:52, 9 December 2010 (UTC)Luke
- It's false, as far as I know; bats have been present in Australia since the Eocene. Ucucha 03:58, 9 December 2010 (UTC)
What this article doesn't mention is if males have pouches
- Males don't have pouches. Only females have pouches. Figaro (talk) 12:31, 4 June 2011 (UTC)
North America / Mexico
The introduction mentions that there is one species of marsupial in North America -- but the Virginia Opossum seems to always be mentioned as the only North American marsupial "north of Mexico." Are there other species in Mexico? Since it is part of North America, the "one species" phrasing should probably be changed/clarified. -Tim D (talk) 18:44, 3 June 2011 (UTC)
- There are several other marsupials in Mexico; Marmosa mexicana is an obvious example, and Tlacuatzin canescens is even endemic there. I'll correct the article. Ucucha 18:54, 3 June 2011 (UTC)
Deleted misleading and antiquated 1924 reference to migration of marsupials
Since no one in the modern age suggests that marsupials in Sulawesi are relicts of an ancient expansion from China, rather than a fairly recent expansion from Sahul (Ice Age Australia with New Guinea), I've deleted the text "a few species of marsupials presently living in Indonesia as far west as Sulawesi, which is sometimes considered to be in an Asian ecozone, with its citation to Harrison, L., The Migration Route of the Australian Marsupial Fauna, Australian Zoologist, Volume 3, Pages 247-263, 1924 which was added in 2010. The statement " Modern marsupials appear to have reached the islands of Borneo and Sulawesi relatively recently via Australia." is supported by the Dawkins reference.--Wetman (talk) 15:59, 7 August 2012 (UTC)
Could someone who knows the details please replace the jelly bean statement with actual measurements? Sadly, jelly beans are no longer a standard size, there are giant ones and miniatures available. Sminthopsis84 (talk) 23:50, 27 October 2012 (UTC)
Sparassodonta & Marsupials
Can someone provide a citation to verify the removal of Sparassodonta from Marsupialia? Ideally the first study that formally proposed the split (see Talk:Sparassodonta)- I don't doubt that it has occurred, but this fairly drastic taxonomic change needs verifiable documentation. Animalparty (talk) 20:22, 20 October 2013 (UTC)
Multiple statements need citations in this article suck as the Jelly bean statement in reference to the size of a newborn marsupial. Also the statement "except for the largest species of kangaroo; the eastern grey and red kangaroos" in reference to the male reproductive system. Secondly, Citations 9 and 16 are BBC news articles which does not serve as a reliable source for scientific material. Should insert a primary research article that has been peer reviewed.
Multiple sentences should be edited or rearranged so they are more understandable. For example: "Most morphological evidence comparing traits such as number and arrangement of teeth and structure of the reproductive and waste elimination systems favors a closer evolutionary relationship between marsupials and placental mammals than either with the monotremes, as does most genetic and molecular evidence" Edited: "Most morphological, genetic, and molecular evidence comparing traits such as number and arrangement of teeth, structure of the reproductive, and waste elimination systems favors a closer evolutionary relationship between marsupials and placental mammals than either with the monotremes."
Direction of the Marsupial migration
We read in the article: “A new hypothesis suggests that South American microbiotheres resulted from a back-dispersal from eastern Gondwana due to new cranial and post-cranial marsupial fossils from the Djarthia murgonensis from the early Eocene Tingamarra Local Fauna in Australia that indicate the Djarthia murgonensis is the most plesiomorphic, the oldest unequivocal australidelphian, and may be the ancestral morphotype of the Australian marsupial radiation”. Is it really a new hypothesis?
But this hypothesis is from 2008, so it is OLDER than the one (based on genetics, 2010) claiming that the microbiotheres are American autochthons and Djarthia is a result of the South America --> Antarctis --> Australia migration.
Anyway, the citing the two contradicting views in the article needs some clarification.
Regarding dryolestoid affinity
Per recent edits and reverts by myself, Materialscientist and Chaoyangopterus, I believe we should currently give little or no mention of the non-peer-reviewed hypothesis that suggests some marsupials were dryolestoids, as it gives undue weight per WP:UNDUE and WP:BALASPS. There is an ongoing discussion at Talk:Marsupial mole#On supposed dryolestoid affinitiy, which may affect this and articles on marsupial, dryolestoids, and extinct mammals. In the aims of centralizing discussion, interested editors may want to comment there. All the best --Animalparty! (talk) 00:07, 16 October 2015 (UTC)
Citation 45 incomplete
Citation 45 gives a title of "Why are There Fewer Marsupials than Placentals?" and also specifies "December 2013, Volume 20, Issue 4" and page numbers, but doesn't identify the journal. 220.127.116.11 (talk) 13:53, 13 November 2015 (UTC)
Grammatical errors in automatically translated text
@Dunkleosteus77: In your recent addition to this article, several grammatical errors were introduced in the automatic translation from German to English. Can anyone help us to correct these errors? Jarble (talk) 21:36, 1 August 2016 (UTC)