Talk:Monotreme

lactation

This article mentions that Monotremes lactate, but do not have defined nipples. Would it be possible to clarify this to explain where exactly the milk exits the mother?

spelling

Just a note on spelling: Z. bruijnii appears to be correct. Of several sources that agree, I am taking Long, Archer, Flannery & Hand, Prehistoric mammals of Australia and New Guinea (University of NSW Press, 2002, ISBN 0868404357) as authoritive. Trevor will know who there people are already, I guess. Tannin

temperature format

All temperatures seem to be in Celcius, but are not marked as such. is this simply the convention across bio articles, or should it be noted?

A good point. Virtually all scientific articles are done in the SI system to ensure a standard system of measurement. Whether or not the use of Celsius is standard convention is rather moot; it should be. Of course, a typical reader should realise that the average body temperature of placental mammals is not 38 degrees Faranheit. Ingoolemo 02:07, 2004 Jun 1 (UTC)

But it should be noted as "x degrees C" it doesn't take so much effort and space, and it makes the article more clear — Preceding unsigned comment added by Yskwiki (talk • contribs) 23:54, 6 December 2011 (UTC)

About the spur

Is there a spur in both legs? If not, in what leg is it?

Yes, the spur is on both legs.

Zaglossus bartoni

I'm trying to translate this article into Thai. Now, I get stuck at Barton's Long-beaked Echidna, couldn't find any clear references myself. So I need some help! :-P

What is it? If this is 'one more' surviving species of echidnas, why don't you put the name and information in Echidna and Platypus as well? There, it's said quite clear that 'there are only 4 extant species of monotremes, and 3 of them are echidnas'.

• There are four recognised species of echidna, and one species of platypus.--nixie 09:51, 27 December 2005 (UTC)

Platypi

And, should 'Platypi' in Fossil monotremes be corrected? Thank you. --- Nil 17:03, 28 August 2005 (UTC)

Now platypuses. FireWorks 01:41, 27 December 2005 (UTC)

What's the convention for capitalization of platypus? Nixie on the Talk:Fauna of Australia page says it should be capitalized (as is done on the Fauna of Australia page proper), and I did that for a couple at first on this page (since some were, and some weren't), but then noticed the majority of instances on this page are actually lowercase initial. Decisions? FireWorks 01:41, 27 December 2005 (UTC)

If the convention is the same as with birds, an initial capital is used if referring to a particular species, e.g., the Platypus Ornithorhynchus anatinus, but a lower-case initial if referring to any member of a group of species, such as any member of the family Ornithorhynchidae. At any rate, that's the principle I have tried to use in proofreading the article. I hope that makes sense. Old Father Time (talk) 00:29, 11 December 2009 (UTC)

Fossil Species?

Is it possible for more information to be provided on the fossil species? Were they predators or herbivores? what did they look like? did they resemble any modern day mammals?

Australia-New Guinea and Tasmania

What's the deal with "Australia-New Guinea and Tasmania" since Tasmania is part of Australia, shouldn't this be changed to "mainland Australia, New Guinea and Tasmania"? The problem here is the presence of monotremes on other islands off mainland Austrlia. Maybe it would be better just to say "Australia" and leave off the southern state. Also, is that hyphen supposed to be a comma? It could also be confusing if people think it means momotremes are found only in the parts of Australia called New Guinea and Tasmania. Problem with that is that New Guinea ceased to belong to Australia in the 1970s (plus monotremes are everywhere over here). Thoughts? Felix Dance 13:20, 27 December 2005 (UTC)

Look, I'm just gonna take the law into my own hands here. If you have a problem with my definition of Australia-New Guinea and Tasmania then argue it here. Felix Dance 07:55, 3 January 2006 (UTC)

Biological question

I want to know the form of their nitrogenous waste? it is uric acid (like bird and other animal who laid egg) or urea ... (because they lay egg, but the young embryo stay only 10 days in.... ) ??!?! thank you ...

Yes I have to find this out for an AP biology project for H school. This will be a usefull peice of info.

References and external links

References and external links are opposite of each other. They need to either say "References" or "External links". --71.104.190.42 19:23, 22 April 2006 (UTC)

5 species??

Since when have there been 5 species? —The preceding unsigned comment was added by Mitternacht90 (talk • contribs) .

Biological question II

I am wondering. Do the male monotreme carry a penis? Does it have internal testicles? How does copulation take place - Like in birds? How is the uterus of the female monotreme? Some marsupials tend to have two uteri instead of one - right? —The preceding unsigned comment was added by 217.74.211.90 (talk • contribs) .

Australosphenida = Prototheria?

If so, which one is used? Is the prototheria subclass obsolete? --Philo 17:33, 15 December 2006 (UTC)

I tagged both those articles with {{contradict-other}}. It's also worth noting that the current version of the article Monotreme mentions different subclasses in the taxobox (prototheria) and the extant-mammal-orders box (australosphenida). --Mathew5000 22:09, 24 August 2007 (UTC)

Prototheria used to include everything that was a mammal but wasn't a therian — i.e. not just monotremes but also fossil groups like triconodonts, morganucodonts, docodonts and multituberculates. Almost nobody now seems to think this is a natural grouping — some of the 'prototherians' are more closely related to therians than they are to other 'prototherians'. But there's wide disagreement on which ones are closest to Theria and what the exact branching order is. The only thing that is clear is that the old subclass Prototheria can no longer be sustained on cladistic grounds, and should either be abandoned or redefined. The nucleus around Monotremata could be called Prototheria sensu stricto or Australosphenida, according to taste.

If you check out Mammal classification, you'll find that different workers have different schemes. One that isn't mentioned there is Michael J. Benton, Vertebrate Palaeontology (3rd ed., 2005, ISBN 0-632-05637-1) which does assign a rank for Australosphenida, as follows:

• Class Mammalia
  • Subclass Mammaliaformes
    • Infraclass Holotheria
      • Superdivision Australosphenida
      • Superdivision Theriimorpha (includes Triconodonta, Multituberculata & Theria)

Until higher-level mammalian taxonomy settles down, my advice would be to enter Australosphenida in the taxobox as 'unranked'. I would definitely NOT make Monotremata or Australosphenida subordinate to Prototheria, or use Prototheria at all on classification tables and taxoboxes (it means different things to different people). That might change if taxonomists were to reach agreement on a new definition.

Since the name 'Prototheria' could be on the way out but 'Australosphenida' hasn't yet fully established itself, the preferable course might be to merge both articles into Monotreme and deal with it here. Hope I've been of some help and haven't left you more confused than before!

I posted this on Talk:Prototheria and I've copied it here for future reference in case Prototheria finishes up as a redirect. Gnostrat 03:12, 30 August 2007 (UTC)

A monotreme egg

I would like to ask if anyone could foward more information relating to the monotreme eggs, in what way are they different to reptile and other eggs, an image of an egg, and any other relevant information. Thanks. --Francisco Valverde 15:36, 23 January 2007 (UTC)

question on "myth"

The current article reads, "Monotremes were very poorly understood for many years, and to this day some of the 19th century myths that grew up around them endure. It is still sometimes thought, for example, that modern monotremes are the survivors of an early branching of the mammal tree; a later branching is thought to have led to the marsupial and placental groups."

Huh? Monotremes lay eggs, showing a transitional character to reptiles. Marsupials and placentals do not lay eggs. The tree of life web project places monotremes in an early branch, as opposed to marsupials and placentals. My question is: how do marsupials not represent an early branch of the mammal tree? I will delete or edit this example if my question is not started to be resolved in a matter of days. ApostateAbe 08:40, 3 March 2007 (UTC)

I took a look in the history and saw that an earlier text told of the myth like so:

It is still sometimes thought, for example, that the monotremes are "inferior" or quasi-reptilian, and that they are a distant ancestor of the "superior" placental mammals. It now seems plain that modern monotremes are the survivors of an early branching of the mammal tree;

This is indeed a myth, and obviously different from the current telling of the "myth" that would be true, not false. I'll just delete the whole paragraph mentioning the "myth." ApostateAbe 09:16, 3 March 2007 (UTC)

The older version should be restored. It looks like the edit you cite is vandalism. - UtherSRG (talk) 15:09, 3 March 2007 (UTC)

Synapsids?

Are Monotremes actually surviving Synapsids and not Mammals? They have various features that make them seem more related to Synapsids than they are to Mammals, such as: they have poisonous spurs, they have bills, they have scaly skin underneath their fur coats, females have no nipples to feed their young with their milk, and they lay eggs. This is confusing... The Winged Yoshi —Preceding unsigned comment added by The Winged Yoshi (talk • contribs) 00:27, 2 November 2007 (UTC)

They are more primitive than other mammals, but because of the way "mammal" is defined, they count as mammals. Some prehistoric forms that are even more primitive are sometimes considered mammals, sometimes not, depending on the definition used (like the Docodonts). Dinoguy2 03:45, 2 November 2007 (UTC)

Yeah I was thinking of the same thing. Maybe we could find a source that states they maybe missing links with Synapsids. But Winged Yoshi did had a good point.--4444hhhh (talk) 01:34, 4 January 2008 (UTC)

I thought it was generally bad form to speak of one lifeform being more primitive than another, since it implies man has reached the pinacle of evolution, while the others have not. From the platypus' viewpoint, man retained the primitive feature of a regular nose from the reptiles, and never developed an advanced electrolocation bill. I don't know anything about the docodonts, but perhaps the classification is ambiguous because the fossils didn't perserve mammary glands? --Jeff (talk) 16:45, 4 January 2008 (UTC)

Um, I meant what Wing Yoshi was thinking the same thing I was thinking, monotremes has "living" Synapsids. Sorry about the misunderstanding with my first comment on this discussion. However, one thing he is wrong: mammals and synapsids are really the same group, same class in gentics. Just that we use Linnaean classification for the taxomany box. Oh and also I don't think it's wrong to call something ancient "primitive", it just a term for older lifeforms.--4444hhhh (talk) 23:13, 4 January 2008 (UTC)

Protheria?

Never heard of it. Surely this is a misspelling of Prototheria, which is already referred to in the lead? Gnostrat (talk) 03:37, 9 January 2008 (UTC)

Yeah, probably a typo. Dinoguy2 (talk) 05:38, 9 January 2008 (UTC)

Update needed (May, 2008)

Could anyone of the main contributors update the paragraph that starts and ends with "Living monotremes lack teeth as adults. [...] The imminent sequencing of the platypus genome should shed light on this and many other questions regarding the evolutionary history of the monotremes.[9]", under the Physiology section?

Some of its information is probably outdated or can be confirmed, given that presently (May, 2008) the platypus genome has just been sequenced. Other parts of the article could also be restated for the same or analogous reasons. I've made minor changes to some articles, but I wouldn't like to disrupt other's work to such extent, considering that English is not my mother tongue and I believe that it is better for a previous contributor or those more involved with an article to decide how to update the information he/she/others have already provided. Thanks. --Pmronchi (talk) 13:54, 11 May 2008 (UTC)

Facultative Poikilothermy

If there is a reference for the claim that recent monotremes are facultative poikilotherms as an adaptation to extereme weather then please provide it. On the face of it, the claim is highly speculative. Why animals that reside in cold mountain streams (platypus) and warm tropical lowlands (echidna) should have a recent commonly derived form of facultative exothermy rather than simply being retaining it as a primitive state is hard to fathom. As it is, this counterintuitive claim is unreferenced, and as unreferenced it is subject to flagging. —Preceding unsigned comment added by Kjaer (talk • contribs) 11:31, 14 October 2008 (UTC)

Origins ?

Did the monotremes represent a splitting-off from the other mammal lines before other mammals developed placental systems and separate openings? (i.e. were all proto-mammals like monotremes at the time the split happened?) Or are monotremes thought to represent a throwback to an earlier arrangement, that occurred after proto-mammals had already begun to acquire these features?

I think it would be useful for the article to give current thinking on this. Jheald (talk) 10:47, 6 April 2009 (UTC)

The article states "monotremes are the survivors of an early branching of the mammal tree; a later branching is thought to have led to the marsupial and placental groups." That is intended to indicate that the first of your two postulates above is the correct one. I'll see if I can make it clearer, though. Anaxial (talk) 19:44, 6 April 2009 (UTC)

Thanks. So if the monotremes' cloaca and egg-laying were typical of proto-mammals at that time, what were the 'distinctive' features that set their fossil remains apart, and allow them to be identified as something different? Jheald (talk) 11:02, 7 April 2009 (UTC)

Now we're getting technical, and I don't have sufficient references on hand right now to feel confident adding anything to the article. However, I believe, in the case of the Mesozoic fossils, that they had teeth which resembled those of baby platypuses (neither adult platypuses nor echidnas of any age have teeth, which makes this sort of thing quite difficult to do), but did not resemble those of, say, Kuehneotherium. Anaxial (talk) 17:18, 7 April 2009 (UTC)

There was a few distinct characteristics presented in Monotremes that I believe was used to set apart species being Placentals and Monotremes. It was a bone structure called the Epipublic bone that was an expansion to the pelvis that was found in Monotremes, but not Placentals. So I assume you could use this characteristics to set apart Monotremes and Placentals. Marsupials also contained this type of bone extension. In other words, this method can only be used to set apart Monotremes and Placentals. Hope that helps. (KnowledgeRequire (talk) 22:12, 23 July 2009 (UTC))

Eotherapsid hypothesis for the origin of Monotremata

Ivakhnenko, Mikhail F. (2009). "Eotherapsid hypothesis for the origin of Monotremata". Paleontological Journal. 43 (3): 237–250. Aleksey (Alnagov (talk) 09:21, 23 June 2009 (UTC))

What's an "eotherapsid"? Is this an original coinage by the author? Googling turns up no other references to this group outside this paper. Does anyone have access to the paper to see how it defines eotherapsids? Hypnosifl (talk) 19:32, 22 October 2010 (UTC)

It looks like "Eotherapsida" was defined in an earlier paper by the same author (M. F. Ivakhnenko, “Eotherapsids from the East European Placket (Late Permian),” Paleontol. J. 37 (Suppl. 4), 339–365 (2003b).). It includes Sphenacomorpha, Dinocephalia, Gorgodontia, and Anomodontia, the latter apparently including monotremes. I think this hypothesis is outside mainstream paleontology. Ucucha 15:02, 30 July 2011 (UTC)

This is F*cking Stupid

A mammal is an animal that does NOT lay eggs. If an animal lays eggs, it is NOT a mammal! For f*cks sake! There can't be a mammal that lays eggs, or else it wouldn't be a mammal!

--82.34.173.149 (talk) 11:43, 1 November 2009 (UTC)

No... a mammal is either an animal that gives milk from mammary glands, or any descendant of the common ancestor or monotremes, marsupials and placentals. No definitions of the term say anything about eggs. Monotremes are obviously part of the clade including monotremes, and they give milk to their young, therefore they're mammals. Dinoguy2 (talk) 14:51, 1 November 2009 (UTC)

Not to mention, with that thought process 82.34.173.149, sharks and skinks that give live birth are mammals. —Preceding unsigned comment added by 128.135.115.248 (talk) 14:49, 29 April 2011 (UTC)

Temperature?

The article says the Echidna does enter REM sleep, albeit only when the ambient temperature of its environment is around 25 °C (77 °F). At temperatures between 15 °C (59 °F) and 28 °C (82 °F), REMS is suppressed

So at 25°C REM sleep is both active and suppressed?! -- Malvineous (talk) 11:14, 26 June 2010 (UTC)

I suspect the former may be environmental temperature and the latter body temperature; someone will have to check a source to confirm, though. Ucucha 11:45, 26 June 2010 (UTC)

automatic taxobox

There is this really cool thing happening in Wikipedia, called automatic taxoboxes. It is described in Template:Automatic_taxobox. It allows us to modify the taxoboxes of species, genera, families, etc, in a way that reduces duplication of information, making it easy to have uniform, maintainable placement of a taxon in the tree of life. Would it be OK by all of the monotreme editors if I started modifying the taxoboxes of the various monotremes so that they have an "automatic taxobox" (for taxa higher than species) or a "speciesbox" (for species), rather than a "taxobox"? Ben morphett (talk) 13:54, 30 July 2011 (UTC)

Cool though it may be, I don't think the automatic taxobox system is a good idea for basal mammals, because the taxonomy is just too unstable. Do you use the outdated group Prototheria, the controversial Australosphenida, or something quite different? It's something that requires the flexibility of a manual taxobox to be treated correctly. Ucucha 14:44, 30 July 2011 (UTC)

Well, I wasn't proposing that I change the taxonomic classification, merely restructure the same information. So I would leave them in the subclass Prototheria. But further, I would have thought that the instability of the classification would be a good reason to move to automatic taxoboxes. Here's why: if (for example), someone changed the classification of the monotremes so that they moved to a different subclass, then currently, the editors would have to modify the manual taxoboxes of all of the families, genera and species below monotremes to the new classification. On the other hand, if the monotremes have automatic taxoboxes and speciesboxes, then a single edit can reclassify all of them at once. So I consider the instability of the classification to be an argument for automatic taxoboxes. What do you think? Ben morphett (talk) 22:43, 30 July 2011 (UTC)

You are assuming that someone can "change the classification". But there is no "the classification": there is a multitude of classifications, none of which is universally accepted. The automatic taxobox system forces us to select one; manual taxoboxes allow greater flexibility. Ucucha 23:04, 30 July 2011 (UTC)

Actually, I see what you mean. I've just been looking at Prototheria, Australosphenida and Monotremata, and there is no single consistent tree. I think I might withdraw my offer, and let the specialist taxonomists fight it out amongst themselves. But you are right - the assumption of automatic taxoboxes is that there is a single coherent tree, and here, clearly, there is not yet. I guess that when you say flexible, that's another way of saying contended and inconsistent. But fair enough - that's where the science is at the moment. Ben morphett (talk) 23:17, 30 July 2011 (UTC)