View source for Echidna

{{pp-semi-indef|small=yes}}
{{short description|Family of mammals}}
{{other uses}}
{{Use dmy dates|date=September 2020}}
{{Use Australian English|date=September 2018}}
{{Automatic taxobox
| name = Echidnas
| fossil_range = {{Fossil range|Pliocene|Recent}}
| image = Short-beaked echidna in ANBG.jpg
| image_caption = [[Short-beaked echidna]]
| taxon = Tachyglossidae
| authority = [[Theodore Nicholas Gill|Gill]], 1872
| type_genus = ''[[Tachyglossus]]''
| type_genus_authority = [[Johann Karl Wilhelm Illiger|Illiger]], 1811
| subdivision_ranks = Species
| subdivision = Genus ''[[Tachyglossus]]'' <br />
&nbsp;&nbsp;&nbsp;''[[Tachyglossus aculeatus|T. aculeatus]]''<br />
Genus ''[[Zaglossus]]'' <br />
&nbsp;&nbsp;&nbsp;''[[Zaglossus attenboroughi|Z. attenboroughi]]''<br />
&nbsp;&nbsp;&nbsp;''[[Zaglossus bruijnii|Z. bruijnii]]''<br />
&nbsp;&nbsp;&nbsp;''[[Zaglossus bartoni|Z. bartoni]]''<br />
Genus †''[[Megalibgwilia]]''<br />
&nbsp;&nbsp;&nbsp;†''[[Megalibgwilia|M. owenii]]''<br />
&nbsp;&nbsp;&nbsp;†''[[Megalibgwilia|M. robusta]]''<br />
Genus †''[[Murrayglossus]]''<br />
&nbsp;&nbsp;&nbsp;†''[[Murrayglossus|M. hacketti]]''
| range_map = Range map of extant members of the Tachyglossidae.png
| range_map_caption = Echidna range
{{leftlegend|#8d0101|[[Short-beaked echidna]]}}
{{leftlegend|#0076ba|[[Western long-beaked echidna]]}}
{{leftlegend|#1b9e04|[[Eastern long-beaked echidna]]}}
{{leftlegend|#ffda31|[[Sir David's long-beaked echidna]]}}
}}
'''Echidnas''' ({{IPAc-en|ᵻ|ˈ|k|ɪ|d|n|ə|z}}), sometimes known as '''spiny anteaters''',<ref name=pwstSBE/> are quill-covered<ref name=ADW>{{cite web |url= https://animaldiversity.org/collections/spinesquills/|title= Spines and Quills |author=<!--Not stated-->|website=Animal Diversity Web|publisher=University of Michigan|access-date=13 September 2021}}</ref> [[monotreme]]s (egg-laying [[mammals]]) belonging to the [[Family (biology)|family]] '''Tachyglossidae''' {{IPAc-en|t|æ|k|i|'|g|l|Q|s|ᵻ|d|iː}}, living in [[Australia]] and [[New Guinea]]. The four [[Extant taxon|extant]] species of echidnas and the [[platypus]] are the only living mammals that lay eggs and the only surviving members of the [[order (biology)|order]] Monotremata.<ref name=nwf03/> The diet of some species consists of ants and termites, but they are not closely related to the American [[anteater|true anteaters]] or to [[Hedgehog|hedgehogs]]. Their young are called '''puggles'''.

Echidnas evolved between 20 and 50&nbsp;million years ago, descending from a [[platypus]]-like monotreme.<ref name=Phillips/> This ancestor was aquatic, but echidnas adapted to life on land.<ref name=Phillips/>

==Etymology==
Echidnas are possibly named after [[Echidna (mythology)|Echidna]], a creature from [[Greek mythology]] who was half-woman, half-snake, as the animal was perceived to have qualities of both mammals and reptiles.{{cn|date=June 2023}}
An alternative explanation is a confusion with {{Langx|grc|{{Wikt-lang|grc|ἐχῖνος}}|links=no|lit=hedgehog, sea urchin|translit=ekhînos}}.<ref>{{cite dictionary |title=echidna |dictionary=Online Etymology Dictionary |url=http://www.etymonline.com/index.php?search=echidna|access-date=23 November 2014}}</ref>
==Physical characteristics==
Echidnas are medium-sized, solitary mammals covered with coarse hair and [[Spine (zoology)|spine]]s.<ref name=CSIRO06/> The spines are modified hairs and are made of [[keratin]], the same fibrous protein that makes up fur, claws, nails, and horn sheaths in animals.<ref name=ADW/>
[[File:Onkapringa River NP echidna spines P1000601.jpg|thumb|[[Spine (zoology)|Spines]] of the echidna]]
Superficially, they resemble the anteaters of South America and other spiny mammals such as [[hedgehog]]s and [[porcupine]]s. They are usually black or brown in coloration. There have been several reports of [[Albinism|albino]] echidnas with pink eyes and white spines.<ref name=CSIRO06/> They have elongated and slender snouts that function as both mouth and nose, and which have [[Electroreception and electrogenesis|electrosensors]] to find earthworms, termites, ants, and other burrowing prey.<ref name="Bullock-2005">{{Cite book |url=http://link.springer.com/10.1007/0-387-28275-0 |title=Electroreception |date=2005 |publisher=Springer New York |isbn=978-0-387-23192-1 |editor-last=Bullock |editor-first=Theodore H. |series=Springer Handbook of Auditory Research |volume=21 |pages=257 |language=en |doi=10.1007/0-387-28275-0 |editor-last2=Hopkins |editor-first2=Carl D. |editor-last3=Popper |editor-first3=Arthur N. |editor-last4=Fay |editor-first4=Richard R.}}</ref> This is similar to the [[platypus]], which has 40,000 electroreceptors on its bill, but the long-beaked echidna has only 2,000, while the short-beaked echidna, which lives in a drier environment, has no more than 400 at the tip of its snout.<ref name=MOL100707/> 

Echidnas have short, strong limbs with large claws, and are powerful diggers. Their hind claws are elongated and curved backwards to aid in digging. Echidnas have tiny mouths and toothless jaws, and feed by tearing open soft logs, [[anthill]]s and the like, and licking off prey with their long, sticky tongues. The ears are slits on the sides of their heads under the spines. The [[pinna (anatomy)|external ear]] is created by a large cartilaginous funnel, deep in the muscle.<ref name="CSIRO06" /> At 33&nbsp;°C (91.4&nbsp;°F), echidnas also possess the second-lowest active body temperature of all mammals, behind the platypus.

Despite their appearance, echidnas are capable swimmers, as they evolved from [[Steropodontidae|platypus-like ancestors]]. When swimming, they expose their snout and some of their spines, and are known to journey to water to bathe.<ref name = "Short-beak">{{cite web|title=Short-beaked Echidna|url=http://www.dpiw.tas.gov.au/inter/nsf/webpages/bhan-5357k5|publisher=Department of Primary Industries, Parks, Water, and Environment|access-date=13 April 2013}}</ref>

The first European drawing of an echidna was made in [[Adventure Bay, Tasmania]] by {{HMS|Providence|1791|6}}'s third lieutenant [[George Tobin (Royal Navy officer)|George Tobin]] during [[William Bligh]]'s second breadfruit voyage.<ref name="Tobin">{{cite web |title=George Tobin journal and sketches on HMS Providence, 1791-1793, with additional material to 1831 |url=http://archival.sl.nsw.gov.au/Details/archive/110327638 |website=State Library - New South Wales |access-date=4 December 2020 |language=en}}</ref>

==Diet==
The [[short-beaked echidna]]'s diet consists mostly of ants and termites, while the ''Zaglossus'' (long-beaked) species typically eat worms and insect larvae.<ref name=info/> The tongues of [[long-beaked echidna]]s have sharp, tiny spines that help them capture their prey.<ref name=info/> They have no teeth, so they break down their food by grinding it between the bottoms of their mouths and their tongues.<ref name = "NSW">{{cite web|last=Carritt|first=Rachel|title=Echidnas: Helping them in the wild|url=http://www.environment.nsw.gov.au/resources/nature/Factsheet3Echidnas.pdf|publisher=NSW National Parks and Wildlife Service|access-date=13 April 2013}}</ref> Echidnas' [[faeces]] are {{convert|7|cm|in|abbr=on|sigfig=1}} long and are cylindrical in shape; they are usually broken and unrounded, and composed largely of dirt and ant-hill material.<ref name="NSW"/>

Like all mammals, echidnas feed their young on milk, which contains various factors to sustain their growth and development.<ref>{{cite web|last1=Stannard|first1= Hayley J.|last2=Old |first2=Julie M. |title=Wallaby joeys and platypus puggles are tiny and undeveloped when born. But their mother's milk is near-magical|url=https://theconversation.com/wallaby-joeys-and-platypus-puggles-are-tiny-and-undeveloped-when-born-but-their-mothers-milk-is-near-magical-207726|publisher=The Conversation|year=2023}}</ref><ref>{{cite journal|last1=Stannard|first1=Hayley J.|last2=Miller|first2=Robert D.|last3=Old|first3=Julie M.|title=Marsupial and monotreme milk – a review of its nutrients and immune properties|journal=PeerJ|year=2020|volume=8|page=e9335|doi=10.7717/peerj.9335 |pmid=32612884 |pmc=7319036 |doi-access=free }}</ref>

==Habitat==
Echidnas do not tolerate extreme temperatures; they shelter from harsh weather in caves and rock crevices. Echidnas are found in forests and woodlands, hiding under vegetation, roots or piles of debris. They sometimes use the burrows (both abandoned and in use) of animals such as rabbits and [[wombat]]s. Individual echidnas have large, mutually overlapping territories.<ref name="NSW"/>

==Anatomy==
Echidnas and platypuses are the only egg-laying mammals, the [[monotremes]].
The average lifespan of an echidna in the wild is estimated at 14–16 years. Fully grown females can weigh about {{convert|4.5|kg}}, the males 33% larger, at about {{convert|6|kg}}.<ref name="NSW"/> Though the internal reproductive organs differ, both sexes possess an identical single cloaca opening for urination, defecation, and mating.<ref name=CSIRO06/>

Male echidnas have non-venomous [[spur (zoology)|spurs]] on the hind feet, similar to the venomous male platypus.<ref>{{cite book|last=Griffiths|first=Mervyn|title=The biology of the monotremes|year=1978|publisher=Academic Press|location=New York|isbn=0123038502}}</ref>

Due to their low [[metabolism]] and accompanying stress resistance, echidnas are long-lived for their size; the longest recorded lifespan for a captive echidna is 50 years, with anecdotal accounts of wild individuals reaching 45 years.<ref name=andiv09/> 

The echidna's brain is half [[neocortex]],<ref name="bbc121119" /> compared to 80% of a human brain.<ref name="Dunbar1993">{{cite journal |author=Dunbar, R.I.M. |year=1993 |title=Coevolution of neocortical size, group size and language in humans |journal=Behavioral and Brain Sciences |volume=16 |issue=4 |pages=681–735 |doi=10.1017/S0140525X00032325 |s2cid=145583615}}</ref><ref name="Dunbar1998">{{cite web |last=Dunbar |first=R.I.M. |title=The Social Brain Hypothesis |url=http://psych.colorado.edu/~tito/sp03/7536/Dunbar_1998.pdf |url-status=dead |archive-url=https://web.archive.org/web/20160412210459/http://psych.colorado.edu/~tito/sp03/7536/Dunbar_1998.pdf |archive-date=12 April 2016 |access-date=4 January 2014 |website=University of Colorado at Boulder, Department of Psychology and Neuroscience}}</ref> Contrary to previous research, the echidna does enter [[Rapid eye movement (sleep)|REM]] sleep, but only in a comfortable temperature around 25&nbsp;°C (77&nbsp;°F). At lower or higher temperatures of 15&nbsp;°C (59&nbsp;°F) and 28&nbsp;°C (82&nbsp;°F), REM sleep is suppressed.<ref name="nsl0003" />

==Reproduction==
The female lays a single soft-shelled, leathery egg 22 days after mating, and deposits it directly into her pouch. An egg weighs {{convert|1.5|to|2|g|sigfig=1}}<ref>{{cite web|url=http://wildcare.org.au/species-information/echidnas/|title=Echidnas|website=wildcare.org.au|publisher=Wildcare Australia|access-date=20 November 2016}}</ref> and is about {{convert|1.4| cm}} long. While [[Hatchling|hatching]], the baby echidna opens the leather shell with a reptile-like [[egg tooth]].<ref name="ONeil">O'Neil, Dennis. [http://anthro.palomar.edu/animal/echidna_reproduction.htm "Echidna Reproduction"] {{Webarchive|url=https://web.archive.org/web/20150430141149/http://anthro.palomar.edu/animal/echidna_reproduction.htm |date=30 April 2015 }} 12 February 2011. Retrieved on 17 June 2015.</ref> Hatching takes place after 10 days of [[gestation]]; the young echidna, called a puggle,<ref>{{cite journal|last1=Kuruppath|first1=Sanjana|last2=Bisana|first2=Swathi|last3=Sharp|first3=Julie A|last4=Lefevre|first4=Christophe|last5=Kumar|first5=Satish|last6=Nicholas|first6=Kevin R|date=11 August 2012|title=Monotremes and marsupials: Comparative models to better understand the function of milk|journal=Journal of Biosciences|volume=37|issue=4|pages=581–588|doi=10.1007/s12038-012-9247-x|pmid=22922184|quote=Developmental stages of echidna: (A) Echidna eggs; (B) Echidna puggle hatching from egg...|hdl=10536/DRO/DU:30047989|s2cid=15026875|hdl-access=free}}</ref><ref name="Taronga">{{cite news|url=http://www.abc.net.au/news/2016-11-18/puggles-born-at-taronga-zoo-for-first-time-in-30-years/8038510?pfm=ms&pfmredir=sm|title=Taronga Zoo welcomes elusive puggles|last1=Calderwood|first1=Kathleen|date=18 November 2016|work=ABC News|access-date=20 November 2016|location=Sydney|language=en-AU}}</ref> born larval and fetus-like, then sucks [[milk]] from the [[lactiferous duct|pores]] of the two [[Mammary gland|milk patches]] (monotremes have no [[nipples]]) and remains in the pouch for 45 to 55 days,<ref name=arkiveTGA/> at which time it starts to develop spines. The mother digs a nursery burrow and deposits the young, returning every five days to suckle it until it is weaned at seven months. Puggles will stay within their mother's den for up to a year before leaving.<ref name="NSW" />[[File:French Island Echidna.ogg|thumb|A short-beaked echidna building a defensive burrow in [[French Island National Park]] (43 seconds)]]{{anchor|Mating}}Male echidnas have a four-headed penis.<ref>Grützner, F., B. Nixon, and R. C. Jones. "[https://www.researchgate.net/profile/Russell_Jones6/publication/23233860_Reproductive_Biology_in_Egg-Laying_Mammals/links/09e415129f89e4a467000000.pdf Reproductive biology in egg-laying mammals]." Sexual Development 2.3 (2008): 115-127.</ref> During mating, the heads on one side "shut down" and do not grow in size; the other two are used to release semen into the female's two-branched reproductive tract. Each time it [[copulation (zoology)|copulates]], it alternates heads in sets of two.<ref>{{cite journal | last1 = Johnston | first1 = Steve D. | display-authors = etal  | year = 2007 | title = One-Sided Ejaculation of Echidna Sperm Bundles | jstor = 10.1086/522847 | journal = The American Naturalist | volume = 170 | issue = 6| pages = E162–E164 | doi=10.1086/522847 | pmid=18171162| s2cid = 40632746 | url = http://espace.library.uq.edu.au/view/UQ:130591/UQ130591_OA.pdf }}</ref><ref name=nsc071026/> When not in use, the penis is retracted inside a [[Preputial gland|preputial]] sac in the cloaca. The male echidna's penis is {{convert|7|cm}} long when erect, and its shaft is covered with [[penile spines]].<ref name="VogelnestWoods2008">{{cite book|author1=Larry Vogelnest|author2=Rupert Woods|title=Medicine of Australian Mammals|url=https://books.google.com/books?id=lWbgqMsyq8UC&q=echidna+penis|access-date=15 March 2013|date=18 August 2008|publisher=Csiro Publishing|isbn=978-0-643-09928-9}}</ref> These may be used to [[induced ovulation (animals)|induce ovulation]] in the female.<ref>{{cite book |first1=V.D. |last1=Hayssen |first2=A. |last2=Van Tienhoven |chapter=Order Monotremata, Family Tachyglossidae |title=Asdell's Patterns of Mammalian Reproduction: A Compendium of Species-specific Data |chapter-url=https://books.google.com/books?id=yQzSe71g2AcC&pg=PA8 |year=1993 |publisher=Cornell University Press |isbn=0-8014-1753-8 |pages=[https://archive.org/details/asdellspatternso00hays/page/8 8–9] |url-access=registration |url=https://archive.org/details/asdellspatternso00hays/page/8 }}</ref>
<section begin=ejaculation />
It is a challenge to study the echidna in its natural habitat, and they show no interest in mating while in captivity. Prior to 2007, no one had ever seen an echidna ejaculate. There have been previous attempts, trying to force the echidna to ejaculate through the use of [[electroejaculation|electrically stimulated ejaculation]] in order to [[semen collection|obtain semen samples]] but this has only resulted in the penis swelling.<ref name=nsc071026/>
<section end=ejaculation />
[[Breeding season]] begins in late June and extends through September. During mating season, a female may be followed by a line or "train" of up to 10 males, the youngest trailing last, and some males switching between lines.<ref name="NSW"/>

==Threats==
Echidnas are very timid. When frightened, they attempt to partially bury themselves and curl into a ball similar to a [[hedgehog]]. Strong front arms allow echidnas to dig in and hold fast against a predator pulling them from the hole.

Their many predators include [[Cats in Australia#Feral cats|feral cats]], [[Feral foxes in Australia|foxes]], [[Free-ranging dog|domestic dogs]], and [[goannas]]. Snakes pose a large threat when they slither into echidna burrows and prey on the spineless young puggles.

They are easily stressed and injured by handling. Some ways to help echidnas include picking up litter, causing less pollution, planting vegetation for shelter, supervising pets, reporting hurt echidnas, and leaving them undisturbed.<ref name="NSW"/>

==Evolution==
[[File:Echidna skeleton.jpg|thumb|Short-beaked echidna skeleton]]
The divergence between oviparous (egg-laying) and viviparous (offspring develop internally) mammals is believed to date to the [[Triassic]] period.<ref>{{cite journal |vauthors=Rowe T, Rich TH, Vickers-Rich P, Springer M, Woodburne MO |title=The oldest platypus and its bearing on divergence timing of the platypus and echidna clades |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=105 |issue=4 |pages=1238–42 |year=2008 |pmid=18216270 |pmc=2234122 |doi=10.1073/pnas.0706385105 |bibcode=2008PNAS..105.1238R |doi-access=free }}</ref> Most findings from genetics studies (especially of nuclear genes) are in agreement with the paleontological dating, but some other evidence, like mitochondrial DNA, give slightly different dates.<ref>{{cite journal |author=Musser AM |title=Review of the monotreme fossil record and comparison of palaeontological and molecular data |journal=Comp. Biochem. Physiol. A|volume=136 |issue=4 |pages=927–42 |year=2003 |pmid=14667856 |doi=10.1016/s1095-6433(03)00275-7}}</ref>

[[Molecular clock]] data suggest echidnas split from platypuses between 19 and 48&nbsp;million years ago, so that [[Teinolophos|platypus-like fossils]] dating back to over 112.5&nbsp;million years ago represent [[basal (phylogenetics)|basal]] forms, rather than close relatives of the modern platypus.<ref name=Phillips/> This would imply that echidnas evolved from [[Kollikodon|water-foraging ancestors that returned to land living]], which put them in competition with marsupials.{{explain|date=November 2020}} Although extant monotremes lack adult teeth (platypuses have teeth only as juveniles), many extinct monotreme species have been identified based on the morphology of their teeth.<ref name="Bullock-2005" /> Of the eight genes involved in tooth development, four have been lost in both platypus and echidna, indicating that the loss of teeth occurred before the echidna-platypus split.<ref name="ONeil" /> 

Further evidence of [[Australosphenida|water-foraging ancestors]] can be found in some of the echidna's anatomy, including [[hydrodynamic]] streamlining, dorsally projecting hind limbs acting as rudders, and locomotion founded on hypertrophied humeral long-axis rotation, which provides an efficient swimming stroke.<ref name=Phillips/> 

[[Oviparous]] reproduction in monotremes may give them an advantage over [[marsupials]] in some environments.<ref name="Phillips" /> Their observed adaptive radiation contradicts the assumption that monotremes are frozen in morphological and [[molecular evolution]].

It has been suggested that echidnas originally evolved in [[New Guinea]] when it was isolated from Australia and from marsupials. This would explain their rarity in the fossil record, their abundance in present times in New Guinea, and their original adaptation to terrestrial niches, presumably without competition from marsupials.<ref>{{cite journal | doi=10.1080/03115518.2022.2025900 | title=A review of monotreme (Monotremata) evolution | year=2022 | last1=Flannery | first1=Timothy F. | last2=Rich | first2=Thomas H. | last3=Vickers-Rich | first3=Patricia | last4=Ziegler | first4=Tim | last5=Veatch | first5=E. Grace | last6=Helgen | first6=Kristofer M. | journal=Alcheringa: An Australasian Journal of Palaeontology | volume=46 | issue=1 | pages=3–20 | bibcode=2022Alch...46....3F | s2cid=247542433 | doi-access=free }}</ref>

==Taxonomy==
{{cladogram
|title=Cladogram of Tachyglossidae by Upham et al. 2019<ref name="Upham 2019">{{Cite journal |last1=Upham |first1=Nathan S. |last2=Esselstyn |first2=Jacob A. |last3=Jetz |first3=Walter |date=2019 |title=Inferring the mammal tree: Species-level sets of phylogenies for questions in ecology, evolution and conservation |journal=PLOS Biol |volume=17 |issue=12 |pages=e3000494 |doi=10.1371/journal.pbio.3000494 |pmid=31800571 |pmc=6892540 |doi-access=free }}</ref><ref>{{cite journal |last1=Upham |first1=Nathan S. |last2=Esselstyn |first2=Jacob A. |last3=Jetz |first3=Walter |year=2019 |title=DR_on4phylosCompared_linear_richCol_justScale_ownColors_withTips_80in |url=https://github.com/n8upham/MamPhy_v1/blob/master/Fig6_compare_tipDRs/DR_on4phylosCompared_linear_richCol_justScale_ownColors_withTips_80in.pdf |journal=PLOS Biology |volume=17 |issue=12 |pages= e3000494|doi=10.1371/journal.pbio.3000494 |doi-access=free |pmid=31800571 |pmc=6892540 }}</ref>|
{{clade|style=font-size:90%;line-height:80%;width:400px;
|label1=[[Tachyglossidae]]
|1={{clade
  |1=''[[Tachyglossus aculeatus]]''
  |2={{clade
  |label1=''[[Zaglossus]]''
  |1={{clade
    |1=''[[Zaglossus bartoni|Z. bartoni]]''
    |2={{clade
      |1=''[[Zaglossus attenboroughi|Z. attenboroughi]]''
      |2=''[[Zaglossus bruijnii|Z. bruijnii]]''
       }}
       }}
     }}
   }}
}}
|}}

Echidnas are a small [[Cladistics|clade]] with two extant [[genus|genera]] and four [[species]].<ref name=Flannery/> The genus ''[[Zaglossus]]'' includes three extant and two fossil species, with only one extant species from the genus ''[[Tachyglossus]]''. 

===''Zaglossus''===

[[File:Long-beakedEchidna.jpg|thumb|The [[Western long-beaked echidna]], which is endemic to [[New Guinea]]]]

The three living ''Zaglossus'' species are [[endemic (ecology)|endemic]] to [[New Guinea]].<ref name=Flannery/> They are rare and are hunted for food. They forage in [[leaf litter]] on the [[forest floor]], eating [[earthworm]]s and [[insect]]s. The species are
*[[Western long-beaked echidna]] (''Z. bruijni''), of the highland forests;
*[[Sir David's long-beaked echidna]] (''Z. attenboroughi''), discovered by Western science in 1961 (described in 1998) and preferring a still higher habitat;<ref>{{Cite news |date=2023-11-10 |title=First-ever images prove 'lost echidna' not extinct |language=en-GB |work=BBC News |url=https://www.bbc.com/news/science-environment-67363874 |access-date=2023-11-12}}</ref>
*[[Eastern long-beaked echidna]] (''Z. bartoni''), of which four distinct subspecies have been identified.

===''Tachyglossus''===
[[File:EchidnainCanberra.JPG|thumb|In Australia, the short-beaked echidna may be found in many environments, including urban parkland, such as the shores of [[Lake Burley Griffin]] in [[Canberra]], as depicted here.]]
The [[short-beaked echidna]] (''Tachyglossus aculeatus'') is found in southern, southeast and northeast [[New Guinea]], and also occurs in almost all Australian environments, from the snow-clad [[Australian Alps]] to the deep deserts of the [[Outback]], essentially anywhere ants and termites are available. It is smaller than the ''Zaglossus'' species, and it has longer hair.

[[File:Echidna, Exmouth.jpg|thumb|A [[short-beaked echidna]] curled into a ball; the snout is visible on the right]]
Despite the similar dietary habits and methods of consumption to those of an anteater, there is no evidence supporting the idea that echidna-like monotremes have been myrmecophagic (ant or termite-eating) since the [[Cretaceous]]. The fossil evidence of invertebrate-feeding [[bandicoots]] and rat-kangaroos, from around the time of the platypus–echidna [[Genetic divergence|divergence]] and pre-dating ''Tachyglossus'', show evidence that echidnas expanded into new ecospace despite competition from marsupials.<ref>{{cite journal |last1=Phillips |first1=Matthew |last2=Bennett |first2=T. |last3=Lee |first3=Michael |title=Reply to Camens: How recently did modern monotremes diversify? |journal=Proc. Natl. Acad. Sci. U.S.A. |date=2010 |volume=107 |issue=4 |doi=10.1073/pnas.0913152107 |page=E13 |pmc=2824408 |bibcode=2010PNAS..107E..13P |doi-access=free }}</ref>

Additionally, extinct echidnas continue to be [[Species description|described]] by [[taxonomists]];

===''Megalibgwilia''===
The genus ''[[Megalibgwilia]]'' is known only from fossils:<ref name=F22/>

*''M. owenii'' from [[Late Pleistocene]] sites in Australia;
*''M. robusta'' from [[Pliocene]] sites in Australia.

===''Murrayglossus''===
The genus ''[[Murrayglossus]]'' is known only from fossils:<ref name=F22>{{Cite journal |last1=Flannery |first1=T. F. |last2=Rich |first2=T. H. |last3=Vickers-Rich |first3=P. |last4=Ziegler |first4=T. |last5=Veatch |first5=E. G. |last6=Helgen |first6=K. M. |year=2022 |title=A review of monotreme (Monotremata) evolution |journal=Alcheringa: An Australasian Journal of Palaeontology |volume=46 |issue=1 |pages=3–20 |doi=10.1080/03115518.2022.2025900 |bibcode=2022Alch...46....3F |s2cid=247542433 |doi-access=free }}</ref>
* ''M. hacketti'' (previously classified in the genus ''Zaglossus'') from Pleistocene of [[Western Australia]].

== As food ==
The [[Gunwinggu|Kunwinjku]] people of [[Arnhem Land|Western Arnhem Land]] (Australia) call the echidna ''ngarrbek'',<ref>{{cite web |last1=Garde |first1=Murray |title=ngarrbek |url=https://www.njamed.com/#ngarrbek |website=Bininj Kunwok Online Dictionary |publisher=Bininj Kunwok Regional Language Centre |access-date=29 July 2020}}</ref> and regard it as a prized food and "good medicine".{{notetag|Reverend Peterson Nganjmirra, personal comment.}}<ref>{{cite book|title=Fauna of Kakadu and the Top End| last=Goodfellow| first=D.| year=1993| isbn=1862543062|publisher=Wakefield Press | page= 17}}</ref> The echidna is hunted at night, gutted, and filled with hot stones and mandak (''[[Persoonia falcata]]'') leaves.<ref>{{cite web |last1=Garde |first1=Murray |title=mandak |url=https://www.njamed.com/#mandak |website=Bininj Kunwok Online Dictionary |publisher=Bininj Kunwok Regional Language Centre |access-date=29 July 2020}}</ref> According to [[Larrakia people|Larrakia]] elders Una Thompson and Stephanie Thompson Nganjmirra, once captured, an echidna is carried attached to the wrist like a thick bangle.{{Citation needed|date=July 2024}}

==In popular culture==
* The echidna appears on the reverse of the [[Australian five-cent coin]].<ref name=RAM5c>{{cite web |title=Royal Australian Mint: 5 cents |date= 8 January 2016 |url= https://www.ramint.gov.au/five-cents |access-date=3 May 2020}}</ref>
* An echidna named [[Olly, Syd, Millie and Lizzie|Millie]] was one of the three official mascots for the [[2000 Summer Olympics]] in [[Sydney]].<ref>[https://olympics.com/en/olympic-games/sydney-2000/mascot Sydney 2000: The Mascot &ndash; Olympics.com.] Retrieved June 4, 2022.</ref>
* The ''[[Sonic the Hedgehog]]'' franchise features a race of [[Anthropomorphism|anthropomorphic]] echidnas, the most prominent being [[Knuckles the Echidna|Knuckles]].<ref>{{cite magazine|url=https://www.wired.com/2015/06/absurd-creature-of-the-week-long-beaked-echidna/|author=Simon, Matt|magazine=Wired|date=19 June 2015|title=Absurd Creature of the Week: Forget the Platypus. The Echidna Is the True Champ of Weird}}</ref>

==See also==
* [[List of mammal genera]]
* [[List of recently extinct mammals]]
* [[List of prehistoric mammals]]

==Notes==
{{Notefoot}}

==References==
{{Reflist|refs=
<ref name=pwstSBE>{{cite web | url = https://parks.tas.gov.au/?base=4796 | title = Short-Beaked Echidna, ''Tachyglossus aculeatus'' | publisher = Park & Wildlife Service Tasmania | archive-url = https://web.archive.org/web/20160331210345/https://parks.tas.gov.au/?base=4796 | access-date = 21 October 2012 | archive-date = 31 March 2016 }}</ref>

<ref name=nwf03>{{cite news | url = http://www.nwf.org/nationalwildlife/article.cfm?articleId=763&issueId=61 | title = The Enigma of the Echidna | first = Doug | last = Stewart | date = April–May 2003 | publisher = National Wildlife | archive-url=https://web.archive.org/web/20120429194037/http://www.nwf.org/News-and-Magazines/National-Wildlife/Animals/Archives/2003/The-Enigma-of-the-Echidna.aspx | archive-date=2012-04-29 }}</ref>

<ref name=CSIRO06>{{cite book | url= https://books.google.com/books?id=2UQH-YrWwCYC | title= Echidna : extraordinary egg-laying mammal | first1 = Michael | last1= Augee | first2 = Brett | last2 = Gooden | first3 = Anne | last3 = Musser | publisher= CSIRO | year= 2006 | isbn=978-0-643-09204-4 | page=3 | edition=2nd}}</ref>

<ref name=MOL100707>{{cite web | url=http://www.mapoflife.org/topics/topic_41_Electroreception-in-fish-amphibians-and-monotremes/ | title = Electroreception in fish, amphibians and monotremes | publisher=Map of Life | date= 7 July 2010 }}</ref>

<ref name=info>{{cite web | url = http://www.animalinfo.org/species/zaglbrui.htm | title= ''Zaglossus bruijni'' | publisher = AnimalInfo.org }}</ref>

<ref name=arkiveTGA>{{cite web | url = http://www.arkive.org/short-beaked-echidna/tachyglossus-aculeatus/biology.html | title = Short-beaked echidna (''Tachyglossus aculeatus'') | publisher = Arkive.org | access-date = 21 October 2009 | archive-url = https://web.archive.org/web/20090813121709/http://www.arkive.org/short-beaked-echidna/tachyglossus-aculeatus/biology.html | archive-date = 13 August 2009 | url-status = dead}}</ref>

<ref name=bbc121119>{{cite news | url = https://www.bbc.co.uk/news/magazine-20323753 | title = Are these animals too 'ugly' to be saved? | first = Victoria | last = Gill | work = BBC News | date = 19 November 2012 }}</ref>

<ref name=andiv09>{{cite web | url = http://animaldiversity.ummz.umich.edu/accounts/Tachyglossus_aculeatus/ | title = ''Tachyglossus aculeatus'' | first = M. | last = Cason | publisher = Animal Diversity | year = 2009 | access-date = 21 October 2012 }}</ref>

<ref name=nsl0003>{{cite journal | title = The echidna manifests typical characteristics of rapid eye movement sleep | first1 = SC | last1 = Nicol | first2 = NA | last2 = Andersen | first3 = NH | last3 = Phillips | first4 = BJ | last4 = Berger | journal= [[Neuroscience Letters|Neurosci. Lett.]] | date = March 2000 | volume=283 | issue=1 | pages=49–52 | pmid = 10729631 | doi=10.1016/S0304-3940(00)00922-8 | s2cid = 40439226 | url = https://figshare.com/articles/journal_contribution/22839596 }}</ref>

<section begin=nsc071026 /><ref name=nsc071026>{{cite news | url =https://www.newscientist.com/article/dn12838-exhibitionist-spiny-anteater-reveals-bizarre-penis.html | title = Exhibitionist spiny anteater reveals bizarre penis | first = N. | last = Shultz | work = [[New Scientist]] | date = 26 October 2007 | access-date = 12 April 2020 }}</ref><section end=nsc071026 />

<ref name=Phillips>{{cite journal | title = Molecules, morphology, and ecology indicate a recent, amphibious ancestry for echidnas | first1 = MJ | last1 = Phillips | first2 = TH | last2 = Bennett | first3 = MS | last3 = Lee | journal = Proc. Natl. Acad. Sci. U.S.A. | date = October 2009 | volume=106 | issue=40 | pages=17089–94 | pmid= 19805098 | pmc = 2761324 | doi = 10.1073/pnas.0904649106 | bibcode = 2009PNAS..10617089P | doi-access = free }}</ref>

<ref name=Flannery>{{cite journal | title= A revision of the genus ''Zaglossus'' (Monotremata, Tachyglossidae), with description of new species and subspecies | first1 = T.F. | last1 = Flannery | first2 = C.P. | last2 = Groves | journal= Mammalia | year=1998 | volume=62 | issue= 3 | pages=367–396 | doi=10.1515/mamm.1998.62.3.367 | s2cid = 84750399 | url = https://zenodo.org/record/270023 }}</ref>

}}
<!--tag with name "MSW3" defined is not used in prior text
<ref name=MSW3>{{MSW3 Groves|pages=1–2|id=10300002}}</ref>-->

== Bibliography ==
* {{citation | author = Ronald M. Nowak | title = Walker's Mammals of the World | isbn = 0-8018-5789-9 | year = 1999 | publisher = Johns Hopkins University Press | location = Baltimore | edition = 6th | lccn = 98023686 | language = en <!--| GBS-id = T37sFCl43E8C | Ltwork = 257350 -->}}

==External links==
{{Commons|Tachyglossidae|Echidna}}
{{Wikispecies|Tachyglossidae}}
*{{cite web |author=Stewart, Doug |title=The Enigma of the Echidna
 |date=April 2003 |publisher=National Wildlife
 |url=http://www.nwf.org/News-and-Magazines/National-Wildlife/Animals/Archives/2003/The-Enigma-of-the-Echidna.aspx |access-date=3 February 2017}}
*{{cite web
 |author=Parker, J. |title=Echidna Love Trains
 |date=1 June 2000 |work=ABC Science |publisher=Australian Broadcasting Corporation
 |url=http://www.abc.net.au/science/articles/2000/06/01/2688596.htm}}
*{{cite web|author=Rismiller, Peggy|title=Echidna research, Kangaroo island|year=2005|publisher=Pelican Lagoon Research & Wildlife Centre|url=http://www.echidna.edu.au/monotremes/echidna_research.html|access-date=15 July 2012|archive-date=21 February 2015|archive-url=https://web.archive.org/web/20150221201703/http://www.echidna.edu.au/monotremes/echidna_research.html|url-status=dead}}
*{{cite web |title=''Tachyglossidae'' |work=NCBI Taxonomy Browser |url=https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=9259 |id=9259}}

{{Mammaliaformes|Y.|state=autocollapse}}
{{Monotremata}}

{{Taxonbar|from=Q21824}}
{{Authority control}}

[[Category:Electroreceptive animals]]
[[Category:Mammals of the Northern Territory]]
[[Category:Articles containing video clips]]
[[Category:Rolling animals]]
[[Category:Extant Pliocene first appearances]]
[[Category:Taxa named by Theodore Gill]]
[[Category:Endemic fauna of Oceania]]
[[Category:Monotremes]]