Editing Echidna (section)

==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 [[snout]]s, or [[proboscis]]es, 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>